[ROCm] Enable fused_silu_mul_block_quant on ROCm (#38817)

Signed-off-by: Gregory Shtrasberg <Gregory.Shtrasberg@amd.com>

CMakeLists.txt

@@ -299,6 +299,7 @@ set(VLLM_EXT_SRC
   "csrc/quantization/w8a8/int8/scaled_quant.cu"
   "csrc/quantization/w8a8/fp8/common.cu"
   "csrc/quantization/fused_kernels/fused_layernorm_dynamic_per_token_quant.cu"
+  "csrc/quantization/fused_kernels/fused_silu_mul_block_quant.cu"
   "csrc/quantization/gguf/gguf_kernel.cu"
   "csrc/quantization/activation_kernels.cu"
   "csrc/cuda_utils_kernels.cu"
@@ -340,8 +341,7 @@ if(VLLM_GPU_LANG STREQUAL "CUDA")
 
   list(APPEND VLLM_EXT_SRC
     "csrc/quantization/awq/gemm_kernels.cu"
-    "csrc/cutlass_extensions/common.cpp"
-    "csrc/quantization/fused_kernels/fused_silu_mul_block_quant.cu")
+    "csrc/cutlass_extensions/common.cpp")
 
   set_gencode_flags_for_srcs(
     SRCS "${VLLM_EXT_SRC}"

csrc/ops.h

@@ -143,13 +143,11 @@ void rms_norm_per_block_quant(torch::Tensor& out, torch::Tensor const& input,
                               std::optional<torch::Tensor> residual,
                               int64_t group_size, bool is_scale_transposed);
 
-#ifndef USE_ROCM
 void silu_and_mul_per_block_quant(torch::Tensor& out,
                                   torch::Tensor const& input,
                                   torch::Tensor& scales, int64_t group_size,
                                   std::optional<torch::Tensor> scale_ub,
                                   bool is_scale_transposed);
-#endif
 
 void rotary_embedding(torch::Tensor& positions, torch::Tensor& query,
                       std::optional<torch::Tensor> key, int64_t head_size,

csrc/quantization/fused_kernels/quant_conversions.cuh

@@ -6,7 +6,7 @@
 
 #include "libtorch_stable/quantization/vectorization.cuh"
 // TODO(luka/varun):refactor common.cuh to use this file instead
-#include "quantization/w8a8/fp8/common.cuh"
+#include "../w8a8/fp8/common.cuh"
 
 namespace vllm {
 

csrc/quantization/w8a8/fp8/common.cuh

@@ -1,7 +1,7 @@
 #pragma once
 
 #include "libtorch_stable/quantization/vectorization.cuh"
-#include "quantization/utils.cuh"
+#include "../../utils.cuh"
 
 #include <cmath>
 

csrc/torch_bindings.cpp

@@ -110,6 +110,18 @@ TORCH_LIBRARY_EXPAND(TORCH_EXTENSION_NAME, ops) {
       "silu_and_mul_quant(Tensor! result, Tensor input, Tensor scale) -> ()");
   ops.impl("silu_and_mul_quant", torch::kCUDA, &silu_and_mul_quant);
 
+  // Fused SiLU+Mul + per-block quantization
+  ops.def(
+      "silu_and_mul_per_block_quant("
+      "Tensor! out, "
+      "Tensor input, "
+      "Tensor! scales, "
+      "int group_size, "
+      "Tensor? scale_ub=None, "
+      "bool is_scale_transposed=False) -> ()");
+  ops.impl("silu_and_mul_per_block_quant", torch::kCUDA,
+           &silu_and_mul_per_block_quant);
+
   ops.def("mul_and_silu(Tensor! out, Tensor input) -> ()");
   ops.impl("mul_and_silu", torch::kCUDA, &mul_and_silu);
 
@@ -233,17 +245,6 @@ TORCH_LIBRARY_EXPAND(TORCH_EXTENSION_NAME, ops) {
 
   // Quantization ops
 #ifndef USE_ROCM
-  // Fused SiLU+Mul + per-block quantization
-  ops.def(
-      "silu_and_mul_per_block_quant("
-      "Tensor! out, "
-      "Tensor input, "
-      "Tensor! scales, "
-      "int group_size, "
-      "Tensor? scale_ub=None, "
-      "bool is_scale_transposed=False) -> ()");
-  ops.impl("silu_and_mul_per_block_quant", torch::kCUDA,
-           &silu_and_mul_per_block_quant);
   // DeepSeek V3 fused A GEMM (SM 9.0+, bf16 only, 1-16 tokens).
   ops.def(
       "dsv3_fused_a_gemm(Tensor! output, Tensor mat_a, Tensor mat_b) -> ()");

tests/kernels/core/test_fused_silu_mul_block_quant.py

@@ -16,7 +16,7 @@ from vllm.model_executor.layers.quantization.utils.int8_utils import (
 from vllm.platforms import current_platform
 
