Commit 2eefe3d6 authored by luopl's avatar luopl
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add mamba

parent b7535e7c
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# Copyright (c) 2024, Albert Gu and Tri Dao.
"""Minimal implementation of SSD.
This is the same as Listing 1 from the paper.
"""
import torch
import torch.nn.functional as F
from einops import rearrange, repeat
from mamba_ssm.ops.triton.ssd_combined import mamba_chunk_scan_combined
def segsum_unstable(x):
"""Naive segment sum calculation."""
T = x.size(-1)
x_cumsum = torch.cumsum(x, dim=-1)
x_segsum = x_cumsum[..., :, None] - x_cumsum[..., None, :]
mask = torch.tril(torch.ones(T, T, device=x.device, dtype=bool), diagonal=0)
x_segsum = x_segsum.masked_fill(~mask, -torch.inf)
return x_segsum
def segsum(x):
"""More stable segment sum calculation."""
T = x.size(-1)
x = repeat(x, "... d -> ... d e", e=T)
mask = torch.tril(torch.ones(T, T, device=x.device, dtype=bool), diagonal=-1)
x = x.masked_fill(~mask, 0)
x_segsum = torch.cumsum(x, dim=-2)
mask = torch.tril(torch.ones(T, T, device=x.device, dtype=bool), diagonal=0)
x_segsum = x_segsum.masked_fill(~mask, -torch.inf)
return x_segsum
def ssd_minimal_discrete(X, A, B, C, block_len, initial_states=None):
"""
Arguments:
X: (batch, length, n_heads, d_head)
A: (batch, length, n_heads)
B: (batch, length, n_heads, d_state)
C: (batch, length, n_heads, d_state)
Return:
Y: (batch, length, n_heads, d_head)
"""
assert X.dtype == A.dtype == B.dtype == C.dtype
assert X.shape[1] % block_len == 0
# Rearrange into blocks/chunks
X, A, B, C = [rearrange(x, "b (c l) ... -> b c l ...", l=block_len) for x in (X, A, B, C)]
A = rearrange(A, "b c l h -> b h c l")
A_cumsum = torch.cumsum(A, dim=-1)
# 1. Compute the output for each intra-chunk (diagonal blocks)
L = torch.exp(segsum(A))
Y_diag = torch.einsum("bclhn,bcshn,bhcls,bcshp->bclhp", C, B, L, X)
# 2. Compute the state for each intra-chunk
# (right term of low-rank factorization of off-diagonal blocks; B terms)
decay_states = torch.exp((A_cumsum[:, :, :, -1:] - A_cumsum))
states = torch.einsum("bclhn,bhcl,bclhp->bchpn", B, decay_states, X)
# 3. Compute the inter-chunk SSM recurrence; produces correct SSM states at chunk boundaries
# (middle term of factorization of off-diag blocks; A terms)
if initial_states is None:
initial_states = torch.zeros_like(states[:, :1])
states = torch.cat([initial_states, states], dim=1)
decay_chunk = torch.exp(segsum(F.pad(A_cumsum[:, :, :, -1], (1, 0))))
new_states = torch.einsum("bhzc,bchpn->bzhpn", decay_chunk, states)
states, final_state = new_states[:, :-1], new_states[:, -1]
# 4. Compute state -> output conversion per chunk
# (left term of low-rank factorization of off-diagonal blocks; C terms)
state_decay_out = torch.exp(A_cumsum)
Y_off = torch.einsum('bclhn,bchpn,bhcl->bclhp', C, states, state_decay_out)
# Add output of intra-chunk and inter-chunk terms (diagonal and off-diagonal blocks)
Y = rearrange(Y_diag+Y_off, "b c l h p -> b (c l) h p")
return Y, final_state
# Simple test
def test_correctness():
torch.manual_seed(42)
## Dimensions
# Denoted (B, T, Q, D, P) in the paper
batch, seqlen, chunk_size, dim, headdim = 1, 2048, 64, 2048, 64
nheads = dim // headdim # (H) in the paper
ngroups = 1 # (G) in the paper
dstate = 64 # (N) in the paper
dtype = torch.float32
device = "cuda"
x = torch.randn(batch, seqlen, nheads, headdim, dtype=dtype, device=device)
dt = F.softplus(torch.randn(batch, seqlen, nheads, dtype=torch.float32, device=device) - 4).requires_grad_()
A = (-torch.exp(torch.rand(nheads, dtype=torch.float32, device=device))).requires_grad_()
B = torch.randn(batch, seqlen, ngroups, dstate, dtype=dtype, device=device)
C = torch.randn(batch, seqlen, ngroups, dstate, dtype=dtype, device=device)
D = torch.randn(nheads, dtype=dtype, device=device)
# Comparing fused version and minimal version
y = mamba_chunk_scan_combined(x, dt, A, B, C, chunk_size, D=None)
y_min, _ = ssd_minimal_discrete(x*dt.unsqueeze(-1), A*dt, B, C, chunk_size)
# Copyright (c) 2023, Tri Dao, Albert Gu.
import torch
import torch.nn.functional as F
from torch.cuda.amp import custom_bwd, custom_fwd
from einops import rearrange, repeat
try:
from causal_conv1d import causal_conv1d_fn
import causal_conv1d_cuda
except ImportError:
causal_conv1d_fn = None
causal_conv1d_cuda = None
import selective_scan_cuda
class SelectiveScanFn(torch.autograd.Function):
@staticmethod
def forward(ctx, u, delta, A, B, C, D=None, z=None, delta_bias=None, delta_softplus=False,
return_last_state=False):
if u.stride(-1) != 1:
u = u.contiguous()
if delta.stride(-1) != 1:
delta = delta.contiguous()
if D is not None:
D = D.contiguous()
if B.stride(-1) != 1:
B = B.contiguous()
if C.stride(-1) != 1:
C = C.contiguous()
if z is not None and z.stride(-1) != 1:
z = z.contiguous()
if B.dim() == 3:
B = rearrange(B, "b dstate l -> b 1 dstate l")
ctx.squeeze_B = True
if C.dim() == 3:
C = rearrange(C, "b dstate l -> b 1 dstate l")
ctx.squeeze_C = True
out, x, *rest = selective_scan_cuda.fwd(u, delta, A, B, C, D, z, delta_bias, delta_softplus)
ctx.delta_softplus = delta_softplus
ctx.has_z = z is not None
last_state = x[:, :, -1, 1::2] # (batch, dim, dstate)
if not ctx.has_z:
ctx.save_for_backward(u, delta, A, B, C, D, delta_bias, x)
return out if not return_last_state else (out, last_state)
else:
ctx.save_for_backward(u, delta, A, B, C, D, z, delta_bias, x, out)
out_z = rest[0]
return out_z if not return_last_state else (out_z, last_state)
@staticmethod
def backward(ctx, dout, *args):
if not ctx.has_z:
u, delta, A, B, C, D, delta_bias, x = ctx.saved_tensors
z = None
out = None
else:
u, delta, A, B, C, D, z, delta_bias, x, out = ctx.saved_tensors
if dout.stride(-1) != 1:
dout = dout.contiguous()
# The kernel supports passing in a pre-allocated dz (e.g., in case we want to fuse the
# backward of selective_scan_cuda with the backward of chunk).
# Here we just pass in None and dz will be allocated in the C++ code.
du, ddelta, dA, dB, dC, dD, ddelta_bias, *rest = selective_scan_cuda.bwd(
u, delta, A, B, C, D, z, delta_bias, dout, x, out, None, ctx.delta_softplus,
False # option to recompute out_z, not used here
)
dz = rest[0] if ctx.has_z else None
dB = dB.squeeze(1) if getattr(ctx, "squeeze_B", False) else dB
dC = dC.squeeze(1) if getattr(ctx, "squeeze_C", False) else dC
return (du, ddelta, dA, dB, dC,
dD if D is not None else None,
dz,
ddelta_bias if delta_bias is not None else None,
None,
None)
def selective_scan_fn(u, delta, A, B, C, D=None, z=None, delta_bias=None, delta_softplus=False,
return_last_state=False):
"""if return_last_state is True, returns (out, last_state)
last_state has shape (batch, dim, dstate). Note that the gradient of the last state is
not considered in the backward pass.
"""
return SelectiveScanFn.apply(u, delta, A, B, C, D, z, delta_bias, delta_softplus, return_last_state)
def selective_scan_ref(u, delta, A, B, C, D=None, z=None, delta_bias=None, delta_softplus=False,
return_last_state=False):
"""
u: r(B D L)
delta: r(B D L)
A: c(D N) or r(D N)
B: c(D N) or r(B N L) or r(B N 2L) or r(B G N L) or (B G N L)
C: c(D N) or r(B N L) or r(B N 2L) or r(B G N L) or (B G N L)
D: r(D)
z: r(B D L)
delta_bias: r(D), fp32
out: r(B D L)
last_state (optional): r(B D dstate) or c(B D dstate)
"""
dtype_in = u.dtype
u = u.float()
delta = delta.float()
if delta_bias is not None:
delta = delta + delta_bias[..., None].float()
if delta_softplus:
delta = F.softplus(delta)
batch, dim, dstate = u.shape[0], A.shape[0], A.shape[1]
is_variable_B = B.dim() >= 3
is_variable_C = C.dim() >= 3
if A.is_complex():
if is_variable_B:
B = torch.view_as_complex(rearrange(B.float(), "... (L two) -> ... L two", two=2))
if is_variable_C:
C = torch.view_as_complex(rearrange(C.float(), "... (L two) -> ... L two", two=2))
else:
B = B.float()
C = C.float()
x = A.new_zeros((batch, dim, dstate))
ys = []
deltaA = torch.exp(torch.einsum('bdl,dn->bdln', delta, A))
if not is_variable_B:
deltaB_u = torch.einsum('bdl,dn,bdl->bdln', delta, B, u)
else:
if B.dim() == 3:
deltaB_u = torch.einsum('bdl,bnl,bdl->bdln', delta, B, u)
else:
B = repeat(B, "B G N L -> B (G H) N L", H=dim // B.shape[1])
deltaB_u = torch.einsum('bdl,bdnl,bdl->bdln', delta, B, u)
if is_variable_C and C.dim() == 4:
C = repeat(C, "B G N L -> B (G H) N L", H=dim // C.shape[1])
last_state = None
for i in range(u.shape[2]):
x = deltaA[:, :, i] * x + deltaB_u[:, :, i]
if not is_variable_C:
y = torch.einsum('bdn,dn->bd', x, C)
else:
if C.dim() == 3:
y = torch.einsum('bdn,bn->bd', x, C[:, :, i])
else:
y = torch.einsum('bdn,bdn->bd', x, C[:, :, :, i])
if i == u.shape[2] - 1:
last_state = x
if y.is_complex():
y = y.real * 2
ys.append(y)
y = torch.stack(ys, dim=2) # (batch dim L)
out = y if D is None else y + u * rearrange(D, "d -> d 1")
if z is not None:
out = out * F.silu(z)
out = out.to(dtype=dtype_in)
return out if not return_last_state else (out, last_state)
class MambaInnerFn(torch.autograd.Function):
@staticmethod
@custom_fwd
def forward(ctx, xz, conv1d_weight, conv1d_bias, x_proj_weight, delta_proj_weight,
out_proj_weight, out_proj_bias,
A, B=None, C=None, D=None, delta_bias=None, B_proj_bias=None,
C_proj_bias=None, delta_softplus=True, checkpoint_lvl=1):
"""
xz: (batch, dim, seqlen)
"""
assert causal_conv1d_cuda is not None, "causal_conv1d_cuda is not available. Please install causal-conv1d."
assert checkpoint_lvl in [0, 1]
L = xz.shape[-1]
delta_rank = delta_proj_weight.shape[1]
d_state = A.shape[-1] * (1 if not A.is_complex() else 2)
if torch.is_autocast_enabled():
x_proj_weight = x_proj_weight.to(dtype=torch.get_autocast_gpu_dtype())
delta_proj_weight = delta_proj_weight.to(dtype=torch.get_autocast_gpu_dtype())
out_proj_weight = out_proj_weight.to(dtype=torch.get_autocast_gpu_dtype())
out_proj_bias = (out_proj_bias.to(dtype=torch.get_autocast_gpu_dtype())
if out_proj_bias is not None else None)
if xz.stride(-1) != 1:
xz = xz.contiguous()
conv1d_weight = rearrange(conv1d_weight, "d 1 w -> d w")
x, z = xz.chunk(2, dim=1)
conv1d_bias = conv1d_bias.contiguous() if conv1d_bias is not None else None
conv1d_out = causal_conv1d_cuda.causal_conv1d_fwd(
x, conv1d_weight, conv1d_bias, None, None, None, True
)
# We're being very careful here about the layout, to avoid extra transposes.
# We want delta to have d as the slowest moving dimension
# and L as the fastest moving dimension, since those are what the ssm_scan kernel expects.
x_dbl = F.linear(rearrange(conv1d_out, 'b d l -> (b l) d'), x_proj_weight) # (bl d)
delta = rearrange(delta_proj_weight @ x_dbl[:, :delta_rank].t(), "d (b l) -> b d l", l = L)
ctx.is_variable_B = B is None
ctx.is_variable_C = C is None
ctx.B_proj_bias_is_None = B_proj_bias is None
ctx.C_proj_bias_is_None = C_proj_bias is None
if B is None: # variable B
B = x_dbl[:, delta_rank:delta_rank + d_state] # (bl dstate)
if B_proj_bias is not None:
B = B + B_proj_bias.to(dtype=B.dtype)
if not A.is_complex():
# B = rearrange(B, "(b l) dstate -> b dstate l", l=L).contiguous()
B = rearrange(B, "(b l) dstate -> b 1 dstate l", l=L).contiguous()
else:
B = rearrange(B, "(b l) (dstate two) -> b 1 dstate (l two)", l=L, two=2).contiguous()
else:
if B.stride(-1) != 1:
B = B.contiguous()
if C is None: # variable C
C = x_dbl[:, -d_state:] # (bl dstate)
if C_proj_bias is not None:
C = C + C_proj_bias.to(dtype=C.dtype)
if not A.is_complex():
# C = rearrange(C, "(b l) dstate -> b dstate l", l=L).contiguous()
C = rearrange(C, "(b l) dstate -> b 1 dstate l", l=L).contiguous()
else:
C = rearrange(C, "(b l) (dstate two) -> b 1 dstate (l two)", l=L, two=2).contiguous()
else:
if C.stride(-1) != 1:
C = C.contiguous()
if D is not None:
D = D.contiguous()
out, scan_intermediates, out_z = selective_scan_cuda.fwd(
conv1d_out, delta, A, B, C, D, z, delta_bias, delta_softplus
)
ctx.delta_softplus = delta_softplus
ctx.out_proj_bias_is_None = out_proj_bias is None
ctx.checkpoint_lvl = checkpoint_lvl
if checkpoint_lvl >= 1: # Will recompute conv1d_out and delta in the backward pass
conv1d_out, delta = None, None
ctx.save_for_backward(xz, conv1d_weight, conv1d_bias, x_dbl, x_proj_weight,
delta_proj_weight, out_proj_weight, conv1d_out, delta,
A, B, C, D, delta_bias, scan_intermediates, out)
return F.linear(rearrange(out_z, "b d l -> b l d"), out_proj_weight, out_proj_bias)
@staticmethod
@custom_bwd
def backward(ctx, dout):
# dout: (batch, seqlen, dim)
assert causal_conv1d_cuda is not None, "causal_conv1d_cuda is not available. Please install causal-conv1d."
(xz, conv1d_weight, conv1d_bias, x_dbl, x_proj_weight, delta_proj_weight, out_proj_weight,
conv1d_out, delta, A, B, C, D, delta_bias, scan_intermediates, out) = ctx.saved_tensors
L = xz.shape[-1]
delta_rank = delta_proj_weight.shape[1]
d_state = A.shape[-1] * (1 if not A.is_complex() else 2)
x, z = xz.chunk(2, dim=1)
if dout.stride(-1) != 1:
dout = dout.contiguous()
if ctx.checkpoint_lvl == 1:
conv1d_out = causal_conv1d_cuda.causal_conv1d_fwd(
x, conv1d_weight, conv1d_bias, None, None, None, True
)
delta = rearrange(delta_proj_weight @ x_dbl[:, :delta_rank].t(),
"d (b l) -> b d l", l = L)
# The kernel supports passing in a pre-allocated dz (e.g., in case we want to fuse the
# backward of selective_scan_cuda with the backward of chunk).
dxz = torch.empty_like(xz) # (batch, dim, seqlen)
dx, dz = dxz.chunk(2, dim=1)
dout = rearrange(dout, "b l e -> e (b l)")
dout_y = rearrange(out_proj_weight.t() @ dout, "d (b l) -> b d l", l=L)
dconv1d_out, ddelta, dA, dB, dC, dD, ddelta_bias, dz, out_z = selective_scan_cuda.bwd(
conv1d_out, delta, A, B, C, D, z, delta_bias, dout_y, scan_intermediates, out, dz,
ctx.delta_softplus,
True # option to recompute out_z
)
dout_proj_weight = torch.einsum("eB,dB->ed", dout, rearrange(out_z, "b d l -> d (b l)"))
dout_proj_bias = dout.sum(dim=(0, 1)) if not ctx.out_proj_bias_is_None else None
dD = dD if D is not None else None
dx_dbl = torch.empty_like(x_dbl)
dB_proj_bias = None
if ctx.is_variable_B:
if not A.is_complex():
dB = rearrange(dB, "b 1 dstate l -> (b l) dstate").contiguous()
else:
dB = rearrange(dB, "b 1 dstate (l two) -> (b l) (dstate two)", two=2).contiguous()
dB_proj_bias = dB.sum(0) if not ctx.B_proj_bias_is_None else None
dx_dbl[:, delta_rank:delta_rank + d_state] = dB # (bl d)
dB = None
dC_proj_bias = None
if ctx.is_variable_C:
if not A.is_complex():
dC = rearrange(dC, "b 1 dstate l -> (b l) dstate").contiguous()
else:
dC = rearrange(dC, "b 1 dstate (l two) -> (b l) (dstate two)", two=2).contiguous()
dC_proj_bias = dC.sum(0) if not ctx.C_proj_bias_is_None else None
dx_dbl[:, -d_state:] = dC # (bl d)
dC = None
ddelta = rearrange(ddelta, "b d l -> d (b l)")
ddelta_proj_weight = torch.einsum("dB,Br->dr", ddelta, x_dbl[:, :delta_rank])
dx_dbl[:, :delta_rank] = torch.einsum("dB,dr->Br", ddelta, delta_proj_weight)
dconv1d_out = rearrange(dconv1d_out, "b d l -> d (b l)")
dx_proj_weight = torch.einsum("Br,Bd->rd", dx_dbl, rearrange(conv1d_out, "b d l -> (b l) d"))
dconv1d_out = torch.addmm(dconv1d_out, x_proj_weight.t(), dx_dbl.t(), out=dconv1d_out)
dconv1d_out = rearrange(dconv1d_out, "d (b l) -> b d l", b=x.shape[0], l=x.shape[-1])
# The kernel supports passing in a pre-allocated dx (e.g., in case we want to fuse the
# backward of conv1d with the backward of chunk).
dx, dconv1d_weight, dconv1d_bias, *_ = causal_conv1d_cuda.causal_conv1d_bwd(
x, conv1d_weight, conv1d_bias, dconv1d_out, None, None, None, dx, False, True
)
dconv1d_bias = dconv1d_bias if conv1d_bias is not None else None
dconv1d_weight = rearrange(dconv1d_weight, "d w -> d 1 w")
return (dxz, dconv1d_weight, dconv1d_bias, dx_proj_weight, ddelta_proj_weight,
dout_proj_weight, dout_proj_bias,
dA, dB, dC, dD,
ddelta_bias if delta_bias is not None else None,
dB_proj_bias, dC_proj_bias, None)
def mamba_inner_fn(
xz, conv1d_weight, conv1d_bias, x_proj_weight, delta_proj_weight,
out_proj_weight, out_proj_bias,
A, B=None, C=None, D=None, delta_bias=None, B_proj_bias=None,
C_proj_bias=None, delta_softplus=True
):
return MambaInnerFn.apply(xz, conv1d_weight, conv1d_bias, x_proj_weight, delta_proj_weight,
out_proj_weight, out_proj_bias,
A, B, C, D, delta_bias, B_proj_bias, C_proj_bias, delta_softplus)
def mamba_inner_ref(
xz, conv1d_weight, conv1d_bias, x_proj_weight, delta_proj_weight,
out_proj_weight, out_proj_bias,
A, B=None, C=None, D=None, delta_bias=None, B_proj_bias=None,
C_proj_bias=None, delta_softplus=True
):
assert causal_conv1d_fn is not None, "causal_conv1d_fn is not available. Please install causal-conv1d."
L = xz.shape[-1]
delta_rank = delta_proj_weight.shape[1]
d_state = A.shape[-1] * (1 if not A.is_complex() else 2)
x, z = xz.chunk(2, dim=1)
x = causal_conv1d_fn(x, rearrange(conv1d_weight, "d 1 w -> d w"), conv1d_bias, activation="silu")
# We're being very careful here about the layout, to avoid extra transposes.
# We want delta to have d as the slowest moving dimension
# and L as the fastest moving dimension, since those are what the ssm_scan kernel expects.
x_dbl = F.linear(rearrange(x, 'b d l -> (b l) d'), x_proj_weight) # (bl d)
delta = delta_proj_weight @ x_dbl[:, :delta_rank].t()
delta = rearrange(delta, "d (b l) -> b d l", l=L)
if B is None: # variable B
B = x_dbl[:, delta_rank:delta_rank + d_state] # (bl d)
if B_proj_bias is not None:
B = B + B_proj_bias.to(dtype=B.dtype)
if not A.is_complex():
B = rearrange(B, "(b l) dstate -> b dstate l", l=L).contiguous()
else:
B = rearrange(B, "(b l) (dstate two) -> b dstate (l two)", l=L, two=2).contiguous()
if C is None: # variable B
C = x_dbl[:, -d_state:] # (bl d)
if C_proj_bias is not None:
C = C + C_proj_bias.to(dtype=C.dtype)
if not A.is_complex():
C = rearrange(C, "(b l) dstate -> b dstate l", l=L).contiguous()
else:
C = rearrange(C, "(b l) (dstate two) -> b dstate (l two)", l=L, two=2).contiguous()
y = selective_scan_fn(x, delta, A, B, C, D, z=z, delta_bias=delta_bias, delta_softplus=True)
return F.linear(rearrange(y, "b d l -> b l d"), out_proj_weight, out_proj_bias)
# Copyright (c) 2024, Tri Dao, Albert Gu.
import torch
import triton
import triton.language as tl
@triton.autotune(
configs=[
triton.Config({'BLOCK_N': 32}),
triton.Config({'BLOCK_N': 64}),
triton.Config({'BLOCK_N': 128}),
triton.Config({'BLOCK_N': 256}),
triton.Config({'BLOCK_N': 512}),
triton.Config({'BLOCK_N': 1024}),
],
key=['ncols'],
)
@triton.jit
def _swiglu_fwd_kernel(
X,
Y,
OUT,
stride_x_row, # how much to increase the pointer when moving by 1 row
stride_y_row,
stride_out_row,
ncols,
BLOCK_N: tl.constexpr,
):
# Map the program id to the row of X and Y it should compute.
row = tl.program_id(0)
start_col = tl.program_id(1) * BLOCK_N
X += row * stride_x_row
Y += row * stride_y_row
OUT += row * stride_out_row
cols = start_col + tl.arange(0, BLOCK_N)
x = tl.load(X + cols, mask=cols < ncols, other=0.).to(tl.float32)
y = tl.load(Y + cols, mask=cols < ncols, other=0.).to(tl.float32)
out = x * tl.sigmoid(x) * y
tl.store(OUT + cols, out, mask=cols < ncols)
def _swiglu_fwd(xy, out=None):
if xy.stride(-1) != 1:
xy = xy.contiguous()
batch_shape = xy.shape[:-1]
xy = xy.reshape(-1, xy.shape[-1])
x, y = xy.chunk(2, dim=-1)
if out is None:
out = torch.empty_like(x)
else:
out = out.reshape(-1, out.shape[-1])
assert out.shape == x.shape
assert out.stride(-1) == 1
M, N = x.shape
grid = lambda META: (M, triton.cdiv(N, META['BLOCK_N']))
with torch.cuda.device(x.device.index):
_swiglu_fwd_kernel[grid](x, y, out, x.stride(0), y.stride(0), out.stride(0), N)
return out.reshape(*batch_shape, out.shape[-1])
@triton.autotune(
configs=[
triton.Config({'BLOCK_N': 32}),
triton.Config({'BLOCK_N': 64}),
triton.Config({'BLOCK_N': 128}),
triton.Config({'BLOCK_N': 256}),
triton.Config({'BLOCK_N': 512}),
triton.Config({'BLOCK_N': 1024}),
],
key=['ncols'],
)
@triton.heuristics({"RECOMPUTE_OUTPUT": lambda args: args["OUT"] is not None})
@triton.jit
def _swiglu_bwd_kernel(
X,
Y,
DOUT,
OUT,
DX,
DY,
stride_x_row, # how much to increase the pointer when moving by 1 row
stride_y_row,
stride_dout_row,
stride_out_row,
stride_dx_row,
stride_dy_row,
ncols,
BLOCK_N: tl.constexpr,
RECOMPUTE_OUTPUT: tl.constexpr,
):
# Map the program id to the row of X and Y it should compute.
row = tl.program_id(0)
start_col = tl.program_id(1) * BLOCK_N
X += row * stride_x_row
Y += row * stride_y_row
DOUT += row * stride_dout_row
if RECOMPUTE_OUTPUT:
OUT += row * stride_out_row
DX += row * stride_dx_row
DY += row * stride_dy_row
cols = start_col + tl.arange(0, BLOCK_N)
x = tl.load(X + cols, mask=cols < ncols, other=0.).to(tl.float32)
y = tl.load(Y + cols, mask=cols < ncols, other=0.).to(tl.float32)
dout = tl.load(DOUT + cols, mask=cols < ncols, other=0.).to(tl.float32)
x_sigmoid = tl.sigmoid(x)
dx = x_sigmoid * (1 + x * (1 - x_sigmoid)) * y * dout
dy = x * x_sigmoid * dout
tl.store(DX + cols, dx, mask=cols < ncols)
tl.store(DY + cols, dy, mask=cols < ncols)
if RECOMPUTE_OUTPUT:
out = x * x_sigmoid * y
tl.store(OUT + cols, out, mask=cols < ncols)
def _swiglu_bwd(xy, dout, dxy=None, recompute_output=False, out=None):
if xy.stride(-1) != 1:
xy = xy.contiguous()
if dout.stride(-1) != 1:
dout = dout.contiguous()
batch_shape = xy.shape[:-1]
xy = xy.reshape(-1, xy.shape[-1])
x, y = xy.chunk(2, dim=-1)
dout = dout.reshape(-1, dout.shape[-1])
assert dout.shape == x.shape
if dxy is None:
dxy = torch.empty_like(xy)
else:
dxy = dxy.reshape(-1, dxy.shape[-1])
assert dxy.shape == xy.shape
dx, dy = dxy.chunk(2, dim=-1)
assert dx.stride(-1) == 1
assert dy.stride(-1) == 1
if recompute_output:
if out is None:
out = torch.empty_like(x)
else:
out = out.reshape(-1, out.shape[-1])
assert out.shape == x.shape
assert out.stride(-1) == 1
M, N = x.shape
grid = lambda META: (M, triton.cdiv(N, META['BLOCK_N']))
with torch.cuda.device(x.device.index):
_swiglu_bwd_kernel[grid](x, y, dout, out if recompute_output else None, dx, dy,
x.stride(0), y.stride(0), dout.stride(0),
out.stride(0) if recompute_output else 0,
dx.stride(0), dy.stride(0),
N)
if not recompute_output:
return dxy.reshape(*batch_shape, dxy.shape[-1])
else:
return dxy.reshape(*batch_shape, dxy.shape[-1]), out.reshape(*batch_shape, out.shape[-1])
class SwiGLU(torch.autograd.Function):
@staticmethod
def forward(ctx, xy):
ctx.save_for_backward(xy)
return _swiglu_fwd(xy)
@staticmethod
def backward(ctx, dout):
xy, = ctx.saved_tensors
return _swiglu_bwd(xy, dout)
swiglu = SwiGLU.apply
# Copyright (c) 2024, Tri Dao.
# Implement dropout + residual + layer_norm / rms_norm.
# Based on the Triton LayerNorm tutorial: https://triton-lang.org/main/getting-started/tutorials/05-layer-norm.html
# For the backward pass, we keep weight_grad and bias_grad in registers and accumulate.
# This is faster for dimensions up to 8k, but after that it's much slower due to register spilling.
# The models we train have hidden dim up to 8k anyway (e.g. Llama 70B), so this is fine.
import math
import warnings
import torch
import torch.nn.functional as F
from torch.cuda.amp import custom_fwd, custom_bwd
import triton
import triton.language as tl
def layer_norm_ref(
x,
weight,
bias,
residual=None,
x1=None,
weight1=None,
bias1=None,
eps=1e-6,
dropout_p=0.0,
rowscale=None,
prenorm=False,
dropout_mask=None,
dropout_mask1=None,
upcast=False,
):
dtype = x.dtype
if upcast:
x = x.float()
weight = weight.float()
bias = bias.float() if bias is not None else None
residual = residual.float() if residual is not None else residual
x1 = x1.float() if x1 is not None else None
weight1 = weight1.float() if weight1 is not None else None
bias1 = bias1.float() if bias1 is not None else None
if x1 is not None:
assert rowscale is None, "rowscale is not supported with parallel LayerNorm"
if rowscale is not None:
x = x * rowscale[..., None]
if dropout_p > 0.0:
if dropout_mask is not None:
x = x.masked_fill(~dropout_mask, 0.0) / (1.0 - dropout_p)
else:
x = F.dropout(x, p=dropout_p)
if x1 is not None:
if dropout_mask1 is not None:
x1 = x1.masked_fill(~dropout_mask1, 0.0) / (1.0 - dropout_p)
else:
x1 = F.dropout(x1, p=dropout_p)
if x1 is not None:
x = x + x1
if residual is not None:
x = (x + residual).to(x.dtype)
out = F.layer_norm(x.to(weight.dtype), x.shape[-1:], weight=weight, bias=bias, eps=eps).to(
dtype
)
if weight1 is None:
return out if not prenorm else (out, x)
else:
out1 = F.layer_norm(
x.to(weight1.dtype), x.shape[-1:], weight=weight1, bias=bias1, eps=eps
).to(dtype)
return (out, out1) if not prenorm else (out, out1, x)
def rms_norm_ref(
x,
weight,
bias,
residual=None,
x1=None,
weight1=None,
bias1=None,
eps=1e-6,
dropout_p=0.0,
rowscale=None,
prenorm=False,
dropout_mask=None,
dropout_mask1=None,
upcast=False,
):
dtype = x.dtype
if upcast:
x = x.float()
weight = weight.float()
bias = bias.float() if bias is not None else None
residual = residual.float() if residual is not None else residual
x1 = x1.float() if x1 is not None else None
weight1 = weight1.float() if weight1 is not None else None
bias1 = bias1.float() if bias1 is not None else None
if x1 is not None:
assert rowscale is None, "rowscale is not supported with parallel LayerNorm"
if rowscale is not None:
x = x * rowscale[..., None]
if dropout_p > 0.0:
if dropout_mask is not None:
x = x.masked_fill(~dropout_mask, 0.0) / (1.0 - dropout_p)
else:
x = F.dropout(x, p=dropout_p)
if x1 is not None:
if dropout_mask1 is not None:
x1 = x1.masked_fill(~dropout_mask1, 0.0) / (1.0 - dropout_p)
else:
x1 = F.dropout(x1, p=dropout_p)
if x1 is not None:
x = x + x1
if residual is not None:
x = (x + residual).to(x.dtype)
rstd = 1 / torch.sqrt((x.square()).mean(dim=-1, keepdim=True) + eps)
out = ((x * rstd * weight) + bias if bias is not None else (x * rstd * weight)).to(dtype)
if weight1 is None:
return out if not prenorm else (out, x)
else:
out1 = ((x * rstd * weight1) + bias1 if bias1 is not None else (x * rstd * weight1)).to(
dtype
)
return (out, out1) if not prenorm else (out, out1, x)
def config_prune(configs):
if torch.version.hip:
try:
# set warp size based on gcn architecure
gcn_arch_name = torch.cuda.get_device_properties(0).gcnArchName
if "gfx10" in gcn_arch_name or "gfx11" in gcn_arch_name:
# radeon
warp_size = 32
else:
# instinct
warp_size = 64
except AttributeError as e:
# fall back to crude method to set warp size
device_name = torch.cuda.get_device_properties(0).name
if 'instinct' in device_name.lower():
warp_size = 64
else:
warp_size = 32
warnings.warn(f"{e}, warp size set to {warp_size} based on device name: {device_name}", UserWarning)
else:
# cuda
warp_size = 32
max_block_sz = 1024
max_num_warps = max_block_sz // warp_size
pruned_configs = [config for config in configs if config.num_warps <= max_num_warps]
return pruned_configs
configs_autotune = [
triton.Config({}, num_warps=1),
triton.Config({}, num_warps=2),
triton.Config({}, num_warps=4),
triton.Config({}, num_warps=8),
triton.Config({}, num_warps=16),
triton.Config({}, num_warps=32),
]
pruned_configs_autotune = config_prune(configs_autotune)
@triton.autotune(
configs = pruned_configs_autotune,
key=["N", "HAS_RESIDUAL", "STORE_RESIDUAL_OUT", "IS_RMS_NORM", "HAS_BIAS"],
)
# @triton.heuristics({"HAS_BIAS": lambda args: args["B"] is not None})
# @triton.heuristics({"HAS_RESIDUAL": lambda args: args["RESIDUAL"] is not None})
@triton.heuristics({"HAS_X1": lambda args: args["X1"] is not None})
@triton.heuristics({"HAS_W1": lambda args: args["W1"] is not None})
@triton.heuristics({"HAS_B1": lambda args: args["B1"] is not None})
@triton.jit
def _layer_norm_fwd_1pass_kernel(
X, # pointer to the input
Y, # pointer to the output
W, # pointer to the weights
B, # pointer to the biases
RESIDUAL, # pointer to the residual
X1,
W1,
B1,
Y1,
RESIDUAL_OUT, # pointer to the residual
ROWSCALE,
SEEDS, # Dropout seeds for each row
DROPOUT_MASK,
Mean, # pointer to the mean
Rstd, # pointer to the 1/std
stride_x_row, # how much to increase the pointer when moving by 1 row
stride_y_row,
stride_res_row,
stride_res_out_row,
stride_x1_row,
stride_y1_row,
M, # number of rows in X
N, # number of columns in X
eps, # epsilon to avoid division by zero
dropout_p, # Dropout probability
IS_RMS_NORM: tl.constexpr,
BLOCK_N: tl.constexpr,
HAS_RESIDUAL: tl.constexpr,
STORE_RESIDUAL_OUT: tl.constexpr,
HAS_BIAS: tl.constexpr,
HAS_DROPOUT: tl.constexpr,
STORE_DROPOUT_MASK: tl.constexpr,
HAS_ROWSCALE: tl.constexpr,
HAS_X1: tl.constexpr,
HAS_W1: tl.constexpr,
HAS_B1: tl.constexpr,
):
# Map the program id to the row of X and Y it should compute.
row = tl.program_id(0)
X += row * stride_x_row
Y += row * stride_y_row
if HAS_RESIDUAL:
RESIDUAL += row * stride_res_row
if STORE_RESIDUAL_OUT:
RESIDUAL_OUT += row * stride_res_out_row
if HAS_X1:
X1 += row * stride_x1_row
if HAS_W1:
Y1 += row * stride_y1_row
# Compute mean and variance
cols = tl.arange(0, BLOCK_N)
x = tl.load(X + cols, mask=cols < N, other=0.0).to(tl.float32)
if HAS_ROWSCALE:
rowscale = tl.load(ROWSCALE + row).to(tl.float32)
x *= rowscale
if HAS_DROPOUT:
# Compute dropout mask
# 7 rounds is good enough, and reduces register pressure
keep_mask = tl.rand(tl.load(SEEDS + row).to(tl.uint32), cols, n_rounds=7) > dropout_p
x = tl.where(keep_mask, x / (1.0 - dropout_p), 0.0)
if STORE_DROPOUT_MASK:
tl.store(DROPOUT_MASK + row * N + cols, keep_mask, mask=cols < N)
if HAS_X1:
x1 = tl.load(X1 + cols, mask=cols < N, other=0.0).to(tl.float32)
if HAS_ROWSCALE:
rowscale = tl.load(ROWSCALE + M + row).to(tl.float32)
x1 *= rowscale
if HAS_DROPOUT:
# Compute dropout mask
# 7 rounds is good enough, and reduces register pressure
keep_mask = (
tl.rand(tl.load(SEEDS + M + row).to(tl.uint32), cols, n_rounds=7) > dropout_p
)
x1 = tl.where(keep_mask, x1 / (1.0 - dropout_p), 0.0)
if STORE_DROPOUT_MASK:
tl.store(DROPOUT_MASK + (M + row) * N + cols, keep_mask, mask=cols < N)
x += x1
if HAS_RESIDUAL:
residual = tl.load(RESIDUAL + cols, mask=cols < N, other=0.0).to(tl.float32)
x += residual
if STORE_RESIDUAL_OUT:
tl.store(RESIDUAL_OUT + cols, x, mask=cols < N)
if not IS_RMS_NORM:
mean = tl.sum(x, axis=0) / N
tl.store(Mean + row, mean)
xbar = tl.where(cols < N, x - mean, 0.0)
var = tl.sum(xbar * xbar, axis=0) / N
else:
xbar = tl.where(cols < N, x, 0.0)
var = tl.sum(xbar * xbar, axis=0) / N
rstd = 1 / tl.sqrt(var + eps)
tl.store(Rstd + row, rstd)
# Normalize and apply linear transformation
mask = cols < N
w = tl.load(W + cols, mask=mask).to(tl.float32)
if HAS_BIAS:
b = tl.load(B + cols, mask=mask).to(tl.float32)
x_hat = (x - mean) * rstd if not IS_RMS_NORM else x * rstd
y = x_hat * w + b if HAS_BIAS else x_hat * w
# Write output
tl.store(Y + cols, y, mask=mask)
if HAS_W1:
w1 = tl.load(W1 + cols, mask=mask).to(tl.float32)
if HAS_B1:
b1 = tl.load(B1 + cols, mask=mask).to(tl.float32)
y1 = x_hat * w1 + b1 if HAS_B1 else x_hat * w1
tl.store(Y1 + cols, y1, mask=mask)
def _layer_norm_fwd(
x,
weight,
bias,
eps,
residual=None,
x1=None,
weight1=None,
bias1=None,
dropout_p=0.0,
rowscale=None,
out_dtype=None,
residual_dtype=None,
is_rms_norm=False,
return_dropout_mask=False,
):
if residual is not None:
residual_dtype = residual.dtype
M, N = x.shape
assert x.stride(-1) == 1
if residual is not None:
assert residual.stride(-1) == 1
assert residual.shape == (M, N)
assert weight.shape == (N,)
assert weight.stride(-1) == 1
if bias is not None:
assert bias.stride(-1) == 1
assert bias.shape == (N,)
if x1 is not None:
assert x1.shape == x.shape
assert rowscale is None
assert x1.stride(-1) == 1
if weight1 is not None:
assert weight1.shape == (N,)
assert weight1.stride(-1) == 1
if bias1 is not None:
assert bias1.shape == (N,)
assert bias1.stride(-1) == 1
if rowscale is not None:
assert rowscale.is_contiguous()
assert rowscale.shape == (M,)
# allocate output
y = torch.empty_like(x, dtype=x.dtype if out_dtype is None else out_dtype)
assert y.stride(-1) == 1
if weight1 is not None:
y1 = torch.empty_like(y)
assert y1.stride(-1) == 1
else:
y1 = None
if (
residual is not None
or (residual_dtype is not None and residual_dtype != x.dtype)
or dropout_p > 0.0
or rowscale is not None
or x1 is not None
):
residual_out = torch.empty(
M, N, device=x.device, dtype=residual_dtype if residual_dtype is not None else x.dtype
)
assert residual_out.stride(-1) == 1
else:
residual_out = None
mean = torch.empty((M,), dtype=torch.float32, device=x.device) if not is_rms_norm else None
rstd = torch.empty((M,), dtype=torch.float32, device=x.device)
if dropout_p > 0.0:
seeds = torch.randint(
2**32, (M if x1 is None else 2 * M,), device=x.device, dtype=torch.int64
)
else:
seeds = None
if return_dropout_mask and dropout_p > 0.0:
dropout_mask = torch.empty(M if x1 is None else 2 * M, N, device=x.device, dtype=torch.bool)
else:
dropout_mask = None
# Less than 64KB per feature: enqueue fused kernel
MAX_FUSED_SIZE = 65536 // x.element_size()
BLOCK_N = min(MAX_FUSED_SIZE, triton.next_power_of_2(N))
if N > BLOCK_N:
raise RuntimeError("This layer norm doesn't support feature dim >= 64KB.")
with torch.cuda.device(x.device.index):
_layer_norm_fwd_1pass_kernel[(M,)](
x,
y,
weight,
bias,
residual,
x1,
weight1,
bias1,
y1,
residual_out,
rowscale,
seeds,
dropout_mask,
mean,
rstd,
x.stride(0),
y.stride(0),
residual.stride(0) if residual is not None else 0,
residual_out.stride(0) if residual_out is not None else 0,
x1.stride(0) if x1 is not None else 0,
y1.stride(0) if y1 is not None else 0,
M,
N,
eps,
dropout_p,
is_rms_norm,
BLOCK_N,
residual is not None,
residual_out is not None,
bias is not None,
dropout_p > 0.0,
dropout_mask is not None,
rowscale is not None,
)
# residual_out is None if residual is None and residual_dtype == input_dtype and dropout_p == 0.0
if dropout_mask is not None and x1 is not None:
dropout_mask, dropout_mask1 = dropout_mask.tensor_split(2, dim=0)
else:
dropout_mask1 = None
return (
y,
y1,
mean,
rstd,
residual_out if residual_out is not None else x,
seeds,
dropout_mask,
dropout_mask1,
)
@triton.autotune(
configs=pruned_configs_autotune,
key=["N", "HAS_DRESIDUAL", "STORE_DRESIDUAL", "IS_RMS_NORM", "HAS_BIAS", "HAS_DROPOUT"],
)
# @triton.heuristics({"HAS_BIAS": lambda args: args["B"] is not None})
# @triton.heuristics({"HAS_DRESIDUAL": lambda args: args["DRESIDUAL"] is not None})
# @triton.heuristics({"STORE_DRESIDUAL": lambda args: args["DRESIDUAL_IN"] is not None})
@triton.heuristics({"HAS_ROWSCALE": lambda args: args["ROWSCALE"] is not None})
@triton.heuristics({"HAS_DY1": lambda args: args["DY1"] is not None})
@triton.heuristics({"HAS_DX1": lambda args: args["DX1"] is not None})
@triton.heuristics({"HAS_B1": lambda args: args["DB1"] is not None})
@triton.heuristics({"RECOMPUTE_OUTPUT": lambda args: args["Y"] is not None})
@triton.jit
def _layer_norm_bwd_kernel(
X, # pointer to the input
W, # pointer to the weights
B, # pointer to the biases
Y, # pointer to the output to be recomputed
DY, # pointer to the output gradient
DX, # pointer to the input gradient
DW, # pointer to the partial sum of weights gradient
DB, # pointer to the partial sum of biases gradient
DRESIDUAL,
W1,
DY1,
DX1,
DW1,
DB1,
DRESIDUAL_IN,
ROWSCALE,
SEEDS,
Mean, # pointer to the mean
Rstd, # pointer to the 1/std
stride_x_row, # how much to increase the pointer when moving by 1 row
stride_y_row,
stride_dy_row,
stride_dx_row,
stride_dres_row,
stride_dy1_row,
stride_dx1_row,
stride_dres_in_row,
M, # number of rows in X
N, # number of columns in X
eps, # epsilon to avoid division by zero
dropout_p,
rows_per_program,
IS_RMS_NORM: tl.constexpr,
BLOCK_N: tl.constexpr,
HAS_DRESIDUAL: tl.constexpr,
STORE_DRESIDUAL: tl.constexpr,
HAS_BIAS: tl.constexpr,
HAS_DROPOUT: tl.constexpr,
HAS_ROWSCALE: tl.constexpr,
HAS_DY1: tl.constexpr,
HAS_DX1: tl.constexpr,
HAS_B1: tl.constexpr,
RECOMPUTE_OUTPUT: tl.constexpr,
):
# Map the program id to the elements of X, DX, and DY it should compute.
row_block_id = tl.program_id(0)
row_start = row_block_id * rows_per_program
# Do not early exit if row_start >= M, because we need to write DW and DB
cols = tl.arange(0, BLOCK_N)
mask = cols < N
X += row_start * stride_x_row
if HAS_DRESIDUAL:
DRESIDUAL += row_start * stride_dres_row
if STORE_DRESIDUAL:
DRESIDUAL_IN += row_start * stride_dres_in_row
DY += row_start * stride_dy_row
DX += row_start * stride_dx_row
if HAS_DY1:
DY1 += row_start * stride_dy1_row
if HAS_DX1:
DX1 += row_start * stride_dx1_row
if RECOMPUTE_OUTPUT:
Y += row_start * stride_y_row
w = tl.load(W + cols, mask=mask).to(tl.float32)
if RECOMPUTE_OUTPUT and HAS_BIAS:
b = tl.load(B + cols, mask=mask, other=0.0).to(tl.float32)
if HAS_DY1:
w1 = tl.load(W1 + cols, mask=mask).to(tl.float32)
dw = tl.zeros((BLOCK_N,), dtype=tl.float32)
if HAS_BIAS:
db = tl.zeros((BLOCK_N,), dtype=tl.float32)
if HAS_DY1:
dw1 = tl.zeros((BLOCK_N,), dtype=tl.float32)
if HAS_B1:
db1 = tl.zeros((BLOCK_N,), dtype=tl.float32)
row_end = min((row_block_id + 1) * rows_per_program, M)
for row in range(row_start, row_end):
# Load data to SRAM
x = tl.load(X + cols, mask=mask, other=0).to(tl.float32)
dy = tl.load(DY + cols, mask=mask, other=0).to(tl.float32)
if HAS_DY1:
dy1 = tl.load(DY1 + cols, mask=mask, other=0).to(tl.float32)
if not IS_RMS_NORM:
mean = tl.load(Mean + row)
rstd = tl.load(Rstd + row)
# Compute dx
xhat = (x - mean) * rstd if not IS_RMS_NORM else x * rstd
xhat = tl.where(mask, xhat, 0.0)
if RECOMPUTE_OUTPUT:
y = xhat * w + b if HAS_BIAS else xhat * w
tl.store(Y + cols, y, mask=mask)
wdy = w * dy
dw += dy * xhat
if HAS_BIAS:
db += dy
if HAS_DY1:
wdy += w1 * dy1
dw1 += dy1 * xhat
if HAS_B1:
db1 += dy1
if not IS_RMS_NORM:
c1 = tl.sum(xhat * wdy, axis=0) / N
c2 = tl.sum(wdy, axis=0) / N
dx = (wdy - (xhat * c1 + c2)) * rstd
else:
c1 = tl.sum(xhat * wdy, axis=0) / N
dx = (wdy - xhat * c1) * rstd
if HAS_DRESIDUAL:
dres = tl.load(DRESIDUAL + cols, mask=mask, other=0).to(tl.float32)
dx += dres
# Write dx
if STORE_DRESIDUAL:
tl.store(DRESIDUAL_IN + cols, dx, mask=mask)
if HAS_DX1:
if HAS_DROPOUT:
keep_mask = (
tl.rand(tl.load(SEEDS + M + row).to(tl.uint32), cols, n_rounds=7) > dropout_p
)
dx1 = tl.where(keep_mask, dx / (1.0 - dropout_p), 0.0)
else:
dx1 = dx
tl.store(DX1 + cols, dx1, mask=mask)
if HAS_DROPOUT:
keep_mask = tl.rand(tl.load(SEEDS + row).to(tl.uint32), cols, n_rounds=7) > dropout_p
dx = tl.where(keep_mask, dx / (1.0 - dropout_p), 0.0)
if HAS_ROWSCALE:
rowscale = tl.load(ROWSCALE + row).to(tl.float32)
dx *= rowscale
tl.store(DX + cols, dx, mask=mask)
X += stride_x_row
if HAS_DRESIDUAL:
DRESIDUAL += stride_dres_row
if STORE_DRESIDUAL:
DRESIDUAL_IN += stride_dres_in_row
if RECOMPUTE_OUTPUT:
Y += stride_y_row
DY += stride_dy_row
DX += stride_dx_row
if HAS_DY1:
DY1 += stride_dy1_row
if HAS_DX1:
DX1 += stride_dx1_row
tl.store(DW + row_block_id * N + cols, dw, mask=mask)
if HAS_BIAS:
tl.store(DB + row_block_id * N + cols, db, mask=mask)
if HAS_DY1:
tl.store(DW1 + row_block_id * N + cols, dw1, mask=mask)
if HAS_B1:
tl.store(DB1 + row_block_id * N + cols, db1, mask=mask)
def _layer_norm_bwd(
dy,
x,
weight,
bias,
eps,
mean,
rstd,
dresidual=None,
dy1=None,
weight1=None,
bias1=None,
seeds=None,
dropout_p=0.0,
rowscale=None,
has_residual=False,
has_x1=False,
is_rms_norm=False,
x_dtype=None,
recompute_output=False,
):
M, N = x.shape
assert x.stride(-1) == 1
assert dy.stride(-1) == 1
assert dy.shape == (M, N)
if dresidual is not None:
assert dresidual.stride(-1) == 1
assert dresidual.shape == (M, N)
assert weight.shape == (N,)
assert weight.stride(-1) == 1
if bias is not None:
assert bias.stride(-1) == 1
assert bias.shape == (N,)
if dy1 is not None:
assert weight1 is not None
assert dy1.shape == dy.shape
assert dy1.stride(-1) == 1
if weight1 is not None:
assert weight1.shape == (N,)
assert weight1.stride(-1) == 1
if bias1 is not None:
assert bias1.shape == (N,)
assert bias1.stride(-1) == 1
if seeds is not None:
assert seeds.is_contiguous()
assert seeds.shape == (M if not has_x1 else M * 2,)
if rowscale is not None:
assert rowscale.is_contiguous()
assert rowscale.shape == (M,)
# allocate output
dx = (
torch.empty_like(x)
if x_dtype is None
else torch.empty(M, N, dtype=x_dtype, device=x.device)
)
dresidual_in = (
torch.empty_like(x)
if has_residual
and (dx.dtype != x.dtype or dropout_p > 0.0 or rowscale is not None or has_x1)
else None
)
dx1 = torch.empty_like(dx) if (has_x1 and dropout_p > 0.0) else None
y = torch.empty(M, N, dtype=dy.dtype, device=dy.device) if recompute_output else None
if recompute_output:
assert weight1 is None, "recompute_output is not supported with parallel LayerNorm"
# Less than 64KB per feature: enqueue fused kernel
MAX_FUSED_SIZE = 65536 // x.element_size()
BLOCK_N = min(MAX_FUSED_SIZE, triton.next_power_of_2(N))
if N > BLOCK_N:
raise RuntimeError("This layer norm doesn't support feature dim >= 64KB.")
