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AstrAI/astrai/extension/ops/rotary.py
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ViperEkura 7540acb43e perf: dispatch linear gemv by decode batch size and unify extension style
- replace the per-shape auto tables in the linear backend with an M-banded rule (M in [2,4] on compute capability 8.0+) that measured at the HBM bandwidth floor across every family, and fold the capability check into the capable guard
- drop the unreachable swiglu auto shape-table machinery so both backends share one env-mode ladder via the new dispatch.env_mode helper
- add __all__ across extension modules, name the rotary registration records, and unify typing to the typing-module style
- rewrite test_linear_dispatch.py around behavioral routing assertions and document the M-banded policy in the developer docs
- Benchmark: L20 SM89, Python dispatch overhead 2.9us to 1.5us, auto now covers every projection shape at M in [2,4].
2026-09-03 07:23:13 +08:00

35 lines
1000 B
Python

"""Rotary embedding CUDA kernel wrapper.
Calls the compiled CUDA kernel directly. If the kernel is not available,
raises ``RuntimeError``. Fallback to torch complex multiply is the
responsibility of ``astrai.extension.backend.rotary.apply_rotary_emb``.
Layout: x is packed [tokens, n_heads, head_dim] or dense
[batch, seq_len, n_heads, head_dim]. ``freqs_cis`` has matching token axes.
"""
import torch
from astrai.extension.loader import get_module
def rotary_emb(x: torch.Tensor, freqs_cis: torch.Tensor) -> torch.Tensor:
"""Fused rotary embedding kernel.
Args:
x: packed 3D or dense 4D bf16 tensor.
freqs_cis: matching token axes followed by [head_dim/2, 2].
Returns:
Tensor with the same shape as ``x``.
"""
mod = get_module("rotary_emb")
if not x.is_contiguous():
x = x.contiguous()
if not freqs_cis.is_contiguous():
freqs_cis = freqs_cis.contiguous()
return mod.rotary_emb(x, freqs_cis)
__all__ = ["rotary_emb"]