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sglang/python/sglang/jit_kernel/per_tensor_quant_fp8.py

61 lines
1.8 KiB
Python

from __future__ import annotations
import os
from typing import TYPE_CHECKING
import flashinfer
import torch
from torch.utils.cpp_extension import CUDA_HOME
from sglang.jit_kernel.utils import cache_once, load_jit, make_cpp_args
from sglang.srt.utils.custom_op import register_custom_op
if TYPE_CHECKING:
from tvm_ffi.module import Module
@cache_once
def _jit_per_tensor_quant_fp8_module(is_static: bool) -> Module:
args = make_cpp_args(is_static)
flashinfer_include = os.path.join(
os.path.dirname(flashinfer.__file__), "data", "include"
)
cub_include = os.path.join(CUDA_HOME, "include")
return load_jit(
"per_tensor_quant_fp8",
*args,
cuda_files=["gemm/per_tensor_quant_fp8.cuh"],
cuda_wrappers=[("per_tensor_quant_fp8", f"per_tensor_quant_fp8<{args}>")],
extra_include_paths=[flashinfer_include, cub_include],
)
@register_custom_op(
op_name="per_tensor_quant_fp8",
mutates_args=["output_q", "output_s"],
)
def per_tensor_quant_fp8(
input: torch.Tensor,
output_q: torch.Tensor,
output_s: torch.Tensor,
is_static: bool = False,
) -> None:
"""
Per-tensor quantization to FP8 format.
Args:
input: Input tensor to quantize (float, half, or bfloat16)
output_q: Output quantized tensor (fp8_e4m3)
output_s: Output scale tensor (float scalar or 1D tensor with 1 element)
is_static: If True, assumes scale is pre-computed and skips absmax computation
"""
# Ensure output_s has shape [1] instead of being a 0D scalar
# The JIT kernel expects a 1D tensor
if output_s.ndim == 0:
output_s = output_s.reshape(1)
module = _jit_per_tensor_quant_fp8_module(is_static)
module.per_tensor_quant_fp8(input, output_q, output_s)