sm_count = torch.cuda.get_device_properties(x.device).multi_processor_count
_dw = torch.empty((sm_count, N), dtype=torch.float32, device=weight.device)
_db = (
torch.empty((sm_count, N), dtype=torch.float32, device=bias.device)
if bias is not None
else None
)
_dw1 = torch.empty_like(_dw) if weight1 is not None else None
_db1 = torch.empty_like(_db) if bias1 is not None else None
rows_per_program = math.ceil(M / sm_count)
grid = (sm_count,)
with torch.cuda.device(x.device.index):
_layer_norm_bwd_kernel[grid](
x,
weight,
bias,
y,
dy,
dx,
_dw,
_db,
dresidual,
weight1,
dy1,
dx1,
_dw1,
_db1,
dresidual_in,
rowscale,
seeds,
mean,
rstd,
x.stride(0),
0 if not recompute_output else y.stride(0),
dy.stride(0),
dx.stride(0),
dresidual.stride(0) if dresidual is not None else 0,
dy1.stride(0) if dy1 is not None else 0,
dx1.stride(0) if dx1 is not None else 0,
dresidual_in.stride(0) if dresidual_in is not None else 0,
M,
N,
eps,
dropout_p,
rows_per_program,
is_rms_norm,
BLOCK_N,
dresidual is not None,
dresidual_in is not None,
bias is not None,
dropout_p > 0.0,
)
dw = _dw.sum(0).to(weight.dtype)
db = _db.sum(0).to(bias.dtype) if bias is not None else None
dw1 = _dw1.sum(0).to(weight1.dtype) if weight1 is not None else None
db1 = _db1.sum(0).to(bias1.dtype) if bias1 is not None else None
# Don't need to compute dresidual_in separately in this case
if has_residual and dx.dtype == x.dtype and dropout_p == 0.0 and rowscale is None:
dresidual_in = dx
if has_x1 and dropout_p == 0.0:
dx1 = dx
return (
(dx, dw, db, dresidual_in, dx1, dw1, db1)
if not recompute_output
else (dx, dw, db, dresidual_in, dx1, dw1, db1, y)
)
class LayerNormFn(torch.autograd.Function):
@staticmethod
def forward(
ctx,
x,
weight,
bias,
residual=None,
x1=None,
weight1=None,
bias1=None,
eps=1e-6,
dropout_p=0.0,
rowscale=None,
prenorm=False,
residual_in_fp32=False,
is_rms_norm=False,
return_dropout_mask=False,
):
x_shape_og = x.shape
# reshape input data into 2D tensor
x = x.reshape(-1, x.shape[-1])
if x.stride(-1) != 1:
x = x.contiguous()
if residual is not None:
assert residual.shape == x_shape_og
residual = residual.reshape(-1, residual.shape[-1])
if residual.stride(-1) != 1:
residual = residual.contiguous()
if x1 is not None:
assert x1.shape == x_shape_og
assert rowscale is None, "rowscale is not supported with parallel LayerNorm"
x1 = x1.reshape(-1, x1.shape[-1])
if x1.stride(-1) != 1:
x1 = x1.contiguous()
weight = weight.contiguous()
if bias is not None:
bias = bias.contiguous()
if weight1 is not None:
weight1 = weight1.contiguous()
if bias1 is not None:
bias1 = bias1.contiguous()
if rowscale is not None:
rowscale = rowscale.reshape(-1).contiguous()
residual_dtype = (
residual.dtype
if residual is not None
else (torch.float32 if residual_in_fp32 else None)
)
y, y1, mean, rstd, residual_out, seeds, dropout_mask, dropout_mask1 = _layer_norm_fwd(
x,
weight,
bias,
eps,
residual,
x1,
weight1,
bias1,
dropout_p=dropout_p,
rowscale=rowscale,
residual_dtype=residual_dtype,
is_rms_norm=is_rms_norm,
return_dropout_mask=return_dropout_mask,
)
ctx.save_for_backward(
residual_out, weight, bias, weight1, bias1, rowscale, seeds, mean, rstd
)
ctx.x_shape_og = x_shape_og
ctx.eps = eps
ctx.dropout_p = dropout_p
ctx.is_rms_norm = is_rms_norm
ctx.has_residual = residual is not None
ctx.has_x1 = x1 is not None
ctx.prenorm = prenorm
ctx.x_dtype = x.dtype
y = y.reshape(x_shape_og)
y1 = y1.reshape(x_shape_og) if y1 is not None else None
residual_out = residual_out.reshape(x_shape_og) if residual_out is not None else None
dropout_mask = dropout_mask.reshape(x_shape_og) if dropout_mask is not None else None
dropout_mask1 = dropout_mask1.reshape(x_shape_og) if dropout_mask1 is not None else None
if not return_dropout_mask:
if weight1 is None:
return y if not prenorm else (y, residual_out)
else:
return (y, y1) if not prenorm else (y, y1, residual_out)
else:
if weight1 is None:
return (
(y, dropout_mask, dropout_mask1)
if not prenorm
else (y, residual_out, dropout_mask, dropout_mask1)
)
else:
return (
(y, y1, dropout_mask, dropout_mask1)
if not prenorm
else (y, y1, residual_out, dropout_mask, dropout_mask1)
)
@staticmethod
def backward(ctx, dy, *args):
x, weight, bias, weight1, bias1, rowscale, seeds, mean, rstd = ctx.saved_tensors
dy = dy.reshape(-1, dy.shape[-1])
if dy.stride(-1) != 1:
dy = dy.contiguous()
assert dy.shape == x.shape
if weight1 is not None:
dy1, args = args[0], args[1:]
dy1 = dy1.reshape(-1, dy1.shape[-1])
if dy1.stride(-1) != 1:
dy1 = dy1.contiguous()
assert dy1.shape == x.shape
else:
dy1 = None
if ctx.prenorm:
dresidual = args[0]
dresidual = dresidual.reshape(-1, dresidual.shape[-1])
if dresidual.stride(-1) != 1:
dresidual = dresidual.contiguous()
assert dresidual.shape == x.shape
else:
dresidual = None
dx, dw, db, dresidual_in, dx1, dw1, db1 = _layer_norm_bwd(
dy,
x,
weight,
bias,
ctx.eps,
mean,
rstd,
dresidual,
dy1,
weight1,
bias1,
seeds,
ctx.dropout_p,
rowscale,
ctx.has_residual,
ctx.has_x1,
ctx.is_rms_norm,
x_dtype=ctx.x_dtype,
)
return (
dx.reshape(ctx.x_shape_og),
dw,
db,
dresidual_in.reshape(ctx.x_shape_og) if ctx.has_residual else None,
dx1.reshape(ctx.x_shape_og) if dx1 is not None else None,
dw1,
db1,
None,
None,
None,
None,
None,
None,
None,
)
def layer_norm_fn(
x,
weight,
bias,
residual=None,
x1=None,
weight1=None,
bias1=None,
eps=1e-6,
dropout_p=0.0,
rowscale=None,
prenorm=False,
residual_in_fp32=False,
is_rms_norm=False,
return_dropout_mask=False,
):
return LayerNormFn.apply(
x,
weight,
bias,
residual,
x1,
weight1,
bias1,
eps,
dropout_p,
rowscale,
prenorm,
residual_in_fp32,
is_rms_norm,
return_dropout_mask,
)
def rms_norm_fn(
x,
weight,
bias,
residual=None,
x1=None,
weight1=None,
bias1=None,
eps=1e-6,
dropout_p=0.0,
rowscale=None,
prenorm=False,
residual_in_fp32=False,
return_dropout_mask=False,
):
return LayerNormFn.apply(
x,
weight,
bias,
residual,
x1,
weight1,
bias1,
eps,
dropout_p,
rowscale,
prenorm,
residual_in_fp32,
True,
return_dropout_mask,
)
class RMSNorm(torch.nn.Module):
def __init__(self, hidden_size, eps=1e-5, dropout_p=0.0, device=None, dtype=None):
factory_kwargs = {"device": device, "dtype": dtype}
super().__init__()
self.eps = eps
if dropout_p > 0.0:
self.drop = torch.nn.Dropout(dropout_p)
else:
self.drop = None
self.weight = torch.nn.Parameter(torch.empty(hidden_size, **factory_kwargs))
self.register_parameter("bias", None)
self.reset_parameters()
def reset_parameters(self):
torch.nn.init.ones_(self.weight)
def forward(self, x, residual=None, prenorm=False, residual_in_fp32=False):
return rms_norm_fn(
x,
self.weight,
self.bias,
residual=residual,
eps=self.eps,
dropout_p=self.drop.p if self.drop is not None and self.training else 0.0,
prenorm=prenorm,
residual_in_fp32=residual_in_fp32,
)
class LayerNormLinearFn(torch.autograd.Function):
@staticmethod
@custom_fwd
def forward(
ctx,
x,
norm_weight,
norm_bias,
linear_weight,
linear_bias,
residual=None,
eps=1e-6,
prenorm=False,
residual_in_fp32=False,
is_rms_norm=False,
):
x_shape_og = x.shape
# reshape input data into 2D tensor
x = x.reshape(-1, x.shape[-1])
if x.stride(-1) != 1:
x = x.contiguous()
if residual is not None:
assert residual.shape == x_shape_og
residual = residual.reshape(-1, residual.shape[-1])
if residual.stride(-1) != 1:
residual = residual.contiguous()
norm_weight = norm_weight.contiguous()
if norm_bias is not None:
norm_bias = norm_bias.contiguous()
residual_dtype = (
residual.dtype
if residual is not None
else (torch.float32 if residual_in_fp32 else None)
)
y, _, mean, rstd, residual_out, *rest = _layer_norm_fwd(
x,
norm_weight,
norm_bias,
eps,
residual,
out_dtype=None if not torch.is_autocast_enabled() else torch.get_autocast_gpu_dtype(),
residual_dtype=residual_dtype,
is_rms_norm=is_rms_norm,
)
y = y.reshape(x_shape_og)
dtype = torch.get_autocast_gpu_dtype() if torch.is_autocast_enabled() else y.dtype
linear_weight = linear_weight.to(dtype)
linear_bias = linear_bias.to(dtype) if linear_bias is not None else None
out = F.linear(y.to(linear_weight.dtype), linear_weight, linear_bias)
# We don't store y, will be recomputed in the backward pass to save memory
ctx.save_for_backward(residual_out, norm_weight, norm_bias, linear_weight, mean, rstd)
ctx.x_shape_og = x_shape_og
ctx.eps = eps
ctx.is_rms_norm = is_rms_norm
ctx.has_residual = residual is not None
ctx.prenorm = prenorm
ctx.x_dtype = x.dtype
ctx.linear_bias_is_none = linear_bias is None
return out if not prenorm else (out, residual_out.reshape(x_shape_og))
@staticmethod
@custom_bwd
def backward(ctx, dout, *args):
x, norm_weight, norm_bias, linear_weight, mean, rstd = ctx.saved_tensors
dout = dout.reshape(-1, dout.shape[-1])
dy = F.linear(dout, linear_weight.t())
dlinear_bias = None if ctx.linear_bias_is_none else dout.sum(0)
if dy.stride(-1) != 1:
dy = dy.contiguous()
assert dy.shape == x.shape
if ctx.prenorm:
dresidual = args[0]
dresidual = dresidual.reshape(-1, dresidual.shape[-1])
if dresidual.stride(-1) != 1:
dresidual = dresidual.contiguous()
assert dresidual.shape == x.shape
else:
dresidual = None
dx, dnorm_weight, dnorm_bias, dresidual_in, _, _, _, y = _layer_norm_bwd(
dy,
x,
norm_weight,
norm_bias,
ctx.eps,
mean,
rstd,
dresidual=dresidual,
has_residual=ctx.has_residual,
is_rms_norm=ctx.is_rms_norm,
x_dtype=ctx.x_dtype,
recompute_output=True,
)
dlinear_weight = torch.einsum("bo,bi->oi", dout, y)
return (
dx.reshape(ctx.x_shape_og),
dnorm_weight,
dnorm_bias,
dlinear_weight,
dlinear_bias,
dresidual_in.reshape(ctx.x_shape_og) if ctx.has_residual else None,
None,
None,
None,
None,
)
def layer_norm_linear_fn(
x,
norm_weight,
norm_bias,
linear_weight,
linear_bias,
residual=None,
eps=1e-6,
prenorm=False,
residual_in_fp32=False,
is_rms_norm=False,
):
return LayerNormLinearFn.apply(
x,
norm_weight,
norm_bias,
linear_weight,
linear_bias,
residual,
eps,
prenorm,
residual_in_fp32,
is_rms_norm,
)
# Copyright (c) 2024, Tri Dao.
# Based on the Triton LayerNorm tutorial: https://triton-lang.org/main/getting-started/tutorials/05-layer-norm.html
# For the backward pass, we keep weight_grad and bias_grad in registers and accumulate.
# This backward pass is faster for dimensions up to 8k, but after that it's much slower due to register spilling.
# The models we train have hidden dim up to 8k anyway (e.g. Llama 70B), so this is fine.
import math
import torch
import torch.nn.functional as F
import triton
import triton.language as tl
from einops import rearrange
def rms_norm_ref(x, weight, bias, z=None, eps=1e-6, group_size=None, norm_before_gate=True, upcast=True):
dtype = x.dtype
N = x.shape[-1]
weight = weight.float()
bias = bias.float() if bias is not None else None
if upcast:
x = x.float()
z = z.float() if z is not None else z
if z is not None and not norm_before_gate:
x = x * F.silu(z)
if group_size is None:
rstd = 1 / torch.sqrt((x.square()).mean(dim=-1, keepdim=True) + eps)
out = (x * rstd * weight) + bias if bias is not None else (x * rstd * weight)
else:
x_group = rearrange(x, "... (g d) -> ... g d", d=group_size)
rstd = 1 / torch.sqrt((x_group.square()).mean(dim=-1, keepdim=True) + eps)
out = rearrange(x_group * rstd, "... g d -> ... (g d)") * weight
if bias is not None:
out = out + bias
if z is not None and norm_before_gate:
out *= F.silu(z)
return out.to(dtype)
@triton.heuristics({"HAS_BIAS": lambda args: args["B"] is not None})
@triton.heuristics({"HAS_Z": lambda args: args["Z"] is not None})
@triton.jit
def _layer_norm_fwd_1pass_kernel(
X, # pointer to the input
Y, # pointer to the output
W, # pointer to the weights
B, # pointer to the biases
Z, # pointer to the other branch
Mean, # pointer to the mean
Rstd, # pointer to the 1/std
stride_x_row, # how much to increase the pointer when moving by 1 row
stride_y_row,
stride_z_row,
M, # number of rows in X
N, # number of columns in X
eps, # epsilon to avoid division by zero
BLOCK_N: tl.constexpr,
HAS_BIAS: tl.constexpr,
HAS_Z: tl.constexpr,
NORM_BEFORE_GATE: tl.constexpr,
IS_RMS_NORM: tl.constexpr,
):
# Map the program id to the row of X and Y it should compute.
row = tl.program_id(0)
group = tl.program_id(1)
X += row * stride_x_row + group * N
Y += row * stride_y_row + group * N
if HAS_Z:
Z += row * stride_z_row + group * N
if not IS_RMS_NORM:
Mean += group * M
Rstd += group * M
W += group * N
if HAS_BIAS:
B += group * N
# Compute mean and variance
cols = tl.arange(0, BLOCK_N)
x = tl.load(X + cols, mask=cols < N, other=0.).to(tl.float32)
if HAS_Z and not NORM_BEFORE_GATE:
z = tl.load(Z + cols, mask=cols < N).to(tl.float32)
x *= z * tl.sigmoid(z)
if not IS_RMS_NORM:
mean = tl.sum(x, axis=0) / N
tl.store(Mean + row, mean)
xbar = tl.where(cols < N, x - mean, 0.)
var = tl.sum(xbar * xbar, axis=0) / N
else:
xbar = tl.where(cols < N, x, 0.)
var = tl.sum(xbar * xbar, axis=0) / N
rstd = 1 / tl.sqrt(var + eps)
tl.store(Rstd + row, rstd)
# Normalize and apply linear transformation
mask = cols < N
w = tl.load(W + cols, mask=mask).to(tl.float32)
if HAS_BIAS:
b = tl.load(B + cols, mask=mask).to(tl.float32)
x_hat = (x - mean) * rstd if not IS_RMS_NORM else x * rstd
y = x_hat * w + b if HAS_BIAS else x_hat * w
if HAS_Z and NORM_BEFORE_GATE:
z = tl.load(Z + cols, mask=mask).to(tl.float32)
y *= z * tl.sigmoid(z)
# Write output
tl.store(Y + cols, y, mask=mask)
def _layer_norm_fwd(x, weight, bias, eps, z=None, out=None, group_size=None, norm_before_gate=True, is_rms_norm=False):
M, N = x.shape
if group_size is None:
group_size = N
assert N % group_size == 0
ngroups = N // group_size
assert x.stride(-1) == 1
if z is not None:
assert z.stride(-1) == 1
assert z.shape == (M, N)
assert weight.shape == (N,)
assert weight.stride(-1) == 1
if bias is not None:
assert bias.stride(-1) == 1
assert bias.shape == (N,)
# allocate output
if out is not None:
assert out.shape == x.shape
else:
out = torch.empty_like(x)
assert out.stride(-1) == 1
mean = torch.empty((ngroups * M, ), dtype=torch.float32, device=x.device) if not is_rms_norm else None
rstd = torch.empty((ngroups * M, ), dtype=torch.float32, device=x.device)
# Less than 64KB per feature: enqueue fused kernel
MAX_FUSED_SIZE = 65536 // x.element_size()
BLOCK_N = min(MAX_FUSED_SIZE, triton.next_power_of_2(group_size))
if group_size > BLOCK_N:
raise RuntimeError("This layer norm doesn't support feature dim >= 64KB.")
# heuristics for number of warps
num_warps = min(max(BLOCK_N // 256, 1), 8)
grid = (M, ngroups)
with torch.cuda.device(x.device.index):
_layer_norm_fwd_1pass_kernel[grid](x, out, weight, bias, z, mean, rstd,
x.stride(0), out.stride(0), z.stride(0) if z is not None else 0,
M, group_size, eps,
BLOCK_N=BLOCK_N,
NORM_BEFORE_GATE=norm_before_gate,
IS_RMS_NORM=is_rms_norm,
num_warps=num_warps)
return out, mean, rstd
@triton.heuristics({"HAS_BIAS": lambda args: args["B"] is not None})
@triton.heuristics({"HAS_Z": lambda args: args["Z"] is not None})
@triton.heuristics({"RECOMPUTE_OUTPUT": lambda args: args["Y"] is not None})
@triton.jit
def _layer_norm_bwd_kernel(
X, # pointer to the input
W, # pointer to the weights
B, # pointer to the biases
Z, # pointer to the other branch
Y, # pointer to the output to be recomputed
DY, # pointer to the output gradient
DX, # pointer to the input gradient
DW, # pointer to the partial sum of weights gradient
DB, # pointer to the partial sum of biases gradient
DZ, # pointer to the other branch
Mean, # pointer to the mean
Rstd, # pointer to the 1/std
stride_x_row, # how much to increase the pointer when moving by 1 row
stride_z_row,
stride_y_row,
stride_dy_row,
stride_dx_row,
stride_dz_row,
stride_dw_row,
stride_db_row,
M, # number of rows in X
N, # number of columns in X
eps, # epsilon to avoid division by zero
rows_per_program,
NORM_BEFORE_GATE: tl.constexpr,
IS_RMS_NORM: tl.constexpr,
HAS_BIAS: tl.constexpr,
HAS_Z: tl.constexpr,
RECOMPUTE_OUTPUT: tl.constexpr,
BLOCK_N: tl.constexpr,
):
# Map the program id to the elements of X, DX, and DY it should compute.
row_block_id = tl.program_id(0)
group = tl.program_id(1)
row_start = row_block_id * rows_per_program
cols = tl.arange(0, BLOCK_N)
mask = cols < N
X += row_start * stride_x_row + group * N
if HAS_Z:
Z += row_start * stride_z_row + group * N
DZ += row_start * stride_dz_row + group * N
DY += row_start * stride_dy_row + group * N
DX += row_start * stride_dx_row + group * N
if RECOMPUTE_OUTPUT:
Y += row_start * stride_y_row + group * N
if not IS_RMS_NORM:
Mean += group * M
Rstd += group * M
W += group * N
w = tl.load(W + cols, mask=mask).to(tl.float32)
if (RECOMPUTE_OUTPUT or HAS_Z) and HAS_BIAS:
B += group * N
b = tl.load(B + cols, mask=mask, other=0.).to(tl.float32)
dw = tl.zeros((BLOCK_N,), dtype=tl.float32)
if HAS_BIAS:
db = tl.zeros((BLOCK_N,), dtype=tl.float32)
row_end = min((row_block_id + 1) * rows_per_program, M)
for row in range(row_start, row_end):
# Load data to SRAM
x = tl.load(X + cols, mask=mask, other=0).to(tl.float32)
dy = tl.load(DY + cols, mask=mask, other=0).to(tl.float32)
if not IS_RMS_NORM:
mean = tl.load(Mean + row)
if HAS_Z and not NORM_BEFORE_GATE:
z = tl.load(Z + cols, mask=mask, other=0.).to(tl.float32)
x_og = x
x = x_og * z * tl.sigmoid(z)
rstd = tl.load(Rstd + row)
# Compute dx
xhat = (x - mean) * rstd if not IS_RMS_NORM else x * rstd
xhat = tl.where(mask, xhat, 0.)
if HAS_Z and NORM_BEFORE_GATE:
z = tl.load(Z + cols, mask=mask, other=0.).to(tl.float32)
z_sigmoid = tl.sigmoid(z)
y = xhat * w + b if HAS_BIAS else xhat * w
if RECOMPUTE_OUTPUT:
tl.store(Y + cols, y * z * z_sigmoid, mask=mask)
dz = dy * y * z_sigmoid * (1 + z * (1 - z_sigmoid))
tl.store(DZ + cols, dz, mask=mask)
dy *= z * z_sigmoid
else:
if RECOMPUTE_OUTPUT:
y = xhat * w + b if HAS_BIAS else xhat * w
tl.store(Y + cols, y, mask=mask)
wdy = w * dy
c1 = tl.sum(xhat * wdy, axis=0) / N
if not IS_RMS_NORM:
c2 = tl.sum(wdy, axis=0) / N
dx = (wdy - (xhat * c1 + c2)) * rstd
else:
dx = (wdy - xhat * c1) * rstd
dw += dy * xhat
if HAS_BIAS:
db += dy
if HAS_Z and not NORM_BEFORE_GATE:
z_sigmoid = tl.sigmoid(z)
dz = dx * x_og * z_sigmoid * (1 + z * (1 - z_sigmoid))
tl.store(DZ + cols, dz, mask=mask)
dx *= z * z_sigmoid
# Write dx
tl.store(DX + cols, dx, mask=mask)
X += stride_x_row
if HAS_Z:
Z += stride_z_row
DZ += stride_dz_row
if RECOMPUTE_OUTPUT:
Y += stride_y_row
DY += stride_dy_row
DX += stride_dx_row
tl.store(DW + row_block_id * stride_dw_row + group * N + cols, dw, mask=mask)
if HAS_BIAS:
tl.store(DB + row_block_id * stride_db_row + group * N + cols, db, mask=mask)
def _layer_norm_bwd(dy, x, weight, bias, eps, mean, rstd, z=None, group_size=None,
norm_before_gate=True, is_rms_norm=False, recompute_output=False, dz=None, out=None):
M, N = x.shape
if group_size is None:
group_size = N
assert N % group_size == 0
ngroups = N // group_size
assert x.stride(-1) == 1
assert dy.stride(-1) == 1
assert dy.shape == (M, N)
if z is not None:
assert z.stride(-1) == 1
assert z.shape == (M, N)
assert weight.shape == (N,)
assert weight.stride(-1) == 1
if bias is not None:
assert bias.stride(-1) == 1
assert bias.shape == (N,)
# allocate output
dx = torch.empty_like(x)
if dz is not None:
assert z is not None
assert dz.shape == z.shape
assert dz.stride(-1) == 1
else:
dz = torch.empty_like(z) if z is not None else None
if recompute_output:
if out is None:
out = torch.empty_like(x)
assert out.shape == x.shape
# Less than 64KB per feature: enqueue fused kernel
MAX_FUSED_SIZE = 65536 // x.element_size()
BLOCK_N = min(MAX_FUSED_SIZE, triton.next_power_of_2(group_size))
if group_size > BLOCK_N:
raise RuntimeError("This layer norm doesn't support feature dim >= 64KB.")
# heuristics for number of warps
num_warps = min(max(BLOCK_N // 256, 1), 8)
sm_count = torch.cuda.get_device_properties(x.device).multi_processor_count
# If group size is small (e.g., 64), we're only using 1 warp. So having just 108 programs
# would limit the occupancy.
nrow_groups = math.ceil(sm_count * math.ceil(4 / num_warps) / ngroups)
_dw = torch.empty((nrow_groups, N), dtype=torch.float32, device=weight.device)
_db = torch.empty((nrow_groups, N), dtype=torch.float32, device=bias.device) if bias is not None else None
rows_per_program = math.ceil(M / nrow_groups)
grid = (nrow_groups, ngroups)
with torch.cuda.device(x.device.index):
_layer_norm_bwd_kernel[grid](x, weight, bias, z, out if recompute_output else None,
dy, dx, _dw, _db, dz, mean, rstd,
x.stride(0),
z.stride(0) if z is not None else 0,
0 if not recompute_output else out.stride(0),
dy.stride(0), dx.stride(0),
dz.stride(0) if dz is not None else 0,
_dw.stride(0),
_db.stride(0) if _db is not None else 0,
M, group_size, eps,
rows_per_program,
BLOCK_N=BLOCK_N,
NORM_BEFORE_GATE=norm_before_gate,
IS_RMS_NORM=is_rms_norm,
num_warps=num_warps)
dw = _dw.sum(0).to(weight.dtype)
db = _db.sum(0).to(bias.dtype) if bias is not None else None
return (dx, dw, db, dz) if not recompute_output else (dx, dw, db, dz, out)
class LayerNormFn(torch.autograd.Function):
@staticmethod
def forward(ctx, x, weight, bias, z=None, eps=1e-6, group_size=None, norm_before_gate=True,
is_rms_norm=False):
"""If z is not None, we do norm(x) * silu(z) if norm_before_gate, else norm(x * silu(z))
"""
x_shape_og = x.shape
# reshape input data into 2D tensor
x = x.reshape(-1, x.shape[-1])
if x.stride(-1) != 1:
x = x.contiguous()
if z is not None:
assert z.shape == x_shape_og
z = z.reshape(-1, z.shape[-1])
if z.stride(-1) != 1:
z = z.contiguous()
weight = weight.contiguous()
if bias is not None:
bias = bias.contiguous()
y, mean, rstd = _layer_norm_fwd(x, weight, bias, eps, z=z, group_size=group_size, norm_before_gate=norm_before_gate, is_rms_norm=is_rms_norm)
ctx.save_for_backward(x, weight, bias, mean, rstd, z)
ctx.x_shape_og = x_shape_og
ctx.eps = eps
ctx.group_size = group_size
ctx.norm_before_gate = norm_before_gate
ctx.is_rms_norm = is_rms_norm
return y.reshape(x_shape_og)
@staticmethod
def backward(ctx, dy):
x, weight, bias, mean, rstd, z = ctx.saved_tensors
dy = dy.reshape(-1, dy.shape[-1])
if dy.stride(-1) != 1:
dy = dy.contiguous()
assert dy.shape == x.shape
dx, dw, db, dz = _layer_norm_bwd(dy, x, weight, bias, ctx.eps, mean, rstd, z, ctx.group_size,
ctx.norm_before_gate, ctx.is_rms_norm)
return dx.reshape(ctx.x_shape_og), dw, db, dz.reshape(ctx.x_shape_og) if dz is not None else None, None, None, None, None
def layernorm_fn(x, weight, bias, z=None, eps=1e-6, group_size=None, norm_before_gate=True, is_rms_norm=False):
return LayerNormFn.apply(x, weight, bias, z, eps, group_size, norm_before_gate, is_rms_norm)
def rmsnorm_fn(x, weight, bias, z=None, eps=1e-6, group_size=None, norm_before_gate=True):
return LayerNormFn.apply(x, weight, bias, z, eps, group_size, norm_before_gate, True)
class LayerNorm(torch.nn.Module):
def __init__(self, hidden_size, eps=1e-5, group_size=None, norm_before_gate=True, device=None, dtype=None):
"""If group_size is not None, we do GroupNorm with each group having group_size elements.
group_size=None is equivalent to group_size=hidden_size (i.e. there's only 1 group).
"""
factory_kwargs = {"device": device, "dtype": dtype}
super().__init__()
self.eps = eps
self.weight = torch.nn.Parameter(torch.empty(hidden_size, **factory_kwargs))
self.bias = torch.nn.Parameter(torch.empty(hidden_size, **factory_kwargs))
self.group_size = group_size
self.norm_before_gate = norm_before_gate
self.reset_parameters()
def reset_parameters(self):
torch.nn.init.ones_(self.weight)
torch.nn.init.zeros_(self.bias)
def forward(self, x, z=None):
"""If z is not None, we do norm(x) * silu(z) if norm_before_gate, else norm(x * silu(z))
"""
return layernorm_fn(x, self.weight, self.bias, z=z, group_size=self.group_size, eps=self.eps,
norm_before_gate=self.norm_before_gate)
class RMSNorm(torch.nn.Module):
def __init__(self, hidden_size, eps=1e-5, group_size=None, norm_before_gate=True, device=None, dtype=None):
"""If group_size is not None, we do GroupNorm with each group having group_size elements.
group_size=None is equivalent to group_size=hidden_size (i.e. there's only 1 group).
"""
factory_kwargs = {"device": device, "dtype": dtype}
super().__init__()
self.eps = eps
self.weight = torch.nn.Parameter(torch.empty(hidden_size, **factory_kwargs))
self.register_parameter("bias", None)
self.group_size = group_size
self.norm_before_gate = norm_before_gate
self.reset_parameters()
def reset_parameters(self):
torch.nn.init.ones_(self.weight)
def forward(self, x, z=None):
"""If z is not None, we do norm(x) * silu(z) if norm_before_gate, else norm(x * silu(z))
"""
return rmsnorm_fn(x, self.weight, self.bias, z=z, eps=self.eps, group_size=self.group_size,
norm_before_gate=self.norm_before_gate)
# Copyright (c) 2024, Tri Dao, Albert Gu.
"""We want triton==2.1.0 or triton==2.2.0 or triton==2.3.0 for this
"""
import math
import torch
import torch.nn.functional as F
import triton
import triton.language as tl
from einops import rearrange, repeat
from mamba_ssm.ops.triton.softplus import softplus
@triton.heuristics({"HAS_DT_BIAS": lambda args: args["dt_bias_ptr"] is not None})
@triton.heuristics({"HAS_D": lambda args: args["D_ptr"] is not None})
@triton.heuristics({"HAS_Z": lambda args: args["z_ptr"] is not None})
@triton.heuristics({"BLOCK_SIZE_DSTATE": lambda args: triton.next_power_of_2(args["dstate"])})
@triton.jit
def _selective_scan_update_kernel(
# Pointers to matrices
state_ptr, x_ptr, dt_ptr, dt_bias_ptr, A_ptr, B_ptr, C_ptr, D_ptr, z_ptr, out_ptr,
# Matrix dimensions
batch, nheads, dim, dstate, nheads_ngroups_ratio,
# Strides
stride_state_batch, stride_state_head, stride_state_dim, stride_state_dstate,
stride_x_batch, stride_x_head, stride_x_dim,
stride_dt_batch, stride_dt_head, stride_dt_dim,
stride_dt_bias_head, stride_dt_bias_dim,
stride_A_head, stride_A_dim, stride_A_dstate,
stride_B_batch, stride_B_group, stride_B_dstate,
stride_C_batch, stride_C_group, stride_C_dstate,
stride_D_head, stride_D_dim,
stride_z_batch, stride_z_head, stride_z_dim,
stride_out_batch, stride_out_head, stride_out_dim,
# Meta-parameters
DT_SOFTPLUS: tl.constexpr,
TIE_HDIM: tl.constexpr,
BLOCK_SIZE_M: tl.constexpr,
HAS_DT_BIAS: tl.constexpr,
HAS_D: tl.constexpr,
HAS_Z: tl.constexpr,
BLOCK_SIZE_DSTATE: tl.constexpr,
):
pid_m = tl.program_id(axis=0)
pid_b = tl.program_id(axis=1)
pid_h = tl.program_id(axis=2)
state_ptr += pid_b * stride_state_batch + pid_h * stride_state_head
x_ptr += pid_b * stride_x_batch + pid_h * stride_x_head
dt_ptr += pid_b * stride_dt_batch + pid_h * stride_dt_head
if HAS_DT_BIAS:
dt_bias_ptr += pid_h * stride_dt_bias_head
A_ptr += pid_h * stride_A_head
B_ptr += pid_b * stride_B_batch + (pid_h // nheads_ngroups_ratio) * stride_B_group
C_ptr += pid_b * stride_C_batch + (pid_h // nheads_ngroups_ratio) * stride_C_group
if HAS_Z:
z_ptr += pid_b * stride_z_batch + pid_h * stride_z_head
out_ptr += pid_b * stride_out_batch + pid_h * stride_out_head
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = tl.arange(0, BLOCK_SIZE_DSTATE)
state_ptrs = state_ptr + (offs_m[:, None] * stride_state_dim + offs_n[None, :] * stride_state_dstate)
x_ptrs = x_ptr + offs_m * stride_x_dim
dt_ptrs = dt_ptr + offs_m * stride_dt_dim
if HAS_DT_BIAS:
dt_bias_ptrs = dt_bias_ptr + offs_m * stride_dt_bias_dim
if HAS_D:
D_ptr += pid_h * stride_D_head
A_ptrs = A_ptr + (offs_m[:, None] * stride_A_dim + offs_n[None, :] * stride_A_dstate)
B_ptrs = B_ptr + offs_n * stride_B_dstate
C_ptrs = C_ptr + offs_n * stride_C_dstate
if HAS_D:
D_ptrs = D_ptr + offs_m * stride_D_dim
if HAS_Z:
z_ptrs = z_ptr + offs_m * stride_z_dim
out_ptrs = out_ptr + offs_m * stride_out_dim
state = tl.load(state_ptrs, mask=(offs_m[:, None] < dim) & (offs_n[None, :] < dstate), other=0.0)
x = tl.load(x_ptrs, mask=offs_m < dim, other=0.0).to(tl.float32)
if not TIE_HDIM:
dt = tl.load(dt_ptrs, mask=offs_m < dim, other=0.0).to(tl.float32)
if HAS_DT_BIAS:
dt += tl.load(dt_bias_ptrs, mask=offs_m < dim, other=0.0).to(tl.float32)
if DT_SOFTPLUS:
dt = softplus(dt)
A = tl.load(A_ptrs, mask=(offs_m[:, None] < dim) & (offs_n[None, :] < dstate), other=0.0).to(tl.float32)
dA = tl.exp(A * dt[:, None])
else:
dt = tl.load(dt_ptr).to(tl.float32)
if HAS_DT_BIAS:
dt += tl.load(dt_bias_ptr).to(tl.float32)
if DT_SOFTPLUS:
dt = softplus(dt)
A = tl.load(A_ptr).to(tl.float32)
dA = tl.exp(A * dt) # scalar, not a matrix
B = tl.load(B_ptrs, mask=offs_n < dstate, other=0.0).to(tl.float32)
C = tl.load(C_ptrs, mask=offs_n < dstate, other=0.0).to(tl.float32)
if HAS_D:
D = tl.load(D_ptrs, mask=offs_m < dim, other=0.0).to(tl.float32)
if HAS_Z:
z = tl.load(z_ptrs, mask=offs_m < dim, other=0.0).to(tl.float32)
if not TIE_HDIM:
dB = B[None, :] * dt[:, None]
else:
dB = B * dt # vector of size (dstate,)
state = state * dA + dB * x[:, None]
tl.store(state_ptrs, state, mask=(offs_m[:, None] < dim) & (offs_n[None, :] < dstate))
out = tl.sum(state * C[None, :], axis=1)
if HAS_D:
out += x * D
if HAS_Z:
out *= z * tl.sigmoid(z)
tl.store(out_ptrs, out, mask=offs_m < dim)
def selective_state_update(state, x, dt, A, B, C, D=None, z=None, dt_bias=None, dt_softplus=False):
"""
Argument:
state: (batch, dim, dstate) or (batch, nheads, dim, dstate)
x: (batch, dim) or (batch, nheads, dim)
dt: (batch, dim) or (batch, nheads, dim)
A: (dim, dstate) or (nheads, dim, dstate)
B: (batch, dstate) or (batch, ngroups, dstate)
C: (batch, dstate) or (batch, ngroups, dstate)
D: (dim,) or (nheads, dim)
z: (batch, dim) or (batch, nheads, dim)
dt_bias: (dim,) or (nheads, dim)
Return:
out: (batch, dim) or (batch, nheads, dim)
"""
has_heads = state.dim() > 3
if state.dim() == 3:
state = state.unsqueeze(1)
if x.dim() == 2:
x = x.unsqueeze(1)
if dt.dim() == 2:
dt = dt.unsqueeze(1)
if A.dim() == 2:
A = A.unsqueeze(0)
if B.dim() == 2:
B = B.unsqueeze(1)
if C.dim() == 2:
C = C.unsqueeze(1)
if D is not None and D.dim() == 1:
D = D.unsqueeze(0)
if z is not None and z.dim() == 2:
z = z.unsqueeze(1)
if dt_bias is not None and dt_bias.dim() == 1:
dt_bias = dt_bias.unsqueeze(0)
batch, nheads, dim, dstate = state.shape
assert x.shape == (batch, nheads, dim)
assert dt.shape == x.shape
assert A.shape == (nheads, dim, dstate)
ngroups = B.shape[1]
assert nheads % ngroups == 0, "nheads must be divisible by ngroups"
assert B.shape == (batch, ngroups, dstate)
assert C.shape == B.shape
if D is not None:
assert D.shape == (nheads, dim)
if z is not None:
assert z.shape == x.shape
if dt_bias is not None:
assert dt_bias.shape == (nheads, dim)
out = torch.empty_like(x)
grid = lambda META: (triton.cdiv(dim, META['BLOCK_SIZE_M']), batch, nheads)
z_strides = ((z.stride(0), z.stride(1), z.stride(2)) if z is not None else (0, 0, 0))
# We don't want autotune since it will overwrite the state
# We instead tune by hand.
BLOCK_SIZE_M, num_warps = ((32, 4) if dstate <= 16
else ((16, 4) if dstate <= 32 else
((8, 4) if dstate <= 64 else
((4, 4) if dstate <= 128 else
((4, 8))))))
tie_hdim = A.stride(-1) == 0 and A.stride(-2) == 0 and dt.stride(-1) == 0 and dt_bias.stride(-1) == 0
with torch.cuda.device(x.device.index):
_selective_scan_update_kernel[grid](
state, x, dt, dt_bias, A, B, C, D, z, out,
batch, nheads, dim, dstate, nheads // ngroups,
state.stride(0), state.stride(1), state.stride(2), state.stride(3),
x.stride(0), x.stride(1), x.stride(2),
dt.stride(0), dt.stride(1), dt.stride(2),
*(dt_bias.stride(0), dt_bias.stride(1)) if dt_bias is not None else 0,
A.stride(0), A.stride(1), A.stride(2),
B.stride(0), B.stride(1), B.stride(2),
C.stride(0), C.stride(1), C.stride(2),
*(D.stride(0), D.stride(1)) if D is not None else 0,
z_strides[0], z_strides[1], z_strides[2],
out.stride(0), out.stride(1), out.stride(2),
dt_softplus,
tie_hdim,
BLOCK_SIZE_M,
num_warps=num_warps,
)
if not has_heads:
out = out.squeeze(1)
return out
def selective_state_update_ref(state, x, dt, A, B, C, D=None, z=None, dt_bias=None, dt_softplus=False):
"""
Argument:
state: (batch, dim, dstate) or (batch, nheads, dim, dstate)
x: (batch, dim) or (batch, nheads, dim)
dt: (batch, dim) or (batch, nheads, dim)
A: (dim, dstate) or (nheads, dim, dstate)
B: (batch, dstate) or (batch, ngroups, dstate)
C: (batch, dstate) or (batch, ngroups, dstate)
D: (dim,) or (nheads, dim)
z: (batch, dim) or (batch, nheads, dim)
dt_bias: (dim,) or (nheads, dim)
Return:
out: (batch, dim) or (batch, nheads, dim)
"""
has_heads = state.dim() > 3
if state.dim() == 3:
state = state.unsqueeze(1)
if x.dim() == 2:
x = x.unsqueeze(1)
if dt.dim() == 2:
dt = dt.unsqueeze(1)
if A.dim() == 2:
A = A.unsqueeze(0)
if B.dim() == 2:
B = B.unsqueeze(1)
if C.dim() == 2:
C = C.unsqueeze(1)
if D is not None and D.dim() == 1:
D = D.unsqueeze(0)
if z is not None and z.dim() == 2:
z = z.unsqueeze(1)
if dt_bias is not None and dt_bias.dim() == 1:
dt_bias = dt_bias.unsqueeze(0)
batch, nheads, dim, dstate = state.shape
assert x.shape == (batch, nheads, dim)
assert dt.shape == x.shape
assert A.shape == (nheads, dim, dstate)
ngroups = B.shape[1]
assert nheads % ngroups == 0, "nheads must be divisible by ngroups"
assert B.shape == (batch, ngroups, dstate)
assert C.shape == B.shape
if D is not None:
assert D.shape == (nheads, dim)
if z is not None:
assert z.shape == x.shape
if dt_bias is not None:
assert dt_bias.shape == (nheads, dim)
dt = dt + dt_bias
dt = F.softplus(dt) if dt_softplus else dt
dA = torch.exp(rearrange(dt, "b h d -> b h d 1") * A) # (batch, nheads, dim, dstate)
B = repeat(B, "b g n -> b (g h) n", h=nheads // ngroups) # (batch, nheads, dstate)
C = repeat(C, "b g n -> b (g h) n", h=nheads // ngroups) # (batch, nheads, dstate)
dB = rearrange(dt, "b h d -> b h d 1") * rearrange(B, "b h n -> b h 1 n") # (batch, nheads, dim, dstate)
state.copy_(state * dA + dB * rearrange(x, "b h d -> b h d 1")) # (batch, dim, dstate
out = torch.einsum("bhdn,bhn->bhd", state.to(C.dtype), C)
if D is not None:
out += (x * D).to(out.dtype)
out = (out if z is None else out * F.silu(z)).to(x.dtype)
if not has_heads:
out = out.squeeze(1)
return out
import triton
import triton.language as tl
from packaging import version
TRITON3 = version.parse(triton.__version__) >= version.parse("3.0.0")
if TRITON3:
@triton.jit
def softplus(dt):
dt = tl.where(dt <= 20.0, tl.math.log(tl.math.exp(dt) + 1), dt)
return dt
else:
@triton.jit
def softplus(dt):
dt = tl.where(dt <= 20.0, tl.math.log1p(tl.exp(dt)), dt)
return dt
\ No newline at end of file
# Copyright (c) 2024, Tri Dao, Albert Gu.
"""We want triton==2.1.0 or 2.2.0 for this
"""
import math
import torch
import torch.nn.functional as F
import triton
import triton.language as tl
from einops import rearrange, repeat
def init_to_zero(names):
return lambda nargs: [nargs[name].zero_() for name in names if nargs[name] is not None]
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 64}, num_stages=3, num_warps=8),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=2),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=2),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=2),
],
key=['chunk_size', 'K', 'IS_CAUSAL'],
)
@triton.jit
def _bmm_chunk_fwd_kernel(
# Pointers to matrices
a_ptr, b_ptr, out_ptr, seq_idx_ptr,
# Matrix dimensions
seqlen, chunk_size, K, ngroups,
stride_a_batch, stride_a_seqlen, stride_a_head, stride_ak,
stride_b_batch, stride_b_seqlen, stride_b_head, stride_bk,
stride_out_batch, stride_out_chunk, stride_out_head, stride_outm, stride_outn,
stride_seq_idx_batch, stride_seq_idx_seqlen,
# Meta-parameters
IS_CAUSAL: tl.constexpr,
dot_dtype: tl.constexpr,
HAS_SEQ_IDX: tl.constexpr,
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr, BLOCK_SIZE_K: tl.constexpr,
):
pid_b = tl.program_id(axis=1)
pid_ch = tl.program_id(axis=2)
pid_c = pid_ch // ngroups
pid_h = pid_ch - pid_c * ngroups
num_pid_n = tl.cdiv(chunk_size, BLOCK_SIZE_N)
pid_m = tl.program_id(axis=0) // num_pid_n
pid_n = tl.program_id(axis=0) % num_pid_n
if IS_CAUSAL:
if pid_n * BLOCK_SIZE_N >= (pid_m + 1) * BLOCK_SIZE_M:
return
a_ptr += pid_b * stride_a_batch + pid_c * chunk_size * stride_a_seqlen + pid_h * stride_a_head
b_ptr += pid_b * stride_b_batch + pid_c * chunk_size * stride_b_seqlen + pid_h * stride_b_head
if HAS_SEQ_IDX:
seq_idx_ptr += pid_b * stride_seq_idx_batch + pid_c * chunk_size * stride_seq_idx_seqlen
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
offs_k = tl.arange(0, BLOCK_SIZE_K)
a_ptrs = a_ptr + (offs_m[:, None] * stride_a_seqlen + offs_k[None, :] * stride_ak)
b_ptrs = b_ptr + (offs_k[:, None] * stride_bk + offs_n[None, :] * stride_b_seqlen)
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
acc = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=tl.float32)
for k in range(0, tl.cdiv(K, BLOCK_SIZE_K)):
a = tl.load(a_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_k[None, :] < K - k * BLOCK_SIZE_K), other=0.0).to(dot_dtype)
b = tl.load(b_ptrs, mask=(offs_k[:, None] < K - k * BLOCK_SIZE_K) & (offs_n[None, :] < chunk_size_limit), other=0.0).to(dot_dtype)
acc += tl.dot(a, b)
a_ptrs += BLOCK_SIZE_K * stride_ak
b_ptrs += BLOCK_SIZE_K * stride_bk
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
if HAS_SEQ_IDX:
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
seq_idx_m = tl.load(seq_idx_ptr + offs_m * stride_seq_idx_seqlen, mask=offs_m < chunk_size_limit, other=-1)
seq_idx_n = tl.load(seq_idx_ptr + offs_n * stride_seq_idx_seqlen, mask=offs_n < chunk_size_limit, other=-2)
acc = tl.where(seq_idx_m[:, None] == seq_idx_n[None, :], acc, 0.0)
out = acc.to(out_ptr.dtype.element_ty)
out_ptr += pid_b * stride_out_batch + pid_c * stride_out_chunk + pid_h * stride_out_head
out_ptrs = out_ptr + (stride_outm * offs_m[:, None] + offs_n[None, :] * stride_outn)
tl.store(out_ptrs, out, mask=(offs_m[:, None] < chunk_size) & (offs_n[None, :] < chunk_size))
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_CS': 64}, num_stages=3, num_warps=8),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_CS': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_CS': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_CS': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_CS': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_CS': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_CS': 32}, num_stages=5, num_warps=2),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_CS': 32}, num_stages=5, num_warps=2),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_CS': 32}, num_stages=4, num_warps=2),
],
key=['chunk_size', 'K'],
)
@triton.jit
def _bmm_chunk_bwd_kernel(
# Pointers to matrices
a_ptr, dout_ptr, db_ptr, res_ptr,
# Matrix dimensions
seqlen, chunk_size, K, ngroups,
stride_a_batch, stride_a_seqlen, stride_a_head, stride_ak,
stride_dout_batch, stride_dout_chunk, stride_dout_head, stride_dout_csize_m, stride_dout_csize_n,
stride_db_batch, stride_db_seqlen, stride_db_head, stride_db_k,
stride_res_batch, stride_res_seqlen, stride_res_head, stride_res_k,
# Meta-parameters
dot_dtype: tl.constexpr,
HAS_RESIDUAL: tl.constexpr,
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr, BLOCK_SIZE_CS: tl.constexpr,
):
pid_b = tl.program_id(axis=1)
pid_ch = tl.program_id(axis=2)
pid_c = pid_ch // ngroups
pid_h = pid_ch - pid_c * ngroups
num_pid_n = tl.cdiv(K, BLOCK_SIZE_N)
pid_m = tl.program_id(axis=0) // num_pid_n
pid_n = tl.program_id(axis=0) % num_pid_n
a_ptr += pid_b * stride_a_batch + pid_c * chunk_size * stride_a_seqlen + pid_h * stride_a_head
dout_ptr += pid_b * stride_dout_batch + pid_c * stride_dout_chunk + pid_h * stride_dout_head
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
offs_cs = tl.arange(0, BLOCK_SIZE_CS)
dout_ptrs = dout_ptr + (offs_m[:, None] * stride_dout_csize_n + offs_cs[None, :] * stride_dout_csize_m)
a_ptrs = a_ptr + (offs_cs[:, None] * stride_a_seqlen + offs_n[None, :] * stride_ak)
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
acc = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=tl.float32)
for cs in range(0, tl.cdiv(chunk_size_limit, BLOCK_SIZE_CS)):
dout = tl.load(dout_ptrs, mask=(offs_m[:, None] < chunk_size) & (offs_cs[None, :] < chunk_size_limit - cs * BLOCK_SIZE_CS), other=0.0).to(dot_dtype)
a = tl.load(a_ptrs, mask=(offs_cs[:, None] < chunk_size_limit - cs * BLOCK_SIZE_CS) & (offs_n[None, :] < K), other=0.0).to(dot_dtype)
acc += tl.dot(dout, a)
dout_ptrs += BLOCK_SIZE_CS * stride_dout_csize_m
a_ptrs += BLOCK_SIZE_CS * stride_a_seqlen
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
if HAS_RESIDUAL:
res_ptr += pid_b * stride_res_batch + pid_c * chunk_size * stride_res_seqlen + pid_h * stride_res_head
res_ptrs = res_ptr + (offs_m[:, None] * stride_res_seqlen + offs_n[None, :] * stride_res_k)
res = tl.load(res_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < K)).to(tl.float32)
acc += res
db = acc.to(db_ptr.dtype.element_ty)
db_ptr += pid_b * stride_db_batch + pid_c * chunk_size * stride_db_seqlen + pid_h * stride_db_head
db_ptrs = db_ptr + (offs_m[:, None] * stride_db_seqlen + offs_n[None, :] * stride_db_k)
tl.store(db_ptrs, db, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < K))
def _bmm_chunk_fwd(a, b, chunk_size, seq_idx=None, causal=False, output_dtype=None):
"""
Argument:
a: (batch, seqlen, k) or (batch, seqlen, ngroups, k)
b: (batch, seqlen, k) or (batch, seqlen, ngroups, k)
seq_idx: (batch, seqlen) or None. out[i, j] for seq_idx[i] != seq_idx[j] will be zeroed out.
causal: if True, then out[i, j] for i > j will be arbitrary, only out[i, j] for i <= j are
guaranteed to be correct.