 DTYPES = [torch.float16, torch.bfloat16]
-QUANT_DTYPES = [torch.float8_e4m3fn, torch.int8]
+QUANT_DTYPES = [current_platform.fp8_dtype(), torch.int8]
 VEC_HIDDEN_SIZES = [1024, 1025, 1027, 1029]
 NUM_TOKENS_HIDDEN_SIZES = [
     *[(1, i) for i in [64, *VEC_HIDDEN_SIZES, 2048, 5120]],
@@ -28,9 +28,7 @@ SCALE_UBS = [False]
 GROUP_SIZES = [64, 128]
 IS_SCALE_TRANSPOSED = [False, True]
 SEEDS = [0]
-CUDA_DEVICES = [
-    f"cuda:{i}" for i in range(1 if torch.accelerator.device_count() == 1 else 2)
-]
+CUDA_DEVICES = [i for i in range(1 if torch.accelerator.device_count() == 1 else 2)]
 
 
 def ref_silu_and_mul_per_block_quant(
@@ -60,7 +58,7 @@ def ref_silu_and_mul_per_block_quant(
 @pytest.mark.parametrize("group_size", GROUP_SIZES)
 @pytest.mark.parametrize("is_scale_transposed", IS_SCALE_TRANSPOSED)
 @pytest.mark.parametrize("seed", SEEDS)
-@pytest.mark.parametrize("device", CUDA_DEVICES)
+@pytest.mark.parametrize("device_idx", CUDA_DEVICES)
 @torch.inference_mode()
 def test_silu_and_mul_per_block_quant(
     default_vllm_config,
@@ -72,9 +70,11 @@ def test_silu_and_mul_per_block_quant(
     group_size: int,
     is_scale_transposed: bool,
     seed: int,
-    device: str,
+    device_idx: str,
 ) -> None:
     """Test SiLU+Mul+Block Quantization kernel correctness."""
+    torch.accelerator.set_device_index(device_idx)
+    device = f"cuda:{device_idx}"
     torch.random.manual_seed(seed)
     torch.set_default_device(device)
 
@@ -147,7 +147,7 @@ def test_silu_block_quant_shapes(
     out, scales = ops.silu_and_mul_per_block_quant(
         x,
         group_size=group_size,
-        quant_dtype=torch.float8_e4m3fn,
+        quant_dtype=current_platform.fp8_dtype(),
         is_scale_transposed=False,
     )
     assert out.shape == (num_tokens, hidden_size)
@@ -157,7 +157,7 @@ def test_silu_block_quant_shapes(
     out, scales = ops.silu_and_mul_per_block_quant(
         x,
         group_size=group_size,
-        quant_dtype=torch.float8_e4m3fn,
+        quant_dtype=current_platform.fp8_dtype(),
         is_scale_transposed=True,
     )
     assert out.shape == (num_tokens, hidden_size)
@@ -177,12 +177,12 @@ def test_silu_block_quant_edge_cases(
     out, scales = ops.silu_and_mul_per_block_quant(
         x,
         group_size=128,
-        quant_dtype=torch.float8_e4m3fn,
+        quant_dtype=current_platform.fp8_dtype(),
         is_scale_transposed=False,
     )
 
     assert out.shape == (batch_size, hidden_size)
-    assert out.dtype == torch.float8_e4m3fn
+    assert out.dtype == current_platform.fp8_dtype()
     assert scales.dtype == torch.float32
     assert not torch.isnan(out.float()).any()
     assert not torch.isnan(scales).any()

vllm/compilation/passes/fusion/act_quant_fusion.py

@@ -45,7 +45,7 @@ silu_and_mul_nvfp4_quant_supported = current_platform.is_cuda() and hasattr(
 if silu_and_mul_nvfp4_quant_supported:
     FUSED_OPS[kNvfp4Dynamic] = torch.ops._C.silu_and_mul_nvfp4_quant.default  # noqa: E501
 
-if current_platform.is_cuda():
+if current_platform.is_cuda_alike():
     FUSED_OPS[kFp8Dynamic128Sym] = torch.ops._C.silu_and_mul_per_block_quant.default
     FUSED_OPS[kFp8Dynamic64Sym] = torch.ops._C.silu_and_mul_per_block_quant.default
 
@@ -301,7 +301,7 @@ class ActivationQuantFusionPass(VllmPatternMatcherPass):
             pattern_silu_mul_nvfp4 = SiluMulNvfp4QuantPattern()
             pattern_silu_mul_nvfp4.register(self.patterns)
 
-        if current_platform.is_cuda():
+        if current_platform.is_cuda_alike():
             for quant_key in [kFp8Dynamic128Sym, kFp8Dynamic64Sym]:
                 for is_scale_transposed in [False, True]:
                     for is_e8m0 in [True, False]: