Feature/unswizzle

tests/cpp/operator/test_swizzle.cu

@@ -56,6 +56,35 @@ void compute_ref_swizzle(const uint8_t *h_input, uint8_t *h_output,
   }
 }
 
+template <int SF_TILE_DIM_M, int SF_TILE_DIM_K, bool row_scaling>
+void compute_ref_unswizzle(const uint8_t *h_input, uint8_t *h_output,
+                           const size_t M, const size_t K) {
+
+  constexpr int NEW_SF_TILE_DIM_M = SF_TILE_DIM_M / 4;
+  constexpr int NEW_SF_TILE_DIM_K = SF_TILE_DIM_K * 4;
+  constexpr int SF_TILE_SIZE = SF_TILE_DIM_M * SF_TILE_DIM_K;
+
+  for (int m = 0; m < M; m++) {
+    for (int k = 0; k < K; k++) {
+
+      int tile_id_m = m / SF_TILE_DIM_M;
+      int tile_id_k = k / SF_TILE_DIM_K;
+      int m_in_tile = m % SF_TILE_DIM_M;
+      int k_in_tile = k % SF_TILE_DIM_K;
+
+      int row_in_new_tile = m_in_tile % NEW_SF_TILE_DIM_M;
+      int col_in_new_tile = m_in_tile / NEW_SF_TILE_DIM_M * SF_TILE_DIM_K + k_in_tile;
+
+      int tile_input_ptr = tile_id_m * SF_TILE_DIM_M * K + tile_id_k * SF_TILE_SIZE;
+      int in_index = tile_input_ptr + row_in_new_tile * NEW_SF_TILE_DIM_K + col_in_new_tile;
+      if constexpr(row_scaling)
+        h_output[k + m * K] = h_input[in_index];
+      else
+        h_output[k * M + m] = h_input[in_index];
+    }
+  }
+}
+
 void performTestSwizzle1D(const int num_tiles_M, const int num_tiles_K, bool rowwise, bool columnwise, const bool transa) {
   using namespace test;
 
@@ -110,6 +139,66 @@ void performTestSwizzle1D(const int num_tiles_M, const int num_tiles_K, bool row
   }
 }
 
+void performTestUnswizzle1D(const size_t M, const size_t K, bool rowwise, bool columnwise, const bool transa) {
+  using namespace test;
+
+  int SF_MODE_X, SF_MODE_Y;
+  if (rowwise) {
+    SF_MODE_X = 1;
+    SF_MODE_Y = 32;
+  }
+  if (columnwise) {
+    SF_MODE_X = 32;
+    SF_MODE_Y = 1;
+  }
+
+  if (!rowwise && !columnwise) {
+    GTEST_SKIP() << "TEST SKIPPED, Either rowwise or columnwise scaling mode must be true.";
+  }
+  if (rowwise && columnwise) {
+    GTEST_SKIP() << "TEST SKIPPED, The scaling mode " + std::to_string(SF_MODE_X) + "x" +
+      std::to_string(SF_MODE_Y) + " is not implemented.";
+  }
+
+  DType dtype = DType::kFloat8E4M3;
+
+  const auto data_shape = transa ? std::vector<size_t>{M, K} : std::vector<size_t>{K, M};
+
+  Tensor input("input", data_shape, dtype, rowwise, columnwise, NVTE_MXFP8_1D_SCALING);
+  input.set_with_gemm_swizzled_scales(true);
+  Tensor output("output", data_shape, dtype, rowwise, columnwise, NVTE_MXFP8_1D_SCALING);
+
+  fillUniform(&input);
+
+  // Use the actual padded compact scale shape from the tensor for both the reference
+  // and the comparison. This correctly covers padded cases where M is not a multiple
+  // of 128 or K/32 is not a multiple of 4.
+  const auto padded_scale_shape = rowwise
+    ? input.rowwise_scale_inv_shape()
+    : input.columnwise_scale_inv_shape();
+  const size_t padded_dim0 = padded_scale_shape.data[0];
+  const size_t padded_dim1 = padded_scale_shape.data[1];
+  std::unique_ptr<uint8_t[]> ref_output = std::make_unique<uint8_t[]>(padded_dim0 * padded_dim1);
+
+  nvte_unswizzle_scaling_factors(input.data(), output.data(), 0);
+
+  if (rowwise)
+    compute_ref_unswizzle<128, 4, true>(input.rowwise_cpu_scale_inv_ptr<uint8_t>(), ref_output.get(), padded_dim0, padded_dim1);
+  else
+    compute_ref_unswizzle<128, 4, false>(input.columnwise_cpu_scale_inv_ptr<uint8_t>(), ref_output.get(), padded_dim1, padded_dim0);
+
+  cudaDeviceSynchronize();
+  auto err = cudaGetLastError();
+  ASSERT_EQ(err, cudaSuccess) << cudaGetErrorString(err);
+
+  output.to_cpu();
+  if (rowwise) {
+    compareResults("output_unswizzle", output.rowwise_cpu_scale_inv_ptr<uint8_t>(), ref_output.get(), padded_dim0 * padded_dim1);
+  } else {
+    compareResults("output_unswizzle", output.columnwise_cpu_scale_inv_ptr<uint8_t>(), ref_output.get(), padded_dim0 * padded_dim1);
+  }
+}
+
 class SwizzleTestSuite : public ::testing::TestWithParam<std::tuple<std::pair<int, int>, std::pair<bool, bool>, bool>> {};
 