Return:
out: (batch, nchunks, chunk_size, chunk_size) or (batch, nchunks, ngroups, chunk_size, chunk_size)
"""
# Check constraints.
has_groups = a.dim() == 4
if not has_groups:
batch, seqlen, k = a.shape
else:
batch, seqlen, ngroups, k = a.shape
assert b.shape == a.shape
if seq_idx is not None:
assert seq_idx.shape == (batch, seqlen)
if a.stride(-1) != 1 and a.stride(1) != 1:
a = a.contiguous()
if b.stride(-1) != 1 and b.stride(1) != 1:
b = b.contiguous()
nchunks = math.ceil(seqlen / chunk_size)
# Allocates output.
out_dtype = a.dtype if output_dtype is None else output_dtype
out = torch.empty((batch, nchunks, chunk_size, chunk_size) if not has_groups else (batch, nchunks, ngroups, chunk_size, chunk_size),
device=a.device, dtype=out_dtype)
dot_dtype = (tl.bfloat16 if a.dtype == torch.bfloat16 or b.dtype == torch.bfloat16 else
(tl.float16 if a.dtype == torch.float16 or b.dtype == torch.float16 else tl.float32))
grid = lambda META: (triton.cdiv(chunk_size, META['BLOCK_SIZE_M']) * triton.cdiv(chunk_size, META['BLOCK_SIZE_N']),
batch, nchunks if not has_groups else nchunks * ngroups)
with torch.cuda.device(a.device.index):
_bmm_chunk_fwd_kernel[grid](
a, b, out, seq_idx,
seqlen, chunk_size, k, ngroups if has_groups else 1,
a.stride(0), a.stride(1), 0 if not has_groups else a.stride(2), a.stride(-1),
b.stride(0), b.stride(1), 0 if not has_groups else b.stride(2), b.stride(-1),
out.stride(0), out.stride(1), 0 if not has_groups else out.stride(2), out.stride(-2), out.stride(-1),
*((seq_idx.stride(0), seq_idx.stride(1)) if seq_idx is not None else (0, 0)),
causal,
dot_dtype,
HAS_SEQ_IDX=seq_idx is not None,
)
return out
def _bmm_chunk_bwd(a, dout, residual=None, out=None):
"""
Argument:
a: (batch, seqlen, k) or (batch, seqlen, ngroups, k)
dout: (batch, nchunks, chunk_size, chunk_size) or (batch, nchunks, ngroups, chunk_size, chunk_size)
residual: (batch, seqlen, k) or (batch, seqlen, ngroups, k)
Return:
out: (batch, seqlen, k) or (batch, seqlen, ngroups, k)
If there was seq_idx in the fwd pass, then dout[i, j] for seq_idx[i] != seq_idx[j] should already be
zeroed out before calling this function.
"""
# Check constraints.
has_groups = a.dim() == 4
if not has_groups:
batch, seqlen, k = a.shape
else:
batch, seqlen, ngroups, k = a.shape
nchunks, chunk_size = dout.shape[1], dout.shape[-1]
if a.stride(-1) != 1 and a.stride(-2) != 1:
a = a.contiguous()
if dout.stride(-1) != 1 and dout.stride(-2) != 1:
dout = dout.contiguous()
if residual is not None:
assert residual.shape == (batch, seqlen, k) if not has_groups else (batch, seqlen, ngroups, k)
if residual.stride(-1) != 1 and residual.stride(1) != 1:
residual = residual.contiguous()
# Allocates output.
if out is not None:
assert out.shape == a.shape
assert out.stride(-1) == 1 or out.stride(1) == 1
else:
out = torch.empty_like(a)
dot_dtype = (tl.bfloat16 if a.dtype == torch.bfloat16 or dout.dtype == torch.bfloat16 else
(tl.float16 if a.dtype == torch.float16 or dout.dtype == torch.float16 else tl.float32))
grid = lambda META: (triton.cdiv(chunk_size, META['BLOCK_SIZE_M']) * triton.cdiv(k, META['BLOCK_SIZE_N']), batch,
nchunks if not has_groups else nchunks * ngroups)
residual_strides = ((residual.stride(0), residual.stride(1), 0 if not has_groups else residual.stride(2),
residual.stride(-1))
if residual is not None else (0, 0, 0, 0))
with torch.cuda.device(a.device.index):
_bmm_chunk_bwd_kernel[grid](
a, dout, out, residual,
seqlen, chunk_size, k, ngroups if has_groups else 1,
a.stride(0), a.stride(1), 0 if not has_groups else a.stride(2), a.stride(-1),
dout.stride(0), dout.stride(1), 0 if not has_groups else dout.stride(2), dout.stride(-2), dout.stride(-1),
out.stride(0), out.stride(1), 0 if not has_groups else out.stride(2), out.stride(-1),
residual_strides[0], residual_strides[1], residual_strides[2], residual_strides[3],
dot_dtype,
HAS_RESIDUAL=residual is not None,
)
return out
# Copyright (c) 2024, Tri Dao, Albert Gu.
"""We want triton==2.1.0 or 2.2.0 for this
"""
import math
from packaging import version
import torch
import torch.nn.functional as F
import triton
import triton.language as tl
from einops import rearrange, repeat
from mamba_ssm.ops.triton.ssd_bmm import _bmm_chunk_fwd, _bmm_chunk_bwd
TRITON_22 = version.parse(triton.__version__) >= version.parse('2.2.0')
def init_to_zero(names):
return lambda nargs: [nargs[name].zero_() for name in names if nargs[name] is not None]
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 64}, num_stages=3, num_warps=8),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 64}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 64}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=2),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=2),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=2),
],
key=['chunk_size', 'hdim', 'dstate', 'IS_CAUSAL'],
)
@triton.jit
def _chunk_scan_fwd_kernel(
# Pointers to matrices
cb_ptr, x_ptr, z_ptr, out_ptr, out_x_ptr, dt_ptr, dA_cumsum_ptr, seq_idx_ptr, C_ptr, prev_states_ptr, D_ptr,
# Matrix dimensions
chunk_size, hdim, dstate,
batch, seqlen, nheads_ngroups_ratio,
# Strides
stride_cb_batch, stride_cb_chunk, stride_cb_head, stride_cb_csize_m, stride_cb_csize_k,
stride_x_batch, stride_x_seqlen, stride_x_head, stride_x_hdim,
stride_z_batch, stride_z_seqlen, stride_z_head, stride_z_hdim,
stride_out_batch, stride_out_seqlen, stride_out_head, stride_out_hdim,
stride_dt_batch, stride_dt_chunk, stride_dt_head, stride_dt_csize,
stride_dA_cs_batch, stride_dA_cs_chunk, stride_dA_cs_head, stride_dA_cs_csize,
stride_seq_idx_batch, stride_seq_idx_seqlen,
stride_C_batch, stride_C_seqlen, stride_C_head, stride_C_dstate,
stride_states_batch, stride_states_chunk, stride_states_head, stride_states_hdim, stride_states_dstate,
stride_D_head,
# Meta-parameters
IS_CAUSAL: tl.constexpr,
HAS_D: tl.constexpr,
D_HAS_HDIM: tl.constexpr,
HAS_Z: tl.constexpr,
HAS_SEQ_IDX: tl.constexpr,
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr, BLOCK_SIZE_K: tl.constexpr,
BLOCK_SIZE_DSTATE: tl.constexpr,
IS_TRITON_22: tl.constexpr,
):
pid_bc = tl.program_id(axis=1)
pid_c = pid_bc // batch
pid_b = pid_bc - pid_c * batch
pid_h = tl.program_id(axis=2)
num_pid_n = tl.cdiv(hdim, BLOCK_SIZE_N)
pid_m = tl.program_id(axis=0) // num_pid_n
pid_n = tl.program_id(axis=0) % num_pid_n
cb_ptr += pid_b * stride_cb_batch + pid_c * stride_cb_chunk + (pid_h // nheads_ngroups_ratio) * stride_cb_head
x_ptr += pid_b * stride_x_batch + pid_c * chunk_size * stride_x_seqlen + pid_h * stride_x_head
dt_ptr += pid_b * stride_dt_batch + pid_c * stride_dt_chunk + pid_h * stride_dt_head
dA_cumsum_ptr += pid_b * stride_dA_cs_batch + pid_c * stride_dA_cs_chunk + pid_h * stride_dA_cs_head
C_ptr += pid_b * stride_C_batch + pid_c * chunk_size * stride_C_seqlen + (pid_h // nheads_ngroups_ratio) * stride_C_head
prev_states_ptr += pid_b * stride_states_batch + pid_c * stride_states_chunk + pid_h * stride_states_head
if HAS_SEQ_IDX:
seq_idx_ptr += pid_b * stride_seq_idx_batch + pid_c * chunk_size * stride_seq_idx_seqlen
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
dA_cs_m = tl.load(dA_cumsum_ptr + offs_m * stride_dA_cs_csize, mask=offs_m < chunk_size, other=0.0).to(tl.float32)
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
if HAS_SEQ_IDX:
seq_idx_prev = tl.load(seq_idx_ptr - stride_seq_idx_seqlen, mask=pid_c >= 1, other=0)
seq_idx_m = tl.load(seq_idx_ptr + offs_m * stride_seq_idx_seqlen, mask=offs_m < chunk_size_limit, other=-1)
acc = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=tl.float32)
# Without the if (pid_c > -1), with Triton 2.1.0, I get
# Assertion `!(srcMmaLayout && dstMmaLayout) && "Unexpected mma -> mm a layout conversion"' failed.
# With Triton 2.2.0, this works
if IS_TRITON_22 or pid_c > -1:
# Faster to just do 1 iteration with larger BLOCK_SIZE_K, up to block size 128
offs_k_dstate = tl.arange(0, BLOCK_SIZE_DSTATE if BLOCK_SIZE_DSTATE <= 128 else BLOCK_SIZE_K)
C_ptrs = C_ptr + (offs_m[:, None] * stride_C_seqlen + offs_k_dstate[None, :] * stride_C_dstate)
prev_states_ptrs = prev_states_ptr + (offs_n[None, :] * stride_states_hdim + offs_k_dstate[:, None] * stride_states_dstate)
if not HAS_SEQ_IDX:
scale_m = tl.exp(dA_cs_m)
else:
scale_m = tl.where(seq_idx_m == seq_idx_prev, tl.exp(dA_cs_m), 0.0)
if BLOCK_SIZE_DSTATE <= 128:
C = tl.load(C_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_k_dstate[None, :] < dstate), other=0.0)
prev_states = tl.load(prev_states_ptrs, mask=(offs_k_dstate[:, None] < dstate) & (offs_n[None, :] < hdim), other=0.0)
prev_states = prev_states.to(C_ptr.dtype.element_ty)
acc = tl.dot(C, prev_states) * scale_m[:, None]
else:
for k in range(0, dstate, BLOCK_SIZE_K):
C = tl.load(C_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_k_dstate[None, :] < dstate - k), other=0.0)
# C = (C * scale_m[:, None]).to(C_ptr.dtype.element_ty)
prev_states = tl.load(prev_states_ptrs, mask=(offs_k_dstate[:, None] < dstate - k) & (offs_n[None, :] < hdim), other=0.0)
prev_states = prev_states.to(C_ptr.dtype.element_ty)
acc += tl.dot(C, prev_states)
C_ptrs += BLOCK_SIZE_K
prev_states_ptrs += BLOCK_SIZE_K
acc *= scale_m[:, None]
offs_k = tl.arange(0, BLOCK_SIZE_K)
cb_ptrs = cb_ptr + (offs_m[:, None] * stride_cb_csize_m + offs_k[None, :] * stride_cb_csize_k)
x_ptrs = x_ptr + (offs_k[:, None] * stride_x_seqlen + offs_n[None, :] * stride_x_hdim)
dt_ptrs = dt_ptr + offs_k * stride_dt_csize
dA_cumsum_ptrs = dA_cumsum_ptr + offs_k * stride_dA_cs_csize
K_MAX = chunk_size_limit if not IS_CAUSAL else min((pid_m + 1) * BLOCK_SIZE_M, chunk_size_limit)
for k in range(0, K_MAX, BLOCK_SIZE_K):
cb = tl.load(cb_ptrs, mask=(offs_m[:, None] < chunk_size) & (offs_k[None, :] < chunk_size - k), other=0.0).to(tl.float32)
dA_cs_k = tl.load(dA_cumsum_ptrs, mask=offs_k < chunk_size - k, other=0.0).to(tl.float32)
# If there's seq_idx, we already set cb[i, j] = 0 for seq_idx[i] != seq_idx[j].
# So we don't need masking wrt seq_idx here.
cb *= tl.exp((dA_cs_m[:, None] - dA_cs_k[None, :]))
dt_k = tl.load(dt_ptrs, mask=offs_k < chunk_size - k, other=0.0).to(tl.float32)
cb *= dt_k
if IS_CAUSAL:
mask = offs_m[:, None] >= k + offs_k[None, :]
cb = tl.where(mask, cb, 0.0)
cb = cb.to(x_ptr.dtype.element_ty)
x = tl.load(x_ptrs, mask=(offs_k[:, None] < chunk_size_limit - k) & (offs_n[None, :] < hdim), other=0.0)
acc += tl.dot(cb, x)
cb_ptrs += BLOCK_SIZE_K * stride_cb_csize_k
x_ptrs += BLOCK_SIZE_K * stride_x_seqlen
dt_ptrs += BLOCK_SIZE_K * stride_dt_csize
dA_cumsum_ptrs += BLOCK_SIZE_K * stride_dA_cs_csize
offs_out_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_out_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
if HAS_D:
if D_HAS_HDIM:
D = tl.load(D_ptr + pid_h * stride_D_head + offs_n, mask=offs_n < hdim, other=0.0).to(tl.float32)
else:
D = tl.load(D_ptr + pid_h * stride_D_head).to(tl.float32)
x_residual = tl.load(x_ptr + (offs_m[:, None] * stride_x_seqlen + offs_n[None, :] * stride_x_hdim),
mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim), other=0.0).to(tl.float32)
acc += x_residual * D
if HAS_Z:
out_x_ptr += pid_b * stride_out_batch + pid_c * chunk_size * stride_out_seqlen + pid_h * stride_out_head
out_x_ptrs = out_x_ptr + (stride_out_seqlen * offs_out_m[:, None] + offs_out_n[None, :])
tl.store(out_x_ptrs, acc, mask=(offs_out_m[:, None] < chunk_size_limit) & (offs_out_n[None, :] < hdim))
z_ptr += pid_b * stride_z_batch + pid_c * chunk_size * stride_z_seqlen + pid_h * stride_z_head
z_ptrs = z_ptr + (stride_z_seqlen * offs_out_m[:, None] + stride_z_hdim * offs_out_n[None, :])
z = tl.load(z_ptrs, mask=(offs_out_m[:, None] < chunk_size_limit) & (offs_out_n[None, :] < hdim), other=0.0).to(tl.float32)
acc *= z * tl.sigmoid(z)
out_ptr += pid_b * stride_out_batch + pid_c * chunk_size * stride_out_seqlen + pid_h * stride_out_head
out_ptrs = out_ptr + (stride_out_seqlen * offs_out_m[:, None] + offs_out_n[None, :] * stride_out_hdim)
tl.store(out_ptrs, acc, mask=(offs_out_m[:, None] < chunk_size_limit) & (offs_out_n[None, :] < hdim))
@triton.autotune(
configs=[
# triton.Config({'BLOCK_SIZE_N': 256}, num_stages=4, num_warps=4),
# triton.Config({'BLOCK_SIZE_N': 128}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_N': 64}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_N': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_N': 64}, num_stages=4, num_warps=8),
triton.Config({'BLOCK_SIZE_N': 32}, num_stages=4, num_warps=8),
],
key=['chunk_size', 'hdim', 'dstate'],
)
@triton.jit
def _chunk_scan_fwd_kernel_wip(
# Pointers to matrices
cb_ptr, x_ptr, z_ptr, out_ptr, out_x_ptr, dt_ptr, dA_cumsum_ptr, seq_idx_ptr, C_ptr, B_ptr, prev_states_ptr, D_ptr,
# Matrix dimensions
chunk_size, hdim, dstate,
batch, seqlen, nheads_ngroups_ratio,
# Strides
stride_cb_batch, stride_cb_chunk, stride_cb_head, stride_cb_csize_m, stride_cb_csize_k,
stride_x_batch, stride_x_seqlen, stride_x_head, stride_x_hdim,
stride_z_batch, stride_z_seqlen, stride_z_head, stride_z_hdim,
stride_out_batch, stride_out_seqlen, stride_out_head, stride_out_hdim,
stride_dt_batch, stride_dt_chunk, stride_dt_head, stride_dt_csize,
stride_dA_cs_batch, stride_dA_cs_chunk, stride_dA_cs_head, stride_dA_cs_csize,
stride_seq_idx_batch, stride_seq_idx_seqlen,
stride_C_batch, stride_C_seqlen, stride_C_head, stride_C_dstate,
stride_B_batch, stride_B_seqlen, stride_B_head, stride_B_dstate,
stride_states_batch, stride_states_chunk, stride_states_head, stride_states_hdim, stride_states_dstate,
stride_D_head,
# Meta-parameters
HAS_D: tl.constexpr,
D_HAS_HDIM: tl.constexpr,
HAS_Z: tl.constexpr,
HAS_SEQ_IDX: tl.constexpr,
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr,
BLOCK_SIZE_DSTATE: tl.constexpr,
):
pid_bc = tl.program_id(axis=1)
pid_c = pid_bc // batch
pid_b = pid_bc - pid_c * batch
pid_h = tl.program_id(axis=2)
pid_n = tl.program_id(axis=0)
cb_ptr += pid_b * stride_cb_batch + pid_c * stride_cb_chunk + (pid_h // nheads_ngroups_ratio) * stride_cb_head
x_ptr += pid_b * stride_x_batch + pid_c * chunk_size * stride_x_seqlen + pid_h * stride_x_head
dt_ptr += pid_b * stride_dt_batch + pid_c * stride_dt_chunk + pid_h * stride_dt_head
dA_cumsum_ptr += pid_b * stride_dA_cs_batch + pid_c * stride_dA_cs_chunk + pid_h * stride_dA_cs_head
C_ptr += pid_b * stride_C_batch + pid_c * chunk_size * stride_C_seqlen + (pid_h // nheads_ngroups_ratio) * stride_C_head
B_ptr += pid_b * stride_B_batch + pid_c * chunk_size * stride_B_seqlen + (pid_h // nheads_ngroups_ratio) * stride_B_head
prev_states_ptr += pid_b * stride_states_batch + pid_c * stride_states_chunk + pid_h * stride_states_head
if HAS_SEQ_IDX:
seq_idx_ptr += pid_b * stride_seq_idx_batch + pid_c * chunk_size * stride_seq_idx_seqlen
out_ptr += pid_b * stride_out_batch + pid_c * chunk_size * stride_out_seqlen + pid_h * stride_out_head
offs_m = tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
offs_k_dstate = tl.arange(0, BLOCK_SIZE_DSTATE)
C_ptrs = C_ptr + (offs_m[:, None] * stride_C_seqlen + offs_k_dstate[None, :] * stride_C_dstate)
B_ptrs = B_ptr + (offs_m[None, :] * stride_B_seqlen + offs_k_dstate[:, None] * stride_B_dstate)
prev_states_ptrs = prev_states_ptr + (offs_n[None, :] * stride_states_hdim + offs_k_dstate[:, None] * stride_states_dstate)
num_pid_n = tl.cdiv(hdim, BLOCK_SIZE_N)
cb_ptrs = cb_ptr + (offs_m[:, None] * stride_cb_csize_m + offs_m[None, :] * stride_cb_csize_k)
x_ptrs = x_ptr + (offs_m[:, None] * stride_x_seqlen + offs_n[None, :] * stride_x_hdim)
dt_ptrs = dt_ptr + offs_m * stride_dt_csize
out_ptrs = out_ptr + (offs_m[:, None] * stride_out_seqlen + offs_n[None, :] * stride_out_hdim)
prev_states = tl.load(prev_states_ptrs, mask=(offs_k_dstate[:, None] < dstate) & (offs_n[None, :] < hdim), other=0.0)
# if pid_c == 0:
# if pid_b == 0:
# if pid_h == 0:
# tl.device_print("", prev_states)
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
# dA_cs_m = tl.load(dA_cumsum_ptr + offs_m * stride_dA_cs_csize, mask=offs_m < chunk_size, other=0.0).to(tl.float32)
# scale_m = tl.exp(dA_cs_m)
# C = tl.load(C_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_k_dstate[None, :] < dstate), other=0.0)
# acc = tl.dot(C, prev_states.to(C_ptr.dtype.element_ty)) * scale_m[:, None]
# cb = tl.load(cb_ptrs, mask=(offs_m[:, None] < chunk_size) & (offs_m[None, :] < chunk_size), other=0.0).to(tl.float32)
# cb *= tl.exp((dA_cs_m[:, None] - dA_cs_m[None, :]))
# dt_m = tl.load(dt_ptrs, mask=offs_m < chunk_size, other=0.0).to(tl.float32)
# cb *= dt_m
# mask = offs_m[:, None] >= offs_m[None, :]
# cb = tl.where(mask, cb, 0.0)
# cb = cb.to(x_ptr.dtype.element_ty)
# x = tl.load(x_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim), other=0.0)
# acc += tl.dot(cb, x)
# if HAS_D:
# if D_HAS_HDIM:
# D = tl.load(D_ptr + pid_h * stride_D_head + offs_n, mask=offs_n < hdim, other=0.0).to(tl.float32)
# else:
# D = tl.load(D_ptr + pid_h * stride_D_head).to(tl.float32)
# acc += x.to(tl.float32) * D
# tl.store(out_ptrs, acc, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim))
for start_m in range(0, chunk_size_limit, BLOCK_SIZE_M):
start_m = tl.multiple_of(start_m, BLOCK_SIZE_M)
dA_cs_m = tl.load(dA_cumsum_ptr + (start_m + offs_m) * stride_dA_cs_csize, mask=offs_m < chunk_size - start_m, other=0.0).to(tl.float32)
if HAS_SEQ_IDX:
seq_idx_prev = tl.load(seq_idx_ptr + start_m - stride_seq_idx_seqlen, mask=pid_c >= 1, other=0)
seq_idx_m = tl.load(seq_idx_ptr + (start_m + offs_m) * stride_seq_idx_seqlen, mask=offs_m < chunk_size_limit - start_m, other=-1)
if not HAS_SEQ_IDX:
scale_m = tl.exp(dA_cs_m)
else:
scale_m = tl.where(seq_idx_m == seq_idx_prev, tl.exp(dA_cs_m), 0.0)
C = tl.load(C_ptrs, mask=(offs_m[:, None] < chunk_size_limit - start_m) & (offs_k_dstate[None, :] < dstate), other=0.0)
acc = tl.dot(C, prev_states.to(C_ptr.dtype.element_ty)) * scale_m[:, None]
# cb = tl.load(cb_ptrs, mask=(offs_m[:, None] < chunk_size - start_m) & (offs_m[None, :] < chunk_size - start_m), other=0.0).to(tl.float32)
# cb *= tl.exp((dA_cs_m[:, None] - dA_cs_m[None, :]))
dt_m = tl.load(dt_ptrs, mask=offs_m < chunk_size - start_m, other=0.0).to(tl.float32)
# cb *= dt_m
# mask = offs_m[:, None] >= offs_m[None, :]
# cb = tl.where(mask, cb, 0.0)
# cb = cb.to(x_ptr.dtype.element_ty)
x = tl.load(x_ptrs, mask=(offs_m[:, None] < chunk_size_limit - start_m) & (offs_n[None, :] < hdim), other=0.0)
# acc += tl.dot(cb, x)
if HAS_D:
if D_HAS_HDIM:
D = tl.load(D_ptr + pid_h * stride_D_head + offs_n, mask=offs_n < hdim, other=0.0).to(tl.float32)
else:
D = tl.load(D_ptr + pid_h * stride_D_head).to(tl.float32)
acc += x.to(tl.float32) * D
# if HAS_Z:
# out_x_ptr += pid_b * stride_out_batch + pid_c * chunk_size * stride_out_seqlen + pid_h * stride_out_head
# out_x_ptrs = out_x_ptr + (stride_out_seqlen * offs_out_m[:, None] + offs_out_n[None, :])
# tl.store(out_x_ptrs, acc, mask=(offs_out_m[:, None] < chunk_size_limit) & (offs_out_n[None, :] < hdim))
# z_ptr += pid_b * stride_z_batch + pid_c * chunk_size * stride_z_seqlen + pid_h * stride_z_head
# z_ptrs = z_ptr + (stride_z_seqlen * offs_out_m[:, None] + stride_z_hdim * offs_out_n[None, :])
# z = tl.load(z_ptrs, mask=(offs_out_m[:, None] < chunk_size_limit) & (offs_out_n[None, :] < hdim), other=0.0).to(tl.float32)
# acc *= z * tl.sigmoid(z)
tl.store(out_ptrs, acc, mask=(offs_m[:, None] < chunk_size_limit - start_m) & (offs_n[None, :] < hdim))
# TODO: this is not correct, and quite a bit slower
if start_m + BLOCK_SIZE_M < chunk_size_limit:
# B = tl.load(B_ptrs, mask=(offs_m[None, :] < chunk_size_limit - start_m) & (offs_k_dstate[:, None] < dstate), other=0.0).to(tl.float32)
B = tl.load(B_ptrs, mask=(offs_m[None, :] < chunk_size_limit - start_m) & (offs_k_dstate[:, None] < dstate), other=0.0)
dA_cs_last = tl.load(dA_cumsum_ptr + (start_m + BLOCK_SIZE_M) * stride_dA_cs_csize).to(tl.float32)
# TODO: seq_idx
scale = tl.exp((dA_cs_last - dA_cs_m)) * dt_m
# B *= scale
B = B.to(x_ptr.dtype.element_ty)
tmp = tl.dot(B, x)
prev_states += tmp.to(prev_states.dtype)
C_ptrs += BLOCK_SIZE_M * stride_C_seqlen
B_ptrs += BLOCK_SIZE_M * stride_B_seqlen
cb_ptrs += BLOCK_SIZE_M * stride_cb_csize_m + BLOCK_SIZE_M * stride_cb_csize_k
x_ptrs += BLOCK_SIZE_M * stride_x_seqlen
dt_ptrs += BLOCK_SIZE_M * stride_dt_csize
out_ptrs += BLOCK_SIZE_M * stride_out_seqlen
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_M': 32}),
triton.Config({'BLOCK_SIZE_M': 64}),
triton.Config({'BLOCK_SIZE_M': 128}),
triton.Config({'BLOCK_SIZE_M': 256}),
],
key=["chunk_size", "hdim"],
)
@triton.jit
def _chunk_scan_bwd_dz_kernel(
# Pointers to matrices
dout_ptr, out_ptr, z_ptr, x_ptr, D_ptr, outz_ptr, dz_ptr, dout_x_ptr, dD_ptr, ddA_cumsum_ptr,
# Matrix dimensions
chunk_size, hdim,
batch, seqlen,
# Strides
stride_dout_batch, stride_dout_seqlen, stride_dout_head, stride_dout_hdim,
stride_out_batch, stride_out_seqlen, stride_out_head, stride_out_hdim,
stride_z_batch, stride_z_seqlen, stride_z_head, stride_z_hdim,
stride_x_batch, stride_x_seqlen, stride_x_head, stride_x_hdim,
stride_D_head,
stride_outz_batch, stride_outz_seqlen, stride_outz_head, stride_outz_hdim,
stride_dz_batch, stride_dz_seqlen, stride_dz_head, stride_dz_hdim,
stride_doutx_batch, stride_doutx_seqlen, stride_doutx_head, stride_doutx_hdim,
stride_dD_batch, stride_dD_chunk, stride_dD_head, stride_dD_csize, stride_dD_hdim,
stride_ddA_cs_batch, stride_ddA_cs_chunk, stride_ddA_cs_head, stride_ddA_cs_csize,
# Meta-parameters
HAS_D: tl.constexpr,
D_HAS_HDIM: tl.constexpr,
HAS_DDACS: tl.constexpr,
RECOMPUTE_OUTPUT: tl.constexpr,
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr,
):
pid_bc = tl.program_id(axis=1)
pid_c = pid_bc // batch
pid_b = pid_bc - pid_c * batch
pid_h = tl.program_id(axis=2)
pid_m = tl.program_id(axis=0)
dout_ptr += pid_b * stride_dout_batch + pid_c * chunk_size * stride_dout_seqlen + pid_h * stride_dout_head
dout_x_ptr += pid_b * stride_doutx_batch + pid_c * chunk_size * stride_doutx_seqlen + pid_h * stride_doutx_head
out_ptr += pid_b * stride_out_batch + pid_c * chunk_size * stride_out_seqlen + pid_h * stride_out_head
z_ptr += pid_b * stride_z_batch + pid_c * chunk_size * stride_z_seqlen + pid_h * stride_z_head
dz_ptr += pid_b * stride_dz_batch + pid_c * chunk_size * stride_dz_seqlen + pid_h * stride_dz_head
if RECOMPUTE_OUTPUT:
outz_ptr += pid_b * stride_outz_batch + pid_c * chunk_size * stride_outz_seqlen + pid_h * stride_outz_head
if HAS_DDACS:
ddA_cumsum_ptr += pid_b * stride_ddA_cs_batch + pid_c * stride_ddA_cs_chunk + pid_h * stride_ddA_cs_head
if HAS_D:
x_ptr += pid_b * stride_x_batch + pid_c * chunk_size * stride_x_seqlen + pid_h * stride_x_head
dD_ptr += pid_b * stride_dD_batch + pid_c * stride_dD_chunk + pid_h * stride_dD_head + pid_m * stride_dD_csize
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = tl.arange(0, BLOCK_SIZE_N)
dout_ptrs = dout_ptr + (offs_m[:, None] * stride_dout_seqlen + offs_n[None, :] * stride_dout_hdim)
dout_x_ptrs = dout_x_ptr + (offs_m[:, None] * stride_doutx_seqlen + offs_n[None, :] * stride_doutx_hdim)
out_ptrs = out_ptr + (offs_m[:, None] * stride_out_seqlen + offs_n[None, :] * stride_out_hdim)
z_ptrs = z_ptr + (offs_m[:, None] * stride_z_seqlen + offs_n[None, :] * stride_z_hdim)
dz_ptrs = dz_ptr + (offs_m[:, None] * stride_dz_seqlen + offs_n[None, :] * stride_dz_hdim)
if RECOMPUTE_OUTPUT:
outz_ptrs = outz_ptr + (offs_m[:, None] * stride_outz_seqlen + offs_n[None, :] * stride_outz_hdim)
if HAS_D:
x_ptrs = x_ptr + (offs_m[:, None] * stride_x_seqlen + offs_n[None, :] * stride_x_hdim)
if D_HAS_HDIM:
dD_ptrs = dD_ptr + offs_n * stride_dD_hdim
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
dout = tl.load(dout_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim), other=0.0).to(tl.float32)
out = tl.load(out_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim), other=0.0).to(tl.float32)
z = tl.load(z_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim), other=0.0).to(tl.float32)
z_sigmoid = tl.sigmoid(z)
if RECOMPUTE_OUTPUT:
outz = out * z * z_sigmoid
tl.store(outz_ptrs, outz, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim))
dz = dout * out * z_sigmoid * (1 + z * (1 - z_sigmoid))
tl.store(dz_ptrs, dz, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim))
dout *= z * z_sigmoid
tl.store(dout_x_ptrs, dout, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim))
if HAS_D:
x = tl.load(x_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim), other=0.0).to(tl.float32)
if D_HAS_HDIM:
dD = tl.sum(dout * x, axis=0)
tl.store(dD_ptrs, dD, mask=offs_n < hdim)
D = tl.load(D_ptr + pid_h * stride_D_head + offs_n, mask=offs_n < hdim, other=0.0).to(tl.float32)
else:
dD = tl.sum(dout * x)
tl.store(dD_ptr, dD)
D = tl.load(D_ptr + pid_h * stride_D_head).to(tl.float32)
out -= x * D
if HAS_DDACS:
ddA_cs = tl.sum(dout * out, axis=1)
tl.store(ddA_cumsum_ptr + offs_m * stride_ddA_cs_csize, ddA_cs, mask=offs_m < chunk_size)
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 64}, num_stages=3, num_warps=8),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=2),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=2),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=2),
],
key=['hdim', 'dstate', 'chunk_size'],
)
@triton.jit
def _chunk_scan_bwd_dstates_kernel(
# Pointers to matrices
dout_ptr, c_ptr, dprev_states_ptr, dA_cumsum_ptr, seq_idx_ptr,
# Matrix dimensions
hdim, dstate, chunk_size,
batch, seqlen, nchunks, nheads_ngroups_ratio,
# Strides
stride_dout_batch, stride_dout_seqlen, stride_dout_head, stride_dout_hdim,
stride_c_batch, stride_c_seqlen, stride_c_head, stride_c_dstate,
stride_dprev_states_batch, stride_dprev_states_chunk, stride_dprev_states_head, stride_dprev_states_hdim, stride_dprev_states_dstate,
stride_dA_cs_batch, stride_dA_cs_chunk, stride_dA_cs_head, stride_dA_cs_csize,
stride_seq_idx_batch, stride_seq_idx_seqlen,
# Meta-parameters
HAS_SEQ_IDX: tl.constexpr,
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr, BLOCK_SIZE_K: tl.constexpr,
):
pid_bc = tl.program_id(axis=1)
pid_c = pid_bc // batch
pid_b = pid_bc - pid_c * batch
pid_h = tl.program_id(axis=2)
num_pid_n = tl.cdiv(dstate, BLOCK_SIZE_N)
pid_m = tl.program_id(axis=0) // num_pid_n
pid_n = tl.program_id(axis=0) % num_pid_n
c_ptr += pid_b * stride_c_batch + pid_c * chunk_size * stride_c_seqlen + (pid_h // nheads_ngroups_ratio) * stride_c_head
dout_ptr += pid_b * stride_dout_batch + pid_c * chunk_size * stride_dout_seqlen + pid_h * stride_dout_head
dA_cumsum_ptr += pid_b * stride_dA_cs_batch + pid_c * stride_dA_cs_chunk + pid_h * stride_dA_cs_head
if HAS_SEQ_IDX:
seq_idx_ptr += pid_b * stride_seq_idx_batch + pid_c * chunk_size * stride_seq_idx_seqlen
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
offs_k = tl.arange(0, BLOCK_SIZE_K)
dout_ptrs = dout_ptr + (offs_m[:, None] * stride_dout_hdim + offs_k[None, :] * stride_dout_seqlen)
c_ptrs = c_ptr + (offs_n[None, :] * stride_c_dstate + offs_k[:, None] * stride_c_seqlen)
dA_cumsum_ptrs = dA_cumsum_ptr + offs_k * stride_dA_cs_csize
if HAS_SEQ_IDX:
seq_idx_ptrs = seq_idx_ptr + offs_k * stride_seq_idx_seqlen
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
acc = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=tl.float32)
if HAS_SEQ_IDX:
seq_idx_prev = tl.load(seq_idx_ptr - stride_seq_idx_seqlen, mask=pid_c >= 1, other=0)
for k in range(0, chunk_size_limit, BLOCK_SIZE_K):
dout = tl.load(dout_ptrs, mask=(offs_m[:, None] < hdim) & (offs_k[None, :] < chunk_size_limit - k), other=0.0).to(tl.float32)
dA_cs_k = tl.load(dA_cumsum_ptrs, mask=offs_k < chunk_size - k, other=0.0).to(tl.float32)
if not HAS_SEQ_IDX:
scale_k = tl.exp(dA_cs_k)
else:
seq_idx_k = tl.load(seq_idx_ptrs, mask=offs_k < chunk_size_limit - k, other=-1)
scale_k = tl.where(seq_idx_k == seq_idx_prev, tl.exp(dA_cs_k), 0.0)
dout = (dout * scale_k).to(dout_ptr.dtype.element_ty)
c = tl.load(c_ptrs, mask=(offs_k[:, None] < chunk_size_limit - k) & (offs_n[None, :] < dstate), other=0.0)
acc += tl.dot(dout, c)
dout_ptrs += BLOCK_SIZE_K * stride_dout_seqlen
c_ptrs += BLOCK_SIZE_K * stride_c_seqlen
dA_cumsum_ptrs += BLOCK_SIZE_K * stride_dA_cs_csize
if HAS_SEQ_IDX:
seq_idx_ptrs += BLOCK_SIZE_K * stride_seq_idx_seqlen
out = acc.to(dprev_states_ptr.dtype.element_ty)
dprev_states_ptr += pid_b * stride_dprev_states_batch + pid_c * stride_dprev_states_chunk + pid_h * stride_dprev_states_head
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
dprev_states_ptrs = dprev_states_ptr + (offs_m[:, None] * stride_dprev_states_hdim + offs_n[None, :] * stride_dprev_states_dstate)
tl.store(dprev_states_ptrs, out, mask=(offs_m[:, None] < hdim) & (offs_n[None, :] < dstate))
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 128}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 32}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 128}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 64}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 64}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 32}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 64}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 32}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
],
key=['chunk_size', 'dstate', 'hdim'],
)
@triton.jit
def _chunk_scan_bwd_dc_kernel(
# Pointers to matrices
dout_ptr, prev_states_ptr, C_ptr, dA_cumsum_ptr, seq_idx_ptr,
dc_ptr, ddA_cumsum_ptr,
# Matrix dimensions
chunk_size, dstate, hdim,
batch, seqlen, nheads, nheads_per_program, ngroups,
# Strides
stride_dout_batch, stride_dout_seqlen, stride_dout_head, stride_dout_hdim,
stride_prev_states_batch, stride_prev_states_chunk, stride_prev_states_head, stride_prev_states_hdim, stride_prev_states_dstate,
stride_C_batch, stride_C_seqlen, stride_C_head, stride_C_dstate,
stride_dA_cs_batch, stride_dA_cs_chunk, stride_dA_cs_head, stride_dA_cs_csize,
stride_seq_idx_batch, stride_seq_idx_seqlen,
stride_dc_batch, stride_dc_seqlen, stride_dc_split, stride_dc_group, stride_dc_dstate,
stride_ddA_cs_batch, stride_ddA_cs_chunk, stride_ddA_cs_head, stride_ddA_cs_csize,
# Meta-parameters
HAS_DDA_CS: tl.constexpr,
HAS_SEQ_IDX: tl.constexpr,
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr, BLOCK_SIZE_K: tl.constexpr,
):
pid_bc = tl.program_id(axis=1)
pid_c = pid_bc // batch
pid_b = pid_bc - pid_c * batch
pid_sg = tl.program_id(axis=2)
pid_s = pid_sg // ngroups
pid_g = pid_sg - pid_s * ngroups
num_pid_n = tl.cdiv(dstate, BLOCK_SIZE_N)
pid_m = tl.program_id(axis=0) // num_pid_n
pid_n = tl.program_id(axis=0) % num_pid_n
dout_ptr += pid_b * stride_dout_batch + pid_c * chunk_size * stride_dout_seqlen + (pid_g * (nheads // ngroups) + pid_s * nheads_per_program) * stride_dout_head
dc_ptr += pid_b * stride_dc_batch + pid_c * chunk_size * stride_dc_seqlen + pid_g * stride_dc_group + pid_s * stride_dc_split
prev_states_ptr += pid_b * stride_prev_states_batch + pid_c * stride_prev_states_chunk + (pid_g * (nheads // ngroups) + pid_s * nheads_per_program) * stride_prev_states_head
dA_cumsum_ptr += pid_b * stride_dA_cs_batch + pid_c * stride_dA_cs_chunk + (pid_g * (nheads // ngroups) + pid_s * nheads_per_program) * stride_dA_cs_head
if HAS_DDA_CS:
C_ptr += pid_b * stride_C_batch + pid_c * chunk_size * stride_C_seqlen + pid_g * stride_C_head
ddA_cumsum_ptr += pid_b * stride_ddA_cs_batch + pid_c * stride_ddA_cs_chunk + (pid_g * (nheads // ngroups) + pid_s * nheads_per_program) * stride_ddA_cs_head
if HAS_SEQ_IDX:
seq_idx_ptr += pid_b * stride_seq_idx_batch + pid_c * chunk_size * stride_seq_idx_seqlen
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
offs_k = tl.arange(0, BLOCK_SIZE_K)
dout_ptrs = dout_ptr + (offs_m[:, None] * stride_dout_seqlen + offs_k[None, :] * stride_dout_hdim)
prev_states_ptrs = prev_states_ptr + (offs_n[None, :] * stride_prev_states_dstate + offs_k[:, None] * stride_prev_states_hdim)
dA_cumsum_ptrs = dA_cumsum_ptr + offs_m * stride_dA_cs_csize
if HAS_DDA_CS:
C_ptrs = C_ptr + (offs_m[:, None] * stride_C_seqlen + offs_n[None, :] * stride_C_dstate)
ddA_cumsum_ptrs = ddA_cumsum_ptr + offs_m * stride_ddA_cs_csize
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
acc = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=tl.float32)
if HAS_DDA_CS:
c = tl.load(C_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < dstate), other=0.0).to(tl.float32)
if HAS_SEQ_IDX:
seq_idx_prev = tl.load(seq_idx_ptr - stride_seq_idx_seqlen, mask=pid_c >= 1, other=0)
seq_idx_m = tl.load(seq_idx_ptr + offs_m * stride_seq_idx_seqlen, mask=offs_m < chunk_size_limit, other=-1)
nheads_iter = min(nheads_per_program, nheads // ngroups - pid_s * nheads_per_program)
for h in range(nheads_iter):
dout = tl.load(dout_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_k[None, :] < hdim), other=0.0)
prev_states = tl.load(prev_states_ptrs, mask=(offs_k[:, None] < hdim) & (offs_n[None, :] < dstate), other=0.0)
prev_states = prev_states.to(dout_ptrs.dtype.element_ty)
dc = tl.dot(dout, prev_states)
dA_cs_m = tl.load(dA_cumsum_ptrs, mask=offs_m < chunk_size_limit, other=0.0).to(tl.float32)
if not HAS_SEQ_IDX:
scale = tl.exp(dA_cs_m)
else:
scale = tl.where(seq_idx_m == seq_idx_prev, tl.exp(dA_cs_m), 0.0)
dc *= scale[:, None]
if HAS_DDA_CS:
ddA_cs = tl.sum(dc * c, axis=1)
tl.atomic_add(ddA_cumsum_ptrs, ddA_cs, mask=offs_m < chunk_size)
acc += dc
dout_ptrs += stride_dout_head
prev_states_ptrs += stride_prev_states_head
dA_cumsum_ptrs += stride_dA_cs_head
if HAS_DDA_CS:
ddA_cumsum_ptrs += stride_ddA_cs_head
# if HAS_SEQ_IDX:
# seq_idx_prev = tl.load(seq_idx_ptr - stride_seq_idx_seqlen, mask=pid_c >= 1, other=0)
# seq_idx_m = tl.load(seq_idx_ptr + offs_m * stride_seq_idx_seqlen, mask=offs_m < chunk_size_limit, other=-1)
# acc = tl.where(seq_idx_m[:, None] == seq_idx_prev, acc, 0.0)
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
dc_ptrs = dc_ptr + (offs_m[:, None] * stride_dc_seqlen + offs_n[None, :] * stride_dc_dstate)
tl.store(dc_ptrs, acc, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < dstate))
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 64}, num_stages=3, num_warps=8, pre_hook=init_to_zero(["ddt_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr"])),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr"])),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr"])),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=4, pre_hook=init_to_zero(["ddt_ptr"])),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=4, pre_hook=init_to_zero(["ddt_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr"])),
],
key=['chunk_size', 'hdim'],
)
@triton.jit
def _chunk_scan_bwd_dx_kernel(
# Pointers to matrices
x_ptr, cb_ptr, dout_ptr, dt_ptr, dA_cumsum_ptr, D_ptr,
dx_ptr, ddt_ptr, # dD_ptr,
# Matrix dimensions
chunk_size, hdim,
batch, seqlen, nheads_ngroups_ratio,
# Strides
stride_x_batch, stride_x_seqlen, stride_x_head, stride_x_hdim,
stride_cb_batch, stride_cb_chunk, stride_cb_head, stride_cb_csize_m, stride_cb_csize_k,
stride_dout_batch, stride_dout_seqlen, stride_dout_head, stride_dout_hdim,
stride_dt_batch, stride_dt_chunk, stride_dt_head, stride_dt_csize,
stride_dA_cs_batch, stride_dA_cs_chunk, stride_dA_cs_head, stride_dA_cs_csize,
stride_D_head,
stride_dx_batch, stride_dx_seqlen, stride_dx_head, stride_dx_hdim,
stride_ddt_batch, stride_ddt_chunk, stride_ddt_head, stride_ddt_csize,
# stride_dD_batch, stride_dD_chunk, stride_dD_head, stride_dD_hdim, stride_dD_csize,
# Meta-parameters
HAS_D: tl.constexpr,
D_HAS_HDIM: tl.constexpr,
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr, BLOCK_SIZE_K: tl.constexpr,
):
pid_bc = tl.program_id(axis=1)
pid_c = pid_bc // batch
pid_b = pid_bc - pid_c * batch
pid_h = tl.program_id(axis=2)
num_pid_n = tl.cdiv(hdim, BLOCK_SIZE_N)
pid_m = tl.program_id(axis=0) // num_pid_n
pid_n = tl.program_id(axis=0) % num_pid_n
x_ptr += pid_b * stride_x_batch + pid_c * chunk_size * stride_x_seqlen + pid_h * stride_x_head
cb_ptr += pid_b * stride_cb_batch + pid_c * stride_cb_chunk + (pid_h // nheads_ngroups_ratio) * stride_cb_head
dout_ptr += pid_b * stride_dout_batch + pid_c * chunk_size * stride_dout_seqlen + pid_h * stride_dout_head
dt_ptr += pid_b * stride_dt_batch + pid_c * stride_dt_chunk + pid_h * stride_dt_head
ddt_ptr += pid_b * stride_ddt_batch + pid_c * stride_ddt_chunk + pid_h * stride_ddt_head
dA_cumsum_ptr += pid_b * stride_dA_cs_batch + pid_c * stride_dA_cs_chunk + pid_h * stride_dA_cs_head
# if HAS_D:
# dD_ptr += pid_b * stride_dD_batch + pid_c * stride_dD_chunk + pid_h * stride_dD_head + pid_m * stride_dD_csize
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
offs_k = tl.arange(0, BLOCK_SIZE_K)
cb_ptrs = cb_ptr + (offs_m[:, None] * stride_cb_csize_m + offs_k[None, :] * stride_cb_csize_k)
dout_ptrs = dout_ptr + (offs_k[:, None] * stride_dout_seqlen + offs_n[None, :] * stride_dout_hdim)
dA_cumsum_ptrs = dA_cumsum_ptr + offs_k * stride_dA_cs_csize
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
dA_cs_m = tl.load(dA_cumsum_ptr + offs_m * stride_dA_cs_csize, mask=offs_m < chunk_size_limit, other=0.0).to(tl.float32)
acc = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=tl.float32)
