[common] Add support for cuBLASLt GEMM for GroupedTensor

tests/cpp/operator/CMakeLists.txt

@@ -30,6 +30,7 @@ add_executable(test_operator
                test_causal_softmax.cu
                test_swizzle.cu
                test_swap_first_dims.cu
+               test_grouped_gemm.cu
                ../test_common.cu)
 
 # Find required packages

tests/cpp/operator/test_grouped_gemm.cu

@@ -0,0 +1,308 @@
+/*************************************************************************
+ * Copyright (c) 2022-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+ *
+ * See LICENSE for license information.
+ ************************************************************************/
+
+#include <cublasLt.h>
+#include <cuda_bf16.h>
+#include <cuda_runtime.h>
+#include <gtest/gtest.h>
+
+#include <algorithm>
+#include <memory>
+#include <numeric>
+#include <optional>
+#include <random>
+#include <tuple>
+#include <vector>
+
+#include <transformer_engine/cast.h>
+#include <transformer_engine/gemm.h>
+#include <transformer_engine/recipe.h>
+#include <transformer_engine/transformer_engine.h>
+
+#include "../test_common.h"
+
+using namespace transformer_engine;
+using namespace test;
+
+namespace {
+
+enum class InputCase {
+  kFP8Current,
+  kBF16,
+};
+
+enum class ShapeCase {
+  kAllSame,
+  kSameFirst,
+  kSameLast,
+  kAllDifferent,
+};
+
+size_t grouped_setup_workspace_size(const size_t num_tensors) {
+  const size_t ptr_bytes = num_tensors * sizeof(void*);
+  const size_t int_bytes = num_tensors * sizeof(int);
+  // Layout: 6 pointer arrays (A, B, C, D, alpha, beta) + 3 int arrays (M, N, K)
+  size_t size = 6 * ptr_bytes + 3 * int_bytes;
+  const size_t alignment = 256;
+  size = ((size + alignment - 1) / alignment) * alignment;
+  return size;
+}
+
+Tensor make_fp8_operand(const std::string& name, const std::vector<size_t>& shape) {
+  Tensor input_fp32(name + "_fp32", shape, DType::kFloat32);
+  fillUniform(&input_fp32);
+
+  Tensor fp8(name, shape, TypeInfo<fp8e4m3>::dtype, true, true, NVTE_DELAYED_TENSOR_SCALING);
+
+  nvte_compute_amax(input_fp32.data(), fp8.data(), 0);
+  QuantizationConfigWrapper config;
+  nvte_compute_scale_from_amax(fp8.data(), config, 0);
+  nvte_quantize(input_fp32.data(), fp8.data(), 0);
+  return fp8;
+}
+
+Tensor make_bf16_operand(const std::string& name, const std::vector<size_t>& shape) {
+  Tensor t(name, shape, DType::kBFloat16);
+  const size_t numel = shape[0] * shape[1];
+  std::vector<__nv_bfloat16> ones(numel, __float2bfloat16(1.0f));
+  NVTE_CHECK_CUDA(cudaMemcpy(t.rowwise_dptr(), ones.data(),
+                             numel * sizeof(__nv_bfloat16), cudaMemcpyHostToDevice));
+  return t;
+}
+
+struct TestParams {
+  InputCase input_case;
+  bool transa;
+  bool transb;
+  ShapeCase shape_case;
+  bool use_null_c = false;  // When true, pass nullptr for C (valid when beta=0)
+};
+
+// Returns a vector of (M, N, K) tuples for each GEMM in the group.
+// M - number of rows in output D
+// N - number of columns in output D
+// K - reduction dimension shared between A and B
+std::vector<std::tuple<size_t, size_t, size_t>> make_shapes(ShapeCase scase) {
+  switch (scase) {
+    case ShapeCase::kAllSame:
+      return {{64, 64, 32}, {64, 64, 32}, {64, 64, 32}};
+    case ShapeCase::kSameFirst:
+      // Same M (first dim), varying N and K
+      return {{64, 80, 32}, {64, 96, 48}, {64, 112, 64}};
+    case ShapeCase::kSameLast:
+      // Same N (last dim), varying M and K
+      return {{64, 80, 32}, {80, 80, 48}, {96, 80, 64}};
+    case ShapeCase::kAllDifferent:
+    default:
+      return {{64, 96, 32}, {80, 112, 48}, {96, 128, 64}};
+  }
+}
+
+void run_grouped_gemm_case(const TestParams& params) {
+#if CUBLAS_VERSION < 130100
+  GTEST_SKIP() << "Grouped GEMM requires cuBLAS 13.1+, but compile-time cuBLAS version is "
+               << CUBLAS_VERSION << ".";
+#else
+  if (getDeviceComputeCapability() < blackwellComputeCapability) {
+    GTEST_SKIP() << "Grouped GEMM requires Blackwell (SM100) or newer.";
+  }
+
+  const std::vector<std::tuple<size_t, size_t, size_t>> shapes = make_shapes(params.shape_case);
+
+  const size_t num_gemms = shapes.size();
+  std::vector<Tensor> A_tensors;
+  std::vector<Tensor> B_tensors;
+  std::vector<Tensor> D_multi;
+
+  A_tensors.reserve(num_gemms);
+  B_tensors.reserve(num_gemms);
