Merge pull request #192 from YdrMaster/random-sample-cuda

issue/191/docs: 规范 random sample 算子构造过程，添加 cuda 接口

README.md

@@ -175,6 +175,10 @@ options:
     {
         "clangd.arguments": [
             "--compile-commands-dir=.vscode"
-        ]
+        ],
+        "xmake.additionalConfigArguments": [
+            // 在这里配置 XMAKE_CONFIG_FLAGS
+            "--nv-gpu=y"
+        ],
     }
     ```

src/infiniop/ops/random_sample/cpu/random_sample_cpu.cc

 #include "random_sample_cpu.h"
 #include "../../../devices/cpu/common_cpu.h"
-#include "../../../devices/cpu/cpu_handle.h"
-#include "../../../tensor.h"
+#include "../info.h"
+#include "infinicore.h"
 #include <algorithm>
 
 namespace op::random_sample::cpu {
@@ -15,29 +15,14 @@ infiniStatus_t Descriptor::create(
     infiniopTensorDescriptor_t probs_desc) {
     auto handle = reinterpret_cast<device::cpu::Handle *>(handle_);
 
-    auto dt_i = result_desc->dtype();
-    auto dt_p = probs_desc->dtype();
-
-    CHECK_DTYPE(dt_i,
-                INFINI_DTYPE_U8, INFINI_DTYPE_U16, INFINI_DTYPE_U32, INFINI_DTYPE_U64,
-                INFINI_DTYPE_I8, INFINI_DTYPE_I16, INFINI_DTYPE_I32, INFINI_DTYPE_I64);
-    CHECK_DTYPE(dt_p, INFINI_DTYPE_F16, INFINI_DTYPE_F32, INFINI_DTYPE_F64);
-
-    CHECK_API_OR(result_desc->ndim(), 0,
-                 return INFINI_STATUS_BAD_TENSOR_SHAPE);
-    CHECK_API_OR(probs_desc->ndim(), 1,
-                 return INFINI_STATUS_BAD_TENSOR_SHAPE);
-    CHECK_API_OR(probs_desc->stride(0), 1,
-                 return INFINI_STATUS_BAD_TENSOR_STRIDES);
+    auto result = RandomSampleInfo::create(result_desc, probs_desc);
+    CHECK_RESULT(result);
 
     *desc_ptr = new Descriptor(
-        dt_i,
-        dt_p,
-        probs_desc->dim(0),
+        result.take(),
         0,
         nullptr,
-        handle->device,
-        handle->device_id);
+        handle->device, handle->device_id);
     return INFINI_STATUS_SUCCESS;
 }
 
@@ -55,36 +40,42 @@ struct ComputeType<fp16_t> {
     using type = float;
 };
 
-template <class Tidx, class Tval>
-struct Scheme {
-    using Tcompute = typename ComputeType<Tval>::type;
+struct Algo {
 
-    static Tcompute get(void const *ptr, size_t i) {
-        return utils::cast<Tcompute, Tval>(reinterpret_cast<Tval const *>(ptr)[i]);
+    template <class Tidx, class Tval>
+    static auto get(void const *ptr, size_t i) {
+        return utils::cast<typename ComputeType<Tval>::type, Tval>(reinterpret_cast<Tval const *>(ptr)[i]);
     }
 
-    static void argmax(
-        void *result, void const *probs, size_t n) {
-
+    template <class Tidx, class Tval>
+    infiniStatus_t argmax(
+        void *workspace, size_t workspace_size,
+        void *result, void const *probs, size_t n,
+        void *stream) {
         auto idx = reinterpret_cast<Tidx *>(result);
         *idx = 0;
 
-        auto max_val = get(probs, 0);
+        auto max_val = get<Tidx, Tval>(probs, 0);
         for (size_t i = 0; i < n; i++) {
-            if (auto val = get(probs, i); val > max_val) {
+            if (auto val = get<Tidx, Tval>(probs, i); val > max_val) {
                 max_val = val;
                 *idx = static_cast<Tidx>(i);
             }
         }
+
+        return INFINI_STATUS_SUCCESS;
     }
 