# Idk why limiting K_MAX gives wrong results, is it a Triton bug?
# K_MAX = min((pid_m + 1) * BLOCK_SIZE_M, chunk_size_limit)
K_MAX = chunk_size_limit
for k in range(0, K_MAX, BLOCK_SIZE_K):
# For some reason setting mask to (offs_m[:, None] < chunk_size_limit) is much slower
cb = tl.load(cb_ptrs, mask=(offs_m[:, None] < chunk_size) & (offs_k[None, :] < K_MAX - k), other=0.0)
dout = tl.load(dout_ptrs, mask=(offs_k[:, None] < K_MAX - k) & (offs_n[None, :] < hdim), other=0.0)
dA_cs_k = tl.load(dA_cumsum_ptrs, mask=offs_k < K_MAX - k, other=0.0).to(tl.float32)
cb *= tl.exp(dA_cs_k[None, :] - dA_cs_m[:, None])
# If we don't have the (k + offs_k[None, :] < K_MAX) mask, for indices outside this range,
# we might have dA_cs_m = 0.0 and dA_cs_k very negative, and tl.exp will return inf.
# Multiplying with cb, which is 0.0 outside the range, will make the result NaN.
# This will cause NaN in acc, and hence NaN in dx and ddt.
mask = (k + offs_k[None, :] >= offs_m[:, None]) & (k + offs_k[None, :] < K_MAX)
cb = tl.where(mask, cb, 0.0)
cb = cb.to(dout_ptr.dtype.element_ty)
acc += tl.dot(cb, dout)
cb_ptrs += BLOCK_SIZE_K * stride_cb_csize_k
dout_ptrs += BLOCK_SIZE_K * stride_dout_seqlen
dA_cumsum_ptrs += BLOCK_SIZE_K * stride_dA_cs_csize
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
dt_ptrs = dt_ptr + offs_m * stride_dt_csize
dt_m = tl.load(dt_ptrs, mask=offs_m < chunk_size_limit, other=0.0).to(tl.float32)
dx = acc * dt_m[:, None]
dx_ptr += pid_b * stride_dx_batch + pid_c * chunk_size * stride_dx_seqlen + pid_h * stride_dx_head
dx_ptrs = dx_ptr + (offs_m[:, None] * stride_dx_seqlen + offs_n[None, :] * stride_dx_hdim)
if HAS_D:
dout_res_ptrs = dout_ptr + (offs_m[:, None] * stride_dout_seqlen + offs_n[None, :] * stride_dout_hdim)
dout_res = tl.load(dout_res_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim), other=0.0).to(tl.float32)
if D_HAS_HDIM:
D = tl.load(D_ptr + pid_h * stride_D_head + offs_n, mask=offs_n < hdim, other=0.0).to(tl.float32)
else:
D = tl.load(D_ptr + pid_h * stride_D_head).to(tl.float32)
dx += dout_res * D
tl.store(dx_ptrs, dx, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim))
x_ptrs = x_ptr + (offs_m[:, None] * stride_x_seqlen + offs_n[None, :] * stride_x_hdim)
x = tl.load(x_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim), other=0.0).to(tl.float32)
ddt = tl.sum(acc * x, axis=1)
ddt_ptrs = ddt_ptr + offs_m * stride_ddt_csize
tl.atomic_add(ddt_ptrs, ddt, mask=offs_m < chunk_size)
# if HAS_D:
# dout_new_ptrs = dout_ptr + (offs_m[:, None] * stride_dout_csize + offs_n[None, :] * stride_dout_hdim)
# dout = tl.load(dout_new_ptrs, mask=(offs_m[:, None] < M) & (offs_n[None, :] < N), other=0.0).to(tl.float32)
# dD = tl.sum(x * dout, axis=0)
# tl.store(dD_ptr + offs_n * stride_dD_hdim, dD, mask=offs_n < N)
# Disabling HAS_DDA_CS for now since it's much slower
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 128}, num_stages=3, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 32}, num_stages=3, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 64}, num_stages=3, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 32}, num_stages=3, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 64}, num_stages=3, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 32}, num_stages=3, num_warps=4),
# triton.Config({'BLOCK_SIZE_M': 16}, num_stages=3, num_warps=4),
# triton.Config({'BLOCK_SIZE_M': 32}, num_stages=3, num_warps=4),
# triton.Config({'BLOCK_SIZE_M': 64}, num_stages=3, num_warps=4),
# triton.Config({'BLOCK_SIZE_M': 128}, num_stages=3, num_warps=4),
# triton.Config({'BLOCK_SIZE_M': 16}, num_stages=4, num_warps=8),
# triton.Config({'BLOCK_SIZE_M': 32}, num_stages=4, num_warps=8),
# triton.Config({'BLOCK_SIZE_M': 64}, num_stages=4, num_warps=8),
# triton.Config({'BLOCK_SIZE_M': 128}, num_stages=4, num_warps=8),
],
key=['chunk_size', 'hdim'],
)
# @triton.heuristics({"BLOCK_SIZE_N": lambda args: max(triton.next_power_of_2(args["chunk_size"]), 16)})
# @triton.heuristics({"BLOCK_SIZE_N": lambda args: 32})
@triton.jit
def _chunk_scan_bwd_dcb_kernel(
# Pointers to matrices
x_ptr, dout_ptr, cb_ptr, dt_ptr, dA_cumsum_ptr, seq_idx_ptr,
dcb_ptr, ddA_cumsum_ptr,
# Matrix dimensions
chunk_size, hdim,
batch, seqlen, nheads, nheads_per_program, ngroups,
# Strides
stride_x_batch, stride_x_seqlen, stride_x_head, stride_x_hdim,
stride_dout_batch, stride_dout_seqlen, stride_dout_head, stride_dout_hdim,
stride_cb_batch, stride_cb_chunk, stride_cb_head, stride_cb_csize_m, stride_cb_csize_n,
stride_dt_batch, stride_dt_chunk, stride_dt_head, stride_dt_csize,
stride_dA_cs_batch, stride_dA_cs_chunk, stride_dA_cs_head, stride_dA_cs_csize,
stride_seq_idx_batch, stride_seq_idx_seqlen,
stride_dcb_batch, stride_dcb_chunk, stride_dcb_split, stride_dcb_group, stride_dcb_csize_m, stride_dcb_csize_n,
stride_ddA_cs_batch, stride_ddA_cs_chunk, stride_ddA_cs_head, stride_ddA_cs_csize_m, stride_ddA_cs_csize_n,
# Meta-parameters
HAS_DDA_CS: tl.constexpr,
HAS_SEQ_IDX: tl.constexpr,
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr, BLOCK_SIZE_K: tl.constexpr,
):
pid_bc = tl.program_id(axis=1)
pid_c = pid_bc // batch
pid_b = pid_bc - pid_c * batch
pid_sg = tl.program_id(axis=2)
pid_s = pid_sg // ngroups
pid_g = pid_sg - pid_s * ngroups
num_pid_n = tl.cdiv(chunk_size, BLOCK_SIZE_N)
pid_m = tl.program_id(axis=0) // num_pid_n
pid_n = tl.program_id(axis=0) % num_pid_n
x_ptr += pid_b * stride_x_batch + pid_c * chunk_size * stride_x_seqlen + (pid_g * (nheads // ngroups) + pid_s * nheads_per_program) * stride_x_head
dout_ptr += pid_b * stride_dout_batch + pid_c * chunk_size * stride_dout_seqlen + (pid_g * (nheads // ngroups) + pid_s * nheads_per_program) * stride_dout_head
dt_ptr += pid_b * stride_dt_batch + pid_c * stride_dt_chunk + (pid_g * (nheads // ngroups) + pid_s * nheads_per_program) * stride_dt_head
dA_cumsum_ptr += pid_b * stride_dA_cs_batch + pid_c * stride_dA_cs_chunk + (pid_g * (nheads // ngroups) + pid_s * nheads_per_program) * stride_dA_cs_head
if HAS_DDA_CS:
cb_ptr += pid_b * stride_cb_batch + pid_c * stride_cb_chunk + pid_g * stride_cb_head
ddA_cumsum_ptr += pid_b * stride_ddA_cs_batch + pid_c * stride_ddA_cs_chunk + (pid_g * (nheads // ngroups) + pid_s * nheads_per_program) * stride_ddA_cs_head + pid_m * stride_ddA_cs_csize_m
if HAS_SEQ_IDX:
seq_idx_ptr += pid_b * stride_seq_idx_batch + pid_c * chunk_size * stride_seq_idx_seqlen
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
offs_k = tl.arange(0, BLOCK_SIZE_K)
dout_ptrs = dout_ptr + (offs_m[:, None] * stride_dout_seqlen + offs_k[None, :] * stride_dout_hdim)
x_ptrs = x_ptr + (offs_n[None, :] * stride_x_seqlen + offs_k[:, None] * stride_x_hdim)
dt_ptrs = dt_ptr + offs_n * stride_dt_csize
if HAS_DDA_CS:
cb_ptrs = cb_ptr + (offs_m[:, None] * stride_cb_csize_m + offs_n[None, :] * stride_cb_csize_n)
ddA_cumsum_ptrs = ddA_cumsum_ptr + offs_n * stride_ddA_cs_csize_n
if pid_n * BLOCK_SIZE_N >= (pid_m + 1) * BLOCK_SIZE_M:
dcb_ptr += pid_b * stride_dcb_batch + pid_c * stride_dcb_chunk + pid_g * stride_dcb_group + pid_s * stride_dcb_split
dcb_ptrs = dcb_ptr + (offs_m[:, None] * stride_dcb_csize_m + offs_n[None, :] * stride_dcb_csize_n)
tl.store(dcb_ptrs, tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=dcb_ptr.dtype.element_ty), mask=(offs_m[:, None] < chunk_size) & (offs_n[None, :] < chunk_size))
return
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
chunk_size_limit_n = min(chunk_size_limit, (pid_m + 1) * BLOCK_SIZE_M)
acc = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=tl.float32)
if HAS_DDA_CS:
cb = tl.load(cb_ptrs, mask=(offs_m[:, None] < chunk_size) & (offs_n[None, :] < chunk_size), other=0.0).to(tl.float32)
nheads_iter = min(nheads_per_program, nheads // ngroups - pid_s * nheads_per_program)
for h in range(nheads_iter):
dout = tl.load(dout_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_k[None, :] < hdim), other=0.0)
x = tl.load(x_ptrs, mask=(offs_k[:, None] < hdim) & (offs_n[None, :] < chunk_size_limit_n), other=0.0)
dcb = tl.dot(dout, x)
dt_n = tl.load(dt_ptrs, mask=offs_n < chunk_size, other=0.0).to(tl.float32)
dcb *= dt_n
dA_cs_m = tl.load(dA_cumsum_ptr + offs_m * stride_dA_cs_csize, mask=offs_m < chunk_size_limit, other=0.0).to(tl.float32)
dA_cs_n = tl.load(dA_cumsum_ptr + offs_n * stride_dA_cs_csize, mask=offs_n < chunk_size_limit, other=0.0).to(tl.float32)
dcb *= tl.exp(dA_cs_m[:, None] - dA_cs_n[None, :])
if HAS_DDA_CS:
tl.static_assert(not HAS_SEQ_IDX, "HAS_SEQ_IDX not supported with HAS_DDA_CS yet")
ddA_cs = dcb * cb
mask = offs_m[:, None] >= offs_n[None, :] + 1
ddA_cs = tl.where(mask, ddA_cs, 0.0)
ddA_cs = tl.cumsum(ddA_cs, axis=1)
ddA_cs = tl.where(mask, ddA_cs, 0.0)
ddA_cs = tl.sum(ddA_cs, axis=0)
tl.store(ddA_cumsum_ptrs + stride_ddA_cs_csize_n, ddA_cs, mask=offs_n < chunk_size - 1)
tl.store(ddA_cumsum_ptr, 0.0)
acc += dcb
dout_ptrs += stride_dout_head
x_ptrs += stride_x_head
dt_ptrs += stride_dt_head
dA_cumsum_ptr += stride_dA_cs_head
if HAS_DDA_CS:
ddA_cumsum_ptr += stride_ddA_cs_head
ddA_cumsum_ptrs += stride_ddA_cs_head
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
if HAS_SEQ_IDX:
seq_idx_m = tl.load(seq_idx_ptr + offs_m * stride_seq_idx_seqlen, mask=offs_m < chunk_size_limit, other=-1)
seq_idx_n = tl.load(seq_idx_ptr + offs_n * stride_seq_idx_seqlen, mask=offs_n < chunk_size_limit, other=-2)
acc = tl.where(seq_idx_m[:, None] == seq_idx_n[None, :], acc, 0.0)
mask = offs_m[:, None] >= offs_n[None, :]
acc = tl.where(mask, acc, 0.0)
dcb_ptr += pid_b * stride_dcb_batch + pid_c * stride_dcb_chunk + pid_g * stride_dcb_group + pid_s * stride_dcb_split
dcb_ptrs = dcb_ptr + (offs_m[:, None] * stride_dcb_csize_m + offs_n[None, :] * stride_dcb_csize_n)
tl.store(dcb_ptrs, acc, mask=(offs_m[:, None] < chunk_size) & (offs_n[None, :] < chunk_size))
# Not numerically stable and should not be used. Leaving here for reference.
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_M': 32}),
triton.Config({'BLOCK_SIZE_M': 64}),
triton.Config({'BLOCK_SIZE_M': 128}),
triton.Config({'BLOCK_SIZE_M': 256}),
],
key=["chunk_size", "hdim"],
)
@triton.jit
def _chunk_scan_bwd_ddAcs_unstable_kernel(
# Pointers to matrices
dout_ptr, out_ptr, dt_ptr, ddt_ptr, x_ptr, D_ptr,
ddA_cumsum_ptr, dD_ptr,
# Matrix dimensions
chunk_size, hdim,
batch, seqlen,
# Strides
stride_dout_batch, stride_dout_seqlen, stride_dout_head, stride_dout_hdim,
stride_out_batch, stride_out_seqlen, stride_out_head, stride_out_hdim,
stride_dt_batch, stride_dt_chunk, stride_dt_head, stride_dt_csize,
stride_ddt_batch, stride_ddt_chunk, stride_ddt_head, stride_ddt_csize,
stride_x_batch, stride_x_seqlen, stride_x_head, stride_x_hdim,
stride_D_head,
stride_ddA_cs_batch, stride_ddA_cs_chunk, stride_ddA_cs_head, stride_ddA_cs_csize,
stride_dD_batch, stride_dD_chunk, stride_dD_head, stride_dD_csize, stride_dD_hdim,
# Meta-parameters
HAS_D: tl.constexpr,
D_HAS_HDIM: tl.constexpr,
SUBTRACT_DDTDT: tl.constexpr,
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr,
):
pid_bc = tl.program_id(axis=1)
pid_c = pid_bc // batch
pid_b = pid_bc - pid_c * batch
pid_h = tl.program_id(axis=2)
pid_m = tl.program_id(axis=0)
dout_ptr += pid_b * stride_dout_batch + pid_c * chunk_size * stride_dout_seqlen + pid_h * stride_dout_head
out_ptr += pid_b * stride_out_batch + pid_c * chunk_size * stride_out_seqlen + pid_h * stride_out_head
dt_ptr += pid_b * stride_dt_batch + pid_c * stride_dt_chunk + pid_h * stride_dt_head
ddt_ptr += pid_b * stride_ddt_batch + pid_c * stride_ddt_chunk + pid_h * stride_ddt_head
ddA_cumsum_ptr += pid_b * stride_ddA_cs_batch + pid_c * stride_ddA_cs_chunk + pid_h * stride_ddA_cs_head
if HAS_D:
x_ptr += pid_b * stride_x_batch + pid_c * chunk_size * stride_x_seqlen + pid_h * stride_x_head
dD_ptr += pid_b * stride_dD_batch + pid_c * stride_dD_chunk + pid_h * stride_dD_head + pid_m * stride_dD_csize
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = tl.arange(0, BLOCK_SIZE_N)
dout_ptrs = dout_ptr + (offs_m[:, None] * stride_dout_seqlen + offs_n[None, :] * stride_dout_hdim)
out_ptrs = out_ptr + (offs_m[:, None] * stride_out_seqlen + offs_n[None, :] * stride_out_hdim)
if HAS_D:
x_ptrs = x_ptr + (offs_m[:, None] * stride_x_seqlen + offs_n[None, :] * stride_x_hdim)
if D_HAS_HDIM:
dD_ptrs = dD_ptr + offs_n * stride_dD_hdim
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
dout = tl.load(dout_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim), other=0.0).to(tl.float32)
out = tl.load(out_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim), other=0.0).to(tl.float32)
if HAS_D:
x = tl.load(x_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim), other=0.0).to(tl.float32)
if D_HAS_HDIM:
dD = tl.sum(dout * x, axis=0)
tl.store(dD_ptrs, dD, mask=offs_n < hdim)
D = tl.load(D_ptr + pid_h * stride_D_head + offs_n, mask=offs_n < hdim, other=0.0).to(tl.float32)
else:
dD = tl.sum(dout * x)
tl.store(dD_ptr, dD)
D = tl.load(D_ptr + pid_h * stride_D_head).to(tl.float32)
out -= x * D
ddA_cs = tl.sum(dout * out, axis=1)
if SUBTRACT_DDTDT:
dt = tl.load(dt_ptr + offs_m * stride_dt_csize, mask=offs_m < chunk_size, other=0.0).to(tl.float32)
ddt = tl.load(ddt_ptr + offs_m * stride_ddt_csize, mask=offs_m < chunk_size, other=0.0).to(tl.float32)
ddA_cs -= dt * ddt
tl.store(ddA_cumsum_ptr + offs_m * stride_ddA_cs_csize, ddA_cs, mask=offs_m < chunk_size)
@triton.autotune(
configs=[
# triton.Config({'BLOCK_SIZE_M': 16, 'BLOCK_SIZE_K': 32}, num_stages=3, num_warps=4),
# triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_K': 32}, num_stages=3, num_warps=4),
# triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_K': 32}, num_stages=3, num_warps=4),
# triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_K': 32}, num_stages=3, num_warps=4),
# triton.Config({'BLOCK_SIZE_M': 16, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=8),
# triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=8),
# triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=8),
# triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=8),
triton.Config({'BLOCK_SIZE_M': 16}, num_stages=3, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 32}, num_stages=3, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64}, num_stages=3, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128}, num_stages=3, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 16}, num_stages=4, num_warps=8),
triton.Config({'BLOCK_SIZE_M': 32}, num_stages=4, num_warps=8),
triton.Config({'BLOCK_SIZE_M': 64}, num_stages=4, num_warps=8),
triton.Config({'BLOCK_SIZE_M': 128}, num_stages=4, num_warps=8),
],
key=['chunk_size', 'hdim'],
)
@triton.jit
def _chunk_scan_bwd_ddAcs_stable_kernel_old(
# Pointers to matrices
x_ptr, dout_ptr, dt_ptr, dA_cumsum_ptr, cb_ptr,
ddAcs_ptr,
# Matrix dimensions
chunk_size, hdim,
batch, seqlen, nheads_ngroups_ratio,
# Strides
stride_x_batch, stride_x_seqlen, stride_x_head, stride_x_hdim,
stride_dout_batch, stride_dout_seqlen, stride_dout_head, stride_dout_hdim,
stride_dt_batch, stride_dt_chunk, stride_dt_head, stride_dt_csize,
stride_dA_cs_batch, stride_dA_cs_chunk, stride_dA_cs_head, stride_dA_cs_csize,
stride_cb_batch, stride_cb_chunk, stride_cb_head, stride_cb_csize_m, stride_cb_csize_n,
stride_ddAcs_batch, stride_ddAcs_chunk, stride_ddAcs_head, stride_ddAcs_csize_m, stride_ddAcs_csize_n,
# Meta-parameters
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr, BLOCK_SIZE_K: tl.constexpr,
):
pid_bc = tl.program_id(axis=1)
pid_c = pid_bc // batch
pid_b = pid_bc - pid_c * batch
pid_h = tl.program_id(axis=2)
num_pid_n = tl.cdiv(chunk_size, BLOCK_SIZE_N)
pid_m = tl.program_id(axis=0) // num_pid_n
pid_n = tl.program_id(axis=0) % num_pid_n
x_ptr += pid_b * stride_x_batch + pid_c * chunk_size * stride_x_seqlen + pid_h * stride_x_head
dout_ptr += pid_b * stride_dout_batch + pid_c * chunk_size * stride_dout_seqlen + pid_h * stride_dout_head
dt_ptr += pid_b * stride_dt_batch + pid_c * stride_dt_chunk + pid_h * stride_dt_head
dA_cumsum_ptr += pid_b * stride_dA_cs_batch + pid_c * stride_dA_cs_chunk + pid_h * stride_dA_cs_head
cb_ptr += pid_b * stride_cb_batch + pid_c * stride_cb_chunk + (pid_h // nheads_ngroups_ratio) * stride_cb_head
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
offs_k = tl.arange(0, BLOCK_SIZE_K)
dout_ptrs = dout_ptr + (offs_m[:, None] * stride_dout_seqlen + offs_k[None, :] * stride_dout_hdim)
x_ptrs = x_ptr + (offs_n[None, :] * stride_x_seqlen + offs_k[:, None] * stride_x_hdim)
dt_ptrs = dt_ptr + offs_n * stride_dt_csize
cb_ptrs = cb_ptr + (offs_m[:, None] * stride_cb_csize_m + offs_n[None, :] * stride_cb_csize_n)
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
chunk_size_limit_n = min(chunk_size_limit, (pid_m + 1) * BLOCK_SIZE_M)
# Doing a matmul loop with cumsum later on will cause Triton to crash
# Instead we do just one big matmul
# acc = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=tl.float32)
# for k in range(0, hdim, BLOCK_SIZE_K):
# dout = tl.load(dout_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_k[None, :] < hdim - k), other=0.0)
# x = tl.load(x_ptrs, mask=(offs_k[:, None] < hdim - k) & (offs_n[None, :] < chunk_size_limit), other=0.0)
# acc += tl.dot(dout, x)
# dout_ptrs += BLOCK_SIZE_K * stride_dout_hdim
# x_ptrs += BLOCK_SIZE_K * stride_x_hdim
dout = tl.load(dout_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_k[None, :] < hdim), other=0.0)
x = tl.load(x_ptrs, mask=(offs_k[:, None] < hdim) & (offs_n[None, :] < chunk_size_limit_n), other=0.0)
acc = tl.dot(dout, x)
cb = tl.load(cb_ptrs, mask=(offs_m[:, None] < chunk_size) & (offs_n[None, :] < chunk_size), other=0.0).to(tl.float32)
acc *= cb
dt_n = tl.load(dt_ptrs, mask=offs_n < chunk_size, other=0.0).to(tl.float32)
acc *= dt_n
dA_cs_m = tl.load(dA_cumsum_ptr + offs_m * stride_dA_cs_csize, mask=offs_m < chunk_size, other=0.0).to(tl.float32)
dA_cs_n = tl.load(dA_cumsum_ptr + offs_n * stride_dA_cs_csize, mask=offs_n < chunk_size, other=0.0).to(tl.float32)
acc *= tl.exp(dA_cs_m[:, None] - dA_cs_n[None, :])
mask = offs_m[:, None] >= offs_n[None, :] + 1
acc = tl.where(mask, acc, 0.0)
acc = tl.cumsum(acc, axis=1)
acc = tl.where(mask, acc, 0.0)
ddA_cs = tl.sum(acc, axis=0)
ddAcs_ptr += pid_b * stride_ddAcs_batch + pid_c * stride_ddAcs_chunk + pid_h * stride_ddAcs_head + pid_m * stride_ddAcs_csize_m
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
ddAcs_ptrs = ddAcs_ptr + offs_n * stride_ddAcs_csize_n
tl.store(ddAcs_ptrs + stride_ddAcs_csize_n, ddA_cs, mask=offs_n < chunk_size - 1)
tl.store(ddAcs_ptr, 0.0)
# offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, 64)
# offs_k = tl.arange(0, BLOCK_SIZE_K)
# dout_ptrs = dout_ptr + (offs_m[:, None] * stride_dout_seqlen + offs_k[None, :] * stride_dout_hdim)
# x_ptrs = x_ptr + (offs_n[None, :] * stride_x_seqlen + offs_k[:, None] * stride_x_hdim)
# dt_ptrs = dt_ptr + offs_n * stride_dt_csize
# cb_ptrs = cb_ptr + (offs_m[:, None] * stride_cb_csize_m + offs_n[None, :] * stride_cb_csize_n)
# chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
# chunk_size_limit_n = min(chunk_size_limit, (pid_m + 1) * BLOCK_SIZE_M)
# rowsum = tl.zeros((BLOCK_SIZE_M,), dtype=tl.float32)
# dout = tl.load(dout_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_k[None, :] < hdim), other=0.0)
# dA_cs_m = tl.load(dA_cumsum_ptr + offs_m * stride_dA_cs_csize, mask=offs_m < chunk_size, other=0.0).to(tl.float32)
# ddAcs_ptr += pid_b * stride_ddAcs_batch + pid_c * stride_ddAcs_chunk + pid_h * stride_ddAcs_head + pid_m * stride_ddAcs_csize_m
# ddAcs_ptrs = ddAcs_ptr + offs_n * stride_ddAcs_csize_n
# for n in range(0, chunk_size_limit_n, 64):
# x = tl.load(x_ptrs, mask=(offs_k[:, None] < hdim) & (offs_n[None, :] < chunk_size_limit_n - n), other=0.0)
# acc = tl.dot(dout, x)
# cb = tl.load(cb_ptrs, mask=(offs_m[:, None] < chunk_size) & (offs_n[None, :] < chunk_size - n), other=0.0).to(tl.float32)
# acc *= cb
# dt_n = tl.load(dt_ptrs, mask=offs_n < chunk_size - n, other=0.0).to(tl.float32)
# acc *= dt_n
# dA_cs_n = tl.load(dA_cumsum_ptr + offs_n * stride_dA_cs_csize, mask=offs_n < chunk_size - n, other=0.0).to(tl.float32)
# acc *= tl.exp(dA_cs_m[:, None] - dA_cs_n[None, :])
# mask = offs_m[:, None] >= offs_n[None, :] + 1 + n
# acc = tl.where(mask, acc, 0.0)
# acc = tl.cumsum(acc, axis=1)
# acc = tl.where(mask, acc, 0.0)
# ddA_cs = tl.sum(acc, axis=0)
# tl.store(ddAcs_ptrs, ddA_cs, mask=offs_n < chunk_size - 1 - n)
# # tl.store(ddAcs_ptr, 0.0)
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 32}, num_stages=3, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 64}, num_stages=3, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 128}, num_stages=3, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 32}, num_stages=3, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 64}, num_stages=3, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 128}, num_stages=3, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 32}, num_stages=3, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 64}, num_stages=3, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 128}, num_stages=3, num_warps=4),
],
key=['chunk_size', 'hdim'],
)
@triton.jit
def _chunk_scan_bwd_ddAcs_stable_kernel(
# Pointers to matrices
x_ptr, dout_ptr, dt_ptr, dA_cumsum_ptr, cb_ptr,
ddA_cumsum_ptr,
# Matrix dimensions
chunk_size, hdim,
batch, seqlen, nheads_ngroups_ratio,
# Strides
stride_x_batch, stride_x_seqlen, stride_x_head, stride_x_hdim,
stride_dout_batch, stride_dout_seqlen, stride_dout_head, stride_dout_hdim,
stride_dt_batch, stride_dt_chunk, stride_dt_head, stride_dt_csize,
stride_dA_cs_batch, stride_dA_cs_chunk, stride_dA_cs_head, stride_dA_cs_csize,
stride_cb_batch, stride_cb_chunk, stride_cb_head, stride_cb_csize_m, stride_cb_csize_n,
stride_ddA_cs_batch, stride_ddA_cs_chunk, stride_ddA_cs_head, stride_ddA_cs_csize_m, stride_ddA_cs_csize_n,
# Meta-parameters
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr, BLOCK_SIZE_K: tl.constexpr,
):
pid_bc = tl.program_id(axis=1)
pid_c = pid_bc // batch
pid_b = pid_bc - pid_c * batch
pid_h = tl.program_id(axis=2)
pid_m = tl.program_id(axis=0)
x_ptr += pid_b * stride_x_batch + pid_c * chunk_size * stride_x_seqlen + pid_h * stride_x_head
dout_ptr += pid_b * stride_dout_batch + pid_c * chunk_size * stride_dout_seqlen + pid_h * stride_dout_head
dt_ptr += pid_b * stride_dt_batch + pid_c * stride_dt_chunk + pid_h * stride_dt_head
dA_cumsum_ptr += pid_b * stride_dA_cs_batch + pid_c * stride_dA_cs_chunk + pid_h * stride_dA_cs_head
cb_ptr += pid_b * stride_cb_batch + pid_c * stride_cb_chunk + (pid_h // nheads_ngroups_ratio) * stride_cb_head
ddA_cumsum_ptr += pid_b * stride_ddA_cs_batch + pid_c * stride_ddA_cs_chunk + pid_h * stride_ddA_cs_head + pid_m * stride_ddA_cs_csize_m
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = tl.arange(0, BLOCK_SIZE_N)
offs_k = tl.arange(0, BLOCK_SIZE_K)
dout_ptrs = dout_ptr + (offs_m[:, None] * stride_dout_seqlen + offs_k[None, :] * stride_dout_hdim)
x_ptrs = x_ptr + (offs_n[None, :] * stride_x_seqlen + offs_k[:, None] * stride_x_hdim)
dt_ptrs = dt_ptr + offs_n * stride_dt_csize
cb_ptrs = cb_ptr + (offs_m[:, None] * stride_cb_csize_m + offs_n[None, :] * stride_cb_csize_n)
ddAcs_ptrs = ddA_cumsum_ptr + offs_n * stride_ddA_cs_csize_n
tl.store(ddA_cumsum_ptr, 0.0)
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
rowsum = tl.zeros((BLOCK_SIZE_M,), dtype=tl.float32)
dout = tl.load(dout_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_k[None, :] < hdim), other=0.0)
dA_cs_m = tl.load(dA_cumsum_ptr + offs_m * stride_dA_cs_csize, mask=offs_m < chunk_size, other=0.0).to(tl.float32)
# Actually hi is (pid_m + 1) * BLOCK_SIZE_M - 1 but subtracting 1 makes it slower
lo, hi = 0, (pid_m + 1) * BLOCK_SIZE_M
# lo, hi = 0, chunk_size
for start_n in range(lo, hi, BLOCK_SIZE_N):
start_n = tl.multiple_of(start_n, BLOCK_SIZE_N)
# Doing a matmul loop with cumsum later on will cause Triton to crash
# Instead we do just one big matmul
# acc = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=tl.float32)
# for k in range(0, hdim, BLOCK_SIZE_K):
# dout = tl.load(dout_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_k[None, :] < hdim - k), other=0.0)
# x = tl.load(x_ptrs, mask=(offs_k[:, None] < hdim - k) & (offs_n[None, :] < chunk_size_limit), other=0.0)
# acc += tl.dot(dout, x)
# dout_ptrs += BLOCK_SIZE_K * stride_dout_hdim
# x_ptrs += BLOCK_SIZE_K * stride_x_hdim
# x = tl.load(x_ptrs, mask=(offs_k[:, None] < hdim) & (offs_n[None, :] < chunk_size_limit_n), other=0.0)
x = tl.load(x_ptrs, mask=(offs_k[:, None] < hdim) & (offs_n[None, :] < chunk_size_limit - start_n), other=0.0)
acc = tl.dot(dout, x)
dt_n = tl.load(dt_ptrs, mask=offs_n < chunk_size - start_n, other=0.0).to(tl.float32)
acc *= dt_n
# If there's seq_idx, we already zero'ed out cb[i, j] for seq_idx[i] != seq_idx[j]
cb = tl.load(cb_ptrs, mask=(offs_m[:, None] < chunk_size) & (offs_n[None, :] < chunk_size - start_n), other=0.0).to(tl.float32)
acc *= cb
dA_cs_n = tl.load(dA_cumsum_ptr + start_n + offs_n * stride_dA_cs_csize, mask=offs_n < chunk_size - start_n, other=0.0).to(tl.float32)
acc *= tl.exp(dA_cs_m[:, None] - dA_cs_n[None, :])
mask = offs_m[:, None] >= start_n + offs_n[None, :] + 1
acc = tl.where(mask, acc, 0.0)
rowsum_new = rowsum + tl.sum(acc, axis=1)
acc = rowsum[:, None] + tl.cumsum(acc, axis=1)
rowsum = rowsum_new
acc = tl.where(mask, acc, 0.0)
ddA_cs = tl.sum(acc, axis=0)
tl.store(ddAcs_ptrs + stride_ddA_cs_csize_n, ddA_cs, mask=offs_n < chunk_size - start_n - 1)
x_ptrs += BLOCK_SIZE_N * stride_x_seqlen
dt_ptrs += BLOCK_SIZE_N * stride_dt_csize
cb_ptrs += BLOCK_SIZE_N * stride_cb_csize_n
ddAcs_ptrs += BLOCK_SIZE_N * stride_ddA_cs_csize_n
# Need to zero out the rest, since we'll be summing the rows together
for start_n in range(hi, chunk_size, BLOCK_SIZE_N):
tl.store(ddAcs_ptrs + stride_ddA_cs_csize_n, tl.zeros((BLOCK_SIZE_N,), dtype=tl.float32), mask=offs_n < chunk_size - start_n - 1)
ddAcs_ptrs += BLOCK_SIZE_N * stride_ddA_cs_csize_n
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 128}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 32}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 64}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 32}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 64}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 32}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
],
key=['chunk_size', 'dstate', 'hdim'],
)
@triton.jit
def _chunk_scan_bwd_ddAcs_prev_kernel(
# Pointers to matrices
dout_ptr, prev_states_ptr, C_ptr, dA_cumsum_ptr, seq_idx_ptr,
ddA_cumsum_ptr,
# Matrix dimensions
chunk_size, dstate, hdim,
batch, seqlen, nchunks, nheads_ngroups_ratio,
# Strides
stride_dout_batch, stride_dout_seqlen, stride_dout_head, stride_dout_hdim,
stride_prev_states_batch, stride_prev_states_chunk, stride_prev_states_head, stride_prev_states_hdim, stride_prev_states_dstate,
stride_C_batch, stride_C_seqlen, stride_C_head, stride_C_dstate,
stride_dA_cs_batch, stride_dA_cs_chunk, stride_dA_cs_head, stride_dA_cs_csize,
stride_seq_idx_batch, stride_seq_idx_seqlen,
stride_ddA_cs_batch, stride_ddA_cs_chunk, stride_ddA_cs_head, stride_ddA_cs_csize,
# Meta-parameters
HAS_SEQ_IDX: tl.constexpr,
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr, BLOCK_SIZE_K: tl.constexpr,
):
pid_bc = tl.program_id(axis=1)
pid_c = pid_bc // batch
pid_b = pid_bc - pid_c * batch
pid_h = tl.program_id(axis=2)
num_pid_n = tl.cdiv(dstate, BLOCK_SIZE_N)
pid_m = tl.program_id(axis=0) // num_pid_n
pid_n = tl.program_id(axis=0) % num_pid_n
dout_ptr += pid_b * stride_dout_batch + pid_c * chunk_size * stride_dout_seqlen + pid_h * stride_dout_head
prev_states_ptr += pid_b * stride_prev_states_batch + pid_c * stride_prev_states_chunk + pid_h * stride_prev_states_head
C_ptr += pid_b * stride_C_batch + pid_c * chunk_size * stride_C_seqlen + (pid_h // nheads_ngroups_ratio) * stride_C_head
ddA_cumsum_ptr += pid_b * stride_ddA_cs_batch + pid_c * stride_ddA_cs_chunk + pid_h * stride_ddA_cs_head
dA_cumsum_ptr += pid_b * stride_dA_cs_batch + pid_c * stride_dA_cs_chunk + pid_h * stride_dA_cs_head
if HAS_SEQ_IDX:
seq_idx_ptr += pid_b * stride_seq_idx_batch + pid_c * chunk_size * stride_seq_idx_seqlen
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
offs_k = tl.arange(0, BLOCK_SIZE_K)
dout_ptrs = dout_ptr + (offs_m[:, None] * stride_dout_seqlen + offs_k[None, :] * stride_dout_hdim)
prev_states_ptrs = prev_states_ptr + (offs_n[None, :] * stride_prev_states_dstate + offs_k[:, None] * stride_prev_states_hdim)
C_ptrs = C_ptr + (offs_m[:, None] * stride_C_seqlen + offs_n[None, :] * stride_C_dstate)
dA_cumsum_ptrs = dA_cumsum_ptr + offs_m * stride_dA_cs_csize
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
dout = tl.load(dout_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_k[None, :] < hdim), other=0.0)
prev_states = tl.load(prev_states_ptrs, mask=(offs_k[:, None] < hdim) & (offs_n[None, :] < dstate), other=0.0)
prev_states = prev_states.to(dout_ptrs.dtype.element_ty)
acc = tl.dot(dout, prev_states)
c = tl.load(C_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < dstate), other=0.0).to(tl.float32)
ddA_cs = tl.sum(acc * c, axis=1)
dA_cs_m = tl.load(dA_cumsum_ptrs, mask=offs_m < chunk_size_limit, other=0.0).to(tl.float32)
if not HAS_SEQ_IDX:
scale = tl.exp(dA_cs_m)
if HAS_SEQ_IDX:
seq_idx_prev = tl.load(seq_idx_ptr - stride_seq_idx_seqlen, mask=pid_c >= 1, other=0)
seq_idx_m = tl.load(seq_idx_ptr + offs_m * stride_seq_idx_seqlen, mask=offs_m < chunk_size_limit, other=-1)
scale = tl.where(seq_idx_m == seq_idx_prev, tl.exp(dA_cs_m), 0.0)
ddA_cs *= scale
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
ddA_cumsum_ptrs = ddA_cumsum_ptr + offs_m * stride_ddA_cs_csize
tl.atomic_add(ddA_cumsum_ptrs, ddA_cs, mask=offs_m < chunk_size)
def _chunk_scan_fwd(cb, x, dt, dA_cumsum, C, states, D=None, z=None, seq_idx=None):
batch, seqlen, nheads, headdim = x.shape
_, _, nchunks, chunk_size = dt.shape
_, _, ngroups, dstate = C.shape
assert nheads % ngroups == 0
assert C.shape == (batch, seqlen, ngroups, dstate)
assert cb.shape == (batch, nchunks, ngroups, chunk_size, chunk_size)
if z is not None:
assert z.shape == x.shape
if D is not None:
assert D.shape == (nheads, headdim) or D.shape == (nheads,)
assert dt.shape == (batch, nheads, nchunks, chunk_size)
assert dA_cumsum.shape == (batch, nheads, nchunks, chunk_size)
assert states.shape == (batch, nchunks, nheads, headdim, dstate)
if seq_idx is not None:
assert seq_idx.shape == (batch, seqlen)
# Allocates output.
out = torch.empty(batch, seqlen, nheads, headdim, device=x.device, dtype=x.dtype)
if z is not None:
out_x = torch.empty(batch, seqlen, nheads, headdim, device=x.device, dtype=x.dtype)
assert out_x.stride() == out.stride()
else:
out_x = None
grid = lambda META: (triton.cdiv(chunk_size, META['BLOCK_SIZE_M']) * triton.cdiv(headdim, META['BLOCK_SIZE_N']),
batch * nchunks, nheads)
z_strides = ((z.stride(0), z.stride(1), z.stride(2), z.stride(3))
if z is not None else (0, 0, 0, 0))
_chunk_scan_fwd_kernel[grid](
cb, x, z, out, out_x, dt, dA_cumsum, seq_idx, C, states, D,
chunk_size, headdim, dstate,
batch, seqlen, nheads // ngroups,
cb.stride(0), cb.stride(1), cb.stride(2), cb.stride(3), cb.stride(4),
x.stride(0), x.stride(1), x.stride(2), x.stride(3),
z_strides[0], z_strides[1], z_strides[2], z_strides[3],
out.stride(0), out.stride(1), out.stride(2), out.stride(3),
dt.stride(0), dt.stride(2), dt.stride(1), dt.stride(3),
dA_cumsum.stride(0), dA_cumsum.stride(2), dA_cumsum.stride(1), dA_cumsum.stride(3),
*((seq_idx.stride(0), seq_idx.stride(1)) if seq_idx is not None else (0, 0)),
C.stride(0), C.stride(1), C.stride(2), C.stride(3),
states.stride(0), states.stride(1), states.stride(2), states.stride(3), states.stride(4),
D.stride(0) if D is not None else 0,
True,
D is not None,
D.dim() == 2 if D is not None else True,
BLOCK_SIZE_DSTATE=max(triton.next_power_of_2(dstate), 16),
HAS_Z=z is not None,
HAS_SEQ_IDX=seq_idx is not None,
IS_TRITON_22=TRITON_22,
)
return out, out_x
def _chunk_scan_fwd_wip(cb, x, dt, dA_cumsum, C, B, states, D=None, z=None, seq_idx=None):
batch, seqlen, nheads, headdim = x.shape
_, _, nchunks, chunk_size = dt.shape
_, _, ngroups, dstate = C.shape
assert nheads % ngroups == 0
assert C.shape == (batch, seqlen, ngroups, dstate)
assert B.shape == C.shape
assert cb.shape == (batch, nchunks, ngroups, chunk_size, chunk_size)
if z is not None:
assert z.shape == x.shape
if D is not None:
assert D.shape == (nheads, headdim) or D.shape == (nheads,)
assert dt.shape == (batch, nheads, nchunks, chunk_size)
assert dA_cumsum.shape == (batch, nheads, nchunks, chunk_size)
assert states.shape == (batch, nchunks, nheads, headdim, dstate)
if seq_idx is not None:
assert seq_idx.shape == (batch, seqlen)
