[FlashInver v0.6.7] Integrate flashinfer_trtllm mxfp8 gemm (#21576)

This commit is contained in:
Ziang Li
2026-04-01 15:55:06 -04:00
committed by GitHub
parent a1c725bdc5
commit a19ef3a615
3 changed files with 75 additions and 28 deletions
+33 -13
View File
@@ -495,20 +495,44 @@ class Fp8LinearMethod(LinearMethodBase):
return
if get_fp8_gemm_runner_backend().is_flashinfer_trtllm():
from flashinfer import shuffle_matrix_a, shuffle_matrix_sf_a
weight = layer.weight.data
scale_u8 = layer.weight_scale_inv.data
n, k = weight.shape
epilogue_tile_m = 128
copy_or_rebind_param(
layer,
"weight",
shuffle_matrix_a(
weight.contiguous().view(torch.uint8), epilogue_tile_m
).view(torch.float8_e4m3fn),
)
copy_or_rebind_param(
layer,
"weight_scale_inv",
shuffle_matrix_sf_a(
scale_u8.contiguous().view(torch.uint8).reshape(n, k // 32),
epilogue_tile_m,
num_elts_per_sf=32,
)
.reshape_as(scale_u8)
.contiguous(),
)
elif get_fp8_gemm_runner_backend().is_flashinfer_cutlass():
from flashinfer import block_scale_interleave
scale_u8 = layer.weight_scale_inv.data
new_swizzled = block_scale_interleave(scale_u8.contiguous()).contiguous()
copy_or_rebind_param(
layer,
"weight_scale_inv",
block_scale_interleave(scale_u8.contiguous()).contiguous(),
)
else:
# Triton path consumes canonical 2D UE8M0 scales directly.
return
copy_or_rebind_param(layer, "weight_scale_inv_swizzled", new_swizzled)
layer._weight_scale_inv_swizzled_src_version = layer.weight_scale_inv._version
layer._weight_scale_inv_swizzled_src_data_ptr = (
layer.weight_scale_inv.data_ptr()
)
def _quantize_mxfp8_weights(self, layer: Module) -> None:
weight = layer.weight.data
qweight, weight_scale = mxfp8_group_quantize(weight)
@@ -657,22 +681,18 @@ class Fp8LinearMethod(LinearMethodBase):
)
if self.use_mxfp8:
if get_fp8_gemm_runner_backend().is_flashinfer_trtllm():
weight_scale = layer.weight_scale_inv_swizzled
else:
weight_scale = layer.weight_scale_inv
if isinstance(x, tuple):
return self.w8a8_mxfp8_linear(
input=x[0],
weight=layer.weight,
weight_scale=weight_scale,
weight_scale=layer.weight_scale_inv,
input_scale=x[1],
bias=bias,
)
return self.w8a8_mxfp8_linear(
input=x,
weight=layer.weight,
weight_scale=weight_scale,
weight_scale=layer.weight_scale_inv,
input_scale=None,
bias=bias,
)
@@ -214,6 +214,7 @@ def _check_cutlass_block_fp8_hardware_support() -> bool:
if is_blackwell_supported() and is_flashinfer_available():
from flashinfer import SfLayout
from flashinfer import mm_mxfp8 as _raw_flashinfer_mm_mxfp8
from flashinfer import mxfp8_quantize as _raw_flashinfer_mxfp8_quantize
from flashinfer.gemm import gemm_fp8_nt_groupwise as _raw_gemm_fp8_nt_groupwise
@@ -303,12 +304,13 @@ if is_blackwell_supported() and is_flashinfer_available():
input,
is_sf_swizzled_layout=is_sf_swizzled_layout,
alignment=alignment,
sf_swizzle_layout=SfLayout.layout_128x4,
)
@register_custom_op(
op_name="flashinfer_mm_mxfp8",
mutates_args=[],
fake_impl=lambda q_input, weight_t, x_scale_u8, weight_scale_t, out_dtype, backend="auto": (
fake_impl=lambda q_input, weight_t, x_scale_u8, weight_scale_t, out_dtype, use_8x4_sf_layout=False, backend="auto": (
q_input.new_empty((q_input.shape[0], weight_t.shape[1]), dtype=out_dtype)
),
)
@@ -318,6 +320,7 @@ if is_blackwell_supported() and is_flashinfer_available():
x_scale_u8: torch.Tensor,
weight_scale_t: torch.Tensor,
out_dtype: torch.dtype,
use_8x4_sf_layout: bool = False,
backend: str = "auto",
) -> torch.Tensor:
return _raw_flashinfer_mm_mxfp8(
@@ -326,6 +329,7 @@ if is_blackwell_supported() and is_flashinfer_available():
x_scale_u8,
weight_scale_t,
out_dtype=out_dtype,
use_8x4_sf_layout=use_8x4_sf_layout,
backend=backend,
)
@@ -357,11 +361,13 @@ def dispatch_w8a8_mxfp8_linear() -> Callable:
"""Dispatch MXFP8 linear kernel by --fp8-gemm-backend.
For MXFP8, Triton remains the default path. We only route to FlashInfer
when backend is explicitly set to flashinfer_trtllm.
when backend is explicitly set to flashinfer_cutlass or flashinfer_trtllm.
"""
backend = get_fp8_gemm_runner_backend()
if backend.is_flashinfer_trtllm():
return flashinfer_mxfp8_blockscaled_linear
elif backend.is_flashinfer_cutlass():
return flashinfer_mxfp8_blockscaled_linear
return triton_mxfp8_blockscaled_linear
@@ -962,6 +968,7 @@ def flashinfer_mxfp8_blockscaled_linear(
)
else:
q_input = input_2d
x_scale_u8 = input_scale.contiguous()
if output_dtype is None:
if input_2d.dtype in (torch.float16, torch.bfloat16, torch.float32):
@@ -971,19 +978,34 @@ def flashinfer_mxfp8_blockscaled_linear(
# Ensure transposed tensors are contiguous for FlashInfer's internal runner.
weight_t = weight.contiguous().t()
weight_scale_t = (
weight_scale.contiguous().t()
if weight_scale.ndim == 2
else weight_scale.contiguous()
)
output = flashinfer_mm_mxfp8(
q_input,
weight_t,
x_scale_u8,
weight_scale_t,
out_dtype=output_dtype,
backend="auto",
)
if get_fp8_gemm_runner_backend().is_flashinfer_trtllm():
weight_scale_t = weight_scale.contiguous().view(-1)
output = flashinfer_mm_mxfp8(
q_input,
weight_t,
x_scale_u8,
weight_scale_t,
out_dtype=output_dtype,
use_8x4_sf_layout=False,
backend="trtllm",
)
elif get_fp8_gemm_runner_backend().is_flashinfer_cutlass():
weight_scale_t = (
weight_scale.contiguous().t()
if weight_scale.ndim == 2
else weight_scale.contiguous()
)
output = flashinfer_mm_mxfp8(
q_input,
weight_t,
x_scale_u8,
weight_scale_t,
out_dtype=output_dtype,
use_8x4_sf_layout=False,
backend="cutlass",
)
if bias is not None:
output += bias