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# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""Utility methods for model layers."""
from typing import Callable, Optional
import torch
from vllm import _custom_ops as ops
from vllm import envs
from vllm.platforms import current_platform
def get_token_bin_counts_and_mask(
tokens: torch.Tensor,
vocab_size: int,
num_seqs: int,
) -> tuple[torch.Tensor, torch.Tensor]:
# Compute the bin counts for the tokens.
# vocab_size + 1 for padding.
bin_counts = torch.zeros((num_seqs, vocab_size + 1),
dtype=torch.long,
device=tokens.device)
bin_counts.scatter_add_(1, tokens, torch.ones_like(tokens))
bin_counts = bin_counts[:, :vocab_size]
mask = bin_counts > 0
return bin_counts, mask
def apply_penalties(logits: torch.Tensor, prompt_tokens_tensor: torch.Tensor,
output_tokens_tensor: torch.Tensor,
presence_penalties: torch.Tensor,
frequency_penalties: torch.Tensor,
repetition_penalties: torch.Tensor) -> torch.Tensor:
"""
Applies penalties in place to the logits tensor
logits : The input logits tensor of shape [num_seqs, vocab_size]
prompt_tokens_tensor: A tensor containing the prompt tokens. The prompts
are padded to the maximum prompt length within the batch using
`vocab_size` as the padding value. The value `vocab_size` is used
for padding because it does not correspond to any valid token ID
in the vocabulary.
output_tokens_tensor: The output tokens tensor.
presence_penalties: The presence penalties of shape (num_seqs, )
frequency_penalties: The frequency penalties of shape (num_seqs, )
repetition_penalties: The repetition penalties of shape (num_seqs, )
"""
num_seqs, vocab_size = logits.shape
_, prompt_mask = get_token_bin_counts_and_mask(prompt_tokens_tensor,
vocab_size, num_seqs)
output_bin_counts, output_mask = get_token_bin_counts_and_mask(
output_tokens_tensor, vocab_size, num_seqs)
# Apply repetition penalties as a custom op
from vllm._custom_ops import apply_repetition_penalties
apply_repetition_penalties(logits, prompt_mask, output_mask,
repetition_penalties)
# We follow the definition in OpenAI API.
# Refer to https://platform.openai.com/docs/api-reference/parameter-details
logits -= frequency_penalties.unsqueeze(dim=1) * output_bin_counts
logits -= presence_penalties.unsqueeze(dim=1) * output_mask
return logits
def rocm_unquantized_gemm(x: torch.Tensor,
weight: torch.Tensor,
bias: Optional[torch.Tensor] = None):
from vllm.platforms.rocm import on_gfx9
k = weight.shape[1]
use_skinny = (envs.VLLM_ROCM_USE_SKINNY_GEMM and on_gfx9() and \
x.dtype in [torch.float16, torch.bfloat16] \
and k % 8 == 0 and bias is None)
if use_skinny is not True:
return torch.nn.functional.linear(x, weight, bias)
x_view = x.view(-1, x.size(-1))
n = x_view.shape[0]
m = weight.shape[0]
cu_count = current_platform.get_cu_count()
if m > 8 and 0 < n <= 4:
out = ops.wvSplitK(weight, x_view, cu_count)
return out.view(*x.shape[:-1], weight.shape[0])
elif m % 4 == 0 and n == 1 and k <= 8192:
out = ops.LLMM1(weight, x_view, 4)
return out.view(*x.shape[:-1], weight.shape[0])
return torch.nn.functional.linear(x, weight, bias)
def dispatch_unquantized_gemm() -> Callable[..., torch.Tensor]:
if current_platform.is_rocm():
return rocm_unquantized_gemm
return torch.nn.functional.linear