# Allocates output.
out = torch.empty(batch, seqlen, nheads, headdim, device=x.device, dtype=x.dtype)
if z is not None:
out_x = torch.empty(batch, seqlen, nheads, headdim, device=x.device, dtype=x.dtype)
assert out_x.stride() == out.stride()
else:
out_x = None
grid = lambda META: (triton.cdiv(headdim, META['BLOCK_SIZE_N']), batch * nchunks, nheads)
z_strides = ((z.stride(0), z.stride(1), z.stride(2), z.stride(3))
if z is not None else (0, 0, 0, 0))
_chunk_scan_fwd_kernel_wip[grid](
cb, x, z, out, out_x, dt, dA_cumsum, seq_idx, C, B, states, D,
chunk_size, headdim, dstate,
batch, seqlen, nheads // ngroups,
cb.stride(0), cb.stride(1), cb.stride(2), cb.stride(3), cb.stride(4),
x.stride(0), x.stride(1), x.stride(2), x.stride(3),
z_strides[0], z_strides[1], z_strides[2], z_strides[3],
out.stride(0), out.stride(1), out.stride(2), out.stride(3),
dt.stride(0), dt.stride(2), dt.stride(1), dt.stride(3),
dA_cumsum.stride(0), dA_cumsum.stride(2), dA_cumsum.stride(1), dA_cumsum.stride(3),
*((seq_idx.stride(0), seq_idx.stride(1)) if seq_idx is not None else (0, 0)),
C.stride(0), C.stride(1), C.stride(2), C.stride(3),
B.stride(0), B.stride(1), B.stride(2), B.stride(3),
states.stride(0), states.stride(1), states.stride(2), states.stride(3), states.stride(4),
D.stride(0) if D is not None else 0,
D is not None,
D.dim() == 2 if D is not None else True,
BLOCK_SIZE_DSTATE=max(triton.next_power_of_2(dstate), 16),
BLOCK_SIZE_M=128,
HAS_Z=z is not None,
HAS_SEQ_IDX=seq_idx is not None,
)
return out, out_x
def _chunk_scan_bwd_dz(x, z, out, dout, chunk_size, has_ddAcs=True, D=None, dz=None, recompute_output=False):
batch, seqlen, nheads, headdim = x.shape
assert z.shape == x.shape
assert out.shape == x.shape
assert dout.shape == out.shape
nchunks = math.ceil(seqlen / chunk_size)
if D is not None:
assert D.shape == (nheads, headdim) or D.shape == (nheads,)
assert D.stride(-1) == 1
if has_ddAcs:
ddA_cumsum = torch.empty(batch, nheads, nchunks, chunk_size, device=x.device, dtype=torch.float32)
if D is not None:
BLOCK_SIZE_min = 32
dD = torch.empty(triton.cdiv(chunk_size, BLOCK_SIZE_min), batch, nchunks, nheads,
headdim if D.dim() == 2 else 1, device=D.device, dtype=torch.float32)
else:
dD = None
if dz is not None:
assert dz.shape == z.shape
else:
dz = torch.empty_like(z)
if recompute_output:
outz = torch.empty_like(x)
dout_x = torch.empty_like(dout)
dD_strides = ((dD.stride(0), dD.stride(1), dD.stride(2), dD.stride(3), dD.stride(4))
if D is not None else (0, 0, 0, 0, 0))
grid_dz = lambda META: (triton.cdiv(chunk_size, META['BLOCK_SIZE_M']), batch * nchunks, nheads)
with torch.cuda.device(x.device.index):
_chunk_scan_bwd_dz_kernel[grid_dz](
dout, out, z, x, D, outz if recompute_output else None,
dz, dout_x, dD, ddA_cumsum if has_ddAcs else None,
chunk_size, headdim,
batch, seqlen,
dout.stride(0), dout.stride(1), dout.stride(2), dout.stride(3),
out.stride(0), out.stride(1), out.stride(2), out.stride(3),
z.stride(0), z.stride(1), z.stride(2), z.stride(3),
x.stride(0), x.stride(1), x.stride(2), x.stride(3),
D.stride(0) if D is not None else 0,
*((outz.stride(0), outz.stride(1), outz.stride(2), outz.stride(3)) if recompute_output else (0, 0, 0, 0)),
dz.stride(0), dz.stride(1), dz.stride(2), dz.stride(3),
dout_x.stride(0), dout_x.stride(1), dout_x.stride(2), dout_x.stride(3),
dD_strides[1], dD_strides[2], dD_strides[3], dD_strides[0], dD_strides[4],
*((ddA_cumsum.stride(0), ddA_cumsum.stride(2), ddA_cumsum.stride(1), ddA_cumsum.stride(3))
if has_ddAcs else (0, 0, 0, 0)),
D is not None,
D.dim() == 2 if D is not None else True,
has_ddAcs,
BLOCK_SIZE_N=max(triton.next_power_of_2(headdim), 16),
RECOMPUTE_OUTPUT=recompute_output,
)
if D is not None:
BLOCK_SIZE_actual = _chunk_scan_bwd_dz_kernel.best_config.kwargs["BLOCK_SIZE_M"]
n_valid_blocks = (chunk_size + BLOCK_SIZE_actual - 1) // BLOCK_SIZE_actual
dD = dD[:n_valid_blocks].sum(dim=(0, 1, 2)).to(dtype=D.dtype)
if D.dim() == 1:
dD = rearrange(dD, "h 1 -> h")
return_vals = (dz, dout_x, dD, ddA_cumsum) if has_ddAcs else (dz, dout_x, dD)
return return_vals if not recompute_output else (*return_vals, outz)
def _chunk_scan_bwd_dstates(C, dA_cumsum, dout, seq_idx=None, dtype=None):
batch, seqlen, nheads, headdim = dout.shape
_, _, nchunks, chunk_size = dA_cumsum.shape
_, _, ngroups, dstate = C.shape
assert nheads % ngroups == 0
assert C.shape == (batch, seqlen, ngroups, dstate)
assert dA_cumsum.shape == (batch, nheads, nchunks, chunk_size)
if seq_idx is not None:
assert seq_idx.shape == (batch, seqlen)
dtype = C.dtype if dtype is None else dtype
dprev_states = torch.empty(batch, nchunks, nheads, headdim, dstate, device=C.device, dtype=dtype)
grid_dstates = lambda META: (triton.cdiv(headdim, META['BLOCK_SIZE_M']) * triton.cdiv(dstate, META['BLOCK_SIZE_N']),
batch * nchunks, nheads)
with torch.cuda.device(C.device.index):
_chunk_scan_bwd_dstates_kernel[grid_dstates](
dout, C, dprev_states, dA_cumsum, seq_idx,
headdim, dstate, chunk_size,
batch, seqlen, nchunks, nheads // ngroups,
dout.stride(0), dout.stride(1), dout.stride(2), dout.stride(3),
C.stride(0), C.stride(1), C.stride(2), C.stride(3),
dprev_states.stride(0), dprev_states.stride(1), dprev_states.stride(2), dprev_states.stride(3), dprev_states.stride(4),
dA_cumsum.stride(0), dA_cumsum.stride(2), dA_cumsum.stride(1), dA_cumsum.stride(3),
*((seq_idx.stride(0), seq_idx.stride(1)) if seq_idx is not None else (0, 0)),
HAS_SEQ_IDX=seq_idx is not None,
)
return dprev_states
def _chunk_scan_bwd_dC(prev_states, dA_cumsum, dout, seq_idx=None, C=None, ngroups=1):
batch, nchunks, nheads, headdim, dstate = prev_states.shape
_, seqlen, _, _ = dout.shape
_, _, _, chunk_size = dA_cumsum.shape
assert prev_states.shape == (batch, nchunks, nheads, headdim, dstate)
assert dA_cumsum.shape == (batch, nheads, nchunks, chunk_size)
assert dout.shape == (batch, seqlen, nheads, headdim)
if seq_idx is not None:
assert seq_idx.shape == (batch, seqlen)
if C is not None:
assert C.shape == (batch, seqlen, ngroups, dstate)
C_strides = (C.stride(0), C.stride(1), C.stride(2), C.stride(3))
ddA_cumsum_prev = torch.empty(batch, nheads, nchunks, chunk_size, device=dout.device, dtype=torch.float32)
ddA_cumsum_prev_strides = (ddA_cumsum_prev.stride(0), ddA_cumsum_prev.stride(2), ddA_cumsum_prev.stride(1), ddA_cumsum_prev.stride(3))
else:
C_strides = (0, 0, 0, 0)
ddA_cumsum_prev = None
ddA_cumsum_prev_strides = (0, 0, 0, 0)
nheads_ngroups_ratio = nheads // ngroups
sm_count = torch.cuda.get_device_properties(dout.device).multi_processor_count
nheads_per_program = max(min(math.ceil(batch * nchunks * nheads / sm_count), nheads_ngroups_ratio), 1)
nsplits = triton.cdiv(nheads_ngroups_ratio, nheads_per_program)
dC = torch.empty(batch, seqlen, nsplits, ngroups, dstate, device=dout.device, dtype=torch.float32)
grid_dc = lambda META: (triton.cdiv(chunk_size, META['BLOCK_SIZE_M']) * triton.cdiv(dstate, META['BLOCK_SIZE_N']),
batch * nchunks, nsplits * ngroups)
with torch.cuda.device(dout.device.index):
_chunk_scan_bwd_dc_kernel[grid_dc](
dout, prev_states, C, dA_cumsum, seq_idx, dC, ddA_cumsum_prev,
chunk_size, dstate, headdim,
batch, seqlen, nheads, nheads_per_program, ngroups,
dout.stride(0), dout.stride(1), dout.stride(2), dout.stride(3),
prev_states.stride(0), prev_states.stride(1), prev_states.stride(2), prev_states.stride(3), prev_states.stride(4),
*C_strides,
dA_cumsum.stride(0), dA_cumsum.stride(2), dA_cumsum.stride(1), dA_cumsum.stride(3),
*((seq_idx.stride(0), seq_idx.stride(1)) if seq_idx is not None else (0, 0)),
dC.stride(0), dC.stride(1), dC.stride(2), dC.stride(3), dC.stride(4),
*ddA_cumsum_prev_strides,
HAS_DDA_CS=ddA_cumsum_prev is not None,
HAS_SEQ_IDX=seq_idx is not None,
BLOCK_SIZE_K=max(triton.next_power_of_2(headdim), 16),
)
dC = dC.sum(2)
return dC if C is None else (dC, ddA_cumsum_prev)
def _chunk_scan_bwd_dcb(x, dt, dA_cumsum, dout, seq_idx=None, CB=None, ngroups=1):
batch, seqlen, nheads, headdim = x.shape
_, _, nchunks, chunk_size = dt.shape
assert dt.shape == (batch, nheads, nchunks, chunk_size)
assert dA_cumsum.shape == dt.shape
assert dout.shape == x.shape
if seq_idx is not None:
assert seq_idx.shape == (batch, seqlen)
if CB is not None:
assert CB.shape == (batch, nchunks, ngroups, chunk_size, chunk_size)
CB_strides = (CB.stride(0), CB.stride(1), CB.stride(2), CB.stride(3), CB.stride(4))
BLOCK_SIZE_M_min = 16
ddA_cumsum = torch.empty(batch, nheads, nchunks, triton.cdiv(chunk_size, BLOCK_SIZE_M_min),
chunk_size, device=x.device, dtype=torch.float32)
ddA_cumsum_strides = (ddA_cumsum.stride(0), ddA_cumsum.stride(2), ddA_cumsum.stride(1), ddA_cumsum.stride(3), ddA_cumsum.stride(4))
else:
CB_strides = (0, 0, 0, 0, 0)
ddA_cumsum = None
ddA_cumsum_strides = (0, 0, 0, 0, 0)
nheads_ngroups_ratio = nheads // ngroups
sm_count = torch.cuda.get_device_properties(x.device).multi_processor_count
nheads_per_program = max(min(math.ceil(batch * nchunks * nheads / sm_count), nheads_ngroups_ratio), 1)
nsplits = triton.cdiv(nheads_ngroups_ratio, nheads_per_program)
dcb = torch.empty(batch, nchunks, nsplits, ngroups, chunk_size, chunk_size, device=x.device, dtype=torch.float32)
grid_dcb = lambda META: (triton.cdiv(chunk_size, META['BLOCK_SIZE_M']) * triton.cdiv(chunk_size, META['BLOCK_SIZE_N']),
batch * nchunks, nsplits * ngroups)
with torch.cuda.device(x.device.index):
_chunk_scan_bwd_dcb_kernel[grid_dcb](
x, dout, CB, dt, dA_cumsum, seq_idx, dcb, ddA_cumsum,
chunk_size, headdim,
batch, seqlen, nheads, nheads_per_program, ngroups,
x.stride(0), x.stride(1), x.stride(2), x.stride(3),
dout.stride(0), dout.stride(1), dout.stride(2), dout.stride(3),
*CB_strides,
dt.stride(0), dt.stride(2), dt.stride(1), dt.stride(3),
dA_cumsum.stride(0), dA_cumsum.stride(2), dA_cumsum.stride(1), dA_cumsum.stride(3),
*((seq_idx.stride(0), seq_idx.stride(1)) if seq_idx is not None else (0, 0)),
dcb.stride(0), dcb.stride(1), dcb.stride(2), dcb.stride(3), dcb.stride(4), dcb.stride(5),
*ddA_cumsum_strides,
HAS_DDA_CS=ddA_cumsum is not None,
HAS_SEQ_IDX=seq_idx is not None,
BLOCK_SIZE_K=max(triton.next_power_of_2(headdim), 16),
)
dcb = dcb.sum(2)
if ddA_cumsum is not None:
BLOCK_SIZE_M_actual = _chunk_scan_bwd_dcb_kernel.best_config.kwargs["BLOCK_SIZE_M"]
n_valid_blocks = (chunk_size + BLOCK_SIZE_M_actual - 1) // BLOCK_SIZE_M_actual
ddA_cumsum = ddA_cumsum[:, :, :, :n_valid_blocks].sum(dim=3)
return dcb if CB is None else (dcb, ddA_cumsum)
def _chunk_scan_bwd_dx(cb, x, dt, dA_cumsum, dout, D=None):
batch, seqlen, nheads, headdim = x.shape
_, _, nchunks, chunk_size = dt.shape
ngroups = cb.shape[2]
assert nheads % ngroups == 0
assert cb.shape == (batch, nchunks, ngroups, chunk_size, chunk_size)
assert dt.shape == (batch, nheads, nchunks, chunk_size)
assert dA_cumsum.shape == dt.shape
assert dout.shape == x.shape
# if D is not None:
# BLOCK_SIZE_M_min = 32
# dD = torch.empty(triton.cdiv(chunk_size, BLOCK_SIZE_M_min), batch, nchunks, nheads, headdim, device=D.device, dtype=torch.float32)
# else:
# dD = None
dx = torch.empty_like(x)
ddt = torch.empty(batch, nheads, nchunks, chunk_size, device=dout.device, dtype=torch.float32)
grid_dx = lambda META: (triton.cdiv(chunk_size, META['BLOCK_SIZE_M']) * triton.cdiv(headdim, META['BLOCK_SIZE_N']),
batch * nchunks, nheads)
with torch.cuda.device(x.device.index):
_chunk_scan_bwd_dx_kernel[grid_dx](
x, cb, dout, dt, dA_cumsum, D, dx, ddt, # dD,
chunk_size, headdim,
batch, seqlen, nheads // ngroups,
x.stride(0), x.stride(1), x.stride(2), x.stride(3),
cb.stride(0), cb.stride(1), cb.stride(2), cb.stride(-1), cb.stride(-2),
dout.stride(0), dout.stride(1), dout.stride(2), dout.stride(3),
dt.stride(0), dt.stride(2), dt.stride(1), dt.stride(3),
dA_cumsum.stride(0), dA_cumsum.stride(2), dA_cumsum.stride(1), dA_cumsum.stride(3),
D.stride(0) if D is not None else 0,
dx.stride(0), dx.stride(1), dx.stride(2), dx.stride(3),
ddt.stride(0), ddt.stride(2), ddt.stride(1), ddt.stride(3),
# dD.stride(1) if dD is not None else 0, dD.stride(2) if dD is not None else 0, dD.stride(3) if dD is not None else 0, dD.stride(4) if dD is not None else 0, dD.stride(0) if dD is not None else 0,
D is not None,
D.dim() == 2 if D is not None else True,
)
# if D is not None:
# BLOCK_SIZE_actual = _chunk_scan_bwd_dx_kernel.best_config.kwargs["BLOCK_SIZE_M"]
# n_valid_blocks = (chunk_size + BLOCK_SIZE_actual - 1) // BLOCK_SIZE_actual
# dD = dD[:n_valid_blocks].sum(dim=(0, 1, 2)).to(dtype=D.dtype)
return dx, ddt.to(dtype=dt.dtype)
def _chunk_scan_bwd_ddAcs_unstable(x, dt, out, dout, ddt, D=None, subtract_ddtdt=True):
"""Not numerically stable and should not be used. Leaving here for reference.
"""
batch, seqlen, nheads, headdim = x.shape
_, _, nchunks, chunk_size = dt.shape
assert dt.shape == (batch, nheads, nchunks, chunk_size)
assert ddt.shape == dt.shape
assert out.shape == x.shape
assert dout.shape == x.shape
if D is not None:
assert D.shape == (nheads, headdim) or D.shape == (nheads,)
ddA_cumsum = torch.empty_like(dt)
grid_ddtcs = lambda META: (triton.cdiv(chunk_size, META['BLOCK_SIZE_M']), batch * nchunks, nheads)
if D is not None: # Triton gives wrong results if we write to the same location
BLOCK_SIZE_min = 32
dD = torch.empty(triton.cdiv(chunk_size, BLOCK_SIZE_min), batch, nchunks, nheads,
headdim if D.dim() == 2 else 1, device=D.device, dtype=torch.float32)
else:
dD = None
dD_strides = ((dD.stride(0), dD.stride(1), dD.stride(2), dD.stride(3), dD.stride(4))
if D is not None else (0, 0, 0, 0, 0))
with torch.cuda.device(x.device.index):
_chunk_scan_bwd_ddAcs_unstable_kernel[grid_ddtcs](
dout, out, dt, ddt, x, D, ddA_cumsum, dD,
chunk_size, headdim,
batch, seqlen,
dout.stride(0), dout.stride(1), dout.stride(2), dout.stride(3),
out.stride(0), out.stride(1), out.stride(2), out.stride(3),
dt.stride(0), dt.stride(2), dt.stride(1), dt.stride(3),
ddt.stride(0), ddt.stride(2), ddt.stride(1), ddt.stride(3),
x.stride(0), x.stride(1), x.stride(2), x.stride(3),
D.stride(0) if D is not None else 0,
ddA_cumsum.stride(0), ddA_cumsum.stride(2), ddA_cumsum.stride(1), ddA_cumsum.stride(3),
dD_strides[1], dD_strides[2], dD_strides[3], dD_strides[0], dD_strides[4],
D is not None,
D.dim() == 2 if D is not None else True,
subtract_ddtdt,
BLOCK_SIZE_N=max(triton.next_power_of_2(headdim), 16),
)
if D is not None:
BLOCK_SIZE_actual = _chunk_scan_bwd_ddAcs_unstable_kernel.best_config.kwargs["BLOCK_SIZE_M"]
n_valid_blocks = (chunk_size + BLOCK_SIZE_actual - 1) // BLOCK_SIZE_actual
dD = dD[:n_valid_blocks].sum(dim=(0, 1, 2)).to(dtype=D.dtype)
if D.dim() == 1:
dD = rearrange(dD, "h 1 -> h")
return ddA_cumsum, dD
def _chunk_scan_bwd_ddAcs_stable_old(x, dt, dA_cumsum, dout, cb):
batch, seqlen, nheads, headdim = x.shape
_, _, nchunks, chunk_size = dt.shape
assert dt.shape == (batch, nheads, nchunks, chunk_size)
assert dout.shape == x.shape
assert dA_cumsum.shape == dt.shape
ngroups = cb.shape[2]
assert nheads % ngroups == 0
assert cb.shape == (batch, nchunks, ngroups, chunk_size, chunk_size)
BLOCK_SIZE_M_min = 16
ddA_cumsum = torch.empty(batch, nheads, nchunks, triton.cdiv(chunk_size, BLOCK_SIZE_M_min),
chunk_size, device=x.device, dtype=torch.float32)
grid_ddtcs = lambda META: (triton.cdiv(chunk_size, META['BLOCK_SIZE_M']), batch * nchunks, nheads)
with torch.cuda.device(x.device.index):
_chunk_scan_bwd_ddAcs_stable_kernel_old[grid_ddtcs](
x, dout, dt, dA_cumsum, cb, ddA_cumsum,
chunk_size, headdim,
batch, seqlen, nheads // ngroups,
x.stride(0), x.stride(1), x.stride(2), x.stride(3),
dout.stride(0), dout.stride(1), dout.stride(2), dout.stride(3),
dt.stride(0), dt.stride(2), dt.stride(1), dt.stride(3),
dA_cumsum.stride(0), dA_cumsum.stride(2), dA_cumsum.stride(1), dA_cumsum.stride(3),
cb.stride(0), cb.stride(1), cb.stride(2), cb.stride(3), cb.stride(4),
ddA_cumsum.stride(0), ddA_cumsum.stride(2), ddA_cumsum.stride(1), ddA_cumsum.stride(3), ddA_cumsum.stride(4),
BLOCK_SIZE_K=max(triton.next_power_of_2(headdim), 16),
BLOCK_SIZE_N=max(triton.next_power_of_2(chunk_size), 16),
)
BLOCK_SIZE_M_actual = _chunk_scan_bwd_ddAcs_stable_kernel_old.best_config.kwargs["BLOCK_SIZE_M"]
n_valid_blocks = (chunk_size + BLOCK_SIZE_M_actual - 1) // BLOCK_SIZE_M_actual
ddA_cumsum = ddA_cumsum[:, :, :, :n_valid_blocks].sum(dim=3)
return ddA_cumsum
def _chunk_scan_bwd_ddAcs_stable(x, dt, dA_cumsum, dout, cb):
batch, seqlen, nheads, headdim = x.shape
_, _, nchunks, chunk_size = dt.shape
assert dt.shape == (batch, nheads, nchunks, chunk_size)
assert dout.shape == x.shape
assert dA_cumsum.shape == dt.shape
ngroups = cb.shape[2]
assert nheads % ngroups == 0
assert cb.shape == (batch, nchunks, ngroups, chunk_size, chunk_size)
BLOCK_SIZE_M_min = 32
ddA_cumsum = torch.empty(batch, nheads, nchunks, triton.cdiv(chunk_size, BLOCK_SIZE_M_min),
chunk_size, device=x.device, dtype=torch.float32)
grid_ddtcs = lambda META: (triton.cdiv(chunk_size, META['BLOCK_SIZE_M']), batch * nchunks, nheads)
with torch.cuda.device(x.device.index):
_chunk_scan_bwd_ddAcs_stable_kernel[grid_ddtcs](
x, dout, dt, dA_cumsum, cb, ddA_cumsum,
chunk_size, headdim,
batch, seqlen, nheads // ngroups,
x.stride(0), x.stride(1), x.stride(2), x.stride(3),
dout.stride(0), dout.stride(1), dout.stride(2), dout.stride(3),
dt.stride(0), dt.stride(2), dt.stride(1), dt.stride(3),
dA_cumsum.stride(0), dA_cumsum.stride(2), dA_cumsum.stride(1), dA_cumsum.stride(3),
cb.stride(0), cb.stride(1), cb.stride(2), cb.stride(3), cb.stride(4),
ddA_cumsum.stride(0), ddA_cumsum.stride(2), ddA_cumsum.stride(1), ddA_cumsum.stride(3), ddA_cumsum.stride(4),
BLOCK_SIZE_K=max(triton.next_power_of_2(headdim), 16),
)
BLOCK_SIZE_M_actual = _chunk_scan_bwd_ddAcs_stable_kernel.best_config.kwargs["BLOCK_SIZE_M"]
n_valid_blocks = (chunk_size + BLOCK_SIZE_M_actual - 1) // BLOCK_SIZE_M_actual
ddA_cumsum = ddA_cumsum[:, :, :, :n_valid_blocks].sum(dim=3)
return ddA_cumsum
def _chunk_scan_bwd_ddAcs_prev(prev_states, C, dout, dA_cumsum, seq_idx=None):
batch, nchunks, nheads, headdim, dstate = prev_states.shape
_, seqlen, _, _ = dout.shape
_, _, _, chunk_size = dA_cumsum.shape
assert prev_states.shape == (batch, nchunks, nheads, headdim, dstate)
assert dA_cumsum.shape == (batch, nheads, nchunks, chunk_size)
assert dout.shape == (batch, seqlen, nheads, headdim)
ngroups = C.shape[2]
assert nheads % ngroups == 0
assert C.shape == (batch, seqlen, ngroups, dstate)
if seq_idx is not None:
assert seq_idx.shape == (batch, seqlen)
ddA_cumsum_prev = torch.empty(batch, nheads, nchunks, chunk_size, device=dout.device, dtype=torch.float32)
grid_ddAcs = lambda META: (triton.cdiv(chunk_size, META['BLOCK_SIZE_M']) * triton.cdiv(dstate, META['BLOCK_SIZE_N']),
batch * nchunks, nheads)
with torch.cuda.device(dout.device.index):
_chunk_scan_bwd_ddAcs_prev_kernel[grid_ddAcs](
dout, prev_states, C, dA_cumsum, seq_idx, ddA_cumsum_prev,
chunk_size, dstate, headdim,
batch, seqlen, nchunks, nheads // ngroups,
dout.stride(0), dout.stride(1), dout.stride(2), dout.stride(3),
prev_states.stride(0), prev_states.stride(1), prev_states.stride(2), prev_states.stride(3), prev_states.stride(4),
C.stride(0), C.stride(1), C.stride(2), C.stride(3),
dA_cumsum.stride(0), dA_cumsum.stride(2), dA_cumsum.stride(1), dA_cumsum.stride(3),
*((seq_idx.stride(0), seq_idx.stride(1)) if seq_idx is not None else (0, 0)),
ddA_cumsum_prev.stride(0), ddA_cumsum_prev.stride(2), ddA_cumsum_prev.stride(1), ddA_cumsum_prev.stride(3),
HAS_SEQ_IDX=seq_idx is not None,
BLOCK_SIZE_K=max(triton.next_power_of_2(headdim), 16),
)
return ddA_cumsum_prev
class ChunkScanFn(torch.autograd.Function):
@staticmethod
def forward(ctx, B, C, x, dt, dA_cumsum, prev_states, D=None, z=None):
# Check constraints.
batch, seqlen, nheads, headdim = x.shape
_, _, ngroups, dstate = B.shape
assert B.shape == (batch, seqlen, ngroups, dstate)
_, _, nchunks, chunk_size = dt.shape
assert seqlen == nchunks * chunk_size
assert C.shape == B.shape
if z is not None:
assert z.shape == x.shape
if D is not None:
assert D.shape == (nheads, headdim) or D.shape == (nheads,)
assert dt.shape == (batch, nheads, nchunks, chunk_size)
assert dA_cumsum.shape == (batch, nheads, nchunks, chunk_size)
assert prev_states.shape == (batch, nchunks, nheads, headdim, dstate)
if B.stride(-1) != 1:
B = B.contiguous()
if C.stride(-1) != 1:
C = C.contiguous()
if x.stride(-1) != 1 and x.stride(1) != 1: # Either M or K dimension should be contiguous
x = x.contiguous()
if z is not None and z.stride(-1) != 1 and z.stride(1) != 1: # Either M or K dimension should be contiguous
z = z.contiguous()
if D is not None and D.stride(-1) != 1:
D = D.contiguous()
CB = _bmm_chunk_fwd(C, B, chunk_size)
out, out_x = _chunk_scan_fwd(CB, x, dt, dA_cumsum, C, prev_states, D=D, z=z)
ctx.save_for_backward(out if z is None else out_x, B, C, CB, x, dt, dA_cumsum, prev_states, D, z)
return out
@staticmethod
def backward(ctx, dout):
if dout.stride(-1) != 1:
dout = dout.contiguous()
out, B, C, CB, x, dt, dA_cumsum, prev_states, D, z = ctx.saved_tensors
batch, seqlen, nheads, headdim = x.shape
_, _, nchunks, chunk_size = dt.shape
_, _, ngroups, dstate = B.shape
assert dout.shape == (batch, seqlen, nheads, headdim)
if z is not None:
dz, dout, dD, ddA_cumsum = _chunk_scan_bwd_dz(x, z, out, dout, chunk_size=chunk_size, D=D)
else:
dz = None
dprev_states = _chunk_scan_bwd_dstates(C, dA_cumsum, dout, dtype=prev_states.dtype)
dC = _chunk_scan_bwd_dC(prev_states, dA_cumsum, dout, ngroups=ngroups)
dC = dC.to(C.dtype)
dCB = _chunk_scan_bwd_dcb(x, dt, dA_cumsum, dout, ngroups=ngroups)
dCB = dCB.to(CB.dtype)
dB = _bmm_chunk_bwd(C, dCB)
dC = _bmm_chunk_bwd(B, rearrange(dCB, "... l s -> ... s l"), residual=dC)
dx, ddt = _chunk_scan_bwd_dx(CB, x, dt, dA_cumsum, dout, D=D)
# Formula for ddA_cumsum, assuming out is the output of the forward pass before adding x * D.
# ddA_cumsum = torch.einsum("bclhp,bclhp->bhcl", out.float(), dout.float()) - ddt * dt
if z is not None:
ddA_cumsum -= ddt * dt
else: # If z is not None, we already calculated ddA_cumsum and dD when computing dz
ddA_cumsum, dD = _chunk_scan_bwd_ddAcs_unstable(x, dt, out, dout, ddt, D=D)
ddA_cumsum = ddA_cumsum.to(dA_cumsum.dtype)
return dB, dC, dx, ddt, ddA_cumsum, dprev_states, dD, dz
def chunk_scan(B, C, x, dt, dA_cumsum, prev_states, D=None, z=None):
"""
prev_states contains the initial_states at index 0, and the state for the next-to-last chunk at index -1.
Argument:
B: (batch, seqlen, ngroups, dstate)
C: (batch, seqlen, ngroups, dstate)
x: (batch, seqlen, nheads, headdim)
dt: (batch, nheads, nchunks, chunk_size)
dA_cumsum: (batch, nheads, nchunks, chunk_size)
prev_states: (batch, nchunks, nheads, headdim, dstate)
D: (nheads, headdim) or (nheads,)
z: (batch, seqlen, nheads, headdim)
Return:
out: (batch, seqlen, nheads, headdim)
"""
return ChunkScanFn.apply(B, C, x, dt, dA_cumsum, prev_states, D, z)
def chunk_scan_ref(B, C, x, dt, dA_cumsum, prev_states, D=None, z=None):
"""
Argument:
B: (batch, seqlen, ngroups, dstate)
C: (batch, seqlen, ngroups, dstate)
x: (batch, seqlen, nheads, headdim)
dt: (batch, nheads, nchunks, chunk_size)
dA_cumsum: (batch, nheads, nchunks, chunk_size)
prev_states: (batch, nchunks, nheads, headdim, dstate)
D: (nheads, headdim) or (nheads,)
z: (batch, seqlen, nheads, headdim)
Return:
out: (batch, seqlen, nheads, headdim)
"""
batch, seqlen, nheads, headdim = x.shape
_, _, ngroups, dstate = B.shape
assert B.shape == (batch, seqlen, ngroups, dstate)
_, _, nchunks, chunk_size = dt.shape
assert seqlen == nchunks * chunk_size
assert C.shape == B.shape
B = repeat(B, "b l g d -> b l (g h) d", h=nheads // ngroups)
C = repeat(C, "b l g d -> b l (g h) d", h=nheads // ngroups)
CB = torch.einsum("bclhn,bcshn->bchls", rearrange(C, "b (c l) h n -> b c l h n", c=nchunks),
rearrange(B, "b (c s) h n -> b c s h n", c=nchunks))
# (batch, nheads, nchunks, chunksize, chunksize)
dt_segment_sum = dA_cumsum[:, :, :, :, None] - dA_cumsum[:, :, :, None, :]
decay = torch.exp(dt_segment_sum)
scores_decay = CB * rearrange(decay, "b h c l s -> b c h l s")
causal_mask = torch.tril(torch.ones(chunk_size, chunk_size, device=x.device, dtype=bool), diagonal=0)
scores_decay = scores_decay.masked_fill(~causal_mask, 0)
out = torch.einsum('bchls,bhcs,bcshp->bclhp', scores_decay.to(x.dtype), dt.to(x.dtype),
rearrange(x, "b (c s) h p -> b c s h p", c=nchunks))
state_decay_out = torch.exp(rearrange(dA_cumsum, "b h c l -> b c l h 1"))
out_prev = torch.einsum('bclhn,bchpn->bclhp', rearrange(C, "b (c l) h n -> b c l h n", c=nchunks),
prev_states.to(C.dtype)) * state_decay_out
out = out + out_prev
out = rearrange(out, "b c l h p -> b (c l) h p")
if D is not None:
if D.dim() == 1:
D = rearrange(D, "h -> h 1")
out = out + x * D
return out if z is None else out * F.silu(z)
# Copyright (c) 2024, Tri Dao, Albert Gu.
"""We want triton==2.1.0 or 2.2.0 for this
"""
import math
import torch
import torch.nn.functional as F
import triton
import triton.language as tl
from einops import rearrange, repeat
from mamba_ssm.ops.triton.softplus import softplus
def init_to_zero(names):
return lambda nargs: [nargs[name].zero_() for name in names if nargs[name] is not None]
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_H': 1}),
triton.Config({'BLOCK_SIZE_H': 2}),
triton.Config({'BLOCK_SIZE_H': 4}),
triton.Config({'BLOCK_SIZE_H': 8}),
triton.Config({'BLOCK_SIZE_H': 16}),
triton.Config({'BLOCK_SIZE_H': 32}),
triton.Config({'BLOCK_SIZE_H': 64}),
],
key=['chunk_size', 'nheads'],
)
@triton.jit
def _chunk_cumsum_fwd_kernel(
# Pointers to matrices
dt_ptr, A_ptr, dt_bias_ptr, dt_out_ptr, dA_cumsum_ptr,
# Matrix dimension
batch, seqlen, nheads, chunk_size,
dt_min, dt_max,
# Strides
stride_dt_batch, stride_dt_seqlen, stride_dt_head,
stride_A_head,
stride_dt_bias_head,
stride_dt_out_batch, stride_dt_out_chunk, stride_dt_out_head, stride_dt_out_csize,
stride_dA_cs_batch, stride_dA_cs_chunk, stride_dA_cs_head, stride_dA_cs_csize,
# Meta-parameters
DT_SOFTPLUS: tl.constexpr,
HAS_DT_BIAS: tl.constexpr,
BLOCK_SIZE_H: tl.constexpr, BLOCK_SIZE_CHUNK: tl.constexpr,
):
pid_b = tl.program_id(axis=0)
pid_c = tl.program_id(axis=1)
pid_h = tl.program_id(axis=2)
dt_ptr += pid_b * stride_dt_batch + pid_c * chunk_size * stride_dt_seqlen
dt_out_ptr += pid_b * stride_dt_out_batch + pid_c * stride_dt_out_chunk
dA_cumsum_ptr += pid_b * stride_dA_cs_batch + pid_c * stride_dA_cs_chunk
offs_h = pid_h * BLOCK_SIZE_H + tl.arange(0, BLOCK_SIZE_H)
offs_c = tl.arange(0, BLOCK_SIZE_CHUNK)
dt_ptrs = dt_ptr + (offs_h[:, None] * stride_dt_head + offs_c[None, :] * stride_dt_seqlen)
A_ptrs = A_ptr + offs_h * stride_A_head
dt_out_ptrs = dt_out_ptr + (offs_h[:, None] * stride_dt_out_head + offs_c[None, :] * stride_dt_out_csize)
dA_cs_ptrs = dA_cumsum_ptr + (offs_h[:, None] * stride_dA_cs_head + offs_c[None, :] * stride_dA_cs_csize)
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
dt = tl.load(dt_ptrs, mask=(offs_h[:, None] < nheads) & (offs_c[None, :] < chunk_size_limit), other=0.0).to(tl.float32)
if HAS_DT_BIAS:
dt_bias = tl.load(dt_bias_ptr + offs_h * stride_dt_bias_head, mask=offs_h < nheads, other=0.0).to(tl.float32)
dt += dt_bias[:, None]
if DT_SOFTPLUS:
dt = softplus(dt)
# As of Triton 2.2.0, tl.clamp is not available yet
# dt = tl.clamp(dt, dt_min, dt_max)
dt = tl.minimum(tl.maximum(dt, dt_min), dt_max)
dt = tl.where((offs_h[:, None] < nheads) & (offs_c[None, :] < chunk_size_limit), dt, 0.0)
tl.store(dt_out_ptrs, dt, mask=(offs_h[:, None] < nheads) & (offs_c[None, :] < chunk_size))
A = tl.load(A_ptrs, mask=offs_h < nheads, other=0.0).to(tl.float32)
dA = dt * A[:, None]
dA_cs = tl.cumsum(dA, axis=1)
tl.store(dA_cs_ptrs, dA_cs, mask=(offs_h[:, None] < nheads) & (offs_c[None, :] < chunk_size))
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_H': 1}, pre_hook=init_to_zero(["dA_ptr", "ddt_bias_ptr"])),
triton.Config({'BLOCK_SIZE_H': 2}, pre_hook=init_to_zero(["dA_ptr", "ddt_bias_ptr"])),
triton.Config({'BLOCK_SIZE_H': 4}, pre_hook=init_to_zero(["dA_ptr", "ddt_bias_ptr"])),
triton.Config({'BLOCK_SIZE_H': 8}, pre_hook=init_to_zero(["dA_ptr", "ddt_bias_ptr"])),
triton.Config({'BLOCK_SIZE_H': 16}, pre_hook=init_to_zero(["dA_ptr", "ddt_bias_ptr"])),
triton.Config({'BLOCK_SIZE_H': 32}, pre_hook=init_to_zero(["dA_ptr", "ddt_bias_ptr"])),
triton.Config({'BLOCK_SIZE_H': 64}, pre_hook=init_to_zero(["dA_ptr", "ddt_bias_ptr"])),
],
key=['chunk_size', 'nheads'],
)
@triton.jit
def _chunk_cumsum_bwd_kernel(
# Pointers to matrices
ddA_ptr, ddt_out_ptr, dt_ptr, A_ptr, dt_bias_ptr,
ddt_ptr, dA_ptr, ddt_bias_ptr,
# Matrix dimensions
batch, seqlen, nheads, chunk_size,
dt_min, dt_max,
# Strides
stride_ddA_batch, stride_ddA_chunk, stride_ddA_head, stride_ddA_csize,
stride_ddt_out_batch, stride_ddt_out_chunk, stride_ddt_out_head, stride_ddt_out_csize,
stride_dt_batch, stride_dt_seqlen, stride_dt_head,
stride_A_head,
stride_dt_bias_head,
stride_ddt_batch, stride_ddt_seqlen, stride_ddt_head,
stride_dA_head,
stride_ddt_bias_head,
# Meta-parameters
DT_SOFTPLUS: tl.constexpr,
HAS_DT_BIAS: tl.constexpr,
BLOCK_SIZE_H: tl.constexpr, BLOCK_SIZE_CHUNK: tl.constexpr,
):
pid_b = tl.program_id(axis=0)
pid_c = tl.program_id(axis=1)
pid_h = tl.program_id(axis=2)
ddt_out_ptr += pid_b * stride_ddt_out_batch + pid_c * stride_ddt_out_chunk
ddA_ptr += pid_b * stride_ddA_batch + pid_c * stride_ddA_chunk
dt_ptr += pid_b * stride_dt_batch + pid_c * chunk_size * stride_dt_seqlen
ddt_ptr += pid_b * stride_ddt_batch + pid_c * chunk_size * stride_ddt_seqlen
offs_h = pid_h * BLOCK_SIZE_H + tl.arange(0, BLOCK_SIZE_H)
offs_c = tl.arange(0, BLOCK_SIZE_CHUNK)
ddt_out_ptrs = ddt_out_ptr + (offs_h[:, None] * stride_ddt_out_head + offs_c[None, :] * stride_ddt_out_csize)
ddA_ptrs = ddA_ptr + (offs_h[:, None] * stride_ddA_head + offs_c[None, :] * stride_ddA_csize)
dt_ptrs = dt_ptr + (offs_h[:, None] * stride_dt_head + offs_c[None, :] * stride_dt_seqlen)
ddt_ptrs = ddt_ptr + (offs_h[:, None] * stride_ddt_head + offs_c[None, :] * stride_ddt_seqlen)
A_ptrs = A_ptr + offs_h * stride_A_head
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
ddA = tl.load(ddA_ptrs, mask=(offs_h[:, None] < nheads) & (offs_c[None, :] < chunk_size_limit), other=0.0).to(tl.float32)
ddt_out = tl.load(ddt_out_ptrs, mask=(offs_h[:, None] < nheads) & (offs_c[None, :] < chunk_size_limit), other=0.0).to(tl.float32)
A = tl.load(A_ptrs, mask=offs_h < nheads, other=0.0).to(tl.float32)
ddt = ddA * A[:, None] + ddt_out
dt = tl.load(dt_ptrs, mask=(offs_h[:, None] < nheads) & (offs_c[None, :] < chunk_size_limit), other=0.0).to(tl.float32)
if HAS_DT_BIAS:
dt_bias = tl.load(dt_bias_ptr + offs_h * stride_dt_bias_head, mask=offs_h < nheads, other=0.0).to(tl.float32)
dt += dt_bias[:, None]
if DT_SOFTPLUS:
dt_presoftplus = dt
dt = softplus(dt)
clamp_mask = (dt < dt_min) | (dt > dt_max)
# As of Triton 2.2.0, tl.clamp is not available yet
# dt = tl.clamp(dt, dt_min, dt_max)
dt = tl.minimum(tl.maximum(dt, dt_min), dt_max)
dt = tl.where((offs_h[:, None] < nheads) & (offs_c[None, :] < chunk_size_limit), dt, 0.0)
ddt = tl.where((offs_h[:, None] < nheads) & (offs_c[None, :] < chunk_size_limit), ddt, 0.0)
ddt = tl.where(clamp_mask, 0.0, ddt)
if DT_SOFTPLUS:
ddt = tl.where(dt_presoftplus <= 20.0, ddt * tl.sigmoid(dt_presoftplus), ddt)
tl.store(ddt_ptrs, ddt, mask=(offs_h[:, None] < nheads) & (offs_c[None, :] < chunk_size_limit))
dA = tl.sum(ddA * dt, axis=1)
tl.atomic_add(dA_ptr + offs_h * stride_dA_head, dA, mask=offs_h < nheads)
if HAS_DT_BIAS:
ddt_bias = tl.sum(ddt, axis=1)
tl.atomic_add(ddt_bias_ptr + offs_h * stride_ddt_bias_head, ddt_bias, mask=offs_h < nheads)
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 64}, num_stages=3, num_warps=8),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=2),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=2),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=2),
],
key=['hdim', 'dstate', 'chunk_size'],
)
@triton.jit
def _chunk_state_fwd_kernel(
# Pointers to matrices
x_ptr, b_ptr, states_ptr, dt_ptr, dA_cumsum_ptr, seq_idx_ptr,
# Matrix dimensions
hdim, dstate, chunk_size,
batch, seqlen, nheads_ngroups_ratio,
# Strides
stride_x_batch, stride_x_seqlen, stride_x_head, stride_x_hdim,
stride_b_batch, stride_b_seqlen, stride_b_head, stride_b_dstate,
stride_states_batch, stride_states_chunk, stride_states_head, stride_states_hdim, stride_states_dstate,
stride_dt_batch, stride_dt_chunk, stride_dt_head, stride_dt_csize,
stride_dA_cs_batch, stride_dA_cs_chunk, stride_dA_cs_head, stride_dA_cs_csize,
stride_seq_idx_batch, stride_seq_idx_seqlen,
# Meta-parameters
HAS_SEQ_IDX: tl.constexpr,
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr, BLOCK_SIZE_K: tl.constexpr,
):
pid_bc = tl.program_id(axis=1)
pid_c = pid_bc // batch
pid_b = pid_bc - pid_c * batch
pid_h = tl.program_id(axis=2)
num_pid_n = tl.cdiv(dstate, BLOCK_SIZE_N)
pid_m = tl.program_id(axis=0) // num_pid_n
pid_n = tl.program_id(axis=0) % num_pid_n
b_ptr += pid_b * stride_b_batch + pid_c * chunk_size * stride_b_seqlen + (pid_h // nheads_ngroups_ratio) * stride_b_head
x_ptr += pid_b * stride_x_batch + pid_c * chunk_size * stride_x_seqlen + pid_h * stride_x_head
dt_ptr += pid_b * stride_dt_batch + pid_c * stride_dt_chunk + pid_h * stride_dt_head
dA_cumsum_ptr += pid_b * stride_dA_cs_batch + pid_c * stride_dA_cs_chunk + pid_h * stride_dA_cs_head
if HAS_SEQ_IDX:
seq_idx_ptr += pid_b * stride_seq_idx_batch + pid_c * chunk_size * stride_seq_idx_seqlen
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
offs_k = tl.arange(0, BLOCK_SIZE_K)
x_ptrs = x_ptr + (offs_m[:, None] * stride_x_hdim + offs_k[None, :] * stride_x_seqlen)
b_ptrs = b_ptr + (offs_n[None, :] * stride_b_dstate + offs_k[:, None] * stride_b_seqlen)
dt_ptrs = dt_ptr + offs_k * stride_dt_csize
dA_cs_last = tl.load(dA_cumsum_ptr + (chunk_size - 1) * stride_dA_cs_csize).to(tl.float32)
dA_cumsum_ptrs = dA_cumsum_ptr + offs_k * stride_dA_cs_csize
if HAS_SEQ_IDX:
seq_idx_ptrs = seq_idx_ptr + offs_k * stride_seq_idx_seqlen
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
if HAS_SEQ_IDX:
seq_idx_last = tl.load(seq_idx_ptr + (chunk_size_limit - 1) * stride_seq_idx_seqlen)
acc = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=tl.float32)
for k in range(0, chunk_size_limit, BLOCK_SIZE_K):
x = tl.load(x_ptrs, mask=(offs_m[:, None] < hdim) & (offs_k[None, :] < chunk_size_limit - k), other=0.0)
b = tl.load(b_ptrs, mask=(offs_k[:, None] < chunk_size_limit - k) & (offs_n[None, :] < dstate), other=0.0).to(tl.float32)
dA_cs_k = tl.load(dA_cumsum_ptrs, mask=offs_k < chunk_size_limit - k, other=0.0).to(tl.float32)
if HAS_SEQ_IDX:
seq_idx_k = tl.load(seq_idx_ptrs, mask=offs_k < chunk_size_limit - k, other=-1)
dt_k = tl.load(dt_ptrs, mask=offs_k < chunk_size_limit - k, other=0.0).to(tl.float32)
if not HAS_SEQ_IDX:
scale = tl.exp((dA_cs_last - dA_cs_k)) * dt_k
else:
scale = tl.where(seq_idx_k == seq_idx_last, tl.exp((dA_cs_last - dA_cs_k)) * dt_k, 0.0)
b *= scale[:, None]
b = b.to(x_ptr.dtype.element_ty)
acc += tl.dot(x, b)
x_ptrs += BLOCK_SIZE_K * stride_x_seqlen
b_ptrs += BLOCK_SIZE_K * stride_b_seqlen
dt_ptrs += BLOCK_SIZE_K * stride_dt_csize
dA_cumsum_ptrs += BLOCK_SIZE_K * stride_dA_cs_csize
if HAS_SEQ_IDX:
seq_idx_ptrs += BLOCK_SIZE_K * stride_seq_idx_seqlen
states = acc.to(states_ptr.dtype.element_ty)
states_ptr += pid_b * stride_states_batch + pid_c * stride_states_chunk + pid_h * stride_states_head
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
states_ptrs = states_ptr + (offs_m[:, None] * stride_states_hdim + offs_n[None, :] * stride_states_dstate)
c_mask = (offs_m[:, None] < hdim) & (offs_n[None, :] < dstate)
tl.store(states_ptrs, states, mask=c_mask)
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 64}, num_stages=3, num_warps=8, pre_hook=init_to_zero(["ddt_ptr", "ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr", "ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr", "ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr", "ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr", "ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr", "ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=4, pre_hook=init_to_zero(["ddt_ptr", "ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=4, pre_hook=init_to_zero(["ddt_ptr", "ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr", "ddA_cumsum_ptr"])),
],
key=['chunk_size', 'hdim', 'dstate'],
)
@triton.jit
def _chunk_state_bwd_dx_kernel(
# Pointers to matrices
x_ptr, b_ptr, dstates_ptr, dt_ptr, dA_cumsum_ptr,
dx_ptr, ddt_ptr, ddA_cumsum_ptr,
# Matrix dimensions
chunk_size, hdim, dstate,
batch, seqlen, nheads_ngroups_ratio,
# Strides
stride_x_batch, stride_x_seqlen, stride_x_head, stride_x_hdim,
stride_b_batch, stride_b_seqlen, stride_b_head, stride_b_dstate,
stride_dstates_batch, stride_dstates_chunk, stride_states_head, stride_states_hdim, stride_states_dstate,
stride_dt_batch, stride_dt_chunk, stride_dt_head, stride_dt_csize,
stride_dA_cs_batch, stride_dA_cs_chunk, stride_dA_cs_head, stride_dA_cs_csize,
stride_dx_batch, stride_dx_seqlen, stride_dx_head, stride_dx_hdim,
stride_ddt_batch, stride_ddt_chunk, stride_ddt_head, stride_ddt_csize,
stride_ddA_cs_batch, stride_ddA_cs_chunk, stride_ddA_cs_head, stride_ddA_cs_csize,
# Meta-parameters
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr, BLOCK_SIZE_K: tl.constexpr,
BLOCK_SIZE_DSTATE: tl.constexpr,
):
pid_bc = tl.program_id(axis=1)
pid_c = pid_bc // batch
pid_b = pid_bc - pid_c * batch
pid_h = tl.program_id(axis=2)
num_pid_n = tl.cdiv(hdim, BLOCK_SIZE_N)
pid_m = tl.program_id(axis=0) // num_pid_n
pid_n = tl.program_id(axis=0) % num_pid_n
x_ptr += pid_b * stride_x_batch + pid_c * chunk_size * stride_x_seqlen + pid_h * stride_x_head
b_ptr += pid_b * stride_b_batch + pid_c * chunk_size * stride_b_seqlen + (pid_h // nheads_ngroups_ratio) * stride_b_head
dstates_ptr += pid_b * stride_dstates_batch + pid_c * stride_dstates_chunk + pid_h * stride_states_head
dt_ptr += pid_b * stride_dt_batch + pid_c * stride_dt_chunk + pid_h * stride_dt_head
ddt_ptr += pid_b * stride_ddt_batch + pid_c * stride_ddt_chunk + pid_h * stride_ddt_head
ddA_cumsum_ptr += pid_b * stride_ddA_cs_batch + pid_c * stride_ddA_cs_chunk + pid_h * stride_ddA_cs_head
dA_cumsum_ptr += pid_b * stride_dA_cs_batch + pid_c * stride_dA_cs_chunk + pid_h * stride_dA_cs_head
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
# Faster to just do 1 iteration with larger BLOCK_SIZE_K, up to block size 128
offs_k = tl.arange(0, BLOCK_SIZE_DSTATE if BLOCK_SIZE_DSTATE <= 128 else BLOCK_SIZE_K)
b_ptrs = b_ptr + (offs_m[:, None] * stride_b_seqlen + offs_k[None, :] * stride_b_dstate)
dstates_ptrs = dstates_ptr + (offs_n[None, :] * stride_states_hdim + offs_k[:, None] * stride_states_dstate)
if BLOCK_SIZE_DSTATE <= 128:
b = tl.load(b_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_k[None, :] < dstate), other=0.0)
dstates = tl.load(dstates_ptrs, mask=(offs_k[:, None] < dstate) & (offs_n[None, :] < hdim), other=0.0)
dstates = dstates.to(b_ptr.dtype.element_ty)
acc = tl.dot(b, dstates)
else:
acc = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=tl.float32)
for k in range(0, dstate, BLOCK_SIZE_K):
b = tl.load(b_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_k[None, :] < dstate - k), other=0.0)
dstates = tl.load(dstates_ptrs, mask=(offs_k[:, None] < dstate - k) & (offs_n[None, :] < hdim), other=0.0)
dstates = dstates.to(b_ptr.dtype.element_ty)
acc += tl.dot(b, dstates)
b_ptrs += BLOCK_SIZE_K * stride_b_dstate
dstates_ptrs += BLOCK_SIZE_K * stride_states_dstate
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
dA_cs_last = tl.load(dA_cumsum_ptr + (chunk_size - 1) * stride_dA_cs_csize).to(tl.float32)
dt_ptrs = dt_ptr + offs_m * stride_dt_csize
dA_cumsum_ptrs = dA_cumsum_ptr + offs_m * stride_dA_cs_csize
dA_cs_m = tl.load(dA_cumsum_ptrs, mask=offs_m < chunk_size, other=0.0).to(tl.float32)
dt_m = tl.load(dt_ptrs, mask=offs_m < chunk_size, other=0.0).to(tl.float32)
acc *= tl.exp(dA_cs_last - dA_cs_m)[:, None]
x_ptrs = x_ptr + (offs_m[:, None] * stride_x_seqlen + offs_n[None, :] * stride_x_hdim)
x = tl.load(x_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim), other=0.0).to(tl.float32)
ddt = tl.sum(acc * x, axis=1)
ddt_ptrs = ddt_ptr + offs_m * stride_ddt_csize
tl.atomic_add(ddt_ptrs, ddt, mask=offs_m < chunk_size)
ddA_cs = -(ddt * dt_m)
ddA_cs_last = -tl.sum(ddA_cs)
ddA_cumsum_ptrs = ddA_cumsum_ptr + offs_m * stride_ddA_cs_csize
tl.atomic_add(ddA_cumsum_ptrs, ddA_cs, mask=offs_m < chunk_size)
tl.atomic_add(ddA_cumsum_ptr + (chunk_size - 1) * stride_ddA_cs_csize, ddA_cs_last)
dx = (acc * dt_m[:, None]).to(dx_ptr.dtype.element_ty)
dx_ptr += pid_b * stride_dx_batch + pid_c * chunk_size * stride_dx_seqlen + pid_h * stride_dx_head
dx_ptrs = dx_ptr + (offs_m[:, None] * stride_dx_seqlen + offs_n[None, :] * stride_dx_hdim)
tl.store(dx_ptrs, dx, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim))
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 128}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 32}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 128}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 64}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 64}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 32}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 64}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 32}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
],
key=['chunk_size', 'dstate', 'hdim'],
)
@triton.jit
def _chunk_state_bwd_db_kernel(
# Pointers to matrices
x_ptr, dstates_ptr, b_ptr, dt_ptr, dA_cumsum_ptr, seq_idx_ptr,
db_ptr, ddA_cumsum_ptr,
# Matrix dimensions
chunk_size, dstate, hdim,
batch, seqlen, nheads, nheads_per_program, ngroups,
# Strides
stride_x_batch, stride_x_seqlen, stride_x_head, stride_x_hdim,
stride_dstates_batch, stride_dstates_chunk, stride_states_head, stride_states_hdim, stride_states_dstate,
stride_b_batch, stride_b_seqlen, stride_b_head, stride_b_dstate,
stride_dt_batch, stride_dt_chunk, stride_dt_head, stride_dt_csize,
stride_dA_cs_batch, stride_dA_cs_chunk, stride_dA_cs_head, stride_dA_cs_csize,
stride_seq_idx_batch, stride_seq_idx_seqlen,
stride_db_batch, stride_db_seqlen, stride_db_split, stride_db_group, stride_db_dstate,
stride_ddA_cs_batch, stride_ddA_cs_chunk, stride_ddA_cs_head, stride_ddA_cs_csize,
# Meta-parameters
HAS_DDA_CS: tl.constexpr,
HAS_SEQ_IDX: tl.constexpr,
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr, BLOCK_SIZE_K: tl.constexpr,
):
pid_bc = tl.program_id(axis=1)
pid_c = pid_bc // batch
pid_b = pid_bc - pid_c * batch
pid_sg = tl.program_id(axis=2)
pid_s = pid_sg // ngroups
pid_g = pid_sg - pid_s * ngroups
num_pid_n = tl.cdiv(dstate, BLOCK_SIZE_N)
pid_m = tl.program_id(axis=0) // num_pid_n
pid_n = tl.program_id(axis=0) % num_pid_n
x_ptr += pid_b * stride_x_batch + pid_c * chunk_size * stride_x_seqlen + (pid_g * (nheads // ngroups) + pid_s * nheads_per_program) * stride_x_head
db_ptr += pid_b * stride_db_batch + pid_c * chunk_size * stride_db_seqlen + pid_g * stride_db_group + pid_s * stride_db_split
dstates_ptr += pid_b * stride_dstates_batch + pid_c * stride_dstates_chunk + (pid_g * (nheads // ngroups) + pid_s * nheads_per_program) * stride_states_head
dt_ptr += pid_b * stride_dt_batch + pid_c * stride_dt_chunk + (pid_g * (nheads // ngroups) + pid_s * nheads_per_program) * stride_dt_head
dA_cumsum_ptr += pid_b * stride_dA_cs_batch + pid_c * stride_dA_cs_chunk + (pid_g * (nheads // ngroups) + pid_s * nheads_per_program) * stride_dA_cs_head
if HAS_DDA_CS:
b_ptr += pid_b * stride_b_batch + pid_c * chunk_size * stride_b_seqlen + pid_g * stride_b_head
ddA_cumsum_ptr += pid_b * stride_ddA_cs_batch + pid_c * stride_ddA_cs_chunk + (pid_g * (nheads // ngroups) + pid_s * nheads_per_program) * stride_ddA_cs_head
if HAS_SEQ_IDX:
seq_idx_ptr += pid_b * stride_seq_idx_batch + pid_c * chunk_size * stride_seq_idx_seqlen
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
offs_k = tl.arange(0, BLOCK_SIZE_K)
x_ptrs = x_ptr + (offs_m[:, None] * stride_x_seqlen + offs_k[None, :] * stride_x_hdim)
dstates_ptrs = dstates_ptr + (offs_n[None, :] * stride_states_dstate + offs_k[:, None] * stride_states_hdim)
dt_ptrs = dt_ptr + offs_m * stride_dt_csize
dA_cumsum_ptrs = dA_cumsum_ptr + offs_m * stride_dA_cs_csize
if HAS_DDA_CS:
b_ptrs = b_ptr + (offs_m[:, None] * stride_b_seqlen + offs_n[None, :] * stride_b_dstate)
ddA_cumsum_ptrs = ddA_cumsum_ptr + offs_m * stride_ddA_cs_csize
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
acc = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=tl.float32)
if HAS_DDA_CS:
b = tl.load(b_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < dstate), other=0.0).to(tl.float32)
if HAS_SEQ_IDX:
seq_idx_m = tl.load(seq_idx_ptr + offs_m * stride_seq_idx_seqlen, mask=offs_m < chunk_size_limit, other=-1)
seq_idx_last = tl.load(seq_idx_ptr + (chunk_size_limit - 1) * stride_seq_idx_seqlen)
nheads_iter = min(nheads_per_program, nheads // ngroups - pid_s * nheads_per_program)
for h in range(nheads_iter):
x = tl.load(x_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_k[None, :] < hdim), other=0.0)
dstates = tl.load(dstates_ptrs, mask=(offs_k[:, None] < hdim) & (offs_n[None, :] < dstate), other=0.0)
dstates = dstates.to(x_ptrs.dtype.element_ty)
db = tl.dot(x, dstates)
dA_cs_last = tl.load(dA_cumsum_ptr + (chunk_size - 1) * stride_dA_cs_csize).to(tl.float32)
dA_cs_m = tl.load(dA_cumsum_ptrs, mask=offs_m < chunk_size, other=0.0).to(tl.float32)
dt_m = tl.load(dt_ptrs, mask=offs_m < chunk_size, other=0.0).to(tl.float32)
if not HAS_SEQ_IDX:
scale = tl.exp(dA_cs_last - dA_cs_m)
else:
scale = tl.where(seq_idx_m == seq_idx_last, tl.exp(dA_cs_last - dA_cs_m), 0.0)
db *= (scale * dt_m)[:, None]
if HAS_DDA_CS:
# This is the gradient wrt (dA_cs_last - dA_cs_m), i.e. the exclusive reverse cumsum
ddA_cs = tl.sum(db * b, axis=1)
tl.atomic_add(ddA_cumsum_ptrs + stride_ddA_cs_csize, ddA_cs, mask=offs_m < chunk_size - 1)
acc += db
x_ptrs += stride_x_head
dstates_ptrs += stride_states_head
dt_ptrs += stride_dt_head
dA_cumsum_ptr += stride_dA_cs_head
dA_cumsum_ptrs += stride_dA_cs_head
if HAS_DDA_CS:
ddA_cumsum_ptrs += stride_ddA_cs_head
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
# if HAS_SEQ_IDX:
# seq_idx_last = tl.load(seq_idx_ptr + (chunk_size_limit - 1) * stride_seq_idx_seqlen)
# seq_idx_m = tl.load(seq_idx_ptr + offs_m * stride_seq_idx_seqlen, mask=offs_m < chunk_size_limit, other=-1)
# acc = tl.where(seq_idx_m[:, None] == seq_idx_last, acc, 0.0)
db_ptrs = db_ptr + (offs_m[:, None] * stride_db_seqlen + offs_n[None, :] * stride_db_dstate)
tl.store(db_ptrs, acc, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < dstate))
@triton.autotune(
configs=[
# triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 64}, num_stages=3, num_warps=8, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
# triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
# triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
# triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
# triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
# triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
# triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
# triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
# triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_N': 16, 'BLOCK_SIZE_K': 32}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=3, num_warps=4, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_N': 16, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=8, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=8, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=8, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
triton.Config({'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=8, pre_hook=init_to_zero(["ddA_cumsum_ptr"])),
],
key=['chunk_size', 'hdim', 'dstate'],
)
@triton.jit
def _chunk_state_bwd_ddAcs_stable_kernel(
# Pointers to matrices
x_ptr, b_ptr, dstates_ptr, dt_ptr, dA_cumsum_ptr, seq_idx_ptr,
ddA_cumsum_ptr,
# Matrix dimensions
chunk_size, hdim, dstate,
batch, seqlen, nheads_ngroups_ratio,
# Strides
stride_x_batch, stride_x_seqlen, stride_x_head, stride_x_hdim,
stride_b_batch, stride_b_seqlen, stride_b_head, stride_b_dstate,
stride_dstates_batch, stride_dstates_chunk, stride_states_head, stride_states_hdim, stride_states_dstate,
stride_dt_batch, stride_dt_chunk, stride_dt_head, stride_dt_csize,
stride_dA_cs_batch, stride_dA_cs_chunk, stride_dA_cs_head, stride_dA_cs_csize,
stride_seq_idx_batch, stride_seq_idx_seqlen,
stride_ddA_cs_batch, stride_ddA_cs_chunk, stride_ddA_cs_head, stride_ddA_cs_csize,
# Meta-parameters
HAS_SEQ_IDX: tl.constexpr,
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr, BLOCK_SIZE_K: tl.constexpr,
BLOCK_SIZE_DSTATE: tl.constexpr,
):
pid_bc = tl.program_id(axis=1)
pid_c = pid_bc // batch
pid_b = pid_bc - pid_c * batch
pid_h = tl.program_id(axis=2)
num_pid_n = tl.cdiv(hdim, BLOCK_SIZE_N)
pid_m = tl.program_id(axis=0) // num_pid_n
pid_n = tl.program_id(axis=0) % num_pid_n
x_ptr += pid_b * stride_x_batch + pid_c * chunk_size * stride_x_seqlen + pid_h * stride_x_head
b_ptr += pid_b * stride_b_batch + pid_c * chunk_size * stride_b_seqlen + (pid_h // nheads_ngroups_ratio) * stride_b_head
dstates_ptr += pid_b * stride_dstates_batch + pid_c * stride_dstates_chunk + pid_h * stride_states_head
dt_ptr += pid_b * stride_dt_batch + pid_c * stride_dt_chunk + pid_h * stride_dt_head
ddA_cumsum_ptr += pid_b * stride_ddA_cs_batch + pid_c * stride_ddA_cs_chunk + pid_h * stride_ddA_cs_head
dA_cumsum_ptr += pid_b * stride_dA_cs_batch + pid_c * stride_dA_cs_chunk + pid_h * stride_dA_cs_head
if HAS_SEQ_IDX:
seq_idx_ptr += pid_b * stride_seq_idx_batch + pid_c * chunk_size * stride_seq_idx_seqlen
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
# Faster to just do 1 iteration with larger BLOCK_SIZE_K, up to block size 128
offs_k = tl.arange(0, BLOCK_SIZE_DSTATE if BLOCK_SIZE_DSTATE <= 128 else BLOCK_SIZE_K)
b_ptrs = b_ptr + (offs_m[:, None] * stride_b_seqlen + offs_k[None, :] * stride_b_dstate)
dstates_ptrs = dstates_ptr + (offs_n[None, :] * stride_states_hdim + offs_k[:, None] * stride_states_dstate)
if BLOCK_SIZE_DSTATE <= 128:
b = tl.load(b_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_k[None, :] < dstate), other=0.0)
dstates = tl.load(dstates_ptrs, mask=(offs_k[:, None] < dstate) & (offs_n[None, :] < hdim), other=0.0)
dstates = dstates.to(b_ptr.dtype.element_ty)
acc = tl.dot(b, dstates)
else:
acc = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=tl.float32)
for k in range(0, dstate, BLOCK_SIZE_K):
b = tl.load(b_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_k[None, :] < dstate - k), other=0.0)
dstates = tl.load(dstates_ptrs, mask=(offs_k[:, None] < dstate - k) & (offs_n[None, :] < hdim), other=0.0)
dstates = dstates.to(b_ptr.dtype.element_ty)
acc += tl.dot(b, dstates)
b_ptrs += BLOCK_SIZE_K * stride_b_dstate
dstates_ptrs += BLOCK_SIZE_K * stride_states_dstate
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
dA_cs_m = tl.load(dA_cumsum_ptr + offs_m * stride_dA_cs_csize, mask=offs_m < chunk_size, other=0.0).to(tl.float32)
dA_cs_last = tl.load(dA_cumsum_ptr + (chunk_size - 1) * stride_dA_cs_csize).to(tl.float32)
if not HAS_SEQ_IDX:
scale = tl.exp(dA_cs_last - dA_cs_m)
else:
seq_idx_m = tl.load(seq_idx_ptr + offs_m * stride_seq_idx_seqlen, mask=offs_m < chunk_size_limit, other=-1)
seq_idx_last = tl.load(seq_idx_ptr + (chunk_size_limit - 1) * stride_seq_idx_seqlen)
scale = tl.where(seq_idx_m == seq_idx_last, tl.exp(dA_cs_last - dA_cs_m), 0.0)
acc *= scale[:, None]
x_ptrs = x_ptr + (offs_m[:, None] * stride_x_seqlen + offs_n[None, :] * stride_x_hdim)
x = tl.load(x_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim), other=0.0).to(tl.float32)
dt_ptrs = dt_ptr + offs_m * stride_dt_csize
dt_m = tl.load(dt_ptrs, mask=offs_m < chunk_size, other=0.0).to(tl.float32)
ddt = tl.sum(acc * x, axis=1)