-    static void random(
+    template <class Tidx, class Tval>
+    infiniStatus_t random(
+        void *workspace, size_t workspace_size,
         void *result, void const *probs, size_t n,
-        float random_val, float topp, int topk, float temperature) {
+        float random_val, float topp, int topk, float temperature,
+        void *stream) {
 
         struct KVPair {
             Tidx idx;
-            Tcompute val;
+            typename ComputeType<Tval>::type val;
 
             bool operator<(const KVPair &other) const {
                 return val > other.val;
@@ -95,7 +86,7 @@ struct Scheme {
         // build & sort
         std::vector<KVPair> pairs(n);
         for (size_t i = 0; i < n; i++) {
-            pairs[i] = {static_cast<Tidx>(i), get(probs, i)};
+            pairs[i] = {static_cast<Tidx>(i), get<Tidx, Tval>(probs, i)};
         }
         std::sort(pairs.begin(), pairs.end());
         // softmax & sum
@@ -115,68 +106,10 @@ struct Scheme {
                 break;
             }
         }
-    }
-};
-
-template <class Tidx, class Tval>
-void switch_f(
-    size_t n,
-    void *result, const void *probs,
-    float random_val, float topp, int topk, float temperature) {
-    if (random_val == 0 || topp == 0 || topk == 1 || temperature == 0) {
-        Scheme<Tidx, Tval>::argmax(result, probs, n);
-    } else {
-        Scheme<Tidx, Tval>::random(result, probs, n, random_val, topp, topk, temperature);
-    }
-}
 
-template <class Tidx>
-void switch_val(
-    infiniDtype_t dt_p, size_t n,
-    void *result, void const *probs,
-    float random_val, float topp, int topk, float temperature) {
-    switch (dt_p) {
-    case INFINI_DTYPE_F16:
-        switch_f<Tidx, fp16_t>(n, result, probs, random_val, topp, topk, temperature);
-        break;
-    case INFINI_DTYPE_F32:
-        switch_f<Tidx, float>(n, result, probs, random_val, topp, topk, temperature);
-        break;
-    case INFINI_DTYPE_F64:
-        switch_f<Tidx, double>(n, result, probs, random_val, topp, topk, temperature);
-        break;
-    default:
-        // unreachable
-        std::abort();
-    }
-}
-
-void switch_idx(
-    infiniDtype_t dt_i, infiniDtype_t dt_p, size_t n,
-    void *result, void const *probs,
-    float random_val, float topp, int topk, float temperature) {
-
-#define CASE(DT_VAL, DT_TYP)                                                             \
-    case DT_VAL:                                                                         \
-        switch_val<DT_TYP>(dt_p, n, result, probs, random_val, topp, topk, temperature); \
-        break
-
-    switch (dt_i) {
-        CASE(INFINI_DTYPE_I8, int8_t);
-        CASE(INFINI_DTYPE_I16, int16_t);
-        CASE(INFINI_DTYPE_I32, int32_t);
-        CASE(INFINI_DTYPE_I64, int64_t);
-        CASE(INFINI_DTYPE_U8, uint8_t);
-        CASE(INFINI_DTYPE_U16, uint16_t);
-        CASE(INFINI_DTYPE_U32, uint32_t);
-        CASE(INFINI_DTYPE_U64, uint64_t);
-    default:
-        // unreachable
-        std::abort();
+        return INFINI_STATUS_SUCCESS;
     }
-
-#undef CASE
-}
+};
 
 infiniStatus_t Descriptor::calculate(
     void *workspace,
@@ -189,7 +122,11 @@ infiniStatus_t Descriptor::calculate(
     float temperature,
     void *stream) const {
 
-    switch_idx(_dt_i, _dt_p, _n, result, probs, random_val, topp, topk, temperature);
+    Calculate::calculate<Algo>(
+        Algo{}, _info, workspace, workspace_size,
+        result, probs,
+        random_val, topp, topk, temperature,
+        stream);
 