 
@@ -126,6 +215,21 @@ TEST_P(SwizzleTestSuite, TestSwizzle) {
                        transa);
 }
 
+class UnswizzleTestSuite : public ::testing::TestWithParam<std::tuple<std::pair<size_t, size_t>, std::pair<bool, bool>, bool>> {};
+
+TEST_P(UnswizzleTestSuite, TestUnswizzle) {
+    using namespace transformer_engine;
+    using namespace test;
+
+  const auto data_shape = std::get<0>(GetParam());
+  const auto scaling_mode = std::get<1>(GetParam());
+  const auto transa = std::get<2>(GetParam());
+
+  performTestUnswizzle1D(data_shape.first, data_shape.second,
+                         scaling_mode.first, scaling_mode.second,
+                         transa);
+}
+
 namespace {
 
 std::vector<std::pair<int, int>> num_tiles = {
@@ -138,6 +242,23 @@ std::vector<std::pair<int, int>> num_tiles = {
   {65, 259},
 };
 
+// Raw {M, K} data shapes for unswizzle tests. Includes aligned cases (scale dims
+// already multiples of 128 and 4) and padded cases where M or K/32 are not yet
+// aligned, forcing the compact scale_inv to carry a padded tail.
+// All K values must be multiples of 32 (MXFP8 block size).
+std::vector<std::pair<size_t, size_t>> unswizzle_data_shapes = {
+  // Aligned: scale dims are already multiples of 128 and 4
+  {128, 128},
+  {128, 16896},   // K = 132 * 128, large K
+  {16896, 128},   // M = 132 * 128, large M
+  // M-padding only: M not a multiple of 128 (scale-M needs padding to 256)
+  {160, 128},
+  // scale-K padding only: K/32 = 3, padded to 4
+  {128, 96},
+  // Both M and scale-K need padding
+  {160, 96},
+};
+
 std::vector<std::pair<bool, bool>> scaling_mode = {
   {true, false},
   {false, true}
@@ -164,3 +285,108 @@ INSTANTIATE_TEST_SUITE_P(
       std::to_string(std::get<2>(info.param));
     return name;
     });
+
+INSTANTIATE_TEST_SUITE_P(
+  OperatorTest,
+  UnswizzleTestSuite,
+  ::testing::Combine(
+    ::testing::ValuesIn(unswizzle_data_shapes),
+    ::testing::ValuesIn(scaling_mode),
+    ::testing::ValuesIn(transa)
+  ),
+  [](const testing::TestParamInfo<UnswizzleTestSuite::ParamType>& info) {
+    std::string name = "MK" +
+      std::to_string(std::get<0>(info.param).first) + "X" +
+      std::to_string(std::get<0>(info.param).second) + "smode" +
+      std::to_string(std::get<1>(info.param).first) + "X"+
+      std::to_string(std::get<1>(info.param).second) + "trans" +
+      std::to_string(std::get<2>(info.param));
+    return name;
+    });
+
+void performTestSwizzleUnswizzleRoundtrip(const int num_tiles_M, const int num_tiles_K, bool rowwise, bool columnwise, const bool transa) {
+  using namespace test;
+
+  int SF_MODE_X, SF_MODE_Y;
+  if (rowwise) {
+    SF_MODE_X = 1;
+    SF_MODE_Y = 32;
+  }
+  if (columnwise) {
+    SF_MODE_X = 32;
+    SF_MODE_Y = 1;
+  }
+
+  if (!rowwise && !columnwise) {
+    GTEST_SKIP() << "TEST SKIPPED, Either rowwise or columnwise scaling mode must be true.";
+  }
+  if (rowwise && columnwise){
+    GTEST_SKIP() << "TEST SKIPPED, The scaling mode " + std::to_string(SF_MODE_X) + "x" +
+      std::to_string(SF_MODE_Y) + " is not implemented.";
+  }
+
+  DType dtype = DType::kFloat8E4M3;
+
+  const size_t M = num_tiles_M * MAT_TILE_DIM_M;
+  const size_t K = num_tiles_K * MAT_TILE_DIM_K;
+  const auto data_shape = transa ? std::vector<size_t>{M, K} : std::vector<size_t>{K, M};
+
+  const auto scale_shape = std::vector<size_t>{data_shape[0] / SF_MODE_X, data_shape[1] /SF_MODE_Y};
+
+  Tensor input("input", data_shape, dtype, rowwise, columnwise, NVTE_MXFP8_1D_SCALING);
+  Tensor swizzled("swizzled", data_shape, dtype, rowwise, columnwise, NVTE_MXFP8_1D_SCALING);
+  swizzled.set_with_gemm_swizzled_scales(true);
+  Tensor output("output", data_shape, dtype, rowwise, columnwise, NVTE_MXFP8_1D_SCALING);
+
+  fillUniform(&input);
+
+  nvte_swizzle_scaling_factors(input.data(), swizzled.data(), 0);
+  nvte_unswizzle_scaling_factors(swizzled.data(), output.data(), 0);
+
+  cudaDeviceSynchronize();
+  auto err = cudaGetLastError();
+  ASSERT_EQ(err, cudaSuccess) << cudaGetErrorString(err);
+
+  input.to_cpu();
+  output.to_cpu();
+  if (rowwise) {
+    compareResults("roundtrip_rowwise", output.rowwise_cpu_scale_inv_ptr<uint8_t>(),
+                   input.rowwise_cpu_scale_inv_ptr<uint8_t>(), scale_shape[0] * scale_shape[1]);
+  } else {
+    compareResults("roundtrip_columnwise", output.columnwise_cpu_scale_inv_ptr<uint8_t>(),
+                   input.columnwise_cpu_scale_inv_ptr<uint8_t>(), scale_shape[0] * scale_shape[1]);
+  }
+}
+
+class SwizzleUnswizzleRoundtripTestSuite : public ::testing::TestWithParam<std::tuple<std::pair<int, int>, std::pair<bool, bool>, bool>> {};
+
+TEST_P(SwizzleUnswizzleRoundtripTestSuite, TestSwizzleUnswizzleRoundtrip) {
+  using namespace transformer_engine;
+  using namespace test;
+
+  const auto num_tiles = std::get<0>(GetParam());
+  const auto scaling_mode = std::get<1>(GetParam());
+  const auto transa = std::get<2>(GetParam());
+
+  performTestSwizzleUnswizzleRoundtrip(num_tiles.first, num_tiles.second,
+                                       scaling_mode.first, scaling_mode.second,
+                                       transa);
+}
+
+INSTANTIATE_TEST_SUITE_P(
+  OperatorTest,
+  SwizzleUnswizzleRoundtripTestSuite,
+  ::testing::Combine(
+    ::testing::ValuesIn(num_tiles),
+    ::testing::ValuesIn(scaling_mode),
+    ::testing::ValuesIn(transa)
+  ),
+  [](const testing::TestParamInfo<SwizzleUnswizzleRoundtripTestSuite::ParamType>& info) {
+    std::string name = "roundtrip_ntiles" +
+      std::to_string(std::get<0>(info.param).first) + "X" +
+      std::to_string(std::get<0>(info.param).second) + "smode" +
+      std::to_string(std::get<1>(info.param).first) + "X"+
+      std::to_string(std::get<1>(info.param).second) + "trans" +
+      std::to_string(std::get<2>(info.param));
+    return name;
+    });