# ddA_cs = -(ddt * dt_m)
# Triton 2.2.0 errors if we have the cumsum here, so we just write it out
# then call torch.cumsum outside this kernel.
# ddA_cs = tl.cumsum(ddt * dt_m)
ddA_cs = ddt * dt_m
ddA_cumsum_ptrs = ddA_cumsum_ptr + offs_m * stride_ddA_cs_csize
# tl.atomic_add(ddA_cumsum_ptrs, ddA_cs, mask=offs_m < chunk_size)
tl.atomic_add(ddA_cumsum_ptrs + stride_ddA_cs_csize, ddA_cs, mask=offs_m < chunk_size - 1)
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 64}, num_stages=3, num_warps=8),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=2),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=2),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=2),
],
key=['hdim', 'dstate', 'chunk_size'],
)
@triton.jit
def _chunk_state_varlen_kernel(
# Pointers to matrices
x_ptr, b_ptr, dt_ptr, dA_cumsum_ptr, chunk_states_ptr, cu_seqlens_ptr, states_ptr,
# Matrix dimensions
hdim, dstate, chunk_size,
seqlen, nheads_ngroups_ratio,
# Strides
stride_x_seqlen, stride_x_head, stride_x_hdim,
stride_b_seqlen, stride_b_head, stride_b_dstate,
stride_dt_chunk, stride_dt_head, stride_dt_csize,
stride_dA_cs_chunk, stride_dA_cs_head, stride_dA_cs_csize,
stride_chunk_states_chunk, stride_chunk_states_head, stride_chunk_states_hdim, stride_chunk_states_dstate,
stride_states_batch, stride_states_head, stride_states_hdim, stride_states_dstate,
# Meta-parameters
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr, BLOCK_SIZE_K: tl.constexpr,
):
pid_b = tl.program_id(axis=1)
pid_h = tl.program_id(axis=2)
num_pid_n = tl.cdiv(dstate, BLOCK_SIZE_N)
pid_m = tl.program_id(axis=0) // num_pid_n
pid_n = tl.program_id(axis=0) % num_pid_n
end_idx = tl.load(cu_seqlens_ptr + pid_b + 1)
pid_c = (end_idx - 1) // chunk_size
b_ptr += pid_c * chunk_size * stride_b_seqlen + (pid_h // nheads_ngroups_ratio) * stride_b_head
x_ptr += pid_c * chunk_size * stride_x_seqlen + pid_h * stride_x_head
dt_ptr += pid_c * stride_dt_chunk + pid_h * stride_dt_head
dA_cumsum_ptr += pid_c * stride_dA_cs_chunk + pid_h * stride_dA_cs_head
chunk_states_ptr += pid_c * stride_chunk_states_chunk + pid_h * stride_chunk_states_head
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
offs_k = tl.arange(0, BLOCK_SIZE_K)
x_ptrs = x_ptr + (offs_m[:, None] * stride_x_hdim + offs_k[None, :] * stride_x_seqlen)
b_ptrs = b_ptr + (offs_n[None, :] * stride_b_dstate + offs_k[:, None] * stride_b_seqlen)
dt_ptrs = dt_ptr + offs_k * stride_dt_csize
dA_cs_last = tl.load(dA_cumsum_ptr + (end_idx - pid_c * chunk_size - 1) * stride_dA_cs_csize).to(tl.float32)
dA_cumsum_ptrs = dA_cumsum_ptr + offs_k * stride_dA_cs_csize
chunk_size_limit = end_idx - pid_c * chunk_size
start_idx = tl.load(cu_seqlens_ptr + pid_b)
start_idx_cur = tl.maximum(start_idx - pid_c * chunk_size, 0)
acc = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=tl.float32)
for k in range(0, chunk_size_limit, BLOCK_SIZE_K):
x = tl.load(x_ptrs, mask=(offs_m[:, None] < hdim) & (offs_k[None, :] < chunk_size_limit - k) & (offs_k[None, :] >= start_idx_cur - k), other=0.0)
b = tl.load(b_ptrs, mask=(offs_k[:, None] < chunk_size_limit - k) & (offs_n[None, :] < dstate) & (offs_k[:, None] >= start_idx_cur - k), other=0.0).to(tl.float32)
dA_cs_k = tl.load(dA_cumsum_ptrs, mask=offs_k < chunk_size_limit - k, other=0.0).to(tl.float32)
dt_k = tl.load(dt_ptrs, mask=offs_k < chunk_size_limit - k, other=0.0).to(tl.float32)
scale = tl.where((offs_k >= start_idx_cur - k) & (offs_k < chunk_size_limit - k),
tl.exp((dA_cs_last - dA_cs_k)) * dt_k, 0.0)
b *= scale[:, None]
b = b.to(x_ptr.dtype.element_ty)
acc += tl.dot(x, b)
x_ptrs += BLOCK_SIZE_K * stride_x_seqlen
b_ptrs += BLOCK_SIZE_K * stride_b_seqlen
dt_ptrs += BLOCK_SIZE_K * stride_dt_csize
dA_cumsum_ptrs += BLOCK_SIZE_K * stride_dA_cs_csize
# If the sequence starts after the last chunk idx, we don't need to add the contribution from the last chunk
if start_idx < pid_c * chunk_size:
chunk_states_ptrs = chunk_states_ptr + (offs_m[:, None] * stride_chunk_states_hdim + offs_n[None, :] * stride_chunk_states_dstate)
chunk_states = tl.load(chunk_states_ptrs, mask=(offs_m[:, None] < hdim) & (offs_n[None, :] < dstate), other=0.0).to(tl.float32)
# scale = tl.where(start_idx < pid_c * chunk_size, tl.exp(dA_cs_last), 0.0)
scale = tl.exp(dA_cs_last)
acc += chunk_states * scale
states = acc.to(states_ptr.dtype.element_ty)
states_ptr += pid_b * stride_states_batch + pid_h * stride_states_head
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
states_ptrs = states_ptr + (offs_m[:, None] * stride_states_hdim + offs_n[None, :] * stride_states_dstate)
c_mask = (offs_m[:, None] < hdim) & (offs_n[None, :] < dstate)
tl.store(states_ptrs, states, mask=c_mask)
def _chunk_cumsum_fwd(dt, A, chunk_size, dt_bias=None, dt_softplus=False, dt_limit=(0.0, float("inf"))):
batch, seqlen, nheads = dt.shape
assert A.shape == (nheads,)
if dt_bias is not None:
assert dt_bias.shape == (nheads,)
nchunks = math.ceil(seqlen / chunk_size)
dt_out = torch.empty(batch, nheads, nchunks, chunk_size, device=dt.device, dtype=torch.float32)
dA_cumsum = torch.empty(batch, nheads, nchunks, chunk_size, device=dt.device, dtype=torch.float32)
grid_chunk_cs = lambda META: (batch, nchunks, triton.cdiv(nheads, META['BLOCK_SIZE_H']))
with torch.cuda.device(dt.device.index):
_chunk_cumsum_fwd_kernel[grid_chunk_cs](
dt, A, dt_bias, dt_out, dA_cumsum,
batch, seqlen, nheads, chunk_size,
dt_limit[0], dt_limit[1],
dt.stride(0), dt.stride(1), dt.stride(2),
A.stride(0),
dt_bias.stride(0) if dt_bias is not None else 0,
dt_out.stride(0), dt_out.stride(2), dt_out.stride(1), dt_out.stride(3),
dA_cumsum.stride(0), dA_cumsum.stride(2), dA_cumsum.stride(1), dA_cumsum.stride(3),
dt_softplus,
HAS_DT_BIAS=dt_bias is not None,
BLOCK_SIZE_CHUNK=triton.next_power_of_2(chunk_size),
)
return dA_cumsum, dt_out
def _chunk_cumsum_bwd(ddA, ddt_out, dt, A, dt_bias=None, dt_softplus=False, dt_limit=(0.0, float("inf")), ddt=None):
batch, seqlen, nheads = dt.shape
_, _, nchunks, chunk_size = ddA.shape
assert ddA.shape == (batch, nheads, nchunks, chunk_size)
assert ddt_out.shape == (batch, nheads, nchunks, chunk_size)
assert A.shape == (nheads,)
if dt_bias is not None:
assert dt_bias.shape == (nheads,)
ddt_bias = torch.empty_like(dt_bias, dtype=torch.float32)
else:
ddt_bias = None
if ddt is not None:
assert ddt.shape == dt.shape
else:
ddt = torch.empty_like(dt)
dA = torch.empty_like(A, dtype=torch.float32)
grid_chunk_cs = lambda META: (batch, nchunks, triton.cdiv(nheads, META['BLOCK_SIZE_H']))
with torch.cuda.device(dt.device.index):
_chunk_cumsum_bwd_kernel[grid_chunk_cs](
ddA, ddt_out, dt, A, dt_bias, ddt, dA, ddt_bias,
batch, seqlen, nheads, chunk_size,
dt_limit[0], dt_limit[1],
ddA.stride(0), ddA.stride(2), ddA.stride(1), ddA.stride(3),
ddt_out.stride(0), ddt_out.stride(2), ddt_out.stride(1), ddt_out.stride(3),
dt.stride(0), dt.stride(1), dt.stride(2),
A.stride(0),
dt_bias.stride(0) if dt_bias is not None else 0,
ddt.stride(0), ddt.stride(1), ddt.stride(2),
dA.stride(0),
ddt_bias.stride(0) if ddt_bias is not None else 0,
dt_softplus,
HAS_DT_BIAS=dt_bias is not None,
BLOCK_SIZE_CHUNK=triton.next_power_of_2(chunk_size),
)
return ddt, dA, ddt_bias
def _chunk_state_fwd(B, x, dt, dA_cumsum, seq_idx=None, states=None, states_in_fp32=True):
batch, seqlen, nheads, headdim = x.shape
_, _, nchunks, chunk_size = dt.shape
_, _, ngroups, dstate = B.shape
assert nheads % ngroups == 0
assert B.shape == (batch, seqlen, ngroups, dstate)
assert dt.shape == (batch, nheads, nchunks, chunk_size)
assert dA_cumsum.shape == dt.shape
if seq_idx is not None:
assert seq_idx.shape == (batch, seqlen)
if states is not None:
assert states.shape == (batch, nchunks, nheads, headdim, dstate)
else:
states_dtype = torch.float32 if states_in_fp32 else B.dtype
states = torch.empty((batch, nchunks, nheads, headdim, dstate), device=x.device, dtype=states_dtype)
grid = lambda META: (triton.cdiv(headdim, META['BLOCK_SIZE_M']) * triton.cdiv(dstate, META['BLOCK_SIZE_N']),
batch * nchunks, nheads)
with torch.cuda.device(x.device.index):
_chunk_state_fwd_kernel[grid](
x, B, states, dt, dA_cumsum, seq_idx,
headdim, dstate, chunk_size,
batch, seqlen, nheads // ngroups,
x.stride(0), x.stride(1), x.stride(2), x.stride(3),
B.stride(0), B.stride(1), B.stride(2), B.stride(-1),
states.stride(0), states.stride(1), states.stride(2), states.stride(3), states.stride(4),
dt.stride(0), dt.stride(2), dt.stride(1), dt.stride(3),
dA_cumsum.stride(0), dA_cumsum.stride(2), dA_cumsum.stride(1), dA_cumsum.stride(3),
*((seq_idx.stride(0), seq_idx.stride(1)) if seq_idx is not None else (0, 0)),
HAS_SEQ_IDX=seq_idx is not None,
)
return states
def _chunk_state_bwd_dx(B, x, dt, dA_cumsum, dstates, dx=None):
batch, seqlen, nheads, headdim = x.shape
_, _, nchunks, chunk_size = dt.shape
_, _, ngroups, dstate = B.shape
assert nheads % ngroups == 0
assert B.shape == (batch, seqlen, ngroups, dstate)
assert dt.shape == (batch, nheads, nchunks, chunk_size)
assert dA_cumsum.shape == dt.shape
assert dstates.shape == (batch, nchunks, nheads, headdim, dstate)
if dx is not None:
assert dx.shape == x.shape
else:
dx = torch.empty_like(x)
ddt = torch.empty(batch, nheads, nchunks, chunk_size, device=dt.device, dtype=torch.float32)
ddA_cumsum = torch.empty(batch, nheads, nchunks, chunk_size, device=dA_cumsum.device, dtype=torch.float32)
grid_dx = lambda META: (triton.cdiv(chunk_size, META['BLOCK_SIZE_M']) * triton.cdiv(headdim, META['BLOCK_SIZE_N']),
batch * nchunks, nheads)
with torch.cuda.device(x.device.index):
_chunk_state_bwd_dx_kernel[grid_dx](
x, B, dstates, dt, dA_cumsum, dx, ddt, ddA_cumsum,
chunk_size, headdim, dstate,
batch, seqlen, nheads // ngroups,
x.stride(0), x.stride(1), x.stride(2), x.stride(3),
B.stride(0), B.stride(1), B.stride(2), B.stride(-1),
dstates.stride(0), dstates.stride(1), dstates.stride(2), dstates.stride(3), dstates.stride(4),
dt.stride(0), dt.stride(2), dt.stride(1), dt.stride(3),
dA_cumsum.stride(0), dA_cumsum.stride(2), dA_cumsum.stride(1), dA_cumsum.stride(3),
dx.stride(0), dx.stride(1), dx.stride(2), dx.stride(3),
ddt.stride(0), ddt.stride(2), ddt.stride(1), ddt.stride(3),
ddA_cumsum.stride(0), ddA_cumsum.stride(2), ddA_cumsum.stride(1), ddA_cumsum.stride(3),
BLOCK_SIZE_DSTATE=max(triton.next_power_of_2(dstate), 16),
)
return dx, ddt.to(dt.dtype), ddA_cumsum.to(dA_cumsum.dtype)
def _chunk_state_bwd_db(x, dt, dA_cumsum, dstates, seq_idx=None, B=None, ngroups=1):
batch, seqlen, nheads, headdim = x.shape
_, _, nchunks, chunk_size = dt.shape
dstate = dstates.shape[-1]
assert dt.shape == (batch, nheads, nchunks, chunk_size)
assert dA_cumsum.shape == dt.shape
assert dstates.shape == (batch, nchunks, nheads, headdim, dstate)
if seq_idx is not None:
assert seq_idx.shape == (batch, seqlen)
if B is not None:
assert B.shape == (batch, seqlen, ngroups, dstate)
B_strides = (B.stride(0), B.stride(1), B.stride(2), B.stride(3))
# Use torch.empty since the Triton kernel will call init_to_zero
ddA_cumsum = torch.empty(batch, nheads, nchunks, chunk_size, device=x.device, dtype=torch.float32)
ddA_cumsum_strides = (ddA_cumsum.stride(0), ddA_cumsum.stride(2), ddA_cumsum.stride(1), ddA_cumsum.stride(3))
else:
B_strides = (0, 0, 0, 0)
ddA_cumsum = None
ddA_cumsum_strides = (0, 0, 0, 0)
nheads_ngroups_ratio = nheads // ngroups
sm_count = torch.cuda.get_device_properties(x.device).multi_processor_count
nheads_per_program = max(min(math.ceil(batch * nchunks * nheads / sm_count), nheads_ngroups_ratio), 1)
nsplits = triton.cdiv(nheads_ngroups_ratio, nheads_per_program)
dB = torch.empty(batch, seqlen, nsplits, ngroups, dstate, device=x.device, dtype=torch.float32)
grid_db = lambda META: (triton.cdiv(chunk_size, META['BLOCK_SIZE_M']) * triton.cdiv(dstate, META['BLOCK_SIZE_N']),
batch * nchunks, nsplits * ngroups)
with torch.cuda.device(x.device.index):
_chunk_state_bwd_db_kernel[grid_db](
x, dstates, B, dt, dA_cumsum, seq_idx, dB, ddA_cumsum,
chunk_size, dstate, headdim,
batch, seqlen, nheads, nheads_per_program, ngroups,
x.stride(0), x.stride(1), x.stride(2), x.stride(3),
dstates.stride(0), dstates.stride(1), dstates.stride(2), dstates.stride(3), dstates.stride(4),
*B_strides,
dt.stride(0), dt.stride(2), dt.stride(1), dt.stride(3),
dA_cumsum.stride(0), dA_cumsum.stride(2), dA_cumsum.stride(1), dA_cumsum.stride(3),
*((seq_idx.stride(0), seq_idx.stride(1)) if seq_idx is not None else (0, 0)),
dB.stride(0), dB.stride(1), dB.stride(2), dB.stride(3), dB.stride(4),
*ddA_cumsum_strides,
HAS_DDA_CS=ddA_cumsum is not None,
HAS_SEQ_IDX=seq_idx is not None,
BLOCK_SIZE_K=max(triton.next_power_of_2(headdim), 16),
)
dB = dB.sum(2)
if ddA_cumsum is not None:
# The first element of ddA_cumsum is always zero, since that dA_cumsum does not contribute
# to the state of the chunk.
# torch.cumsum(ddA_cumsum[..., 1:], dim=-1, out=ddA_cumsum[..., 1:])
# But it's easier to just do the cumsum for all elements, the result will be the same.
torch.cumsum(ddA_cumsum, dim=-1, out=ddA_cumsum)
return dB if B is None else (dB, ddA_cumsum)
def _chunk_state_bwd_ddAcs_stable(B, x, dt, dA_cumsum, dstates, seq_idx=None):
batch, seqlen, nheads, headdim = x.shape
_, _, nchunks, chunk_size = dt.shape
_, _, ngroups, dstate = B.shape
assert nheads % ngroups == 0
assert B.shape == (batch, seqlen, ngroups, dstate)
assert dt.shape == (batch, nheads, nchunks, chunk_size)
assert dA_cumsum.shape == dt.shape
assert dstates.shape == (batch, nchunks, nheads, headdim, dstate)
if seq_idx is not None:
assert seq_idx.shape == (batch, seqlen)
# Use torch.empty since the Triton kernel will call init_to_zero
ddA_cumsum = torch.empty(batch, nheads, nchunks, chunk_size, device=x.device, dtype=torch.float32)
grid_ddtcs = lambda META: (triton.cdiv(chunk_size, META['BLOCK_SIZE_M']) * triton.cdiv(headdim, META['BLOCK_SIZE_N']),
batch * nchunks, nheads)
with torch.cuda.device(x.device.index):
_chunk_state_bwd_ddAcs_stable_kernel[grid_ddtcs](
x, B, dstates, dt, dA_cumsum, seq_idx, ddA_cumsum,
chunk_size, headdim, dstate,
batch, seqlen, nheads // ngroups,
x.stride(0), x.stride(1), x.stride(2), x.stride(3),
B.stride(0), B.stride(1), B.stride(2), B.stride(-1),
dstates.stride(0), dstates.stride(1), dstates.stride(2), dstates.stride(3), dstates.stride(4),
dt.stride(0), dt.stride(2), dt.stride(1), dt.stride(3),
dA_cumsum.stride(0), dA_cumsum.stride(2), dA_cumsum.stride(1), dA_cumsum.stride(3),
*((seq_idx.stride(0), seq_idx.stride(1)) if seq_idx is not None else (0, 0)),
ddA_cumsum.stride(0), ddA_cumsum.stride(2), ddA_cumsum.stride(1), ddA_cumsum.stride(3),
HAS_SEQ_IDX=seq_idx is not None,
BLOCK_SIZE_M=max(triton.next_power_of_2(chunk_size), 16),
BLOCK_SIZE_DSTATE=max(triton.next_power_of_2(dstate), 16),
)
torch.cumsum(ddA_cumsum[..., 1:], dim=-1, out=ddA_cumsum[..., 1:])
return ddA_cumsum
def chunk_state_varlen(B, x, dt, dA_cumsum, cu_seqlens, chunk_states):
total_seqlen, nheads, headdim = x.shape
_, nchunks, chunk_size = dt.shape
_, ngroups, dstate = B.shape
batch = cu_seqlens.shape[0] - 1
cu_seqlens = cu_seqlens.contiguous()
assert nheads % ngroups == 0
assert B.shape == (total_seqlen, ngroups, dstate)
assert dt.shape == (nheads, nchunks, chunk_size)
assert dA_cumsum.shape == dt.shape
assert chunk_states.shape == (nchunks, nheads, headdim, dstate)
states = torch.empty(batch, nheads, headdim, dstate, dtype=chunk_states.dtype, device=chunk_states.device)
grid = lambda META: (triton.cdiv(headdim, META['BLOCK_SIZE_M']) * triton.cdiv(dstate, META['BLOCK_SIZE_N']),
batch, nheads)
with torch.cuda.device(x.device.index):
_chunk_state_varlen_kernel[grid](
x, B, dt, dA_cumsum, chunk_states, cu_seqlens, states,
headdim, dstate, chunk_size,
total_seqlen, nheads // ngroups,
x.stride(0), x.stride(1), x.stride(2),
B.stride(0), B.stride(1), B.stride(2),
dt.stride(1), dt.stride(0), dt.stride(2),
dA_cumsum.stride(1), dA_cumsum.stride(0), dA_cumsum.stride(2),
chunk_states.stride(0), chunk_states.stride(1), chunk_states.stride(2), chunk_states.stride(3),
states.stride(0), states.stride(1), states.stride(2), states.stride(3),
)
return states
class ChunkStateFn(torch.autograd.Function):
@staticmethod
def forward(ctx, B, x, dt, dA_cumsum, states_in_fp32=True):
batch, seqlen, nheads, headdim = x.shape
_, _, nchunks, chunk_size = dt.shape
assert seqlen <= nchunks * chunk_size
_, _, ngroups, dstate = B.shape
assert B.shape == (batch, seqlen, ngroups, dstate)
assert dt.shape == (batch, nheads, nchunks, chunk_size)
assert dA_cumsum.shape == (batch, nheads, nchunks, chunk_size)
if B.stride(-1) != 1:
B = B.contiguous()
if x.stride(-1) != 1 and x.stride(1) != 1: # Either M or K dimension should be contiguous
x = x.contiguous()
states = _chunk_state_fwd(B, x, dt, dA_cumsum, states_in_fp32=states_in_fp32)
ctx.save_for_backward(B, x, dt, dA_cumsum)
return states
@staticmethod
def backward(ctx, dstates):
B, x, dt, dA_cumsum = ctx.saved_tensors
batch, seqlen, nheads, headdim = x.shape
_, _, nchunks, chunk_size = dt.shape
_, _, ngroups, dstate = B.shape
assert dstates.shape == (batch, nchunks, nheads, headdim, dstate)
if dstates.stride(-1) != 1:
dstates = dstates.contiguous()
dx, ddt, ddA_cumsum = _chunk_state_bwd_dx(B, x, dt, dA_cumsum, dstates)
dB = _chunk_state_bwd_db(x, dt, dA_cumsum, dstates, ngroups=ngroups)
dB = dB.to(B.dtype)
return dB, dx, ddt, ddA_cumsum, None
def chunk_state(B, x, dt, dA_cumsum, states_in_fp32=True):
"""
Argument:
B: (batch, seqlen, ngroups, headdim)
x: (batch, seqlen, nheads, headdim)
dt: (batch, nheads, nchunks, chunk_size)
dA_cumsum: (batch, nheads, nchunks, chunk_size)
Return:
states: (batch, nchunks, nheads, headdim, dstate)
"""
return ChunkStateFn.apply(B, x, dt, dA_cumsum, states_in_fp32)
def chunk_state_ref(B, x, dt, dA_cumsum):
"""
Argument:
B: (batch, seqlen, ngroups, headdim)
x: (batch, seqlen, nheads, headdim)
dt: (batch, nheads, nchunks, chunk_size)
dA_cumsum: (batch, nheads, nchunks, chunk_size)
Return:
states: (batch, nchunks, nheads, headdim, dstate)
"""
# Check constraints.
batch, seqlen, nheads, headdim = x.shape
dstate = B.shape[-1]
_, _, nchunks, chunk_size = dt.shape
assert seqlen <= nchunks * chunk_size
assert x.shape == (batch, seqlen, nheads, headdim)
assert dt.shape == (batch, nheads, nchunks, chunk_size)
ngroups = B.shape[2]
assert nheads % ngroups == 0
assert B.shape == (batch, seqlen, ngroups, dstate)
B = repeat(B, "b l g d -> b l (g h) d", h=nheads // ngroups)
assert dA_cumsum.shape == (batch, nheads, nchunks, chunk_size)
if seqlen < nchunks * chunk_size:
x = F.pad(x, (0, 0, 0, 0, 0, nchunks * chunk_size - seqlen))
B = F.pad(B, (0, 0, 0, 0, 0, nchunks * chunk_size - seqlen))
x = rearrange(x, "b (c l) h p -> b c l h p", l=chunk_size)
B = rearrange(B, "b (c l) ... -> b c l ...", l=chunk_size)
decay_states = torch.exp((dA_cumsum[:, :, :, -1:] - dA_cumsum))
return torch.einsum("bclhn,bhcl,bhcl,bclhp->bchpn", B.to(x.dtype), decay_states.to(x.dtype), dt.to(x.dtype), x)
# Copyright (c) 2024, Tri Dao, Albert Gu.
"""We want triton==2.1.0 or 2.2.0 for this
"""
from typing import Optional
import math
from packaging import version
import torch
import torch.nn.functional as F
from torch import Tensor
from torch.cuda.amp import custom_bwd, custom_fwd
import triton
import triton.language as tl
from einops import rearrange, repeat
try:
from causal_conv1d import causal_conv1d_fn
import causal_conv1d_cuda
except ImportError:
causal_conv1d_fn, causal_conv1d_cuda = None, None
from mamba_ssm.ops.triton.ssd_bmm import _bmm_chunk_fwd, _bmm_chunk_bwd
from mamba_ssm.ops.triton.ssd_chunk_state import _chunk_cumsum_fwd, _chunk_cumsum_bwd
from mamba_ssm.ops.triton.ssd_chunk_state import _chunk_state_fwd, _chunk_state_bwd_db
from mamba_ssm.ops.triton.ssd_chunk_state import _chunk_state_bwd_ddAcs_stable
from mamba_ssm.ops.triton.ssd_chunk_state import chunk_state, chunk_state_ref
from mamba_ssm.ops.triton.ssd_chunk_state import chunk_state_varlen
from mamba_ssm.ops.triton.ssd_state_passing import _state_passing_fwd, _state_passing_bwd
from mamba_ssm.ops.triton.ssd_state_passing import state_passing, state_passing_ref
from mamba_ssm.ops.triton.ssd_chunk_scan import _chunk_scan_fwd, _chunk_scan_bwd_dz, _chunk_scan_bwd_dstates
from mamba_ssm.ops.triton.ssd_chunk_scan import _chunk_scan_bwd_dC, _chunk_scan_bwd_dcb
from mamba_ssm.ops.triton.ssd_chunk_scan import _chunk_scan_bwd_ddAcs_stable
from mamba_ssm.ops.triton.ssd_chunk_scan import chunk_scan, chunk_scan_ref
from mamba_ssm.ops.triton.ssd_chunk_scan import _chunk_scan_bwd_ddAcs_prev
from mamba_ssm.ops.triton.layernorm_gated import rmsnorm_fn, _layer_norm_fwd, _layer_norm_bwd
from mamba_ssm.ops.triton.k_activations import _swiglu_fwd, _swiglu_bwd
TRITON_22 = version.parse(triton.__version__) >= version.parse('2.2.0')
def init_to_zero(names):
return lambda nargs: [nargs[name].zero_() for name in names if nargs[name] is not None]
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 64}, num_stages=3, num_warps=8, pre_hook=init_to_zero(["ddt_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 256, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr"])),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr"])),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 128, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr"])),
triton.Config({'BLOCK_SIZE_M': 128, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 32, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=4, pre_hook=init_to_zero(["ddt_ptr"])),
triton.Config({'BLOCK_SIZE_M': 32, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=5, num_warps=4, pre_hook=init_to_zero(["ddt_ptr"])),
triton.Config({'BLOCK_SIZE_M': 64, 'BLOCK_SIZE_N': 64, 'BLOCK_SIZE_K': 32}, num_stages=4, num_warps=4, pre_hook=init_to_zero(["ddt_ptr"])),
],
key=['chunk_size', 'hdim', 'dstate'],
)
@triton.jit
def _chunk_scan_chunk_state_bwd_dx_kernel(
# Pointers to matrices
x_ptr, cb_ptr, dout_ptr, dt_ptr, dA_cumsum_ptr, seq_idx_ptr, D_ptr,
b_ptr, dstates_ptr,
dx_ptr, ddt_ptr, dD_ptr,
# Matrix dimensions
chunk_size, hdim, dstate,
batch, seqlen, nheads_ngroups_ratio,
# Strides
stride_x_batch, stride_x_seqlen, stride_x_head, stride_x_hdim,
stride_cb_batch, stride_cb_chunk, stride_cb_head, stride_cb_csize_m, stride_cb_csize_k,
stride_dout_batch, stride_dout_seqlen, stride_dout_head, stride_dout_hdim,
stride_dt_batch, stride_dt_chunk, stride_dt_head, stride_dt_csize,
stride_dA_cs_batch, stride_dA_cs_chunk, stride_dA_cs_head, stride_dA_cs_csize,
stride_seq_idx_batch, stride_seq_idx_seqlen,
stride_D_head,
stride_b_batch, stride_b_seqlen, stride_b_head, stride_b_dstate,
stride_dstates_batch, stride_dstates_chunk, stride_dstates_head, stride_dstates_hdim, stride_dstates_dstate,
stride_dx_batch, stride_dx_seqlen, stride_dx_head, stride_dx_hdim,
stride_ddt_batch, stride_ddt_chunk, stride_ddt_head, stride_ddt_csize,
stride_dD_batch, stride_dD_chunk, stride_dD_head, stride_dD_csize, stride_dD_hdim,
# Meta-parameters
HAS_D: tl.constexpr,
D_HAS_HDIM: tl.constexpr,
HAS_SEQ_IDX: tl.constexpr,
BLOCK_SIZE_M: tl.constexpr, BLOCK_SIZE_N: tl.constexpr, BLOCK_SIZE_K: tl.constexpr,
BLOCK_SIZE_DSTATE: tl.constexpr,
IS_TRITON_22: tl.constexpr,
):
pid_bc = tl.program_id(axis=1)
pid_c = pid_bc // batch
pid_b = pid_bc - pid_c * batch
pid_h = tl.program_id(axis=2)
num_pid_n = tl.cdiv(hdim, BLOCK_SIZE_N)
pid_m = tl.program_id(axis=0) // num_pid_n
pid_n = tl.program_id(axis=0) % num_pid_n
x_ptr += pid_b * stride_x_batch + pid_c * chunk_size * stride_x_seqlen + pid_h * stride_x_head
cb_ptr += pid_b * stride_cb_batch + pid_c * stride_cb_chunk + (pid_h // nheads_ngroups_ratio) * stride_cb_head
dout_ptr += pid_b * stride_dout_batch + pid_c * chunk_size * stride_dout_seqlen + pid_h * stride_dout_head
dt_ptr += pid_b * stride_dt_batch + pid_c * stride_dt_chunk + pid_h * stride_dt_head
ddt_ptr += pid_b * stride_ddt_batch + pid_c * stride_ddt_chunk + pid_h * stride_ddt_head
dA_cumsum_ptr += pid_b * stride_dA_cs_batch + pid_c * stride_dA_cs_chunk + pid_h * stride_dA_cs_head
b_ptr += pid_b * stride_b_batch + pid_c * chunk_size * stride_b_seqlen + (pid_h // nheads_ngroups_ratio) * stride_b_head
dstates_ptr += pid_b * stride_dstates_batch + pid_c * stride_dstates_chunk + pid_h * stride_dstates_head
if HAS_SEQ_IDX:
seq_idx_ptr += pid_b * stride_seq_idx_batch + pid_c * chunk_size * stride_seq_idx_seqlen
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
chunk_size_limit = min(chunk_size, seqlen - pid_c * chunk_size)
acc = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=tl.float32)
dA_cs_m = tl.load(dA_cumsum_ptr + offs_m * stride_dA_cs_csize, mask=offs_m < chunk_size_limit, other=0.0).to(tl.float32)
dA_cs_last = tl.load(dA_cumsum_ptr + (chunk_size - 1) * stride_dA_cs_csize).to(tl.float32)
if not HAS_SEQ_IDX:
scale = tl.exp(dA_cs_last - dA_cs_m)
else:
seq_idx_m = tl.load(seq_idx_ptr + offs_m * stride_seq_idx_seqlen, mask=offs_m < chunk_size_limit, other=-1)
seq_idx_last = tl.load(seq_idx_ptr + (chunk_size_limit - 1) * stride_seq_idx_seqlen)
scale = tl.where(seq_idx_m == seq_idx_last, tl.exp(dA_cs_last - dA_cs_m), 0.0)
# Might be faster to just do 1 iteration with larger BLOCK_SIZE_K, up to block size 128
# However, we're getting error with the Triton compiler 2.1.0 for that code path:
# Unexpected mma -> mma layout conversion
# Triton 2.2.0 fixes this
offs_dstate = tl.arange(0, BLOCK_SIZE_DSTATE if IS_TRITON_22 and BLOCK_SIZE_DSTATE <= 128 else BLOCK_SIZE_K)
b_ptrs = b_ptr + (offs_m[:, None] * stride_b_seqlen + offs_dstate[None, :] * stride_b_dstate)
dstates_ptrs = dstates_ptr + (offs_n[None, :] * stride_dstates_hdim + offs_dstate[:, None] * stride_dstates_dstate)
if IS_TRITON_22 and BLOCK_SIZE_DSTATE <= 128:
b = tl.load(b_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_dstate[None, :] < dstate), other=0.0)
dstates = tl.load(dstates_ptrs, mask=(offs_dstate[:, None] < dstate) & (offs_n[None, :] < hdim), other=0.0)
dstates = dstates.to(b_ptr.dtype.element_ty)
acc = tl.dot(b, dstates) * scale[:, None]
else:
for k in range(0, dstate, BLOCK_SIZE_K):
b = tl.load(b_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_dstate[None, :] < dstate - k), other=0.0)
dstates = tl.load(dstates_ptrs, mask=(offs_dstate[:, None] < dstate - k) & (offs_n[None, :] < hdim), other=0.0)
dstates = dstates.to(b_ptr.dtype.element_ty)
acc += tl.dot(b, dstates)
b_ptrs += BLOCK_SIZE_K * stride_b_dstate
dstates_ptrs += BLOCK_SIZE_K * stride_dstates_dstate
acc *= scale[:, None]
# x_ptrs = x_ptr + (offs_m[:, None] * stride_x_seqlen + offs_n[None, :] * stride_x_hdim)
# x = tl.load(x_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim), other=0.0).to(tl.float32)
# dt_ptrs = dt_ptr + offs_m * stride_dt_csize
# dt_m = tl.load(dt_ptrs, mask=offs_m < chunk_size_limit, other=0.0).to(tl.float32)
# ddt = tl.sum(acc * x, axis=1) * dt_m
# ddt_ptrs = ddt_ptr + offs_m * stride_ddt_csize
# tl.atomic_add(ddt_ptrs, ddt, mask=offs_m < chunk_size)
offs_k = tl.arange(0, BLOCK_SIZE_K)
cb_ptrs = cb_ptr + (offs_m[:, None] * stride_cb_csize_m + offs_k[None, :] * stride_cb_csize_k)
dout_ptrs = dout_ptr + (offs_k[:, None] * stride_dout_seqlen + offs_n[None, :] * stride_dout_hdim)
dA_cumsum_ptrs = dA_cumsum_ptr + offs_k * stride_dA_cs_csize
K_MAX = chunk_size_limit
K_MIN = pid_m * BLOCK_SIZE_M
cb_ptrs += K_MIN * stride_cb_csize_k
dout_ptrs += K_MIN * stride_dout_seqlen
dA_cumsum_ptrs += K_MIN * stride_dA_cs_csize
for k in range(K_MIN, K_MAX, BLOCK_SIZE_K):
k = tl.multiple_of(k, BLOCK_SIZE_K)
# For some reason setting mask to (offs_m[:, None] < chunk_size_limit) is much slower
cb = tl.load(cb_ptrs, mask=(offs_m[:, None] < chunk_size) & (offs_k[None, :] < K_MAX - k), other=0.0)
dout = tl.load(dout_ptrs, mask=(offs_k[:, None] < K_MAX - k) & (offs_n[None, :] < hdim), other=0.0)
dA_cs_k = tl.load(dA_cumsum_ptrs, mask=offs_k < K_MAX - k, other=0.0).to(tl.float32)
cb *= tl.exp(dA_cs_k[None, :] - dA_cs_m[:, None])