     return INFINI_STATUS_SUCCESS;
 }

src/infiniop/ops/random_sample/cuda/random_sample_cuda.cu

+#include "../../../devices/cuda/cuda_handle.cuh"
+#include "../info.h"
+#include "random_sample_cuda.cuh"
+#include "random_sample_kernel.cuh"
+
+namespace op::random_sample::cuda {
+
+struct Descriptor::Opaque {
+    std::shared_ptr<device::cuda::Handle::Internal> internal;
+};
+
+Descriptor::~Descriptor() {
+    delete _opaque;
+}
+
+infiniStatus_t Descriptor::create(
+    infiniopHandle_t handle_,
+    Descriptor **desc_ptr,
+    infiniopTensorDescriptor_t result_desc,
+    infiniopTensorDescriptor_t probs_desc) {
+    auto handle = reinterpret_cast<device::cuda::Handle *>(handle_);
+
+    auto result = RandomSampleInfo::create(result_desc, probs_desc);
+    CHECK_RESULT(result);
+
+    auto info = result.take();
+    size_t workspace_size;
+
+#define CASE_P(CASE, Tidx, Tval)                                 \
+    case CASE:                                                   \
+        workspace_size = calculateWorkspace<Tidx, Tval>(info.n); \
+        break
+
+#define CASE_I(CASE, Tidx)                          \
+    case CASE:                                      \
+        switch (info.dt_p) {                        \
+            CASE_P(INFINI_DTYPE_F16, Tidx, half);   \
+            CASE_P(INFINI_DTYPE_F32, Tidx, float);  \
+            CASE_P(INFINI_DTYPE_F64, Tidx, double); \
+        default:                                    \
+            abort();                                \
+        }                                           \
+        break
+
+    switch (info.dt_i) {
+        CASE_I(INFINI_DTYPE_I8, int8_t);
+        CASE_I(INFINI_DTYPE_I16, int16_t);
+        CASE_I(INFINI_DTYPE_I32, int32_t);
+        CASE_I(INFINI_DTYPE_I64, int64_t);
+        CASE_I(INFINI_DTYPE_U8, uint8_t);
+        CASE_I(INFINI_DTYPE_U16, uint16_t);
+        CASE_I(INFINI_DTYPE_U32, uint32_t);
+        CASE_I(INFINI_DTYPE_U64, uint64_t);
+    default:
+        abort();
+    }
+
+#undef CASE_I
+#undef CASE_P
+
+    *desc_ptr = new Descriptor(
+        info,
+        workspace_size,
+        new Opaque{handle->internal()},
+        handle->device, handle->device_id);
+    return INFINI_STATUS_SUCCESS;
+}
+
+size_t Descriptor::minWorkspaceSize() const {
+    return _min_workspace_size;
+}
+
+infiniStatus_t Descriptor::calculate(
+    void *workspace,
+    size_t workspace_size,
+    void *result,
+    const void *probs,
+    float random_val,
+    float topp,
+    int topk,
+    float temperature,
+    void *stream) const {
+
+    if (workspace_size < _min_workspace_size) {
+        return INFINI_STATUS_INSUFFICIENT_WORKSPACE;
+    }
+
+    auto block_size = _opaque->internal->blockSizeX();
+
+    Calculate::calculate<Algo>(
+        Algo{block_size}, _info, workspace, workspace_size,
+        result, probs,
+        random_val, topp, topk, temperature,
+        stream);
+
+    return INFINI_STATUS_SUCCESS;
+}
+
+} // namespace op::random_sample::cuda

src/infiniop/ops/random_sample/cuda/random_sample_cuda.cuh

+#ifndef __RANDOM_SAMPLE_CUDA_CUH__
+#define __RANDOM_SAMPLE_CUDA_CUH__
+
+#include "../random_sample.h"
+
+DESCRIPTOR(cuda)
+
+#endif // __RANDOM_SAMPLE_CUDA_CUH__