+  D_multi.reserve(num_gemms);
+
+  for (size_t i = 0; i < num_gemms; ++i) {
+    const auto [M, N, K] = shapes[i];
+    const std::vector<size_t> a_shape = params.transa ? std::vector<size_t>{M, K}
+                                                      : std::vector<size_t>{K, M};
+    const std::vector<size_t> b_shape = params.transb ? std::vector<size_t>{K, N}
+                                                      : std::vector<size_t>{N, K};
+    switch (params.input_case) {
+      case InputCase::kFP8Current: {
+        A_tensors.emplace_back(make_fp8_operand("A" + std::to_string(i), a_shape));
+        B_tensors.emplace_back(make_fp8_operand("B" + std::to_string(i), b_shape));
+        break;
+      }
+      case InputCase::kBF16: {
+        A_tensors.emplace_back(make_bf16_operand("A" + std::to_string(i), a_shape));
+        B_tensors.emplace_back(make_bf16_operand("B" + std::to_string(i), b_shape));
+        break;
+      }
+    }
+    D_multi.emplace_back(Tensor("D_multi" + std::to_string(i),
+                                std::vector<size_t>{M, N},
+                                DType::kBFloat16));
+  }
+
+  std::vector<NVTETensor> A_ptrs(num_gemms);
+  std::vector<NVTETensor> B_ptrs(num_gemms);
+  std::vector<NVTETensor> D_ptrs(num_gemms);
+  std::vector<Tensor> workspaces(num_gemms);
+  std::vector<NVTETensor> workspace_ptrs(num_gemms, nullptr);
+  std::vector<Tensor*> A_views;
+  std::vector<Tensor*> B_views;
+  A_views.reserve(num_gemms);
+  B_views.reserve(num_gemms);
+
+  // Empty bias/gelu arrays for nvte_multi_tensor_gemm (no epilogues)
+  std::vector<NVTETensor> bias_ptrs(num_gemms, nullptr);
+  std::vector<NVTETensor> gelu_ptrs(num_gemms, nullptr);
+
+  const size_t cublas_ws_bytes = 32ull * 1024 * 1024;
+
+  for (size_t i = 0; i < num_gemms; ++i) {
+    A_ptrs[i] = A_tensors[i].data();
+    B_ptrs[i] = B_tensors[i].data();
+    D_ptrs[i] = D_multi[i].data();
+    workspaces[i] = Tensor("workspace" + std::to_string(i), std::vector<size_t>{cublas_ws_bytes}, DType::kByte);
+    workspace_ptrs[i] = workspaces[i].data();
+    A_views.push_back(&A_tensors[i]);
+    B_views.push_back(&B_tensors[i]);
+  }
+
+  nvte_multi_tensor_gemm(A_ptrs.data(),
+                         B_ptrs.data(),
+                         D_ptrs.data(),
+                         bias_ptrs.data(),
+                         gelu_ptrs.data(),
+                         static_cast<int>(num_gemms),
+                         params.transa,
+                         params.transb,
+                         false,  // grad
+                         workspace_ptrs.data(),
+                         false,  // accumulate
+                         false,  // use_split_accumulator
+                         0,      // sm_count
+                         0);
+
+  GroupedBuffers grouped_A = build_grouped_tensor(A_views, A_tensors[0].scaling_mode());
+  GroupedBuffers grouped_B = build_grouped_tensor(B_views, B_tensors[0].scaling_mode());
+
+  std::vector<Tensor> C_tensors;
+  std::vector<Tensor> D_group_tensors;
+  C_tensors.reserve(num_gemms);
+  D_group_tensors.reserve(num_gemms);
+  for (size_t i = 0; i < num_gemms; ++i) {
+    const auto [M, N, K] = shapes[i];
+    (void)K;
+    if (!params.use_null_c) {
+      C_tensors.emplace_back(Tensor("C" + std::to_string(i),
+                                    std::vector<size_t>{static_cast<size_t>(M), static_cast<size_t>(N)},
+                                    DType::kBFloat16));
+    }
+    D_group_tensors.emplace_back(Tensor("D_group" + std::to_string(i),
+                                        std::vector<size_t>{static_cast<size_t>(M), static_cast<size_t>(N)},
+                                        DType::kBFloat16));
+    NVTE_CHECK_CUDA(cudaMemset(D_group_tensors.back().rowwise_dptr(), 0, bytes(D_group_tensors.back().rowwise_shape(), D_group_tensors.back().dtype())));
+  }
+
+  std::vector<Tensor*> C_views, D_views;
+  for (size_t i = 0; i < num_gemms; ++i) {
+    if (!params.use_null_c) {
+      C_views.push_back(&C_tensors[i]);
+    }
+    D_views.push_back(&D_group_tensors[i]);
+  }
+
+  std::optional<GroupedBuffers> grouped_C;
+  if (!params.use_null_c) {
+    grouped_C = build_grouped_tensor(C_views, NVTE_DELAYED_TENSOR_SCALING);
+  }
+  GroupedBuffers grouped_D = build_grouped_tensor(D_views, NVTE_DELAYED_TENSOR_SCALING);
