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2026-01-19 10:38:50 +08:00

142 lines
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Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
import jax
import jax.numpy as jnp
import torch
import torch.nn.functional as F
import torch_xla.core.xla_builder as xb
from torch.library import impl
from torch_xla.experimental.custom_kernel import XLA_LIB, jax_import_guard
@jax.jit
def bgmv_jax(inputs, loras, idxs):
return jnp.einsum(
"td,tX,Xld->tl",
inputs,
jax.nn.one_hot(idxs, loras.shape[0], dtype=inputs.dtype),
loras,
)
XLA_LIB.define("bgmv(Tensor inputs, Tensor loras, Tensor idxs) -> Tensor")
@impl(XLA_LIB, "bgmv", "XLA")
def bgmv_xla(inputs: torch.Tensor, loras: torch.Tensor, idxs: torch.IntTensor):
if len(loras.shape) == 4:
loras = loras.squeeze(axis=1)
jax_import_guard()
return xb.call_jax(bgmv_jax, (inputs, loras, idxs))
@impl(XLA_LIB, "bgmv", "CompositeExplicitAutograd")
def bgmv_non_xla(inputs: torch.Tensor, loras: torch.Tensor, idxs: torch.IntTensor):
T, _ = inputs.shape
if len(loras.shape) == 4:
loras = loras.squeeze(axis=1)
_, L, _ = loras.shape
return torch.empty((T, L), device=inputs.device)
def bgmv_expand(
inputs: torch.Tensor,
lora_b_weights: torch.Tensor,
output_tensor: torch.Tensor,
lora_indices_tensor: torch.Tensor,
add_inputs: bool = True,
):
"""
Args:
inputs (torch.Tensor): Input tensor of shape [num_tokens, hidden_size].
lora_b_weights (torch.Tensor): LoRA weights of shape
[num_loras, lora_rank, hidden_size].
output_tensor (torch.Tensor): output tensor of shape
[num_tokens, hidden_size * num_slices].
lora_indices_tensor (torch.Tensor): Tensor of shape [num_tokens]
indicating which LoRA matrix to use for each token.
add_inputs (bool): Whether or not to add the input tensor to the output
tensor.
"""
outputs = torch.ops.xla.bgmv(inputs, lora_b_weights, lora_indices_tensor)
limit = output_tensor.shape[0]
if outputs.shape[0] == 1 and output_tensor.shape[0] != 1:
limit = 1
if output_tensor.shape[1] > outputs.shape[1]:
outputs = F.pad(outputs, (0, output_tensor.shape[1] - outputs.shape[1], 0, 0))
if add_inputs:
return output_tensor + outputs[:limit, : output_tensor.shape[1]]
else:
return outputs[:limit, : output_tensor.shape[1]]
def bgmv_shrink(
inputs: torch.Tensor,
lora_b_weights: torch.Tensor,
lora_indices_tensor: torch.Tensor,
scaling: float = 1.0,
):
"""
Args:
inputs (torch.Tensor): Input tensor of shape [num_tokens, hidden_size].
lora_b_weights (torch.Tensor): LoRA weights of shape
[num_loras, lora_rank, hidden_size].
lora_indices_tensor (torch.Tensor): Tensor of shape [num_tokens]
indicating which LoRA matrix to use for each token.
scaling (float, optional): Scalar multiplier applied to the output.
"""
return scaling * torch.ops.xla.bgmv(inputs, lora_b_weights, lora_indices_tensor)
def bgmv_expand_slice(
inputs: torch.Tensor,
lora_b_weights: torch.Tensor,
output_tensor: torch.Tensor,
lora_indices_tensor: torch.Tensor,
slice_offset: int,
slice_size: int,
add_inputs: bool = True,
):
"""
Args:
inputs (torch.Tensor): Input tensor of shape [num_tokens, hidden_size].
lora_b_weights (torch.Tensor): LoRA weights of shape
[num_loras, lora_rank, hidden_size].
output_tensor (torch.Tensor): output tensor of shape
[num_tokens, hidden_size * num_slices].
lora_indices_tensor (torch.Tensor): Tensor of shape [num_tokens]
indicating which LoRA matrix to use for each token.
add_inputs (bool): Whether or not to add the input tensor to the output
tensor.
"""
outputs = torch.ops.xla.bgmv(inputs, lora_b_weights, lora_indices_tensor)
outputs = F.pad(
outputs,
(
slice_offset,
output_tensor.shape[1] - (slice_offset + slice_size),
0,
0,
),
)
if add_inputs:
return output_tensor + outputs
else:
return outputs