text-generation-inference/server/text_generation_server/layers/awq/quantize/qmodule.py
Daniël de Kok 14980df2df
Support AWQ quantization with bias (#2117)
When the AWQ quantizer was used with a layer that uses a bias,
the bias tensor was not correctly passed/used. Instead, the
value `true`/`1.0` was added to the linear transformation.

Correctly pass through the bias when it is not `None`.

Fixes #2106.
2024-06-25 21:09:00 +02:00

51 lines
1.6 KiB
Python

# Copied logic from https://github.com/mit-han-lab/llm-awq/blob/f084f40bd996f3cf3a0633c1ad7d9d476c318aaa/awq/quantize/qmodule.py
import math
from typing import Optional
import torch
import torch.nn as nn
import awq_inference_engine # with CUDA kernels
# class ScaledActivation(nn.Module):
# def __init__(self, module, scales):
# super().__init__()
# self.act = module
# self.scales = nn.Parameter(scales.data)
#
# def forward(self, x):
# return self.act(x) / self.scales.view(1, 1, -1).to(x.device)
class WQLinear(nn.Module):
def __init__(
self, w_bit, group_size, qweight, qzeros, scales, bias: Optional[torch.Tensor]
):
super().__init__()
if w_bit not in [4]:
raise NotImplementedError("Only 4-bit are supported for now.")
self.in_features = qweight.shape[0]
self.out_features = qweight.shape[1] * 32 // w_bit
self.w_bit = w_bit
self.group_size = group_size if group_size != -1 else self.in_features
# quick sanity check (make sure aligment)
assert self.in_features % self.group_size == 0
assert self.out_features % (32 // self.w_bit) == 0
self.qweight = qweight
self.qzeros = qzeros
self.scales = scales
self.bias = bias
@torch.no_grad()
def forward(self, x):
out_shape = x.shape[:-1] + (self.out_features,)
out = awq_inference_engine.gemm_forward_cuda(
x.reshape(-1, x.shape[-1]), self.qweight, self.scales, self.qzeros, 8
)
out = out + self.bias if self.bias is not None else out
return out.reshape(out_shape)