Files
xc-llm-ascend/vllm_ascend/meta_registration.py
wangxiyuan 6c49f95da2 [Ops][Refactor] Remove custom rotary_embedding operator (#6523)
### What this PR does / why we need it?
This PR removes the custom `rotary_embedding` operator and its
associated C++ kernel implementation, PyTorch bindings, and tests.

The codebase now falls back to using the native
`torch_npu._npu_rotary_embedding` implementation. This change simplifies
the codebase by removing custom, platform-specific kernel code and
relying on the standard NPU library implementation, which is presumably
more optimized and easier to maintain.

### Does this PR introduce _any_ user-facing change?
No. This is an internal refactoring and does not introduce any
user-facing changes.

### How was this patch tested?
The tests for the custom `rotary_embedding` operator have been removed
along with the operator itself. The correctness of the fallback to the
native `torch_npu` implementation is verified by existing CI tests for
attention layers and models that use rotary embeddings.

- vLLM version: v0.15.0
- vLLM main: https://github.com/vllm-project/vllm/commit/v0.15.0

Signed-off-by: wangxiyuan <wangxiyuan1007@gmail.com>
2026-02-07 09:24:05 +08:00

92 lines
3.5 KiB
Python

import torch
from torch.library import Library
# This file provides a template and registration utilities for writing "meta" implementations
# of custom operators in Python for the vllm_ascend project.
#
# We offer two ways to implement meta implementations for custom ops:
# 1. Python meta implementation (as shown in this file): Write a Python function that
# takes the same arguments as your operator and returns empty tensors with the correct
# shapes and dtypes. This is useful for rapid prototyping and for ops that are only
# used in Python.
# 2. C++ meta implementation: You can also implement the meta function in C++ for better
# performance or to match the C++ op logic more closely. See `torch_binding_meta.cpp`
# for examples of C++ meta implementations and how to register them.
#
# Both approaches enable tracing, export, and shape inference in PyTorch and vLLM, which
# is essential for supporting `torch.compile` and aclgraph.
# How to add a new meta implementation in Python:
# -------------------------------------
# 1. Write a Python function that takes the same arguments as your operator, and returns
# empty tensors (using torch.empty_like, torch.empty, etc.) with the correct shapes and dtypes.
# Do NOT perform any real computation or allocate device memory.
#
# 2. Register your meta function using `register_meta_if_necessary`, providing:
# - The namespace (usually "_C_ascend" for custom ops)
# - The operator name (as registered in C++)
# - The Python meta function
# - (Optional) The overload name, if your op has overloads
#
# 3. The registration utility will check if a meta implementation already exists for your op,
# and only register if necessary. This avoids duplicate registrations.
#
# 4. Example meta implementations are provided below for get_masked_input_and_mask.
#
# 5. When developing new custom ops, always provide a meta implementation to enable tracing,
# export, and shape inference in PyTorch and vLLM to enable the capture of `torch.compile`
# and aclgraph.
#
# For more details, see: https://pytorch.org/docs/stable/notes/extending.html#meta-tensors
lib = Library("_C_ascend", "IMPL")
def register_meta_if_necessary(ns: str, op_name: str, fn, overload: str = ""):
if overload != "":
op_name = op_name + "." + overload
schema_to_find = ns + "::" + op_name
meta_impl_list = torch._C._dispatch_get_registrations_for_dispatch_key("Meta")
if schema_to_find in meta_impl_list:
return
lib.impl(op_name, fn, "Meta")
def get_masked_input_and_mask_meta(
input: torch.Tensor,
org_vocab_start_index: int,
org_vocab_end_index: int,
num_org_vocab_padding: int,
added_vocab_start_index: int,
added_vocab_end_index: int,
):
masked_input = torch.empty_like(input)
mask = torch.empty_like(input).to(torch.bool)
return masked_input, mask
def bgmv_expand_meta(
x: torch.Tensor, weight: torch.Tensor, indices: torch.Tensor, y: torch.Tensor, slice_offset: int, slice_size: int
):
y_out = torch.empty_like(y)
return y_out
def sgmv_expand_meta(
x: torch.Tensor,
weight: torch.Tensor,
lora_indices: torch.Tensor,
seq_len: torch.Tensor,
y: torch.Tensor,
slice_offset: int,
slice_size: int,
):
y_out = torch.empty_like(y)
return y_out
register_meta_if_necessary("_C_ascend", "get_masked_input_and_mask", get_masked_input_and_mask_meta)
register_meta_if_necessary("_C_ascend", "bgmv_expand", bgmv_expand_meta)
register_meta_if_necessary("_C_ascend", "sgmv_expand", sgmv_expand_meta)