src/infiniop/ops/random_sample/cuda/random_sample_kernel.cuh

+#include "../../../devices/cuda/cuda_kernel_common.cuh"
+#include "infinicore.h"
+#include <cub/device/device_radix_sort.cuh>
+#include <cub/device/device_reduce.cuh>
+#include <cub/device/device_scan.cuh>
+
+namespace op::random_sample::cuda {
+
+// ↓↓↓ 重新封装 cub api，减少模板参数，方便调用
+
+template <class T>
+static cudaError argMax_(
+    cub::KeyValuePair<int, T> *kv_pair,
+    const T *logits,
+    int n,
+    void *workspace_ptr,
+    size_t &workspace_len,
+    cudaStream_t stream) {
+    return cub::DeviceReduce::ArgMax(
+        workspace_ptr, workspace_len,
+        logits, kv_pair, n,
+        stream);
+}
+
+template <class Tval, class Tidx>
+static cudaError radixSort(
+    void *workspace_ptr, size_t &workspace_len,
+    const Tval *key_in, Tval *key_out,
+    const Tidx *val_in, Tidx *val_out,
+    int n,
+    cudaStream_t stream) {
+    return cub::DeviceRadixSort::SortPairsDescending(
+        workspace_ptr, workspace_len,
+        key_in, key_out,
+        val_in, val_out,
+        n,
+        0, sizeof(Tval) * 8,
+        stream);
+}
+
+template <class T>
+static cudaError inclusiveSum(
+    void *workspace_ptr, size_t &workspace_len,
+    T *data, int n,
+    cudaStream_t stream) {
+    return cub::DeviceScan::InclusiveSum(
+        workspace_ptr, workspace_len,
+        data, data, n,
+        stream);
+}
+
+// ↑↑↑ 重新封装 cub api，减少模板参数，方便调用
+// ↓↓↓ 计算 workspace
+
+// 地址对齐到 256
+static constexpr size_t align256(size_t size) {
+    return (size + 255) & (~255);
+}
+
+template <class Tidx, class Tval>
+utils::Result<size_t> calculateWorkspace(size_t n_) {
+    const auto n = static_cast<int>(n_);
+
+    size_t argmax;
+    CHECK_CUDA(argMax_<Tval>(
+        nullptr, nullptr, n,
+        nullptr, argmax,
+        nullptr));
+    // 前 256 字节用于 kv pair
+    argmax += 256;
+
+    // indices
+    size_t size_random = align256(sizeof(Tidx) * n);
+    // sorted
+    size_random += align256(sizeof(Tval) * n);
+    // indices_out
+    size_random += align256(sizeof(Tidx) * n);
+    // cub device api
+    size_t size_radix_sort;
+    CHECK_CUDA((radixSort<Tval, Tidx>(
+        nullptr, size_radix_sort,
+        nullptr, nullptr,
+        nullptr, nullptr,
+        n,
+        nullptr)));
+
+    size_t size_inclusive_sum;
+    CHECK_CUDA(inclusiveSum<Tval>(
+        nullptr, size_inclusive_sum,
+        nullptr, n,
+        nullptr));
+    size_random += cub::Max()(size_radix_sort, size_inclusive_sum);
+
+    return utils::Result<size_t>(cub::Max()(argmax, size_random));
+}
+
+// ↑↑↑ 计算 workspace
+// ↓↓↓ 通过特化将 fp16_t 转换为 half
+
+template <class Tval>
+struct CudaTval {
+    using Type = Tval;
+};
+
+template <>
+struct CudaTval<fp16_t> {
+    using Type = half;
+};
+
+// ↑↑↑ 通过特化将 fp16_t 转换为 half
+// ↓↓↓ 用于采样过程的小型 kernel
+
+// cuda toolkit 11.x 带的 cub::DeviceReduce::ArgMax 只接受 cub::KeyValuePair<int, Tval> 输出。
+// 这个 kernel 用于取出序号
+template <class Tidx, class Tval>
+static __global__ void castIdx(Tidx *result, const cub::KeyValuePair<int, Tval> *kv_pair) {
+    *result = kv_pair->key;
+}
+
+// 填充排序要求的序号数组
+template <class Tidx>
+static __global__ void fillIndices(Tidx *indices, int n) {
+    int i = blockIdx.x * blockDim.x + threadIdx.x;
+    if (i < n) {
+        indices[i] = i;
+    }
+}
+
+// random sample 使用的 softmax 可以简化为一个基本的线性映射
+// 由于已经排序，最大值就是第一个数字
+// 第一个数字需要被多个 block 读取，不能写
+template <class T>
+static __global__ void partialSoftmaxKernel(
+    T *__restrict__ data, int n,
+    float temperature) {
+    int i = blockIdx.x * blockDim.x + threadIdx.x;
+    if (0 < i && i < n) {