# If we don't have the (k + offs_k[None, :] < K_MAX) mask, for indices outside this range,
# we might have dA_cs_m = 0.0 and dA_cs_k very negative, and tl.exp will return inf.
# Multiplying with cb, which is 0.0 outside the range, will make the result NaN.
# This will cause NaN in acc, and hence NaN in dx and ddt.
mask = (k + offs_k[None, :] >= offs_m[:, None]) & (k + offs_k[None, :] < K_MAX)
cb = tl.where(mask, cb, 0.0)
cb = cb.to(dout_ptr.dtype.element_ty)
acc += tl.dot(cb, dout)
cb_ptrs += BLOCK_SIZE_K * stride_cb_csize_k
dout_ptrs += BLOCK_SIZE_K * stride_dout_seqlen
dA_cumsum_ptrs += BLOCK_SIZE_K * stride_dA_cs_csize
offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
dt_ptrs = dt_ptr + offs_m * stride_dt_csize
dt_m = tl.load(dt_ptrs, mask=offs_m < chunk_size_limit, other=0.0).to(tl.float32)
dx = acc * dt_m[:, None]
dx_ptr += pid_b * stride_dx_batch + pid_c * chunk_size * stride_dx_seqlen + pid_h * stride_dx_head
dx_ptrs = dx_ptr + (offs_m[:, None] * stride_dx_seqlen + offs_n[None, :] * stride_dx_hdim)
if HAS_D:
dout_res_ptrs = dout_ptr + (offs_m[:, None] * stride_dout_seqlen + offs_n[None, :] * stride_dout_hdim)
dout_res = tl.load(dout_res_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim), other=0.0).to(tl.float32)
if D_HAS_HDIM:
D = tl.load(D_ptr + pid_h * stride_D_head + offs_n, mask=offs_n < hdim, other=0.0).to(tl.float32)
else:
D = tl.load(D_ptr + pid_h * stride_D_head).to(tl.float32)
dx += dout_res * D
tl.store(dx_ptrs, dx, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim))
x_ptrs = x_ptr + (offs_m[:, None] * stride_x_seqlen + offs_n[None, :] * stride_x_hdim)
x = tl.load(x_ptrs, mask=(offs_m[:, None] < chunk_size_limit) & (offs_n[None, :] < hdim), other=0.0).to(tl.float32)
if HAS_D:
dD_ptr += pid_b * stride_dD_batch + pid_c * stride_dD_chunk + pid_h * stride_dD_head + pid_m * stride_dD_csize
if D_HAS_HDIM:
dD_ptrs = dD_ptr + offs_n * stride_dD_hdim
dD = tl.sum(dout_res * x, axis=0)
tl.store(dD_ptrs, dD, mask=offs_n < hdim)
else:
dD = tl.sum(dout_res * x)
tl.store(dD_ptr, dD)
ddt = tl.sum(acc * x, axis=1)
ddt_ptrs = ddt_ptr + offs_m * stride_ddt_csize
tl.atomic_add(ddt_ptrs, ddt, mask=offs_m < chunk_size)
def _chunk_scan_chunk_state_bwd_dx(x, dt, dA_cumsum, B, CB, dout, dstates, D=None, seq_idx=None, dx=None):
batch, seqlen, nheads, headdim = x.shape
_, _, nchunks, chunk_size = dt.shape
_, _, ngroups, dstate = B.shape
assert nheads % ngroups == 0
assert B.shape == (batch, seqlen, ngroups, dstate)
assert CB.shape == (batch, nchunks, ngroups, chunk_size, chunk_size)
assert dt.shape == (batch, nheads, nchunks, chunk_size)
assert dA_cumsum.shape == dt.shape
assert dout.shape == x.shape
assert dstates.shape == (batch, nchunks, nheads, headdim, dstate)
if seq_idx is not None:
assert seq_idx.shape == (batch, seqlen)
if D is not None:
assert D.shape == (nheads, headdim) or D.shape == (nheads,)
assert D.stride(-1) == 1
BLOCK_SIZE_min = 32
dD = torch.empty(triton.cdiv(chunk_size, BLOCK_SIZE_min), batch, nchunks, nheads,
headdim if D.dim() == 2 else 1, device=D.device, dtype=torch.float32)
else:
dD = None
dD_strides = ((dD.stride(0), dD.stride(1), dD.stride(2), dD.stride(3), dD.stride(4))
if D is not None else (0, 0, 0, 0, 0))
if dx is None:
dx = torch.empty_like(x)
else:
assert dx.shape == x.shape
ddt = torch.empty(batch, nheads, nchunks, chunk_size, device=dout.device, dtype=torch.float32)
grid_dx = lambda META: (triton.cdiv(chunk_size, META['BLOCK_SIZE_M']) * triton.cdiv(headdim, META['BLOCK_SIZE_N']),
batch * nchunks, nheads)
with torch.cuda.device(x.device.index):
_chunk_scan_chunk_state_bwd_dx_kernel[grid_dx](
x, CB, dout, dt, dA_cumsum, seq_idx, D, B, dstates, dx, ddt, dD,
chunk_size, headdim, dstate,
batch, seqlen, nheads // ngroups,
x.stride(0), x.stride(1), x.stride(2), x.stride(3),
CB.stride(0), CB.stride(1), CB.stride(2), CB.stride(-1), CB.stride(-2),
dout.stride(0), dout.stride(1), dout.stride(2), dout.stride(3),
dt.stride(0), dt.stride(2), dt.stride(1), dt.stride(3),
dA_cumsum.stride(0), dA_cumsum.stride(2), dA_cumsum.stride(1), dA_cumsum.stride(3),
*((seq_idx.stride(0), seq_idx.stride(1)) if seq_idx is not None else (0, 0)),
D.stride(0) if D is not None else 0,
B.stride(0), B.stride(1), B.stride(2), B.stride(3),
dstates.stride(0), dstates.stride(1), dstates.stride(2), dstates.stride(3), dstates.stride(4),
dx.stride(0), dx.stride(1), dx.stride(2), dx.stride(3),
ddt.stride(0), ddt.stride(2), ddt.stride(1), ddt.stride(3),
dD_strides[1], dD_strides[2], dD_strides[3], dD_strides[0], dD_strides[4],
D is not None,
D.dim() == 2 if D is not None else True,
HAS_SEQ_IDX=seq_idx is not None,
BLOCK_SIZE_DSTATE=max(triton.next_power_of_2(dstate), 16),
IS_TRITON_22=TRITON_22
)
if D is not None:
BLOCK_SIZE_actual = _chunk_scan_chunk_state_bwd_dx_kernel.best_config.kwargs["BLOCK_SIZE_M"]
n_valid_blocks = (chunk_size + BLOCK_SIZE_actual - 1) // BLOCK_SIZE_actual
dD = dD[:n_valid_blocks].sum(dim=(0, 1, 2)).to(dtype=D.dtype)
if D.dim() == 1:
dD = rearrange(dD, "h 1 -> h")
return dx, ddt.to(dtype=dt.dtype), dD
def _mamba_chunk_scan_combined_fwd(x, dt, A, B, C, chunk_size, D=None, z=None, dt_bias=None, initial_states=None, seq_idx=None, cu_seqlens=None, dt_softplus=False, dt_limit=(0.0, float("inf"))):
batch, seqlen, nheads, headdim = x.shape
_, _, ngroups, dstate = B.shape
assert nheads % ngroups == 0
assert B.shape == (batch, seqlen, ngroups, dstate)
assert x.shape == (batch, seqlen, nheads, headdim)
assert dt.shape == (batch, seqlen, nheads)
assert A.shape == (nheads,)
assert C.shape == B.shape
if z is not None:
assert z.shape == x.shape
if D is not None:
assert D.shape == (nheads, headdim) or D.shape == (nheads,)
if seq_idx is not None:
assert seq_idx.shape == (batch, seqlen)
if B.stride(-1) != 1:
B = B.contiguous()
if C.stride(-1) != 1:
C = C.contiguous()
if x.stride(-1) != 1 and x.stride(1) != 1: # Either M or K dimension should be contiguous
x = x.contiguous()
if z is not None and z.stride(-1) != 1 and z.stride(1) != 1: # Either M or K dimension should be contiguous
z = z.contiguous()
if D is not None and D.stride(-1) != 1:
D = D.contiguous()
if initial_states is not None:
assert initial_states.shape == (batch, nheads, headdim, dstate)
# # (batch, nchunks, chunk_size, chunk_size) or (batch, nchunks, nheads, chunk_size, chunk_size)
# dA_cumsum_tmp0, dt_tmp0 = _chunk_cumsum_fwd(dt[:, :147], A, chunk_size, dt_bias=dt_bias, dt_softplus=dt_softplus)
# dA_cumsum_tmp1, dt_tmp1 = _chunk_cumsum_fwd(dt[:, 147:], A, chunk_size, dt_bias=dt_bias, dt_softplus=dt_softplus)
# dA_cumsum_tmp2, dt_tmp2 = _chunk_cumsum_fwd(dt[:, 147:256], A, chunk_size, dt_bias=dt_bias, dt_softplus=dt_softplus)
dA_cumsum, dt = _chunk_cumsum_fwd(dt, A, chunk_size, dt_bias=dt_bias, dt_softplus=dt_softplus, dt_limit=dt_limit)
states = _chunk_state_fwd(B, x, dt, dA_cumsum, seq_idx=seq_idx, states_in_fp32=True)
# states_tmp0 = _chunk_state_fwd(B[:, :147], x[:, :147], dt_tmp0, dA_cumsum_tmp0, states_in_fp32=True)
# states_tmp1 = _chunk_state_fwd(B[:, 147:], x[:, 147:], dt_tmp1, dA_cumsum_tmp1, states_in_fp32=True)
# states_tmp2 = _chunk_state_fwd(B[:, 147:256], x[:, 147:256], dt_tmp2, dA_cumsum_tmp2, states_in_fp32=True)
states, final_states = _state_passing_fwd(rearrange(states, "... p n -> ... (p n)"), dA_cumsum[:, :, :, -1],
initial_states=rearrange(initial_states, "... p n -> ... (p n)") if initial_states is not None else None,
seq_idx=seq_idx, chunk_size=chunk_size, out_dtype=C.dtype)
states, final_states = [rearrange(t, "... (p n) -> ... p n", n=dstate) for t in [states, final_states]]
# states_tmp0 = rearrange(_state_passing_fwd(rearrange(states_tmp0, "... p n -> ... (p n)"), dA_cumsum_tmp0[:, :, :, -1], chunk_size=chunk_size), "... (p n) -> ... p n", n=dstate)
# states_tmp1 = rearrange(_state_passing_fwd(rearrange(states_tmp1, "... p n -> ... (p n)"), dA_cumsum_tmp1[:, :, :, -1], chunk_size=chunk_size), "... (p n) -> ... p n", n=dstate)
CB = _bmm_chunk_fwd(C, B, chunk_size, seq_idx=seq_idx, output_dtype=torch.float32)
out, out_x = _chunk_scan_fwd(CB, x, dt, dA_cumsum, C, states, D=D, z=z, seq_idx=seq_idx)
if cu_seqlens is None:
return out, out_x, dt, dA_cumsum, states, final_states
else:
assert batch == 1, "passing cu_seqlens to get the varlen states is only supported if batch dimension is 1"
varlen_states = chunk_state_varlen(B.squeeze(0), x.squeeze(0), dt.squeeze(0), dA_cumsum.squeeze(0),
cu_seqlens, states.squeeze(0))
return out, out_x, dt, dA_cumsum, states, final_states, varlen_states
def _mamba_chunk_scan_combined_bwd(dout, x, dt, A, B, C, out, chunk_size, D=None, z=None,
dt_bias=None, initial_states=None, dfinal_states=None, seq_idx=None, dt_softplus=False,
dt_limit=(0.0, float("inf")),
dx=None, ddt=None, dB=None, dC=None, dz=None, recompute_output=False):
if dout.stride(-1) != 1:
dout = dout.contiguous()
batch, seqlen, nheads, headdim = x.shape
nchunks = math.ceil(seqlen / chunk_size)
_, _, ngroups, dstate = B.shape
assert dout.shape == (batch, seqlen, nheads, headdim)
assert dt.shape == (batch, seqlen, nheads)
assert A.shape == (nheads,)
assert nheads % ngroups == 0
assert B.shape == (batch, seqlen, ngroups, dstate)
assert C.shape == B.shape
assert out.shape == x.shape
if initial_states is not None:
assert initial_states.shape == (batch, nheads, headdim, dstate)
if seq_idx is not None:
assert seq_idx.shape == (batch, seqlen)
if dx is not None:
assert dx.shape == x.shape
if dB is not None:
assert dB.shape == B.shape
dB_given = dB
else:
dB_given = torch.empty_like(B)
if dC is not None:
assert dC.shape == C.shape
dC_given = dC
else:
dC_given = torch.empty_like(C)
if dz is not None:
assert z is not None
assert dz.shape == z.shape
if ddt is not None:
assert ddt.shape == dt.shape
ddt_given = ddt
else:
ddt_given = torch.empty_like(dt)
# TD: For some reason Triton (2.1.0 and 2.2.0) errors with
# "[CUDA]: invalid device context" (e.g. during varlne test), and cloning makes it work. Idk why.
dt_in = dt.clone()
dA_cumsum, dt = _chunk_cumsum_fwd(dt_in, A, chunk_size, dt_bias=dt_bias, dt_softplus=dt_softplus,
dt_limit=dt_limit)
CB = _bmm_chunk_fwd(C, B, chunk_size, seq_idx=seq_idx, output_dtype=torch.float32)
states = _chunk_state_fwd(B, x, dt, dA_cumsum, seq_idx=seq_idx, states_in_fp32=True)
states, _ = _state_passing_fwd(rearrange(states, "... p n -> ... (p n)"), dA_cumsum[:, :, :, -1],
initial_states=rearrange(initial_states, "... p n -> ... (p n)") if initial_states is not None else None,
seq_idx=seq_idx, chunk_size=chunk_size)
states = rearrange(states, "... (p n) -> ... p n", n=dstate)
if z is not None:
dz, dout, dD, *rest = _chunk_scan_bwd_dz(x, z, out, dout, chunk_size=chunk_size, has_ddAcs=False, D=D, dz=dz, recompute_output=recompute_output)
outz = rest[0] if recompute_output else out
else:
dz = None
outz = out
dstates = _chunk_scan_bwd_dstates(C, dA_cumsum, dout, seq_idx=seq_idx, dtype=states.dtype)
# dstates has length nchunks, containing the gradient to initial states at index 0 and
# gradient to the states of chunk (nchunks - 2) at index (nchunks - 1)
# Do computation in fp32 but convert dstates and states to fp16/bf16 since dstates and states
# will be used in matmul in the next kernels.
dstates, ddA_chunk_cumsum, dinitial_states, states = _state_passing_bwd(
rearrange(states, "... p n -> ... (p n)"),
dA_cumsum[:, :, :, -1],
rearrange(dstates, "... p n -> ... (p n)"),
dfinal_states=rearrange(dfinal_states, "... p n -> ... (p n)") if dfinal_states is not None else None,
seq_idx=seq_idx,
has_initial_states=initial_states is not None,
dstates_dtype=x.dtype,
states_dtype=x.dtype,
chunk_size=chunk_size,
)
# dstates has length nchunks, containing the gradient to states of chunk 0 at index 0 and
# gradient to the final states at index (nchunks - 1)
# states has length nchunks, containing the initial states at index 0 and the state for chunk (nchunks - 2) at index (nchunks - 1)
# The final states is not stored.
states = rearrange(states, "... (p n) -> ... p n", n=dstate)
dstates = rearrange(dstates, "... (p n) -> ... p n", n=dstate)
dinitial_states = rearrange(dinitial_states, "... (p n) -> ... p n", n=dstate) if dinitial_states is not None else None
dx, ddt, dD_from_x = _chunk_scan_chunk_state_bwd_dx(x, dt, dA_cumsum, B, CB, dout, dstates, D=D, seq_idx=seq_idx, dx=dx)
# dB = _chunk_state_bwd_db(x, dt, dA_cumsum, dstates, seq_idx=seq_idx, ngroups=ngroups)
dB, ddA_next = _chunk_state_bwd_db(x, dt, dA_cumsum, dstates, seq_idx=seq_idx, B=B, ngroups=ngroups)
# dC = _chunk_scan_bwd_dC(states[:, :-1].to(x.dtype), dA_cumsum, dout, seq_idx=seq_idx, ngroups=ngroups)
dC, ddA_cumsum_prev = _chunk_scan_bwd_dC(states.to(x.dtype), dA_cumsum, dout, seq_idx=seq_idx, C=C, ngroups=ngroups)
# Computing ddA with the dcb kernel is much slower, so we're not using it for now
dCB = _chunk_scan_bwd_dcb(x, dt, dA_cumsum, dout, seq_idx=seq_idx, ngroups=ngroups)
# dCB, ddA_tmp = _chunk_scan_bwd_dcb(x, dt, dA_cumsum, dout, seq_idx=seq_idx, CB=CB, ngroups=ngroups)
dCB = dCB.to(CB.dtype)
_bmm_chunk_bwd(C, dCB, residual=dB, out=dB_given)
_bmm_chunk_bwd(B, rearrange(dCB, "... l s -> ... s l"), residual=dC, out=dC_given)
# If we have z, then dout_x is recomputed in fp32 so dD = (dout_x * x).sum() is more accurate
# than dD_from_x = (dout_x * x).sum() where dout_x is in fp16/bf16
if z is None:
dD = dD_from_x
# Formula for ddA_cumsum, assuming out is the output of the forward pass before adding x * D.
# ddA_cumsum = torch.einsum("bclhp,bclhp->bhcl", out.float(), dout.float()) - ddt * dt
# However, this is numerically unstable: when we do the reverse cumsum on ddA_cumsum, there might
# be a lot of underflow.
# This is already done as part of bwd_dC kernel
# ddA_cumsum_prev = _chunk_scan_bwd_ddAcs_prev(states[:, :-1], C, dout, dA_cumsum, seq_idx=seq_idx)
ddA_cumsum_prev[..., -1] += ddA_chunk_cumsum
ddA_prev = ddA_cumsum_prev.flip([-1]).cumsum(dim=-1).flip([-1])
# This is already done as part of bwd_dB kernel
# ddA_next = _chunk_state_bwd_ddAcs_stable(B, x, dt, dA_cumsum, dstates, seq_idx=seq_idx)
# We don't need to pass in seq_idx because CB also zeros out entries where seq_idx[i] != seq_idx[j]
ddA = _chunk_scan_bwd_ddAcs_stable(x, dt, dA_cumsum, dout, CB)
ddA += ddA_next + ddA_prev
ddt_given, dA, ddt_bias = _chunk_cumsum_bwd(ddA, ddt, dt_in, A, dt_bias=dt_bias, dt_softplus=dt_softplus, dt_limit=dt_limit, ddt=ddt_given)
# These 2 lines are just to test ddt and dA being computed by old code
# _, dA = selective_scan_bwd(dout, x, dt, A, B, C, D=D.float(), z=z)
# ddt_given.copy_(ddt)
return_vals = (dx, ddt_given, dA, dB_given, dC_given, dD, dz, ddt_bias, dinitial_states)
return return_vals if not recompute_output else (*return_vals, outz)
def selective_scan_bwd(dout, x, dt, A, B, C, D=None, z=None):
"""
Argument:
dout: (batch, seqlen, nheads, headdim)
x: (batch, seqlen, nheads, headdim)
dt: (batch, nheads, nchunks, chunk_size) or (batch, nheads, headdim, nchunks, chunk_size)
A: (nheads) or (dim, dstate)
B: (batch, seqlen, ngroups, dstate)
C: (batch, seqlen, ngroups, dstate)
D: (nheads, headdim) or (nheads,)
z: (batch, seqlen, nheads, headdim)
Return:
out: (batch, seqlen, nheads, headdim)
"""
import selective_scan
batch, seqlen, nheads, headdim = x.shape
chunk_size = dt.shape[-1]
_, _, ngroups, dstate = B.shape
assert nheads % ngroups == 0
x = rearrange(x, "b l h p -> b (h p) l")
squeeze_dt = dt.dim() == 4
if dt.dim() == 4:
dt = repeat(dt, "b h c l -> b h p c l", p=headdim)
dt = rearrange(dt, "b h p c l -> b (h p) (c l)", p=headdim)
squeeze_A = A.dim() == 1
if A.dim() == 1:
A = repeat(A, "h -> (h p) n", p=headdim, n=dstate).to(dtype=torch.float32)
else:
A = A.to(dtype=torch.float32)
B = rearrange(B, "b l g n -> b g n l")
C = rearrange(C, "b l g n -> b g n l")
if D is not None:
if D.dim() == 2:
D = rearrange(D, "h p -> (h p)")
else:
D = repeat(D, "h -> (h p)", p=headdim)
if z is not None:
z = rearrange(z, "b l h p -> b (h p) l")
if x.stride(-1) != 1:
x = x.contiguous()
if dt.stride(-1) != 1:
dt = dt.contiguous()
if D is not None:
D = D.contiguous()
if B.stride(-1) != 1:
B = B.contiguous()
if C.stride(-1) != 1:
C = C.contiguous()
if z is not None and z.stride(-1) != 1:
z = z.contiguous()
_, intermediate, *rest = selective_scan.fwd(x, dt.to(dtype=x.dtype), A, B, C, D, z, None, False)
if z is not None:
out = rest[0]
else:
out = None
dout = rearrange(dout, "b l h p -> b (h p) l")
if dout.stride(-1) != 1:
dout = dout.contiguous()
# The kernel supports passing in a pre-allocated dz (e.g., in case we want to fuse the
# backward of selective_scan with the backward of chunk).
# Here we just pass in None and dz will be allocated in the C++ code.
_, ddt, dA, *rest = selective_scan.bwd(
x, dt.to(dtype=x.dtype), A, B, C, D, z, None, dout, intermediate, out, None, False,
False # option to recompute out_z, not used here
)
ddt = rearrange(ddt, "b (h p) (c l) -> b h p c l", p=headdim, l=chunk_size)
if squeeze_dt:
ddt = ddt.float().sum(dim=2)
if squeeze_A:
dA = rearrange(dA, "(h p) n -> h p n", p=headdim).sum(dim=(1, 2))
return ddt, dA
class MambaChunkScanCombinedFn(torch.autograd.Function):
@staticmethod
def forward(ctx, x, dt, A, B, C, chunk_size, D=None, z=None, dt_bias=None, initial_states=None, seq_idx=None, cu_seqlens=None, dt_softplus=False, dt_limit=(0.0, float("inf")), return_final_states=False, return_varlen_states=False):
ctx.dt_dtype = dt.dtype
if not return_varlen_states:
cu_seqlens = None
else:
assert cu_seqlens is not None, "cu_seqlens must be provided if return_varlen_states is True"
out, out_x, dt_out, dA_cumsum, states, final_states, *rest = _mamba_chunk_scan_combined_fwd(x, dt, A, B, C, chunk_size, D=D, z=z, dt_bias=dt_bias, initial_states=initial_states, seq_idx=seq_idx, cu_seqlens=cu_seqlens, dt_softplus=dt_softplus, dt_limit=dt_limit)
ctx.save_for_backward(out if z is None else out_x, x, dt, dA_cumsum, A, B, C, D, z, dt_bias, initial_states, seq_idx)
ctx.dt_softplus = dt_softplus
ctx.chunk_size = chunk_size
ctx.dt_limit = dt_limit
ctx.return_final_states = return_final_states
ctx.return_varlen_states = return_varlen_states
if not return_varlen_states:
return out if not return_final_states else (out, final_states)
else:
varlen_states = rest[0]
return (out, varlen_states) if not return_final_states else (out, final_states, varlen_states)
@staticmethod
def backward(ctx, dout, *args):
out, x, dt, dA_cumsum, A, B, C, D, z, dt_bias, initial_states, seq_idx = ctx.saved_tensors
assert not ctx.return_varlen_states, "return_varlen_states is not supported in backward"
dfinal_states = args[0] if ctx.return_final_states else None
dx, ddt, dA, dB, dC, dD, dz, ddt_bias, dinitial_states = _mamba_chunk_scan_combined_bwd(dout, x, dt, A, B, C, out, ctx.chunk_size, D=D, z=z, dt_bias=dt_bias, initial_states=initial_states, dfinal_states=dfinal_states, seq_idx=seq_idx, dt_softplus=ctx.dt_softplus, dt_limit=ctx.dt_limit)
return dx, ddt, dA, dB, dC, None, dD, dz, ddt_bias, dinitial_states, None, None, None, None, None, None
def mamba_chunk_scan_combined(x, dt, A, B, C, chunk_size, D=None, z=None, dt_bias=None, initial_states=None, seq_idx=None, cu_seqlens=None, dt_softplus=False, dt_limit=(0.0, float("inf")), return_final_states=False, return_varlen_states=False):
"""
Argument:
x: (batch, seqlen, nheads, headdim)
dt: (batch, seqlen, nheads)
A: (nheads)
B: (batch, seqlen, ngroups, dstate)
C: (batch, seqlen, ngroups, dstate)
chunk_size: int
D: (nheads, headdim) or (nheads,)
z: (batch, seqlen, nheads, headdim)
dt_bias: (nheads,)
initial_states: (batch, nheads, headdim, dstate)
seq_idx: (batch, seqlen)
cu_seqlens: (num_sequences + 1) or None, only used if return_varlen_states is True
dt_softplus: Whether to apply softplus to dt
Return:
out: (batch, seqlen, nheads, headdim)
"""
return MambaChunkScanCombinedFn.apply(x, dt, A, B, C, chunk_size, D, z, dt_bias, initial_states, seq_idx, cu_seqlens, dt_softplus, dt_limit, return_final_states, return_varlen_states)
def mamba_chunk_scan(x, dt, A, B, C, chunk_size, D=None, z=None, dt_bias=None, dt_softplus=False):
"""
Argument:
x: (batch, seqlen, nheads, headdim)
dt: (batch, seqlen, nheads)
A: (nheads)
B: (batch, seqlen, ngroups, dstate)
C: (batch, seqlen, ngroups, dstate)
D: (nheads, headdim) or (nheads,)
z: (batch, seqlen, nheads, headdim)
dt_bias: (nheads,)
Return:
out: (batch, seqlen, nheads, headdim)
"""
batch, seqlen, nheads, headdim = x.shape
dstate = B.shape[-1]
if seqlen % chunk_size != 0:
dt = F.pad(dt, (0, 0, 0, chunk_size - seqlen % chunk_size))
dt = rearrange(dt, "b (c l) h -> b h c l", l=chunk_size)
dt = dt.float() # We want high precision for this before cumsum
if dt_bias is not None:
dt = dt + rearrange(dt_bias, "h -> h 1 1")
if dt_softplus:
dt = F.softplus(dt)
dA = dt * rearrange(A, "h -> h 1 1")
dA = dt * rearrange(A, "h -> h 1 1")
dA_cumsum = torch.cumsum(dA, dim=-1)
# 1. Compute the state for each chunk
states = chunk_state(B, x, dt, dA_cumsum, states_in_fp32=True)
# 2. Pass the state to all the chunks by weighted cumsum.
states = rearrange(state_passing(rearrange(states, "... p n -> ... (p n)"), dA_cumsum[:, :, :, -1])[0],
"... (p n) -> ... p n", n=dstate)
# 3. Compute the output for each chunk
out = chunk_scan(B, C, x, dt, dA_cumsum, states, D=D, z=z)
return out
def ssd_chunk_scan_combined_ref(x, dt, A, B, C, chunk_size, D=None, z=None, dt_bias=None, dt_softplus=False):
"""
Argument:
x: (batch, seqlen, nheads, headdim)
dt: (batch, seqlen, nheads)
A: (nheads)
B: (batch, seqlen, ngroups, dstate)
C: (batch, seqlen, ngroups, dstate)
D: (nheads, headdim) or (nheads,)
z: (batch, seqlen, nheads, headdim)
dt_bias: (nheads,)
Return:
out: (batch, seqlen, nheads, headdim)
"""
batch, seqlen, nheads, headdim = x.shape
dstate = B.shape[-1]
if seqlen % chunk_size != 0:
dt = F.pad(dt, (0, 0, 0, chunk_size - seqlen % chunk_size))
dt = rearrange(dt, "b (c l) h -> b h c l", l=chunk_size)
dt = dt.float() # We want high precision for this before cumsum
if dt_bias is not None:
dt = dt + rearrange(dt_bias, "h -> h 1 1")
if dt_softplus:
dt = F.softplus(dt)
dA = dt * rearrange(A, "h -> h 1 1")
dA_cumsum = torch.cumsum(dA, dim=-1)
# 1. Compute the state for each chunk
states = chunk_state_ref(B, x, dt, dA_cumsum)
states_dtype = states.dtype
if states.dtype not in [torch.float32, torch.float64]:
states = states.to(torch.float32)
# 2. Pass the state to all the chunks by weighted cumsum.
# state_passing_ref is much less numerically stable
states = rearrange(state_passing_ref(rearrange(states, "... p n -> ... (p n)"), dA_cumsum[:, :, :, -1])[0],
"... (p n) -> ... p n", n=dstate)
states = states.to(states_dtype)
# 3. Compute the output for each chunk
out = chunk_scan_ref(B, C, x, dt, dA_cumsum, states, D=D, z=z)
return out
def ssd_selective_scan(x, dt, A, B, C, D=None, z=None, dt_bias=None, dt_softplus=False, dt_limit=(0.0, float("inf"))):
"""
Argument:
x: (batch, seqlen, nheads, headdim)
dt: (batch, seqlen, nheads) or (batch, seqlen, nheads, headdim)
A: (nheads) or (dim, dstate)
B: (batch, seqlen, ngroups, dstate)
C: (batch, seqlen, ngroups, dstate)
D: (nheads, headdim) or (nheads,)
z: (batch, seqlen, nheads, headdim)
dt_bias: (nheads,) or (nheads, headdim)
Return:
out: (batch, seqlen, nheads, headdim)
"""
from mamba_ssm.ops.selective_scan_interface import selective_scan_fn
batch, seqlen, nheads, headdim = x.shape
_, _, ngroups, dstate = B.shape
x = rearrange(x, "b l h p -> b (h p) l")
if dt.dim() == 3:
dt = repeat(dt, "b l h -> b l h p", p=headdim)
dt = rearrange(dt, "b l h p -> b (h p) l")
if A.dim() == 1:
A = repeat(A, "h -> (h p) n", p=headdim, n=dstate).to(dtype=torch.float32)
else:
A = A.to(dtype=torch.float32)
B = rearrange(B, "b l g n -> b g n l")
C = rearrange(C, "b l g n -> b g n l")
if D is not None:
if D.dim() == 2:
D = rearrange(D, "h p -> (h p)")
else:
D = repeat(D, "h -> (h p)", p=headdim)
if z is not None:
z = rearrange(z, "b l h p -> b (h p) l")
if dt_bias is not None:
if dt_bias.dim() == 1:
dt_bias = repeat(dt_bias, "h -> h p", p=headdim)
dt_bias = rearrange(dt_bias, "h p -> (h p)")
if dt_limit != (0.0, float("inf")):
if dt_bias is not None:
dt = dt + rearrange(dt_bias, "d -> d 1")
if dt_softplus:
dt = F.softplus(dt)
dt = dt.clamp(min=dt_limit[0], max=dt_limit[1]).to(x.dtype)
dt_bias = None
dt_softplus = None
out = selective_scan_fn(x, dt, A, B, C, D=D, z=z, delta_bias=dt_bias, delta_softplus=dt_softplus)
return rearrange(out, "b (h p) l -> b l h p", p=headdim)
def mamba_conv1d_scan_ref(xBC, conv1d_weight, conv1d_bias, dt, A, chunk_size, D=None, z=None,
dt_bias=None, dt_softplus=False, dt_limit=(0.0, float("inf")),
activation="silu", headdim=None, ngroups=1):
"""
Argument:
xBC: (batch, seqlen, dim + 2 * ngroups * dstate) where dim == nheads * headdim
conv1d_weight: (dim + 2 * ngroups * dstate, width)
conv1d_bias: (dim + 2 * ngroups * dstate,)
dt: (batch, seqlen, nheads) or (batch, seqlen, nheads, headdim)
A: (nheads)
D: (nheads, headdim) or (nheads,)
z: (batch, seqlen, dim)
dt_bias: (nheads) or (nheads, headdim)
headdim: if D is 1D and z is None, headdim must be passed in
Return:
out: (batch, seqlen, dim)
"""
batch, seqlen, nheads = dt.shape[:3]
assert nheads % ngroups == 0
if z is not None:
dim = z.shape[-1]
assert dim % nheads == 0
headdim = dim // nheads
else:
if D.dim() == 1:
assert headdim is not None
else:
headdim = D.shape[1]
dim = nheads * headdim
xBC = rearrange(causal_conv1d_fn(rearrange(xBC, "b s d -> b d s"), conv1d_weight, conv1d_bias, activation=activation),
"b d s -> b s d")
dstate = (xBC.shape[-1] - dim) // ngroups // 2
x, B, C = torch.split(xBC, [dim, ngroups * dstate, ngroups * dstate], dim=-1)
x = rearrange(x, "b l (h p) -> b l h p", h=nheads)
B = rearrange(B, "b l (g n) -> b l g n", g=ngroups)
C = rearrange(C, "b l (g n) -> b l g n", g=ngroups)
z = rearrange(z, "b l (h p) -> b l h p", h=nheads) if z is not None else None
out = ssd_selective_scan(x, dt.to(x.dtype), A, B, C, D=D.float(), z=z, dt_bias=dt_bias, dt_softplus=dt_softplus, dt_limit=dt_limit)
return rearrange(out, "b s h p -> b s (h p)")
class MambaSplitConv1dScanCombinedFn(torch.autograd.Function):
@staticmethod
@custom_fwd
def forward(ctx, zxbcdt, conv1d_weight, conv1d_bias, dt_bias, A, D, chunk_size, initial_states=None, seq_idx=None, dt_limit=(0.0, float("inf")), return_final_states=False, activation="silu",
rmsnorm_weight=None, rmsnorm_eps=1e-6, outproj_weight=None, outproj_bias=None, headdim=None,
ngroups=1, norm_before_gate=True):
assert activation in [None, "silu", "swish"]
if D.dim() == 1:
assert headdim is not None
nheads, = D.shape
else:
nheads, headdim = D.shape
batch, seqlen, _ = zxbcdt.shape
dim = nheads * headdim
assert nheads % ngroups == 0
dstate = (conv1d_weight.shape[0] - dim) // ngroups // 2
d_nonssm = (zxbcdt.shape[-1] - 2 * dim - 2 * ngroups * dstate - nheads) // 2
assert d_nonssm >= 0
assert zxbcdt.shape == (batch, seqlen, 2 * d_nonssm + 2 * dim + 2 * ngroups * dstate + nheads)
assert dt_bias.shape == (nheads,)
assert A.shape == (nheads,)
zx0, z, xBC, dt = torch.split(zxbcdt, [2 * d_nonssm, dim, dim + ngroups * dstate * 2, nheads], dim=-1)
seq_idx = seq_idx.contiguous() if seq_idx is not None else None
xBC_conv = rearrange(
causal_conv1d_cuda.causal_conv1d_fwd(rearrange(xBC, "b s d -> b d s"),
conv1d_weight, conv1d_bias, seq_idx, None, None, activation in ["silu", "swish"]),
"b d s -> b s d"
)
x, B, C = torch.split(xBC_conv, [dim, ngroups * dstate, ngroups * dstate], dim=-1)
x = rearrange(x, "b l (h p) -> b l h p", h=nheads)
B = rearrange(B, "b l (g n) -> b l g n", g=ngroups)
C = rearrange(C, "b l (g n) -> b l g n", g=ngroups)
z = rearrange(z, "b l (h p) -> b l h p", h=nheads) if z is not None else None
if rmsnorm_weight is None:
out, out_x, dt_out, dA_cumsum, states, final_states = _mamba_chunk_scan_combined_fwd(x, dt, A, B, C, chunk_size=chunk_size, D=D, z=z, dt_bias=dt_bias, initial_states=initial_states, seq_idx=seq_idx, dt_softplus=True, dt_limit=dt_limit)
out = rearrange(out, "b s h p -> b s (h p)")
rstd = None
if d_nonssm > 0:
out = torch.cat([_swiglu_fwd(zx0), out], dim=-1)
else:
out_x, _, dt_out, dA_cumsum, states, final_states = _mamba_chunk_scan_combined_fwd(x, dt, A, B, C, chunk_size=chunk_size, D=D, z=None, dt_bias=dt_bias, initial_states=initial_states, seq_idx=seq_idx, dt_softplus=True, dt_limit=dt_limit)
# reshape input data into 2D tensor
x_rms = rearrange(out_x, "b s h p -> (b s) (h p)")
z_rms = rearrange(z, "b s h p -> (b s) (h p)")
rmsnorm_weight = rmsnorm_weight.contiguous()
if d_nonssm == 0:
out = None
else:
out01 = torch.empty((batch, seqlen, d_nonssm + dim), dtype=x_rms.dtype, device=x_rms.device)
out = rearrange(out01[..., d_nonssm:], "b s d -> (b s) d")
_swiglu_fwd(zx0, out=out01[..., :d_nonssm])
out, _, rstd = _layer_norm_fwd(x_rms, rmsnorm_weight, None, rmsnorm_eps, z_rms, out=out,
group_size=dim // ngroups,
norm_before_gate=norm_before_gate, is_rms_norm=True)
if d_nonssm == 0:
out = rearrange(out, "(b s) d -> b s d", b=batch)
else:
out = out01
ctx.outproj_weight_dtype = outproj_weight.dtype if outproj_weight is not None else None
if outproj_weight is not None:
if torch.is_autocast_enabled():
dtype = torch.get_autocast_gpu_dtype()
out, outproj_weight = out.to(dtype), outproj_weight.to(dtype)
outproj_bias = outproj_bias.to(dtype) if outproj_bias is not None else None
out = F.linear(out, outproj_weight, outproj_bias)
else:
assert outproj_bias is None
ctx.save_for_backward(zxbcdt, conv1d_weight, conv1d_bias,
out_x, A, D, dt_bias, initial_states, seq_idx, rmsnorm_weight, rstd, outproj_weight, outproj_bias)
ctx.dt_limit = dt_limit
ctx.return_final_states = return_final_states
ctx.activation = activation
ctx.rmsnorm_eps = rmsnorm_eps
ctx.norm_before_gate = norm_before_gate
ctx.chunk_size = chunk_size
ctx.headdim = headdim
ctx.ngroups = ngroups
return out if not return_final_states else (out, final_states)
@staticmethod
@custom_bwd
def backward(ctx, dout, *args):
zxbcdt, conv1d_weight, conv1d_bias, out, A, D, dt_bias, initial_states, seq_idx, rmsnorm_weight, rstd, outproj_weight, outproj_bias = ctx.saved_tensors
dfinal_states = args[0] if ctx.return_final_states else None
headdim = ctx.headdim
nheads = D.shape[0]
dim = nheads * headdim
assert nheads % ctx.ngroups == 0
dstate = (conv1d_weight.shape[0] - dim) // ctx.ngroups // 2
d_nonssm = (zxbcdt.shape[-1] - 2 * dim - 2 * ctx.ngroups * dstate - nheads) // 2
assert d_nonssm >= 0
recompute_output = outproj_weight is not None
if recompute_output:
out_recompute = torch.empty(*out.shape[:2], d_nonssm + dim, device=out.device, dtype=out.dtype)
out0_recompute, out1_recompute = out_recompute.split([d_nonssm, dim], dim=-1)
zx0, z, xBC, dt = torch.split(zxbcdt, [2 * d_nonssm, dim, dim + 2 * ctx.ngroups * dstate, nheads], dim=-1)
# Recompute x, B, C
xBC_conv = rearrange(
causal_conv1d_cuda.causal_conv1d_fwd(rearrange(xBC, "b s d -> b d s"),
conv1d_weight, conv1d_bias, seq_idx, None, None, ctx.activation in ["silu", "swish"]),
"b d s -> b s d"
)
x, B, C = torch.split(xBC_conv, [dim, ctx.ngroups * dstate, ctx.ngroups * dstate], dim=-1)
x = rearrange(x, "b l (h p) -> b l h p", h=nheads)
B = rearrange(B, "b l (g n) -> b l g n", g=ctx.ngroups)
C = rearrange(C, "b l (g n) -> b l g n", g=ctx.ngroups)
dzxbcdt = torch.empty_like(zxbcdt)
dzx0, dz, dxBC_given, ddt_given = torch.split(dzxbcdt, [2 * d_nonssm, dim, dim + 2 * ctx.ngroups * dstate, nheads], dim=-1)
dxBC = torch.empty_like(xBC)
dx, dB, dC = torch.split(dxBC, [dim, ctx.ngroups * dstate, ctx.ngroups * dstate], dim=-1)
z = rearrange(z, "b l (h p) -> b l h p", h=nheads)
dx = rearrange(dx, "b l (h p) -> b l h p", h=nheads)
dB = rearrange(dB, "b l (g n) -> b l g n", g=ctx.ngroups)
dC = rearrange(dC, "b l (g n) -> b l g n", g=ctx.ngroups)
if outproj_weight is not None:
dout_og = dout
dout = F.linear(dout, outproj_weight.t())
if d_nonssm > 0:
dout0, dout = dout.split([d_nonssm, dim], dim=-1)
_swiglu_bwd(zx0, dout0, dxy=dzx0, recompute_output=True, out=out0_recompute)
dout = rearrange(dout, "b s (h p) -> b s h p", p=headdim)
if rmsnorm_weight is None:
dz = rearrange(dz, "b l (h p) -> b l h p", h=nheads)
dx, ddt, dA, dB, dC, dD, dz, ddt_bias, dinitial_states, *rest = _mamba_chunk_scan_combined_bwd(
dout, x, dt, A, B, C, out, ctx.chunk_size, D=D, z=z, dt_bias=dt_bias, initial_states=initial_states, dfinal_states=dfinal_states, seq_idx=seq_idx, dt_softplus=True, dt_limit=ctx.dt_limit, dx=dx, ddt=ddt_given, dB=dB, dC=dC, dz=dz, recompute_output=recompute_output
)
out_for_linear = rearrange(rest[0], "b s h p -> b s (h p)") if recompute_output else None
drmsnorm_weight = None
else:
batch = dout.shape[0]
dy_rms = rearrange(dout, "b s h p -> (b s) (h p)")
dz = rearrange(dz, "b l d -> (b l) d")
x_rms = rearrange(out, "b s h p -> (b s) (h p)")
z_rms = rearrange(z, "b s h p -> (b s) (h p)")
out1_recompute = rearrange(out1_recompute, "b s d -> (b s) d") if recompute_output else None
dout, drmsnorm_weight, _, dz, *rest = _layer_norm_bwd(dy_rms, x_rms, rmsnorm_weight, None, ctx.rmsnorm_eps, None, rstd, z_rms, norm_before_gate=ctx.norm_before_gate, is_rms_norm=True, recompute_output=recompute_output, dz=dz, out=out1_recompute if recompute_output else None)
out_for_linear = out_recompute if recompute_output else None
dout = rearrange(dout, "(b s) (h p) -> b s h p", b=batch, p=headdim)
dx, ddt, dA, dB, dC, dD, _, ddt_bias, dinitial_states = _mamba_chunk_scan_combined_bwd(
dout, x, dt, A, B, C, out, ctx.chunk_size, D=D, z=None, dt_bias=dt_bias, initial_states=initial_states, dfinal_states=dfinal_states, seq_idx=seq_idx, dt_softplus=True, dt_limit=ctx.dt_limit, dx=dx, ddt=ddt_given, dB=dB, dC=dC
)
if outproj_weight is not None:
doutproj_weight = torch.einsum("bso,bsd->od", dout_og, out_for_linear)
doutproj_bias = dout_og.sum(dim=(0, 1)) if outproj_bias is not None else None
else:
doutproj_weight, doutproj_bias = None, None
dxBC_given = rearrange(dxBC_given, "b s d -> b d s")
dxBC_given, dweight, dbias, *_ = causal_conv1d_cuda.causal_conv1d_bwd(
rearrange(xBC, "b s d -> b d s"), conv1d_weight, conv1d_bias,
rearrange(dxBC, "b s d -> b d s"), seq_idx, None, None, dxBC_given, False, ctx.activation in ["silu", "swish"]
)
dxBC_given = rearrange(dxBC_given, "b d s -> b s d")
return dzxbcdt, dweight, dbias, ddt_bias, dA, dD, None, dinitial_states, None, None, None, None, drmsnorm_weight, None, doutproj_weight, doutproj_bias, None, None, None
def mamba_split_conv1d_scan_combined(zxbcdt, conv1d_weight, conv1d_bias, dt_bias, A, D, chunk_size, initial_states=None, seq_idx=None, dt_limit=(0.0, float("inf")), return_final_states=False, activation="silu", rmsnorm_weight=None, rmsnorm_eps=1e-6, outproj_weight=None, outproj_bias=None, headdim=None, ngroups=1, norm_before_gate=True):
"""
Argument:
zxbcdt: (batch, seqlen, 2 * dim + 2 * ngroups * dstate + nheads) where dim == nheads * headdim
conv1d_weight: (dim + 2 * ngroups * dstate, width)
conv1d_bias: (dim + 2 * ngroups * dstate,)
dt_bias: (nheads,)
A: (nheads)
D: (nheads, headdim) or (nheads,)
initial_states: (batch, nheads, headdim, dstate)
seq_idx: (batch, seqlen), int32
rmsnorm_weight: (dim,)
outproj_weight: (out_dim, dim)
outproj_bias: (out_dim,)
headdim: if D is 1D, headdim must be passed in
norm_before_gate: if True, we do RMSNorm(x) * F.silu(z). If False, we do RMSNorm(x * F.silu(z))
Return:
out: (batch, seqlen, dim)
"""
return MambaSplitConv1dScanCombinedFn.apply(zxbcdt, conv1d_weight, conv1d_bias, dt_bias, A, D, chunk_size, initial_states, seq_idx, dt_limit, return_final_states, activation, rmsnorm_weight, rmsnorm_eps, outproj_weight, outproj_bias, headdim, ngroups, norm_before_gate)
def mamba_split_conv1d_scan_ref(zxbcdt, conv1d_weight, conv1d_bias, dt_bias, A, D, chunk_size, dt_limit=(0.0, float("inf")), activation="silu", rmsnorm_weight=None, rmsnorm_eps=1e-6, outproj_weight=None, outproj_bias=None, headdim=None, ngroups=1, norm_before_gate=True):
"""
Argument:
zxbcdt: (batch, seqlen, 2 * dim + 2 * ngroups * dstate + nheads) where dim == nheads * headdim
conv1d_weight: (dim + 2 * ngroups * dstate, width)
conv1d_bias: (dim + 2 * ngroups * dstate,)
dt_bias: (nheads,)
A: (nheads)
D: (nheads, headdim) or (nheads,)
rmsnorm_weight: (dim,)
outproj_weight: (out_dim, dim)
outproj_bias: (out_dim,)
headdim: if D is 1D, headdim must be passed in
norm_before_gate: if True, we do RMSNorm(x) * F.silu(z). If False, we do RMSNorm(x * F.silu(z))
Return:
out: (batch, seqlen, dim)
"""
if D.dim() == 1:
assert headdim is not None
nheads, = D.shape
else:
nheads, headdim = D.shape
assert nheads % ngroups == 0
batch, seqlen, _ = zxbcdt.shape
dim = nheads * headdim
dstate = (zxbcdt.shape[-1] - 2 * dim - nheads) // ngroups // 2
assert zxbcdt.shape == (batch, seqlen, 2 * dim + 2 * ngroups * dstate + nheads)
assert dt_bias.shape == (nheads,)
assert A.shape == (nheads,)
if rmsnorm_weight is not None:
assert rmsnorm_weight.shape == (dim,)
z, xBC, dt = torch.split(zxbcdt, [dim, dim + 2 * ngroups * dstate, nheads], dim=-1)
xBC = rearrange(causal_conv1d_fn(rearrange(xBC, "b s d -> b d s"), conv1d_weight, conv1d_bias, activation=activation),
"b d s -> b s d")
x, B, C = torch.split(xBC, [dim, ngroups * dstate, ngroups * dstate], dim=-1)
x = rearrange(x, "b l (h p) -> b l h p", h=nheads)
B = rearrange(B, "b l (g n) -> b l g n", g=ngroups)
C = rearrange(C, "b l (g n) -> b l g n", g=ngroups)
z = rearrange(z, "b l (h p) -> b l h p", h=nheads)
out = ssd_selective_scan(x, dt.to(x.dtype), A, B, C, D=D.float(),
z=z if rmsnorm_weight is None else None, dt_bias=dt_bias, dt_softplus=True, dt_limit=dt_limit)
out = rearrange(out, "b s h p -> b s (h p)")
if rmsnorm_weight is not None:
out = rmsnorm_fn(out, rmsnorm_weight, None, z=rearrange(z, "b l h p -> b l (h p)"), eps=rmsnorm_eps,
norm_before_gate=norm_before_gate)
if outproj_weight is not None:
out = F.linear(out, outproj_weight, outproj_bias)
