---
id: pr-flashinfer-2563
repo: flashinfer-ai/flashinfer
pr: 2563
title: Add support for the combinations of allreduce, allgather, and reducescatter
author: jinyangyuan-nvidia
date: '2026-04-23'
url: https://github.com/flashinfer-ai/flashinfer/pull/2563
source_category: upstream-code
architectures:
- sm100
tags:
- benchmark
- benchmark_test
- memory_primitives
- moe_routing
techniques: []
hardware_features: []
kernel_types:
- attention
- memory
- moe
languages:
- cuda-cpp
captured_at: '2026-05-16'
status: merged
merge_sha: c9eb3cd92e7b798ccf5341122ce4b6c0975a34e0
inclusion_reason: 'Transfer primitive policy carefully: coalescing, shared-memory staging, partial tiles, and determinism are part of the contract.'
changed_paths:
- benchmarks/flashinfer_benchmark.py
- benchmarks/routines/flashinfer_benchmark_utils.py
- benchmarks/routines/mixed_comm.py
- csrc/mixed_comm.cu
- csrc/mixed_comm_kernel_inst.jinja
- flashinfer/comm/mixed_comm.py
- flashinfer/jit/comm.py
- flashinfer/testing/utils.py
- include/flashinfer/comm/mixed_comm.cuh
- include/flashinfer/comm/mixed_comm_decl.cuh
- tests/comm/conftest.py
- tests/comm/test_mixed_comm.py
artifact_dir: evidence/pull-bundles/flashinfer/gh-2563
head_ref_oid: 74549df82b4303ab91ee874d67aa15ae95643125
---
# Add support for the combinations of allreduce, allgather, and reducescatter

- Repository: `flashinfer-ai/flashinfer`
- PR: [2563](https://github.com/flashinfer-ai/flashinfer/pull/2563)
- Decision: `Transfer primitive policy carefully: coalescing, shared-memory staging, partial tiles, and determinism are part of the contract.`
- Reason: Transfer primitive policy carefully: coalescing, shared-memory staging, partial tiles, and determinism are part of the contract.

## Changed Paths

- `benchmarks/flashinfer_benchmark.py`
- `benchmarks/routines/flashinfer_benchmark_utils.py`
- `benchmarks/routines/mixed_comm.py`
- `csrc/mixed_comm.cu`
- `csrc/mixed_comm_kernel_inst.jinja`
- `flashinfer/comm/mixed_comm.py`
- `flashinfer/jit/comm.py`
- `flashinfer/testing/utils.py`
- `include/flashinfer/comm/mixed_comm.cuh`
- `include/flashinfer/comm/mixed_comm_decl.cuh`
- `tests/comm/conftest.py`
- `tests/comm/test_mixed_comm.py`

## Evidence Bundle

`evidence/pull-bundles/flashinfer/gh-2563`