+        float max = __ldg(data);
+        data[i] = (T)expf(((float)data[i] - max) / temperature);
+    }
+}
+
+// 将第一个数字写成 1，即 exp(0)
+template <class T>
+static __global__ void setSoftmaxMaxKernel(
+    T *__restrict__ data) {
+    *data = 1;
+}
+
+// 直接 for 循环遍历采样
+// 这个 kernel 仅用于避免将数据拷贝到 cpu
+template <class Tval, class Tidx>
+static __global__ void randomSampleKernel(
+    Tidx *__restrict__ result,
+    const Tval *__restrict__ sorted,
+    const Tidx *__restrict__ indices_out,
+    size_t n,
+    float random, float topp, size_t topk) {
+    topk = cub::Min()(topk, n);
+    auto p = (Tval)(random * cub::Min()(topp * (float)sorted[n - 1], (float)sorted[topk - 1]));
+    for (size_t i = 0;; ++i) {
+        if ((sorted[i]) >= p) {
+            *result = indices_out[i];
+            return;
+        }
+    }
+}
+
+// ↑↑↑ 用于采样过程的小型 kernel
+
+struct Algo {
+    int block_size;
+
+    template <class Tidx, class Tval_>
+    infiniStatus_t argmax(
+        void *workspace, size_t workspace_size,
+        void *result, const void *probs, size_t n,
+        void *stream_) const {
+
+        using Tval = typename CudaTval<Tval_>::Type;
+
+        auto stream = (cudaStream_t)stream_;
+        auto logits = (Tval *)probs;
+        auto kv_pair = (cub::KeyValuePair<int, Tval> *)workspace;
+        workspace = (void *)((char *)workspace + 256);
+        workspace_size -= 256;
+
+        argMax_(
+            kv_pair,
+            logits,
+            n,
+            workspace,
+            workspace_size, stream);
+        castIdx<<<1, 1, 0, stream>>>((Tidx *)result, kv_pair);
+
+        return INFINI_STATUS_SUCCESS;
+    }
+
+    template <class Tidx, class Tval_>
+    infiniStatus_t random(
+        void *workspace_, size_t workspace_size,
+        void *result_, const void *probs, size_t n,
+        float random_val, float topp, int topk, float temperature,
+        void *stream_) const {
+
+        using Tval = typename CudaTval<Tval_>::Type;
+
+        auto stream = (cudaStream_t)stream_;
+        auto logits = (Tval *)probs;
+        auto result = (Tidx *)result_;
+
+        auto workspace = reinterpret_cast<size_t>(workspace_);
+        auto workspace_end = workspace + workspace_size;
+
+        auto indices = reinterpret_cast<Tidx *>(workspace);
+        workspace += align256(sizeof(Tidx) * n);
+
+        auto sorted = reinterpret_cast<Tval *>(workspace);
+        workspace += align256(sizeof(Tval) * n);
+
+        auto indices_out = reinterpret_cast<Tidx *>(workspace);
+        workspace += align256(sizeof(Tidx) * n);
+
+        workspace_ = reinterpret_cast<void *>(workspace);
+        workspace_size = workspace_end - workspace;
+
+        auto block = cub::Min()((size_t)block_size, n);
+        auto grid = (n + block - 1) / block;
+        // sort
+        fillIndices<<<grid, block, 0, stream>>>(indices, n);
+        CHECK_CUDA(radixSort(
+            workspace_, workspace_size,
+            logits, sorted,
+            indices, indices_out,
+            n,
+            stream));
+        // softmax
+        partialSoftmaxKernel<<<grid, block, 0, stream>>>(sorted, n, temperature);
+        setSoftmaxMaxKernel<<<1, 1, 0, stream>>>(sorted);
+        // sum
+        CHECK_CUDA(inclusiveSum(
+            workspace_, workspace,
+            sorted, n,
+            stream));
+        // sample
+        randomSampleKernel<<<1, 1, 0, stream>>>(
+            result,
+            sorted, indices_out, n,
+            random_val, topp, topk);
+        return INFINI_STATUS_SUCCESS;
+    }
+};
+
+} // namespace op::random_sample::cuda

