v1.0
This commit is contained in:
578
model_executor/layers/layernorm.py
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578
model_executor/layers/layernorm.py
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@@ -0,0 +1,578 @@
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# SPDX-License-Identifier: Apache-2.0
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# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
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"""Custom normalization layers."""
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import torch
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import torch.nn as nn
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import torch.nn.functional as F
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from vllm._aiter_ops import rocm_aiter_ops
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from vllm.model_executor.custom_op import CustomOp
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from vllm.model_executor.layers.batch_invariant import (
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rms_norm_batch_invariant,
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vllm_is_batch_invariant,
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)
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from vllm.platforms import current_platform
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def rms_norm(
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x: torch.Tensor, weight: torch.Tensor, variance_epsilon: float
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) -> torch.Tensor:
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from vllm import _custom_ops as ops
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if vllm_is_batch_invariant():
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return rms_norm_batch_invariant(x, weight, variance_epsilon)
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out = torch.empty_like(x)
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ops.rms_norm(
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out,
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x,
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weight,
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variance_epsilon,
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)
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return out
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def fused_add_rms_norm(
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x: torch.Tensor,
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residual: torch.Tensor,
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weight: torch.Tensor,
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variance_epsilon: float,
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residual_alpha: float = 1.0
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) -> tuple[torch.Tensor, torch.Tensor]:
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from vllm import _custom_ops as ops
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if vllm_is_batch_invariant():
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return rms_norm_batch_invariant(
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x + residual, weight, variance_epsilon
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), x + residual
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x, residual = ops.fused_add_rms_norm(
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x,
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residual,
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weight,
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variance_epsilon,
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residual_alpha,
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)
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return x, residual
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def poly_norm(
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x: torch.Tensor, weight: torch.Tensor, bias: torch.Tensor, variance_epsilon: float
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) -> torch.Tensor:
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from vllm import _custom_ops as ops
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out = torch.empty_like(x)
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ops.poly_norm(
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out,
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x,
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weight,
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bias,
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variance_epsilon,
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)
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return out
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def dispatch_rocm_rmsnorm_func(
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with_fused_add: bool, dtype: torch.dtype, use_aiter: bool = False
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):
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use_aiter = use_aiter and dtype in [
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torch.float16,
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torch.bfloat16,
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]
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if use_aiter and with_fused_add:
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return rocm_aiter_ops.rms_norm2d_with_add
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if use_aiter:
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return rocm_aiter_ops.rms_norm
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# fall back to CUDA implementation
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if with_fused_add:
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return fused_add_rms_norm
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return rms_norm
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def rms_norm_qk(
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input_q: torch.Tensor,
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input_k: torch.Tensor,
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weight_q: torch.Tensor,
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weight_k: torch.Tensor,
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epsilon: float,
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) -> tuple[torch.Tensor, torch.Tensor]:
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from vllm import _custom_ops as ops
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output_q = torch.empty_like(input_q)
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output_k = torch.empty_like(input_k)
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ops.rms_norm_qk(
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output_q, output_k, input_q, input_k, weight_q, weight_k, epsilon
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)
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return output_q, output_k
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@CustomOp.register("rms_norm_qk")
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class RMSNormQK(CustomOp):
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"""
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Root Mean Square Normalization for Query/Key tensors.