+
+  // Per-matrix alpha/beta (all 1.0 and 0.0 respectively)
+  Tensor alpha_tensor("alpha", std::vector<size_t>{num_gemms}, DType::kFloat32);
+  Tensor beta_tensor("beta", std::vector<size_t>{num_gemms}, DType::kFloat32);
+  std::vector<float> alpha_vals(num_gemms, 1.f);
+  std::vector<float> beta_vals(num_gemms, 0.f);
+  NVTE_CHECK_CUDA(cudaMemcpy(alpha_tensor.rowwise_dptr(), alpha_vals.data(),
+                             num_gemms * sizeof(float), cudaMemcpyHostToDevice));
+  NVTE_CHECK_CUDA(cudaMemcpy(beta_tensor.rowwise_dptr(), beta_vals.data(),
+                             num_gemms * sizeof(float), cudaMemcpyHostToDevice));
+
+  const size_t setup_ws_bytes = grouped_setup_workspace_size(num_gemms);
+  Tensor setup_ws("setup_ws", std::vector<size_t>{setup_ws_bytes}, DType::kByte);
+  Tensor cublas_ws("cublas_ws", std::vector<size_t>{cublas_ws_bytes}, DType::kByte);
+
+  nvte_grouped_gemm(grouped_A.get_handle(),
+                    params.transa,
+                    grouped_B.get_handle(),
+                    params.transb,
+                    params.use_null_c ? nullptr : grouped_C->get_handle(),
+                    grouped_D.get_handle(),
+                    alpha_tensor.data(),
+                    beta_tensor.data(),
+                    setup_ws.data(),
+                    cublas_ws.data(),
+                    nullptr,  // config (use defaults)
+                    0);
+
+  for (size_t i = 0; i < num_gemms; ++i) {
+    Tensor grouped_split("grouped_D" + std::to_string(i),
+                         std::vector<size_t>{static_cast<size_t>(std::get<0>(shapes[i])),
+                                             static_cast<size_t>(std::get<1>(shapes[i]))},
+                         D_multi[i].dtype());
+    const size_t offset_bytes = static_cast<size_t>(grouped_D.offsets_host[i]) * grouped_D.elem_size;
+    NVTE_CHECK_CUDA(cudaMemcpy(grouped_split.rowwise_dptr(),
+                               static_cast<char*>(grouped_D.get_data()) + offset_bytes,
+                               grouped_D.tensor_bytes[i],
+                               cudaMemcpyDeviceToDevice));
+    grouped_split.to_cpu();
+    D_multi[i].to_cpu();
+    auto [atol, rtol] = getTolerances(D_multi[i].dtype());
+    compareResults("grouped_vs_multi",
+                   grouped_split,
+                   D_multi[i].rowwise_cpu_dptr<bf16>(),
+                   true,
+                   atol,
+                   rtol);
+  }
+#endif  // CUBLAS_VERSION >= 130100
+}
+
+class GroupedGemmTest : public ::testing::TestWithParam<TestParams> {};
+
+TEST_P(GroupedGemmTest, CompareWithMultiTensorGemm) {
+  run_grouped_gemm_case(GetParam());
+}
+
+std::string MakeGroupedGemmTestName(const testing::TestParamInfo<GroupedGemmTest::ParamType>& info) {
+  constexpr const char* kInputNames[] = {"FP8Current", "BF16"};
+  constexpr const char* kShapeNames[] = {"AllSame", "SameM", "SameN", "AllDiff"};
+  const std::string layout = std::string("ta") + (info.param.transa ? "T" : "N") +
+                             "tb" + (info.param.transb ? "T" : "N");
+  const std::string null_c = info.param.use_null_c ? "_NullC" : "";
+  return std::string(kInputNames[static_cast<int>(info.param.input_case)]) + "_" +
+         kShapeNames[static_cast<int>(info.param.shape_case)] + "_" + layout + null_c;
+}
+
+// TestParams: {input_case, transa, transb, shape_case, use_null_c}
+const std::vector<TestParams> kTestParams = {
+    // Basic tests
+    {InputCase::kFP8Current, true, false, ShapeCase::kAllDifferent, false},
+    {InputCase::kFP8Current, false, true, ShapeCase::kAllDifferent, false},
+    {InputCase::kFP8Current, false, false, ShapeCase::kAllSame, false},
+    {InputCase::kBF16, true, false, ShapeCase::kSameFirst, false},
+    {InputCase::kBF16, false, true, ShapeCase::kSameLast, false},
+    {InputCase::kBF16, false, false, ShapeCase::kAllSame, false},
+    {InputCase::kBF16, true, true, ShapeCase::kAllDifferent, false},
+    // Test NULL C (valid when beta=0)
+    {InputCase::kBF16, false, false, ShapeCase::kAllSame, true},
+};
+
+INSTANTIATE_TEST_SUITE_P(OperatorTest,
+                         GroupedGemmTest,
+                         ::testing::ValuesIn(kTestParams),
+                         MakeGroupedGemmTestName);
+
+}  // namespace