src/infiniop/ops/random_sample/info.h

+#ifndef __RANDOM_SAMPLE_INFO_H__
+#define __RANDOM_SAMPLE_INFO_H__
+
+#include "../../../utils.h"
+#include "../../tensor.h"
+
+namespace op::random_sample {
+
+struct RandomSampleInfo {
+    infiniDtype_t dt_i, dt_p;
+    size_t n;
+
+    static utils::Result<RandomSampleInfo> create(
+        infiniopTensorDescriptor_t result_desc,
+        infiniopTensorDescriptor_t probs_desc) {
+
+        auto dt_i = result_desc->dtype();
+        auto dt_p = probs_desc->dtype();
+
+        CHECK_DTYPE_ANY_INT(dt_i);
+        CHECK_DTYPE(dt_p, INFINI_DTYPE_F16, INFINI_DTYPE_F32, INFINI_DTYPE_F64);
+
+        CHECK_OR_RETURN(result_desc->ndim() == 0, INFINI_STATUS_BAD_TENSOR_SHAPE);
+        CHECK_OR_RETURN(probs_desc->ndim() == 1, INFINI_STATUS_BAD_TENSOR_SHAPE);
+        CHECK_OR_RETURN(probs_desc->stride(0) == 1, INFINI_STATUS_BAD_TENSOR_STRIDES);
+
+        return utils::Result<RandomSampleInfo>({dt_i, dt_p, probs_desc->dim(0)});
+    }
+};
+
+} // namespace op::random_sample
+
+#endif // __RANDOM_SAMPLE_INFO_H__

src/infiniop/ops/random_sample/operator.cc

@@ -5,6 +5,9 @@
 #ifdef ENABLE_CPU_API
 #include "cpu/random_sample_cpu.h"
 #endif
+#ifdef ENABLE_CUDA_API
+#include "cuda/random_sample_cuda.cuh"
+#endif
 
 __C infiniStatus_t infiniopCreateRandomSampleDescriptor(
     infiniopHandle_t handle,
@@ -25,6 +28,9 @@ __C infiniStatus_t infiniopCreateRandomSampleDescriptor(
 #ifdef ENABLE_CPU_API
         CREATE(INFINI_DEVICE_CPU, cpu);
 #endif
+#ifdef ENABLE_CUDA_API
+        CREATE(INFINI_DEVICE_NVIDIA, cuda);
+#endif
 
     default:
         return INFINI_STATUS_DEVICE_TYPE_NOT_SUPPORTED;
@@ -38,9 +44,10 @@ __C infiniStatus_t infiniopGetRandomSampleWorkspaceSize(
     size_t *size) {
 
 #define GET(CASE, NAMESPACE)                                          \
-    case CASE:                                                        \
+    case CASE: {                                                      \
         using Ptr = const op::random_sample::NAMESPACE::Descriptor *; \
         *size = reinterpret_cast<Ptr>(desc)->minWorkspaceSize();      \
+    }                                                                 \
         return INFINI_STATUS_SUCCESS
 
     switch (desc->device_type) {
@@ -48,6 +55,9 @@ __C infiniStatus_t infiniopGetRandomSampleWorkspaceSize(
 #ifdef ENABLE_CPU_API
         GET(INFINI_DEVICE_CPU, cpu);
 #endif
+#ifdef ENABLE_CUDA_API
+        GET(INFINI_DEVICE_NVIDIA, cuda);
+#endif
 
     default:
         return INFINI_STATUS_DEVICE_TYPE_NOT_SUPPORTED;
@@ -82,6 +92,9 @@ __C infiniStatus_t infiniopRandomSample(
 #ifdef ENABLE_CPU_API
         CALCULATE(INFINI_DEVICE_CPU, cpu);
 #endif
+#ifdef ENABLE_CUDA_API
+        CALCULATE(INFINI_DEVICE_NVIDIA, cuda);
+#endif
 
     default:
         return INFINI_STATUS_DEVICE_TYPE_NOT_SUPPORTED;
@@ -103,6 +116,9 @@ __C infiniStatus_t infiniopDestroyRandomSampleDescriptor(
 #ifdef ENABLE_CPU_API
         DELETE(INFINI_DEVICE_CPU, cpu);
 #endif
+#ifdef ENABLE_CUDA_API
+        DELETE(INFINI_DEVICE_NVIDIA, cuda);
+#endif
 
     default:
         return INFINI_STATUS_DEVICE_TYPE_NOT_SUPPORTED;

src/infiniop/ops/random_sample/random_sample.h

 #ifndef __RANDOM_SAMPLE_H__
 #define __RANDOM_SAMPLE_H__
 
-#include "../../../utils.h"
 #include "../../operator.h"
+#include "info.h"
 