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Computes:
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q -> w_q * q / sqrt(E[q^2] + eps)
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k -> w_k * k / sqrt(E[k^2] + eps)
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"""
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def __init__(
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self,
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hidden_size_q: int,
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hidden_size_k: int,
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eps: float = 1e-6,
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) -> None:
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super().__init__()
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self.hidden_size_q = hidden_size_q
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self.hidden_size_k = hidden_size_k
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self.variance_epsilon = eps
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def forward_native(
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self,
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input_q: torch.Tensor,
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input_k: torch.Tensor,
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weight_q: torch.Tensor,
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weight_k: torch.Tensor,
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) -> tuple[torch.Tensor, torch.Tensor]:
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if input_q.shape[-1] != self.hidden_size_q:
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raise ValueError(
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f"[RMSNormQK] Expected input_q last dim = {self.hidden_size_q}, "
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f"but got {input_q.shape[-1]}"
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)
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if input_k.shape[-1] != self.hidden_size_k:
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raise ValueError(
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f"[RMSNormQK] Expected input_k last dim = {self.hidden_size_k}, "
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f"but got {input_k.shape[-1]}"
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)
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if input_q.dtype != input_k.dtype:
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raise TypeError(
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f"[RMSNormQK] Expected input_q and input_k have same dtype, "
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f"but got {input_q.dtype} vs {input_k.dtype}"
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)
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xq = input_q.to(torch.float32)
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xk = input_k.to(torch.float32)
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var_q = xq.pow(2).mean(dim=-1, keepdim=True)
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var_k = xk.pow(2).mean(dim=-1, keepdim=True)
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out_q = xq * torch.rsqrt(var_q + self.variance_epsilon)
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out_k = xk * torch.rsqrt(var_k + self.variance_epsilon)
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out_q = out_q * weight_q
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out_k = out_k * weight_k
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return out_q.to(input_q.dtype), out_k.to(input_k.dtype)
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def forward_cuda(
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self,
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input_q: torch.Tensor,
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input_k: torch.Tensor,
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weight_q: torch.Tensor,
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weight_k: torch.Tensor,
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) -> tuple[torch.Tensor, torch.Tensor]:
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if input_q.shape[-1] != self.hidden_size_q:
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raise ValueError(
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f"[RMSNormQK] CUDA path: Expected input_q last dim = {self.hidden_size_q}, "
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f"but got {input_q.shape[-1]}"
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)
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if input_k.shape[-1] != self.hidden_size_k:
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raise ValueError(
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f"[RMSNormQK] CUDA path: Expected input_k last dim = {self.hidden_size_k}, "
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f"but got {input_k.shape[-1]}"
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)
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if input_q.dtype != input_k.dtype:
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raise TypeError(
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f"[RMSNormQK] Expected input_q and input_k to have same dtype, "
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f"but got {input_q.dtype} vs {input_k.dtype}"
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)
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return rms_norm_qk(
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input_q,
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input_k,
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weight_q,
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weight_k,
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self.variance_epsilon,
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)
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def forward_xpu(
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self,
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input_q: torch.Tensor,
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input_k: torch.Tensor,
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weight_q: torch.Tensor,
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weight_k: torch.Tensor,
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) -> tuple[torch.Tensor, torch.Tensor]:
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from vllm._ipex_ops import ipex_ops as ops
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out_q = ops.rms_norm(
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input_q,
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weight_q,
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self.variance_epsilon,
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)
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out_k = ops.rms_norm(
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input_k,
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weight_k,
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self.variance_epsilon,
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)
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return out_q, out_k
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def extra_repr(self) -> str:
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return (
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f"RMSNormQK(hidden_size_q={self.hidden_size_q}, "
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f"hidden_size_k={self.hidden_size_k}, "
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f"eps={self.variance_epsilon}, "
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)
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@CustomOp.register("rms_norm")
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class RMSNorm(CustomOp):
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"""Root mean square normalization.
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Computes x -> w * x / sqrt(E[x^2] + eps) where w is the learned weight.
