Intro-ops/python/operator_runtime/ops/softmax.py

56 lines
2.1 KiB
Python

from __future__ import annotations
import ctypes
import torch
from operator_runtime.backend import Backend, normalize_backend
from operator_runtime._internal import PreparedOp, bind_reduce_like, tensor_view
from operator_runtime.ops._common import build_prepared_op
def _check(out: torch.Tensor, src: torch.Tensor, dim: int) -> None:
if not out.is_cuda or not src.is_cuda:
raise ValueError("softmax expects CUDA tensors")
if src.dtype is not torch.float32 or out.dtype is not torch.float32:
raise TypeError("softmax v1 supports float32 only")
if src.ndim != 2 or out.ndim != 2 or dim != 1:
raise ValueError("softmax v1 supports 2D row-wise dim=1")
if out.shape != src.shape:
raise ValueError("softmax output shape must match input")
if not out.is_contiguous() or not src.is_contiguous():
raise ValueError("softmax v1 supports contiguous tensors only")
def prepare_softmax(
out: torch.Tensor,
src: torch.Tensor,
dim: int = 1,
backend: str | Backend = Backend.NVIDIA,
) -> PreparedOp:
backend = normalize_backend(backend)
_check(out, src, dim)
if backend is Backend.TILELANG:
from ops.softmax.tilelang.softmax_tl import prepare_softmax_tl
return prepare_softmax_tl(out, src, dim=dim)
if backend not in (Backend.NVIDIA, Backend.METAX):
raise NotImplementedError(f"backend {backend.value} is not runnable")
funcs = bind_reduce_like("softmax", backend)
out_view = tensor_view(out)
src_view = tensor_view(src)
create_args = (ctypes.byref(out_view), ctypes.byref(src_view), ctypes.c_int64(dim))
return build_prepared_op(funcs, create_args, (out, src), out)
def softmax_(out: torch.Tensor, src: torch.Tensor, dim: int = 1, backend: str | Backend = Backend.NVIDIA) -> torch.Tensor:
with prepare_softmax(out, src, dim, backend) as prepared:
prepared.run()
return out
def softmax(src: torch.Tensor, dim: int = 1, backend: str | Backend = Backend.NVIDIA) -> torch.Tensor:
out = torch.empty_like(src)
return softmax_(out, src, dim, backend)