 #define DESCRIPTOR(NAMESPACE)                             \
                                                           \
@@ -11,22 +11,18 @@
         struct Opaque;                                    \
         Opaque *_opaque;                                  \
                                                           \
-        infiniDtype_t _dt_i, _dt_p;                       \
-        size_t _n, _min_workspace_size;                   \
+        RandomSampleInfo _info;                           \
+        size_t _min_workspace_size;                       \
                                                           \
         Descriptor(                                       \
-            infiniDtype_t dt_i,                           \
-            infiniDtype_t dt_p,                           \
-            size_t n,                                     \
+            RandomSampleInfo info,                        \
             size_t min_workspace_size,                    \
             Opaque *opaque,                               \
             infiniDevice_t device_type,                   \
             int device_id)                                \
             : InfiniopDescriptor{device_type, device_id}, \
               _opaque(opaque),                            \
-              _dt_i(dt_i),                                \
-              _dt_p(dt_p),                                \
-              _n(n),                                      \
+              _info(info),                                \
               _min_workspace_size(min_workspace_size) {}  \
                                                           \
     public:                                               \
@@ -53,4 +49,96 @@
     };                                                    \
     }
 
+namespace op::random_sample {
+
+struct CalculateArgs {
+    void *workspace;
+    size_t workspace_size;
+    void *result;
+    const void *probs;
+    float random_val, topp, temperature;
+    int topk;
+    void *stream;
+};
+
+class Calculate {
+
+    template <class Tidx, class Tval, class Algo>
+    static void switch_f(Algo algo, size_t n, CalculateArgs args) {
+        if (args.random_val == 0 || args.topp == 0 || args.topk == 1 || args.temperature == 0) {
+            algo.template argmax<Tidx, Tval>(
+                args.workspace, args.workspace_size,
+                args.result, args.probs, n,
+                args.stream);
+        } else {
+            algo.template random<Tidx, Tval>(
+                args.workspace, args.workspace_size,
+                args.result, args.probs, n,
+                args.random_val, args.topp, args.topk, args.temperature,
+                args.stream);
+        }
+    }
+
+    template <class Tidx, class Algo>
+    static void switch_val(
+        Algo algo,
+        infiniDtype_t dt_p, size_t n, CalculateArgs args) {
+        switch (dt_p) {
+        case INFINI_DTYPE_F16:
+            switch_f<Tidx, fp16_t>(algo, n, args);
+            break;
+        case INFINI_DTYPE_F32:
+            switch_f<Tidx, float>(algo, n, args);
+            break;
+        case INFINI_DTYPE_F64:
+            switch_f<Tidx, double>(algo, n, args);
+            break;
+        default:
+            // unreachable
+            std::abort();
+        }
+    }
+
+public:
+    template <class Algo>
+    static infiniStatus_t calculate(
+        Algo algo,
+        RandomSampleInfo info,
+        void *workspace, size_t workspace_size,
+        void *result, const void *probs,
+        float random_val, float topp, int topk, float temperature,
+        void *stream) {
+
+#define CASE(DT_VAL, DT_TYP)                      \
+    case DT_VAL:                                  \
+        switch_val<DT_TYP>(                       \
+            algo, info.dt_p, info.n,              \
+            {workspace, workspace_size,           \
+             result, probs,                       \
+             random_val, topp, temperature, topk, \
+             stream});                            \
+        break
+
+        switch (info.dt_i) {
+            CASE(INFINI_DTYPE_I8, int8_t);
+            CASE(INFINI_DTYPE_I16, int16_t);
+            CASE(INFINI_DTYPE_I32, int32_t);
+            CASE(INFINI_DTYPE_I64, int64_t);
+            CASE(INFINI_DTYPE_U8, uint8_t);
+            CASE(INFINI_DTYPE_U16, uint16_t);
+            CASE(INFINI_DTYPE_U32, uint32_t);
+            CASE(INFINI_DTYPE_U64, uint64_t);
+        default:
+            // unreachable
+            std::abort();
+        }
+
+#undef CASE
+
+        return INFINI_STATUS_SUCCESS;
+    }
+};
+
+} // namespace op::random_sample
+
 #endif // __RANDOM_SAMPLE_H__