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Refer to https://arxiv.org/abs/1910.07467
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"""
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def __init__(
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self,
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hidden_size: int,
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eps: float = 1e-6,
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var_hidden_size: int | None = None,
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has_weight: bool = True,
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dtype: torch.dtype | None = None,
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) -> None:
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super().__init__()
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self.hidden_size = hidden_size
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self.variance_epsilon = eps
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self.variance_size_override = (
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None if var_hidden_size == hidden_size else var_hidden_size
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)
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weight_dtype = dtype or torch.get_default_dtype()
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self.has_weight = has_weight
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self.weight = torch.ones(hidden_size, dtype=weight_dtype)
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if self.has_weight:
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self.weight = nn.Parameter(self.weight)
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if current_platform.is_rocm():
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aiter_rmsnorm_enabled = rocm_aiter_ops.is_rmsnorm_enabled()
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self.rocm_norm_func = dispatch_rocm_rmsnorm_func(
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with_fused_add=False,
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dtype=weight_dtype,
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use_aiter=aiter_rmsnorm_enabled,
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)
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self.rocm_norm_func_with_add = dispatch_rocm_rmsnorm_func(
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with_fused_add=True, dtype=weight_dtype, use_aiter=aiter_rmsnorm_enabled
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)
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@staticmethod
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def forward_static(
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x: torch.Tensor,
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variance_epsilon: float,
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hidden_size: int,
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orig_dtype: torch.dtype,
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weight: torch.Tensor | None = None,
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residual: torch.Tensor | None = None,
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variance_size_override: int | None = None,
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) -> torch.Tensor | tuple[torch.Tensor, torch.Tensor]:
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"""PyTorch-native implementation equivalent to forward()."""
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x = x.to(torch.float32)
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if residual is not None:
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# residual promoted f16->f32 automatically,
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# otherwise Inductor eliminates the casts to and from f16,
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# increasing memory usage (and complicating pattern matching)
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x = x + residual
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residual = x.to(orig_dtype)
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if x.shape[-1] != hidden_size:
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raise ValueError(
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f"Expected hidden_size to be {hidden_size}, but found: {x.shape[-1]}"
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)
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if variance_size_override is None:
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x_var = x
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else:
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if hidden_size < variance_size_override:
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raise ValueError(
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"Expected hidden_size to be at least "
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f"{variance_size_override}, but found: {hidden_size}"
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)
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x_var = x[:, :, :variance_size_override]
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variance = x_var.pow(2).mean(dim=-1, keepdim=True)
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x = x * torch.rsqrt(variance + variance_epsilon)
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x = x.to(orig_dtype)
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if weight is not None:
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x = x * weight
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if residual is None:
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return x
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else:
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return x, residual
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def forward_native(
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self,
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x: torch.Tensor,
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residual: torch.Tensor | None = None,
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) -> torch.Tensor | tuple[torch.Tensor, torch.Tensor]:
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"""PyTorch-native implementation equivalent to forward()."""
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return self.forward_static(
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x,
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self.variance_epsilon,
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self.hidden_size,
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x.dtype,
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self.weight.data if self.has_weight else None,
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residual,
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self.variance_size_override,
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)
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def forward_cuda(
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self,
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x: torch.Tensor,
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residual: torch.Tensor | None = None,
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residual_alpha: float = 1.0,
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) -> torch.Tensor | tuple[torch.Tensor, torch.Tensor]:
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if self.variance_size_override is not None:
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return self.forward_native(x, residual)
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add_residual = residual is not None
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if add_residual:
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return fused_add_rms_norm(
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x, residual, self.weight.data, self.variance_epsilon,residual_alpha
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)
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else:
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return rms_norm(x, self.weight.data, self.variance_epsilon)
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def forward_hip(
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self,
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x: torch.Tensor,
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residual: torch.Tensor | None = None,
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) -> torch.Tensor | tuple[torch.Tensor, torch.Tensor]:
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if self.variance_size_override is not None:
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return self.forward_native(x, residual)
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add_residual = residual is not None
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if add_residual:
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return self.rocm_norm_func_with_add(
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x, residual, self.weight.data, self.variance_epsilon
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)
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else:
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return self.rocm_norm_func(x, self.weight.data, self.variance_epsilon)
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def forward_xpu(
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self,
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x: torch.Tensor,
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residual: torch.Tensor | None = None,
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) -> torch.Tensor | tuple[torch.Tensor, torch.Tensor]:
|
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if self.variance_size_override is not None:
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return self.forward_native(x, residual)
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from vllm._ipex_ops import ipex_ops as ops
|
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|
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if residual is not None:
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ops.fused_add_rms_norm(
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x,
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residual,
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self.weight.data,
|
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self.variance_epsilon,
|
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)
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return x, residual
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return ops.rms_norm(
|
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x,
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self.weight.data,
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self.variance_epsilon,
|
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)
|
||||
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def extra_repr(self) -> str:
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s = f"hidden_size={self.weight.data.size(0)}"
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s += f", eps={self.variance_epsilon}"
|
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return s
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|
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@CustomOp.register("gemma_rms_norm")
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class GemmaRMSNorm(CustomOp):
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"""RMS normalization for Gemma.