transformer_engine/common/include/transformer_engine/swizzle.h

@@ -45,6 +45,34 @@ void nvte_swizzle_scaling_factors(const NVTETensor input, NVTETensor output, cud
 void nvte_multi_tensor_swizzle_scaling_factors(const NVTETensor* inputs, NVTETensor* outputs,
                                                const size_t num_tensors, cudaStream_t stream);
 
+/*! \brief Unswizzling scaling factors from the interleaved layout used by GEMM back to row-major
+ *
+ *  \param[in]     input        Input tensor with swizzled scale_inv.
+ *  \param[in,out] output       Output tensor which hosts non-swizzled scale_inv.
+ *  \param[in]     stream       CUDA stream used for the operation.
+ *
+ *  Requirements:
+ *  - scale_inv is stored in row-major in output.
+ *  - scale_inv size is padded to 128x4 for row-scale and 4x128 for col-scale.
+ *  - data is quantitized along K-dimension, i.e. 1D-scaling block lies along the K-dimension.
+ */
+void nvte_unswizzle_scaling_factors(const NVTETensor input, NVTETensor output, cudaStream_t stream);
+
+/*! \brief Unswizzling scaling factors from the interleaved layout used by GEMM back to row-major
+ *
+ *  \param[in]     inputs       Input tensors with swizzled scale_inv.
+ *  \param[in,out] outputs      Output tensors which hosts non-swizzled scale_inv.
+ *  \param[in]     num_tensors  Number of input and output tensors.
+ *  \param[in]     stream       CUDA stream used for the operation.
+ *
+ *  Requirements:
+ *  - scale_inv is stored in row-major in output.
+ *  - scale_inv size is padded to 128x4 for row-scale and 4x128 for col-scale.
+ *  - data is quantitized along K-dimension, i.e. 1D-scaling block lies along the K-dimension.
+ */
+void nvte_multi_tensor_unswizzle_scaling_factors(const NVTETensor* inputs, NVTETensor* outputs,
+                                                 const size_t num_tensors, cudaStream_t stream);
+
 /*! \brief Swizzling FP8 block scaling scaling factors into mxfp8 interleaved layout for GEMM
  *
  *  \param[in]     input        Input FP8 block-scaled tensor.