return out
# Copyright (c) 2024, Tri Dao, Albert Gu.
"""We want triton==2.1.0 or 2.2.0 for this
"""
import math
import torch
import torch.nn.functional as F
import triton
import triton.language as tl
from einops import rearrange, repeat
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE': 64}),
triton.Config({'BLOCK_SIZE': 128}),
triton.Config({'BLOCK_SIZE': 256}),
triton.Config({'BLOCK_SIZE': 512}),
triton.Config({'BLOCK_SIZE': 1024}),
triton.Config({'BLOCK_SIZE': 2048}),
],
key=['dim'],
)
@triton.jit
def _state_passing_fwd_kernel(
# Pointers to matrices
states_ptr, out_ptr, final_states_ptr, dA_cs_ptr, initstates_ptr, seq_idx_ptr,
# Matrix dimensions
dim, nchunks, seqlen, chunk_size,
# Strides
stride_states_batch, stride_states_chunk, stride_states_head, stride_states_dim,
stride_out_batch, stride_out_chunk, stride_out_head, stride_out_dim,
stride_final_states_batch, stride_final_states_head, stride_final_states_dim,
stride_dA_cs_batch, stride_dA_cs_chunk, stride_dA_cs_head,
stride_initstates_batch, stride_initstates_head, stride_initstates_dim,
stride_seq_idx_batch, stride_seq_idx_seqlen,
# Meta-parameters
HAS_INITSTATES: tl.constexpr,
HAS_SEQ_IDX: tl.constexpr,
BLOCK_SIZE: tl.constexpr,
):
pid_b = tl.program_id(axis=1)
pid_h = tl.program_id(axis=2)
pid_m = tl.program_id(axis=0)
states_ptr += pid_b * stride_states_batch + pid_h * stride_states_head
dA_cs_ptr += pid_b * stride_dA_cs_batch + pid_h * stride_dA_cs_head
out_ptr += pid_b * stride_out_batch + pid_h * stride_out_head
final_states_ptr += pid_b * stride_final_states_batch + pid_h * stride_final_states_head
if HAS_INITSTATES:
initstates_ptr += pid_b * stride_initstates_batch + pid_h * stride_initstates_head
if HAS_SEQ_IDX:
seq_idx_ptr += pid_b * stride_seq_idx_batch
offs_m = pid_m * BLOCK_SIZE + tl.arange(0, BLOCK_SIZE)
states_ptrs = states_ptr + offs_m * stride_states_dim
out_ptrs = out_ptr + offs_m * stride_out_dim
final_states_ptrs = final_states_ptr + offs_m * stride_final_states_dim
if not HAS_INITSTATES:
states = tl.zeros((BLOCK_SIZE, ), dtype=tl.float32)
else:
initstates_ptrs = initstates_ptr + offs_m * stride_initstates_dim
states = tl.load(initstates_ptrs, mask=offs_m < dim, other=0.0).to(tl.float32)
tl.store(out_ptrs, states, mask=offs_m < dim)
out_ptrs += stride_out_chunk
seq_idx = 0
for c in range(nchunks):
new_states = tl.load(states_ptrs, mask=offs_m < dim, other=0.0).to(tl.float32)
dA_cs = tl.load(dA_cs_ptr).to(tl.float32)
scale = tl.exp(dA_cs)
if HAS_SEQ_IDX:
seq_idx_new = tl.load(seq_idx_ptr + (min((c + 1) * chunk_size, seqlen) - 1) * stride_seq_idx_seqlen)
scale = tl.where(seq_idx_new == seq_idx, scale, 0.0)
seq_idx = seq_idx_new
states = scale * states + new_states
if c < nchunks - 1:
tl.store(out_ptrs, states, mask=offs_m < dim)
else:
tl.store(final_states_ptrs, states, mask=offs_m < dim)
states_ptrs += stride_states_chunk
dA_cs_ptr += stride_dA_cs_chunk
out_ptrs += stride_out_chunk
@triton.autotune(
configs=[
triton.Config({'BLOCK_SIZE': 64}),
triton.Config({'BLOCK_SIZE': 128}),
triton.Config({'BLOCK_SIZE': 256}),
triton.Config({'BLOCK_SIZE': 512}),
triton.Config({'BLOCK_SIZE': 1024}),
triton.Config({'BLOCK_SIZE': 2048}),
],
key=['dim'],
)
@triton.jit
def _state_passing_bwd_kernel(
# Pointers to matrices
dout_ptr, out_ptr, dA_cs_ptr, dfinal_states_ptr, seq_idx_ptr,
dstates_ptr, ddA_cs_ptr, dinitstates_ptr, states_converted_ptr,
# Matrix dimensions
dim, nchunks, seqlen, chunk_size,
# Strides
stride_dout_batch, stride_dout_chunk, stride_dout_head, stride_dout_dim,
stride_out_batch, stride_out_chunk, stride_out_head, stride_out_dim,
stride_dA_cs_batch, stride_dA_cs_chunk, stride_dA_cs_head,
stride_dfinal_states_batch, stride_dfinal_states_head, stride_dfinal_states_dim,
stride_seq_idx_batch, stride_seq_idx_seqlen,
stride_dstates_batch, stride_dstates_chunk, stride_dstates_head, stride_dstates_dim,
stride_ddA_cs_batch, stride_ddA_cs_chunk, stride_ddA_cs_head,
stride_dinitstates_batch, stride_dinitstates_head, stride_dinitstates_dim,
# Meta-parameters
CONVERT_STATES: tl.constexpr,
HAS_DFINAL_STATES: tl.constexpr,
HAS_DINITSTATES: tl.constexpr,
HAS_SEQ_IDX: tl.constexpr,
BLOCK_SIZE: tl.constexpr,
):
pid_b = tl.program_id(axis=1)
pid_h = tl.program_id(axis=2)
pid_m = tl.program_id(axis=0)
dstates_ptr += pid_b * stride_dstates_batch + pid_h * stride_dstates_head + (nchunks - 1) * stride_dstates_chunk
dA_cs_ptr += pid_b * stride_dA_cs_batch + pid_h * stride_dA_cs_head + (nchunks - 1) * stride_dA_cs_chunk
ddA_cs_ptr += pid_b * stride_ddA_cs_batch + pid_h * stride_ddA_cs_head + (nchunks - 1) * stride_ddA_cs_chunk + pid_m
out_ptr += pid_b * stride_out_batch + pid_h * stride_out_head + (nchunks - 1) * stride_out_chunk
dout_ptr += pid_b * stride_dout_batch + pid_h * stride_dout_head + (nchunks - 1) * stride_dout_chunk
if CONVERT_STATES:
states_converted_ptr += pid_b * stride_out_batch + pid_h * stride_out_head + (nchunks - 1) * stride_out_chunk
if HAS_DFINAL_STATES:
dfinal_states_ptr += pid_b * stride_dfinal_states_batch + pid_h * stride_dfinal_states_head
if HAS_DINITSTATES:
dinitstates_ptr += pid_b * stride_dinitstates_batch + pid_h * stride_dinitstates_head
if HAS_SEQ_IDX:
seq_idx_ptr += pid_b * stride_seq_idx_batch
offs_m = pid_m * BLOCK_SIZE + tl.arange(0, BLOCK_SIZE)
dstates_ptrs = dstates_ptr + offs_m * stride_dstates_dim
out_ptrs = out_ptr + offs_m * stride_out_dim
dout_ptrs = dout_ptr + offs_m * stride_dout_dim
if CONVERT_STATES:
states_converted_ptrs = states_converted_ptr + offs_m * stride_out_dim
if HAS_DFINAL_STATES:
dstates = tl.load(dfinal_states_ptr + offs_m * stride_dfinal_states_dim, mask=offs_m < dim, other=0.0).to(tl.float32)
else:
dstates = tl.zeros((BLOCK_SIZE, ), dtype=tl.float32)
tl.store(dstates_ptrs, dstates, mask=offs_m < dim)
if HAS_SEQ_IDX:
seq_idx = tl.load(seq_idx_ptr + (seqlen - 1) * stride_seq_idx_seqlen)
dstates_ptrs -= stride_dstates_chunk
for c in range(nchunks - 1):
dA_cs = tl.load(dA_cs_ptr).to(tl.float32)
scale = tl.exp(dA_cs)
if HAS_SEQ_IDX:
seq_idx_new = tl.load(seq_idx_ptr + (((nchunks - c - 1) * chunk_size - 1) * stride_seq_idx_seqlen))
scale = tl.where(seq_idx_new == seq_idx, scale, 0.0)
seq_idx = seq_idx_new
out = tl.load(out_ptrs, mask=offs_m < dim, other=0.0).to(tl.float32)
if CONVERT_STATES:
tl.store(states_converted_ptrs, out, mask=offs_m < dim)
ddA = tl.sum(out * dstates) * scale
tl.store(ddA_cs_ptr, ddA)
dout = tl.load(dout_ptrs, mask=offs_m < dim, other=0.0).to(tl.float32)
dstates = scale * dstates + dout
tl.store(dstates_ptrs, dstates, mask=offs_m < dim)
dout_ptrs -= stride_dout_chunk
dstates_ptrs -= stride_dstates_chunk
dA_cs_ptr -= stride_dA_cs_chunk
ddA_cs_ptr -= stride_ddA_cs_chunk
out_ptrs -= stride_out_chunk
if CONVERT_STATES:
states_converted_ptrs -= stride_out_chunk
if CONVERT_STATES:
out = tl.load(out_ptrs, mask=offs_m < dim, other=0.0).to(tl.float32)
tl.store(states_converted_ptrs, out, mask=offs_m < dim)
if not HAS_DINITSTATES:
tl.store(ddA_cs_ptr, 0.0)
else:
dA_cs = tl.load(dA_cs_ptr).to(tl.float32)
scale = tl.exp(dA_cs)
if HAS_SEQ_IDX:
scale = tl.where(seq_idx == 0, scale, 0.0)
out = tl.load(out_ptrs, mask=offs_m < dim, other=0.0).to(tl.float32)
ddA = tl.sum(out * dstates) * scale
tl.store(ddA_cs_ptr, ddA)
dout = tl.load(dout_ptrs, mask=offs_m < dim, other=0.0).to(tl.float32)
dstates = scale * dstates + dout
tl.store(dinitstates_ptr + offs_m * stride_dinitstates_dim, dstates, mask=offs_m < dim)
def _state_passing_fwd(states, dA_chunk_cumsum, initial_states=None, seq_idx=None, chunk_size=None,
out_dtype=None):
batch, nchunks, nheads, dim = states.shape
assert dA_chunk_cumsum.shape == (batch, nheads, nchunks)
if initial_states is not None:
assert initial_states.shape == (batch, nheads, dim)
if seq_idx is not None:
assert chunk_size is not None
seqlen = seq_idx.shape[-1]
assert seq_idx.shape == (batch, seqlen)
out_dtype = states.dtype if out_dtype is None else out_dtype
out = torch.empty((batch, nchunks, nheads, dim), device=states.device, dtype=out_dtype)
final_states = torch.empty((batch, nheads, dim), device=states.device, dtype=torch.float32)
grid = lambda META: (triton.cdiv(dim, META['BLOCK_SIZE']), batch, nheads)
with torch.cuda.device(states.device.index):
_state_passing_fwd_kernel[grid](
states, out, final_states, dA_chunk_cumsum, initial_states, seq_idx,
dim, nchunks, seqlen if seq_idx is not None else 0, chunk_size if seq_idx is not None else 0,
states.stride(0), states.stride(1), states.stride(2), states.stride(3),
out.stride(0), out.stride(1), out.stride(2), out.stride(3),
final_states.stride(0), final_states.stride(1), final_states.stride(2),
dA_chunk_cumsum.stride(0), dA_chunk_cumsum.stride(2), dA_chunk_cumsum.stride(1),
*((initial_states.stride(0), initial_states.stride(1), initial_states.stride(2))
if initial_states is not None else (0, 0, 0)),
*((seq_idx.stride(0), seq_idx.stride(1)) if seq_idx is not None else (0, 0)),
HAS_INITSTATES=initial_states is not None,
HAS_SEQ_IDX=seq_idx is not None,
)
return out, final_states
def _state_passing_bwd(
states, dA_chunk_cumsum, dout, dfinal_states=None, seq_idx=None, has_initial_states=None,
dstates_dtype=None, states_dtype=None, chunk_size=None
):
"""
states contains the initial_states at index 0. The final states are not included in states.
"""
batch, nchunks, nheads, dim = states.shape
assert dA_chunk_cumsum.shape == (batch, nheads, nchunks)
assert dout.shape == (batch, nchunks, nheads, dim)
if seq_idx is not None:
assert chunk_size is not None
seqlen = seq_idx.shape[-1]
assert seq_idx.shape == (batch, seqlen)
dstates = torch.empty_like(dout, dtype=dstates_dtype if dstates_dtype is not None else dout.dtype)
if states_dtype is not None and states_dtype != states.dtype:
states_converted = torch.empty_like(states, dtype=dstates_dtype if dstates_dtype is not None else dout.dtype)
assert states_converted.stride() == states.stride()
else:
states_converted = None
if has_initial_states:
dinitstates = torch.empty_like(dstates[:, 0])
else:
dinitstates = None
if dfinal_states is not None:
assert dfinal_states.shape == (batch, nheads, dim)
BLOCK_SIZE_min = 64
n_blocks = (dim + BLOCK_SIZE_min - 1) // BLOCK_SIZE_min
ddA_chunk_cumsum = torch.empty(batch, nheads, nchunks, n_blocks,
dtype=torch.float32, device=dA_chunk_cumsum.device)
grid = lambda META: (triton.cdiv(dim, META['BLOCK_SIZE']), batch, nheads)
with torch.cuda.device(dout.device.index):
_state_passing_bwd_kernel[grid](
dout, states, dA_chunk_cumsum, dfinal_states, seq_idx,
dstates, ddA_chunk_cumsum, dinitstates, states_converted,
dim, nchunks, seqlen if seq_idx is not None else 0, chunk_size if seq_idx is not None else 0,
dout.stride(0), dout.stride(1), dout.stride(2), dout.stride(3),
states.stride(0), states.stride(1), states.stride(2), states.stride(3),
dA_chunk_cumsum.stride(0), dA_chunk_cumsum.stride(2), dA_chunk_cumsum.stride(1),
*((dfinal_states.stride(0), dfinal_states.stride(1), dfinal_states.stride(2))
if dfinal_states is not None else (0, 0, 0)),
*((seq_idx.stride(0), seq_idx.stride(1)) if seq_idx is not None else (0, 0)),
dstates.stride(0), dstates.stride(1), dstates.stride(2), dstates.stride(3),
ddA_chunk_cumsum.stride(0), ddA_chunk_cumsum.stride(2), ddA_chunk_cumsum.stride(1),
*((dinitstates.stride(0), dinitstates.stride(1), dinitstates.stride(2))
if dinitstates is not None else (0, 0, 0)),
CONVERT_STATES=states_converted is not None,
HAS_DFINAL_STATES=dfinal_states is not None,
HAS_DINITSTATES=dinitstates is not None,
HAS_SEQ_IDX=seq_idx is not None,
)
BLOCK_SIZE_actual = _state_passing_bwd_kernel.best_config.kwargs["BLOCK_SIZE"]
n_valid_blocks = (dim + BLOCK_SIZE_actual - 1) // BLOCK_SIZE_actual
ddA_chunk_cumsum = ddA_chunk_cumsum[..., :n_valid_blocks].sum(dim=-1).to(dtype=dA_chunk_cumsum.dtype)
if states_dtype is not None and states_dtype == states.dtype:
states_converted = states
return (dstates, ddA_chunk_cumsum, dinitstates) if states_dtype is None else (dstates, ddA_chunk_cumsum, dinitstates, states_converted)
class StatePassingFn(torch.autograd.Function):
@staticmethod
def forward(ctx, states, dA_chunk_cumsum, initial_states=None):
batch, nchunks, nheads, dim = states.shape
assert dA_chunk_cumsum.shape == (batch, nheads, nchunks)
if states.stride(-1) != 1:
states = states.contiguous()
out, final_states = _state_passing_fwd(states, dA_chunk_cumsum, initial_states)
ctx.save_for_backward(out, dA_chunk_cumsum)
ctx.has_initial_states = initial_states is not None
return out, final_states
@staticmethod
def backward(ctx, dout, dfinal_states):
out, dA_chunk_cumsum = ctx.saved_tensors
batch, nchunks, nheads, dim = out.shape
assert dout.shape == (batch, nchunks, nheads, dim)
assert dA_chunk_cumsum.shape == (batch, nheads, nchunks)
assert dfinal_states.shape == (batch, nheads, dim)
if dout.stride(-1) != 1:
dout = dout.contiguous()
dstates, ddA_chunk_cumsum, dinitstates = _state_passing_bwd(
out, dA_chunk_cumsum, dout, dfinal_states=dfinal_states , has_initial_states=ctx.has_initial_states
)
return dstates, ddA_chunk_cumsum, dinitstates
def state_passing(states, dA_chunk_cumsum, initial_states=None):
"""
Argument:
states: (batch, nchunks, nheads, dim)
dA_chunk_cumsum: (batch, nheads, nchunks)
initial_states: (batch, nheads, dim)
Return:
out: (batch, nchunks, nheads, dim)
final_states: (batch, nheads, dim)
"""
return StatePassingFn.apply(states, dA_chunk_cumsum, initial_states)
def state_passing_ref(states, dA_chunk_cumsum, initial_states=None):
"""
Argument:
states: (batch, nchunks, nheads, dim)
dA_chunk_cumsum: (batch, nheads, nchunks)
initial_states: (batch, nheads, dim)
Return:
out: (batch, nchunks, nheads, dim)
final_states: (batch, nheads, dim)
"""
if initial_states is None:
initial_states = torch.zeros_like(states[:, 0])
states = torch.cat([rearrange(initial_states, "b h d -> b 1 h d"), states], dim=1)
dA_chunk_cumsum = F.pad(dA_chunk_cumsum, (1, 0))
dA_chunk_cumsum = torch.cumsum(dA_chunk_cumsum, dim=-1)
nchunks = dA_chunk_cumsum.shape[-1]
# (batch, nheads, nchunks, nchunks)
dt_chunk_segment_sum = dA_chunk_cumsum[:, :, :, None] - dA_chunk_cumsum[:, :, None, :]
# (batch, nheads, nchunks, nchunks)
decay_chunk = torch.exp(dt_chunk_segment_sum)
causal_mask = torch.tril(torch.ones(nchunks, nchunks, device=states.device, dtype=bool), diagonal=0)
decay_chunk = decay_chunk.masked_fill(~causal_mask, 0)
out = torch.einsum("bhzc,bchd->bzhd", decay_chunk.to(dtype=states.dtype), states)
return out[:, :-1], out[:, -1]
# Copyright (c) 2023, Albert Gu, Tri Dao.
import gc
import time
from collections import namedtuple
from dataclasses import dataclass, field
from functools import partial
from typing import Callable, Optional, Sequence, Union
import torch
import torch.nn.functional as F
from einops import rearrange, repeat
from torch import Tensor
from torch.profiler import ProfilerActivity, profile, record_function
from transformers.generation import GreedySearchDecoderOnlyOutput, SampleDecoderOnlyOutput, TextStreamer
@dataclass
class InferenceParams:
"""Inference parameters that are passed to the main model in order
to efficienly calculate and store the context during inference."""
max_seqlen: int
max_batch_size: int
seqlen_offset: int = 0
batch_size_offset: int = 0
key_value_memory_dict: dict = field(default_factory=dict)
lengths_per_sample: Optional[Tensor] = None
def reset(self, max_seqlen, max_batch_size):
self.max_seqlen = max_seqlen
self.max_batch_size = max_batch_size
self.seqlen_offset = 0
if self.lengths_per_sample is not None:
self.lengths_per_sample.zero_()
def modify_logits_for_min_p_filtering(logits, min_p):
"""Set the logits for none min_p values to -inf. Done in-place."""
if min_p <= 0.0 or min_p >= 1.0:
return
indices_to_remove = logits < min_p
logits.masked_fill_(indices_to_remove, float("-Inf"))
# https://github.com/NVIDIA/Megatron-LM/blob/0bb597b42c53355a567aba2a1357cc34b9d99ddd/megatron/text_generation/sampling.py
# https://github.com/huggingface/transformers/blob/a44985b41cfa2de48a5e1de7f1f93b7483da25d1/src/transformers/generation/logits_process.py#L231
def modify_logits_for_top_k_filtering(logits, top_k):
"""Set the logits for none top-k values to -inf. Done in-place."""
indices_to_remove = logits < torch.topk(logits, top_k)[0][..., -1, None]
logits.masked_fill_(indices_to_remove, float("-Inf"))
# https://github.com/NVIDIA/Megatron-LM/blob/0bb597b42c53355a567aba2a1357cc34b9d99ddd/megatron/text_generation/sampling.py
# https://github.com/huggingface/transformers/blob/a44985b41cfa2de48a5e1de7f1f93b7483da25d1/src/transformers/generation/logits_process.py#L170
def modify_logits_for_top_p_filtering(logits, top_p):
"""Set the logits for none top-p values to -inf. Done in-place."""
if top_p <= 0.0 or top_p >= 1.0:
return
# First sort and calculate cumulative sum of probabilities.
sorted_logits, sorted_indices = torch.sort(logits, descending=False)
cumulative_probs = sorted_logits.softmax(dim=-1).cumsum(dim=-1)
# Remove tokens with cumulative top_p above the threshold (token with 0 are kept)
sorted_indices_to_remove = cumulative_probs <= (1 - top_p)
# scatter sorted tensors to original indexing
indices_to_remove = sorted_indices_to_remove.scatter(
1, sorted_indices, sorted_indices_to_remove
)
logits.masked_fill_(indices_to_remove, float("-inf"))
def modify_logit_for_repetition_penalty(logits, prev_output_tokens, repetition_penalty=1.0):
"""Apply repetition penalty. See https://arxiv.org/abs/1909.05858
logits: (batch_size, vocab_size)
prev_output_tokens: (batch_size, seq_len)
"""
if repetition_penalty == 1.0:
return logits
score = torch.gather(logits, 1, prev_output_tokens)
# if score < 0 then repetition penalty has to be multiplied to reduce the previous token probability
score = torch.where(score < 0, score * repetition_penalty, score / repetition_penalty)
logits.scatter_(1, prev_output_tokens, score)
return logits
def sample(logits, top_k=1, top_p=0.0, min_p=0.0, temperature=1.0):
"""Sample from top-k logits.
Arguments:
logits: Tensor of shape (batch_size, vocab_size)
"""
if top_k == 1: # Short-circuit for greedy decoding
return logits.argmax(dim=-1)
else:
if top_p > 0.0:
assert top_p <= 1.0, "top-p should be in (0, 1]."
if top_k > 0:
top_k = min(top_k, logits.size(-1)) # Safety check
logits_top, indices = torch.topk(logits, top_k, dim=-1)
if temperature != 1.0:
logits_top /= temperature
modify_logits_for_top_p_filtering(logits_top, top_p)
return indices[
torch.arange(indices.shape[0], device=indices.device),
torch.multinomial(torch.softmax(logits_top, dim=-1), num_samples=1).squeeze(dim=-1),
]
else:
if min_p > 0.0:
logits_top = logits.clone()
max_prob = logits_top[..., 0].item()
min_prob = max_prob * min_p
modify_logits_for_min_p_filtering(logits_top, min_prob)
if temperature != 1.0:
logits_top /= temperature
return torch.multinomial(torch.softmax(logits_top, dim=-1), num_samples=1).squeeze(dim=-1)
# Clone so that when we modify for top_p we don't change the original logits
logits_top = logits / temperature if temperature != 1.0 else logits.clone()
modify_logits_for_top_p_filtering(logits_top, top_p)
return torch.multinomial(torch.softmax(logits_top, dim=-1), num_samples=1).squeeze(
dim=-1
)
@torch.inference_mode()
def decode(
input_ids,
model,
max_length,
top_k=1,
top_p=0.0,
min_p=0.0,
temperature=1.0,
repetition_penalty=1.0,
eos_token_id=None,
teacher_outputs=None,
vocab_size=None,
cg=False,
enable_timing=False,
streamer: Optional[TextStreamer] = None
):
"""Decoding, either greedy or with top-k or top-p sampling.
If top-k = 0, don't limit the number of candidates (pure sampling).
Top-k and top-p can be used together. If top_k > 0 and top_p > 0, then top-k is applied first,
then top-p.
We assume that all sequences in the same batch have the same length.
Arguments:
input_ids: (batch, seq_len)
max_length: int
teacher_outputs (optional): (batch, seq_len). If provided, instead of sampling from the
logits, the next token is taken from the teacher_outputs. Useful for testing.
Returns: GreedySearchDecoderOnlyOutput or SampleDecoderOnlyOutput, with the following fields:
sequences: (batch, max_length)
scores: tuples of (batch, vocab_size)
"""
if streamer is not None:
streamer.put(input_ids.cpu())
batch_size, seqlen_og = input_ids.shape
teacher_output_len = teacher_outputs.shape[1] if teacher_outputs is not None else 0
if cg:
if not hasattr(model, "_decoding_cache"):
model._decoding_cache = None
model._decoding_cache = update_graph_cache(
model,
model._decoding_cache,
batch_size,
seqlen_og,
max_length,
)
inference_params = model._decoding_cache.inference_params
inference_params.reset(max_length, batch_size)
else:
inference_params = InferenceParams(max_seqlen=max_length, max_batch_size=batch_size)
def get_logits(input_ids, inference_params):
decoding = inference_params.seqlen_offset > 0
if decoding:
position_ids = torch.full(
(batch_size, 1),
inference_params.seqlen_offset,
dtype=torch.long,
device=input_ids.device,
)
else:
position_ids = None
if not cg or not decoding:
logits = model(
input_ids,
position_ids=position_ids,
inference_params=inference_params,
num_last_tokens=1,
).logits.squeeze(dim=1)
else:
logits = model._decoding_cache.run(
input_ids, position_ids, inference_params.seqlen_offset
).squeeze(dim=1)
return logits[..., :vocab_size] if vocab_size is not None else logits
def sample_tokens(logits, inference_params):
if teacher_outputs is None or teacher_output_len <= inference_params.seqlen_offset:
token = sample(logits, top_k=top_k, top_p=top_p, min_p=min_p, temperature=temperature)
else:
token = teacher_outputs[:, inference_params.seqlen_offset]
# return rearrange(token, "b -> b 1")
return token.unsqueeze(1)
def should_stop(current_token, inference_params):
if inference_params.seqlen_offset == 0:
return False
if eos_token_id is not None and (current_token == eos_token_id).all():
return True
if inference_params.seqlen_offset >= max_length - 1:
return True
return False
start = torch.cuda.Event(enable_timing=enable_timing)
end = torch.cuda.Event(enable_timing=enable_timing)
if enable_timing:
start.record()
scores, sequences = [], [input_ids]
sequences_cat = input_ids
while not should_stop(sequences[-1], inference_params):
scores.append(get_logits(sequences[-1], inference_params))
inference_params.seqlen_offset += sequences[-1].shape[1]
if repetition_penalty == 1.0:
sampled_tokens = sample_tokens(scores[-1], inference_params)
else:
logits = modify_logit_for_repetition_penalty(
scores[-1].clone(), sequences_cat, repetition_penalty
)
sampled_tokens = sample_tokens(logits, inference_params)
sequences_cat = torch.cat([sequences_cat, sampled_tokens], dim=1)
sequences.append(sampled_tokens)
if streamer is not None:
streamer.put(sampled_tokens.cpu())
if streamer is not None:
streamer.end()
if enable_timing:
end.record()
torch.cuda.synchronize()
print(f"Prompt processing + decoding time: {(start.elapsed_time(end)):.0f}ms")
output_cls = GreedySearchDecoderOnlyOutput if top_k == 1 else SampleDecoderOnlyOutput
return output_cls(sequences=torch.cat(sequences, dim=1), scores=tuple(scores))
class GenerationMixin:
def allocate_inference_cache(self, batch_size, max_seqlen, dtype=None, **kwargs):
raise NotImplementedError
def generate(
self,
input_ids,
max_length,
top_k=1,
top_p=0.0,
min_p=0.0,
temperature=1.0,
return_dict_in_generate=False,
output_scores=False,
**kwargs,
):
output = decode(
input_ids, self, max_length, top_k=top_k, top_p=top_p, min_p = min_p, temperature=temperature, **kwargs
)
if not output_scores:
output.scores = None
return output if return_dict_in_generate else output.sequences
@dataclass
class DecodingCGCache:
max_batch_size: int = 0
max_seqlen: int = 0
device = None
dtype = None
callables: dict = field(default_factory=dict)
mempool = None
inference_params: Optional[InferenceParams] = None
run: Optional[Callable] = None
@torch.inference_mode()
def update_graph_cache(
model,
cache,
batch_size,
seqlen_og,
max_seqlen,
decoding_seqlens=(1,),
dtype=None,
n_warmups=2,
):
if cache is None:
cache = DecodingCGCache()
param_example = next(iter(model.parameters()))
device = param_example.device
if dtype is None:
dtype = param_example.dtype
if (
(device, dtype) != (cache.device, cache.dtype)
or batch_size > cache.max_batch_size
or max_seqlen > cache.max_seqlen
): # Invalidate the cache
cache.callables = {}
cache.mempool = None
cache.inference_params = None
gc.collect()
cache.device, cache.dtype = device, dtype
cache.max_batch_size, cache.max_seqlen = batch_size, max_seqlen
assert hasattr(model, "allocate_inference_cache"), "CUDA graph decoding requires that the model has a method allocate_inference_cache"
inf_cache = model.allocate_inference_cache(batch_size, max_seqlen, dtype)
lengths_per_sample = torch.full((batch_size,), seqlen_og, dtype=torch.int32, device=device)
cache.inference_params = InferenceParams(
max_seqlen=max_seqlen,
max_batch_size=batch_size,
seqlen_offset=seqlen_og,
key_value_memory_dict=inf_cache,
lengths_per_sample=lengths_per_sample,
)
cache.mempool = torch.cuda.graphs.graph_pool_handle()
for decoding_seqlen in decoding_seqlens:
if (batch_size, decoding_seqlen) not in cache.callables:
cache.callables[batch_size, decoding_seqlen] = capture_graph(
model,
cache.inference_params,
batch_size,
max_seqlen,
decoding_seqlen=decoding_seqlen,
mempool=cache.mempool,
n_warmups=n_warmups,
)
def dispatch(input_ids, position_ids, seqlen):
batch_size, decoding_seqlen = input_ids.shape[:2]
return cache.callables[batch_size, decoding_seqlen](input_ids, position_ids, seqlen)
cache.run = dispatch
cache.inference_params.seqlen_offset = 0 # Reset so it's not confusing
return cache
def capture_graph(
model, inference_params, batch_size, max_seqlen, decoding_seqlen=1, mempool=None, n_warmups=2
):
device = next(iter(model.parameters())).device
input_ids = torch.full((batch_size, decoding_seqlen), 0, dtype=torch.long, device=device)
position_ids = torch.full((batch_size, decoding_seqlen), 0, dtype=torch.long, device=device)
seqlen_offset_og = inference_params.seqlen_offset
inference_params.seqlen_offset = max_seqlen - decoding_seqlen
inference_params.lengths_per_sample[:] = inference_params.seqlen_offset
# Warmup before capture
s = torch.cuda.Stream()
s.wait_stream(torch.cuda.current_stream())
with torch.cuda.stream(s):
for _ in range(n_warmups):
logits = model(
input_ids,
position_ids=position_ids,
inference_params=inference_params,
num_last_tokens=decoding_seqlen,
).logits
s.synchronize()
# This might be needed for correctness if we run with NCCL_GRAPH_MIXING_SUPPORT=0,
# which requires that graph launch and non-captured launch to not overlap (I think,
# that's how I interpret the documentation). I'm not sure if this is required.
if torch.distributed.is_initialized():
torch.distributed.barrier()
torch.cuda.current_stream().wait_stream(s)
# Captures the graph
# To allow capture, automatically sets a side stream as the current stream in the context
graph = torch.cuda.CUDAGraph()
with torch.cuda.graph(graph, pool=mempool):
logits = model(
input_ids,
position_ids=position_ids,
inference_params=inference_params,
num_last_tokens=decoding_seqlen,
).logits
def run(new_input_ids, new_position_ids, seqlen):
inference_params.lengths_per_sample[:] = seqlen
input_ids.copy_(new_input_ids)
position_ids.copy_(new_position_ids)
graph.replay()
return logits.clone()
inference_params.seqlen_offset = seqlen_offset_og
return run
import json
import torch
from transformers.utils import WEIGHTS_NAME, CONFIG_NAME
from transformers.utils.hub import cached_file
def load_config_hf(model_name):
resolved_archive_file = cached_file(model_name, CONFIG_NAME, _raise_exceptions_for_missing_entries=False)
return json.load(open(resolved_archive_file))
def load_state_dict_hf(model_name, device=None, dtype=None):
# If not fp32, then we don't want to load directly to the GPU
mapped_device = "cpu" if dtype not in [torch.float32, None] else device
resolved_archive_file = cached_file(model_name, WEIGHTS_NAME, _raise_exceptions_for_missing_entries=False)
return torch.load(resolved_archive_file, map_location=mapped_device)
# Convert dtype before moving to GPU to save memory
if dtype is not None:
state_dict = {k: v.to(dtype=dtype) for k, v in state_dict.items()}
state_dict = {k: v.to(device=device) for k, v in state_dict.items()}
return state_dict
[project]
name = "mamba_ssm"
description = "Mamba state-space model"
readme = "README.md"
authors = [
{ name = "Tri Dao", email = "tri@tridao.me" },
{ name = "Albert Gu", email = "agu@cs.cmu.edu" }
]
requires-python = ">= 3.7"
dynamic = ["version"]
license = { file = "LICENSE" } # Include a LICENSE file in your repo
keywords = ["cuda", "pytorch", "state-space model"]
classifiers = [
"Programming Language :: Python :: 3",
"License :: OSI Approved :: BSD License",
"Operating System :: Unix"
]
dependencies = [
"torch",
"ninja",
"einops",
"triton",
"transformers",
"packaging",
"setuptools>=61.0.0",
]
urls = { name = "Repository", url = "https://github.com/state-spaces/mamba"}
[project.optional-dependencies]
causal-conv1d = [
"causal-conv1d>=1.2.0"
]
dev = [
"pytest"
]
[build-system]
requires = [
"setuptools>=61.0.0",
"wheel",
"torch",
"packaging",
"ninja",
]
build-backend = "setuptools.build_meta"
--- /opt/rocm/include/hip/amd_detail/amd_hip_bf16.h 2023-12-12 20:11:48.000000000 +0000
+++ rocm_update_files/amd_hip_bf16.h 2024-05-20 17:40:26.983349079 +0000
@@ -137,7 +137,7 @@
* \ingroup HIP_INTRINSIC_BFLOAT16_CONV
* \brief Converts float to bfloat16
*/
-__HOST_DEVICE__ __hip_bfloat16 __float2bfloat16(float f) {
+__HOST_DEVICE__ static inline __hip_bfloat16 __float2bfloat16(float f) {
__hip_bfloat16 ret;
union {
float fp32;
@@ -181,7 +181,7 @@
* \ingroup HIP_INTRINSIC_BFLOAT162_CONV
* \brief Converts and moves bfloat162 to float2
*/
-__HOST_DEVICE__ float2 __bfloat1622float2(const __hip_bfloat162 a) {
+__HOST_DEVICE__ static inline float2 __bfloat1622float2(const __hip_bfloat162 a) {
return float2{__bfloat162float(a.x), __bfloat162float(a.y)};
}
@@ -209,7 +209,7 @@
* \ingroup HIP_INTRINSIC_BFLOAT162_CONV
* \brief Convert double to __hip_bfloat16
*/
-__HOST_DEVICE__ __hip_bfloat16 __double2bfloat16(const double a) {
+__HOST_DEVICE__ static inline __hip_bfloat16 __double2bfloat16(const double a) {
return __float2bfloat16((float)a);
}
@@ -217,7 +217,7 @@
* \ingroup HIP_INTRINSIC_BFLOAT162_CONV
* \brief Convert float2 to __hip_bfloat162
*/
-__HOST_DEVICE__ __hip_bfloat162 __float22bfloat162_rn(const float2 a) {
+__HOST_DEVICE__ static inline __hip_bfloat162 __float22bfloat162_rn(const float2 a) {
return __hip_bfloat162{__float2bfloat16(a.x), __float2bfloat16(a.y)};
}
@@ -247,7 +247,7 @@
* \ingroup HIP_INTRINSIC_BFLOAT162_CONV
* \brief Converts high 16 bits of __hip_bfloat162 to float and returns the result
*/
-__HOST_DEVICE__ float __high2float(const __hip_bfloat162 a) { return __bfloat162float(a.y); }
+__HOST_DEVICE__ static inline float __high2float(const __hip_bfloat162 a) { return __bfloat162float(a.y); }
/**
* \ingroup HIP_INTRINSIC_BFLOAT162_CONV
@@ -275,7 +275,7 @@
* \ingroup HIP_INTRINSIC_BFLOAT162_CONV
* \brief Converts low 16 bits of __hip_bfloat162 to float and returns the result
*/
-__HOST_DEVICE__ float __low2float(const __hip_bfloat162 a) { return __bfloat162float(a.x); }
+__HOST_DEVICE__ static inline float __low2float(const __hip_bfloat162 a) { return __bfloat162float(a.x); }
/**
* \ingroup HIP_INTRINSIC_BFLOAT162_CONV
# Copyright (c) 2023, Albert Gu, Tri Dao.
import sys
import warnings
import os
import re
import ast
from pathlib import Path
from packaging.version import parse, Version
import platform
import shutil
from setuptools import setup, find_packages
import subprocess
import urllib.request
import urllib.error
from wheel.bdist_wheel import bdist_wheel as _bdist_wheel
import torch
from torch.utils.cpp_extension import (
BuildExtension,
CUDAExtension,
CUDA_HOME,
HIP_HOME
)
with open("README.md", "r", encoding="utf-8") as fh:
long_description = fh.read()
# ninja build does not work unless include_dirs are abs path
this_dir = os.path.dirname(os.path.abspath(__file__))
PACKAGE_NAME = "mamba_ssm"
BASE_WHEEL_URL = "https://github.com/state-spaces/mamba/releases/download/{tag_name}/{wheel_name}"
# FORCE_BUILD: Force a fresh build locally, instead of attempting to find prebuilt wheels
# SKIP_CUDA_BUILD: Intended to allow CI to use a simple `python setup.py sdist` run to copy over raw files, without any cuda compilation
FORCE_BUILD = os.getenv("MAMBA_FORCE_BUILD", "FALSE") == "TRUE"
SKIP_CUDA_BUILD = os.getenv("MAMBA_SKIP_CUDA_BUILD", "FALSE") == "TRUE"
# For CI, we want the option to build with C++11 ABI since the nvcr images use C++11 ABI
FORCE_CXX11_ABI = os.getenv("MAMBA_FORCE_CXX11_ABI", "FALSE") == "TRUE"
def get_platform():
"""
Returns the platform name as used in wheel filenames.
"""
if sys.platform.startswith("linux"):
return "linux_x86_64"
elif sys.platform == "darwin":
mac_version = ".".join(platform.mac_ver()[0].split(".")[:2])
return f"macosx_{mac_version}_x86_64"
elif sys.platform == "win32":
return "win_amd64"
else:
raise ValueError("Unsupported platform: {}".format(sys.platform))
def get_cuda_bare_metal_version(cuda_dir):
raw_output = subprocess.check_output(
[cuda_dir + "/bin/nvcc", "-V"], universal_newlines=True
)
output = raw_output.split()
release_idx = output.index("release") + 1
bare_metal_ver = parse(output[release_idx].split(",")[0])
return raw_output, bare_metal_ver
def get_hip_version(rocm_dir):
hipcc_bin = "hipcc" if rocm_dir is None else os.path.join(rocm_dir, "bin", "hipcc")
try:
raw_output = subprocess.check_output(
[hipcc_bin, "--version"], universal_newlines=True
)
except Exception as e:
print(
f"hip installation not found: {e} ROCM_PATH={os.environ.get('ROCM_PATH')}"
)
return None, None
for line in raw_output.split("\n"):
if "HIP version" in line:
rocm_version = parse(line.split()[-1].rstrip('-').replace('-', '+')) # local version is not parsed correctly
return line, rocm_version
return None, None
def get_torch_hip_version():
if torch.version.hip:
return parse(torch.version.hip.split()[-1].rstrip('-').replace('-', '+'))
else:
return None
def check_if_hip_home_none(global_option: str) -> None:
if HIP_HOME is not None:
return
# warn instead of error because user could be downloading prebuilt wheels, so hipcc won't be necessary
# in that case.
warnings.warn(
f"{global_option} was requested, but hipcc was not found. Are you sure your environment has hipcc available?"
)
def check_if_cuda_home_none(global_option: str) -> None:
if CUDA_HOME is not None:
return
# warn instead of error because user could be downloading prebuilt wheels, so nvcc won't be necessary
# in that case.
warnings.warn(
f"{global_option} was requested, but nvcc was not found. Are you sure your environment has nvcc available? "
"If you're installing within a container from https://hub.docker.com/r/pytorch/pytorch, "
"only images whose names contain 'devel' will provide nvcc."
)
def append_nvcc_threads(nvcc_extra_args):
return nvcc_extra_args + ["--threads", "4"]
cmdclass = {}
ext_modules = []
HIP_BUILD = bool(torch.version.hip)
if not SKIP_CUDA_BUILD:
print("\n\ntorch.__version__ = {}\n\n".format(torch.__version__))
TORCH_MAJOR = int(torch.__version__.split(".")[0])
TORCH_MINOR = int(torch.__version__.split(".")[1])
cc_flag = []
if HIP_BUILD:
check_if_hip_home_none(PACKAGE_NAME)
rocm_home = os.getenv("ROCM_PATH")
_, hip_version = get_hip_version(rocm_home)
if HIP_HOME is not None:
if hip_version < Version("6.0"):
raise RuntimeError(
f"{PACKAGE_NAME} is only supported on ROCm 6.0 and above. "
"Note: make sure HIP has a supported version by running hipcc --version."
)
if hip_version == Version("6.0"):
warnings.warn(
f"{PACKAGE_NAME} requires a patch to be applied when running on ROCm 6.0. "
"Refer to the README.md for detailed instructions.",
UserWarning
)
cc_flag.append("-DBUILD_PYTHON_PACKAGE")
else:
check_if_cuda_home_none(PACKAGE_NAME)
# Check, if CUDA11 is installed for compute capability 8.0
if CUDA_HOME is not None:
_, bare_metal_version = get_cuda_bare_metal_version(CUDA_HOME)
if bare_metal_version < Version("11.6"):
raise RuntimeError(
f"{PACKAGE_NAME} is only supported on CUDA 11.6 and above. "
"Note: make sure nvcc has a supported version by running nvcc -V."
)
cc_flag.append("-gencode")
cc_flag.append("arch=compute_53,code=sm_53")
cc_flag.append("-gencode")
cc_flag.append("arch=compute_62,code=sm_62")
cc_flag.append("-gencode")
cc_flag.append("arch=compute_70,code=sm_70")
cc_flag.append("-gencode")
cc_flag.append("arch=compute_72,code=sm_72")
cc_flag.append("-gencode")
cc_flag.append("arch=compute_80,code=sm_80")
cc_flag.append("-gencode")
cc_flag.append("arch=compute_87,code=sm_87")
if bare_metal_version >= Version("11.8"):
cc_flag.append("-gencode")
cc_flag.append("arch=compute_90,code=sm_90")
# HACK: The compiler flag -D_GLIBCXX_USE_CXX11_ABI is set to be the same as
# torch._C._GLIBCXX_USE_CXX11_ABI
# https://github.com/pytorch/pytorch/blob/8472c24e3b5b60150096486616d98b7bea01500b/torch/utils/cpp_extension.py#L920
if FORCE_CXX11_ABI:
torch._C._GLIBCXX_USE_CXX11_ABI = True
if HIP_BUILD:
extra_compile_args = {
"cxx": ["-O3", "-std=c++17"],
"nvcc": [
"-O3",
"-std=c++17",
f"--offload-arch={os.getenv('HIP_ARCHITECTURES', 'native')}",
"-U__CUDA_NO_HALF_OPERATORS__",
"-U__CUDA_NO_HALF_CONVERSIONS__",
"-fgpu-flush-denormals-to-zero",
]
+ cc_flag,
}
else:
extra_compile_args = {
"cxx": ["-O3", "-std=c++17"],
"nvcc": append_nvcc_threads(
[
"-O3",
"-std=c++17",
"-U__CUDA_NO_HALF_OPERATORS__",
"-U__CUDA_NO_HALF_CONVERSIONS__",
"-U__CUDA_NO_BFLOAT16_OPERATORS__",
"-U__CUDA_NO_BFLOAT16_CONVERSIONS__",
"-U__CUDA_NO_BFLOAT162_OPERATORS__",
"-U__CUDA_NO_BFLOAT162_CONVERSIONS__",
"--expt-relaxed-constexpr",
"--expt-extended-lambda",
"--use_fast_math",
"--ptxas-options=-v",
"-lineinfo",
]
+ cc_flag
),
}
ext_modules.append(
CUDAExtension(
name="selective_scan_cuda",
sources=[
"csrc/selective_scan/selective_scan.cpp",
"csrc/selective_scan/selective_scan_fwd_fp32.cu",
"csrc/selective_scan/selective_scan_fwd_fp16.cu",
"csrc/selective_scan/selective_scan_fwd_bf16.cu",
"csrc/selective_scan/selective_scan_bwd_fp32_real.cu",
"csrc/selective_scan/selective_scan_bwd_fp32_complex.cu",
"csrc/selective_scan/selective_scan_bwd_fp16_real.cu",
"csrc/selective_scan/selective_scan_bwd_fp16_complex.cu",
"csrc/selective_scan/selective_scan_bwd_bf16_real.cu",
"csrc/selective_scan/selective_scan_bwd_bf16_complex.cu",
],
extra_compile_args=extra_compile_args,
include_dirs=[Path(this_dir) / "csrc" / "selective_scan"],
)
)
def get_package_version():
with open(Path(this_dir) / PACKAGE_NAME / "__init__.py", "r") as f:
version_match = re.search(r"^__version__\s*=\s*(.*)$", f.read(), re.MULTILINE)
public_version = ast.literal_eval(version_match.group(1))
local_version = os.environ.get("MAMBA_LOCAL_VERSION")
if local_version:
return f"{public_version}+{local_version}"
else:
return str(public_version)
def get_wheel_url():
# Determine the version numbers that will be used to determine the correct wheel
torch_version_raw = parse(torch.__version__)
if HIP_BUILD:
# We're using the HIP version used to build torch, not the one currently installed
torch_hip_version = get_torch_hip_version()
hip_ver = f"{torch_hip_version.major}{torch_hip_version.minor}"
else:
# We're using the CUDA version used to build torch, not the one currently installed
# _, cuda_version_raw = get_cuda_bare_metal_version(CUDA_HOME)
torch_cuda_version = parse(torch.version.cuda)
# For CUDA 11, we only compile for CUDA 11.8, and for CUDA 12 we only compile for CUDA 12.2
# to save CI time. Minor versions should be compatible.
torch_cuda_version = parse("11.8") if torch_cuda_version.major == 11 else parse("12.2")
cuda_version = f"{torch_cuda_version.major}{torch_cuda_version.minor}"
gpu_compute_version = hip_ver if HIP_BUILD else cuda_version
cuda_or_hip = "hip" if HIP_BUILD else "cu"
python_version = f"cp{sys.version_info.major}{sys.version_info.minor}"
platform_name = get_platform()
mamba_ssm_version = get_package_version()
torch_version = f"{torch_version_raw.major}.{torch_version_raw.minor}"
cxx11_abi = str(torch._C._GLIBCXX_USE_CXX11_ABI).upper()
# Determine wheel URL based on CUDA version, torch version, python version and OS
wheel_filename = f"{PACKAGE_NAME}-{mamba_ssm_version}+{cuda_or_hip}{gpu_compute_version}torch{torch_version}cxx11abi{cxx11_abi}-{python_version}-{python_version}-{platform_name}.whl"
wheel_url = BASE_WHEEL_URL.format(
tag_name=f"v{mamba_ssm_version}", wheel_name=wheel_filename
)
return wheel_url, wheel_filename
class CachedWheelsCommand(_bdist_wheel):
"""
The CachedWheelsCommand plugs into the default bdist wheel, which is ran by pip when it cannot
find an existing wheel (which is currently the case for all installs). We use
the environment parameters to detect whether there is already a pre-built version of a compatible
wheel available and short-circuits the standard full build pipeline.
"""
def run(self):
if FORCE_BUILD:
return super().run()
wheel_url, wheel_filename = get_wheel_url()
print("Guessing wheel URL: ", wheel_url)
try:
urllib.request.urlretrieve(wheel_url, wheel_filename)
# Make the archive
# Lifted from the root wheel processing command
# https://github.com/pypa/wheel/blob/cf71108ff9f6ffc36978069acb28824b44ae028e/src/wheel/bdist_wheel.py#LL381C9-L381C85
if not os.path.exists(self.dist_dir):
os.makedirs(self.dist_dir)
impl_tag, abi_tag, plat_tag = self.get_tag()
archive_basename = f"{self.wheel_dist_name}-{impl_tag}-{abi_tag}-{plat_tag}"
wheel_path = os.path.join(self.dist_dir, archive_basename + ".whl")
print("Raw wheel path", wheel_path)
shutil.move(wheel_filename, wheel_path)
except urllib.error.HTTPError:
print("Precompiled wheel not found. Building from source...")
# If the wheel could not be downloaded, build from source
super().run()
setup(
name=PACKAGE_NAME,
version=get_package_version(),
packages=find_packages(
exclude=(
"build",
"csrc",
"include",
"tests",
"dist",
"docs",
"benchmarks",
"mamba_ssm.egg-info",
)
),
long_description=long_description,
long_description_content_type="text/markdown",
ext_modules=ext_modules,
cmdclass={"bdist_wheel": CachedWheelsCommand, "build_ext": BuildExtension}
if ext_modules
else {
"bdist_wheel": CachedWheelsCommand,
}
)
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