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Two differences from the above RMSNorm:
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1. x * (1 + w) instead of x * w.
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2. (x * w).to(orig_dtype) instead of x.to(orig_dtype) * w.
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"""
|
||||
|
||||
def __init__(
|
||||
self,
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||||
hidden_size: int,
|
||||
eps: float = 1e-6,
|
||||
) -> None:
|
||||
super().__init__()
|
||||
self.weight = nn.Parameter(torch.zeros(hidden_size))
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self.variance_epsilon = eps
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||||
|
||||
@staticmethod
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||||
def forward_static(
|
||||
weight: torch.Tensor,
|
||||
variance_epsilon: float,
|
||||
x: torch.Tensor,
|
||||
residual: torch.Tensor | None,
|
||||
) -> torch.Tensor | tuple[torch.Tensor, torch.Tensor]:
|
||||
"""PyTorch-native implementation equivalent to forward()."""
|
||||
orig_dtype = x.dtype
|
||||
if residual is not None:
|
||||
x = (
|
||||
x.float() + residual.float()
|
||||
if orig_dtype == torch.float16
|
||||
else x + residual
|
||||
)
|
||||
residual = x
|
||||
|
||||
x = x.float()
|
||||
variance = x.pow(2).mean(dim=-1, keepdim=True)
|
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x = x * torch.rsqrt(variance + variance_epsilon)
|
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# Llama does x.to(float16) * w whilst Gemma is (x * w).to(float16)
|
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# See https://github.com/huggingface/transformers/pull/29402
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||||
x = x * (1.0 + weight.float())
|
||||
x = x.to(orig_dtype)
|
||||
return x if residual is None else (x, residual)
|
||||
|
||||
def forward_native(
|
||||
self,
|
||||
x: torch.Tensor,
|
||||
residual: torch.Tensor | None = None,
|
||||
) -> torch.Tensor | tuple[torch.Tensor, torch.Tensor]:
|
||||
"""PyTorch-native implementation equivalent to forward()."""
|
||||
return self.forward_static(self.weight.data, self.variance_epsilon, x, residual)
|
||||
|
||||
def forward_cuda(
|
||||
self,
|
||||
x: torch.Tensor,
|
||||
residual: torch.Tensor | None = None,
|
||||
) -> torch.Tensor | tuple[torch.Tensor, torch.Tensor]:
|
||||
if torch.compiler.is_compiling():
|
||||
return self.forward_native(x, residual)
|
||||
|
||||
if not getattr(self, "_is_compiled", False):
|
||||
self.forward_static = torch.compile( # type: ignore
|
||||
self.forward_static
|
||||
)
|
||||
self._is_compiled = True
|
||||
return self.forward_native(x, residual)
|
||||
|
||||
|
||||
@CustomOp.register("rms_norm_gated")
|
||||
class RMSNormGated(CustomOp):
|
||||
"""RMS Normalization with optional gating.
|
||||
|
||||
This is a native PyTorch implementation that supports:
|
||||
- Standard RMS normalization
|
||||
- Group RMS normalization
|
||||
- Optional gating with SiLU activation
|
||||
"""
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
hidden_size: int,
|
||||
eps: float = 1e-5,
|
||||
group_size: int | None = None,
|
||||
norm_before_gate: bool = False,
|
||||
device: torch.device | None = None,
|
||||
dtype: torch.dtype | None = None,
|
||||
):
|
||||
"""Initialize RMSNormGated.
|
||||
|
||||
Args:
|
||||
hidden_size: Size of the hidden dimension
|
||||
eps: Epsilon for numerical stability
|
||||
group_size: If not None, do GroupNorm with each group
|
||||
having group_size elements.
|
||||
group_size=None is equivalent to group_size=hidden_size
|
||||
(i.e. there's only 1 group).
|
||||
norm_before_gate: If True and z is provided: out = norm(x) * silu(z)
|
||||
If False and z is provided: out = norm(x * silu(z))
|
||||
device: Device to create parameters on
|
||||
dtype: Data type for parameters
|
||||
"""
|
||||
factory_kwargs = {"device": device, "dtype": dtype}
|
||||
super().__init__()
|
||||
self.eps = eps
|
||||
self.weight = nn.Parameter(torch.empty(hidden_size, **factory_kwargs))
|
||||
self.register_parameter("bias", None)
|
||||
self.group_size = group_size
|
||||
self.norm_before_gate = norm_before_gate
|
||||
self.reset_parameters()
|
||||
|
||||
def reset_parameters(self):
|
||||
torch.nn.init.ones_(self.weight)
|
||||
|
||||
def forward_native(
|
||||
self, x: torch.Tensor, z: torch.Tensor | None = None
|
||||
) -> torch.Tensor:
|
||||
"""
|
||||
Native PyTorch implementation of RMS normalization with gating.
|
||||
|
||||
Args:
|
||||
x: Input tensor
|
||||
z: Optional gating tensor
|
||||
|
||||
Returns:
|
||||
Normalized (and optionally gated) tensor
|
||||
|
||||
If z is not None:
|
||||
- norm_before_gate=True: out = norm(x) * silu(z)
|
||||
- norm_before_gate=False: out = norm(x * silu(z))
|
||||
"""
|
||||
# Apply gating before normalization if needed
|
||||
if z is not None and not self.norm_before_gate:
|
||||
x = x * F.silu(z)
|
||||
|
||||
# RMS Normalization
|
||||
if self.group_size is None:
|
||||
# Standard RMS norm across the last dimension
|
||||
variance = x.pow(2).mean(dim=-1, keepdim=True)
|
||||
x_normed = x * torch.rsqrt(variance + self.eps)
|
||||
out = x_normed * self.weight
|
||||
else:
|
||||
# Group RMS norm
|
||||
from einops import rearrange
|
||||
|
||||
x_group = rearrange(x, "... (g d) -> ... g d", d=self.group_size)
|
||||
variance = x_group.pow(2).mean(dim=-1, keepdim=True)
|
||||
x_normed = x_group * torch.rsqrt(variance + self.eps)
|
||||
out = rearrange(x_normed, "... g d -> ... (g d)") * self.weight
|
||||
|
||||
# Apply gating after normalization if needed
|
||||
if z is not None and self.norm_before_gate:
|
||||
out = out * F.silu(z)
|
||||
|
||||
return out
|
||||
|
||||
def forward_cuda(
|
||||
self, x: torch.Tensor, z: torch.Tensor | None = None
|
||||
) -> torch.Tensor:
|
||||
from vllm.model_executor.layers.fla.ops.layernorm_guard import rmsnorm_fn
|
||||
|
||||
return rmsnorm_fn(
|
||||
x,
|
||||
self.weight,
|
||||
self.bias,
|
||||
z=z,
|
||||
eps=self.eps,
|
||||
group_size=self.group_size,
|
||||
norm_before_gate=self.norm_before_gate,
|
||||
)
|
||||
|
||||
|
||||
class LayerNorm(nn.Module):
|
||||
"""
|
||||
Layer Normalization.
|
||||
"""
|
||||
|
||||
def __init__(self, dim: int, eps: float = 1e-6):
|
||||
super().__init__()
|
||||
self.dim = dim
|
||||
self.eps = eps
|
||||
self.weight = nn.Parameter(torch.ones(dim, dtype=torch.float32))
|
||||
self.bias = nn.Parameter(torch.zeros(dim, dtype=torch.float32))
|
||||
|
||||
def forward(self, x: torch.Tensor):
|
||||
return F.layer_norm(
|
||||
x.float(), (self.dim,), self.weight, self.bias, self.eps
|
||||
).type_as(x)
|
||||
Reference in New Issue
Block a user