LPCD: Unified Framework from Layer-Wise to Submodule Quantization

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Ichikawa, Yuma, Fujimoto, Yudai, Sakai, Akira
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866909937867685888
author Ichikawa, Yuma
Fujimoto, Yudai
Sakai, Akira
author_facet Ichikawa, Yuma
Fujimoto, Yudai
Sakai, Akira
contents Post-training quantization (PTQ) aims to preserve model-level behavior; however, most methods focus on individual linear layers. Even recent extensions, such as QEP and LoaQ, which mitigate error propagation or target specific submodules, still rely on layer-wise formulations and fail to capture the behavior of larger submodules. We introduce Layer-Projected Coordinate Descent (LPCD), a unified framework that extends PTQ beyond layers by optimizing relaxed objectives across arbitrary submodules and projecting the solutions with layer-wise quantizers. LPCD generalizes existing methods and provides a principled approach to quantizing complex submodules while maintaining the efficiency and compatibility of layer-wise PTQ pipelines. Across diverse LLM architectures and bit-widths, LPCD-based submodule quantization consistently enhances both layer-wise PTQ methods and existing submodule approaches.
format Preprint
id arxiv_https___arxiv_org_abs_2512_01546
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle LPCD: Unified Framework from Layer-Wise to Submodule Quantization
Ichikawa, Yuma
Fujimoto, Yudai
Sakai, Akira
Machine Learning
Artificial Intelligence
Computation and Language
Post-training quantization (PTQ) aims to preserve model-level behavior; however, most methods focus on individual linear layers. Even recent extensions, such as QEP and LoaQ, which mitigate error propagation or target specific submodules, still rely on layer-wise formulations and fail to capture the behavior of larger submodules. We introduce Layer-Projected Coordinate Descent (LPCD), a unified framework that extends PTQ beyond layers by optimizing relaxed objectives across arbitrary submodules and projecting the solutions with layer-wise quantizers. LPCD generalizes existing methods and provides a principled approach to quantizing complex submodules while maintaining the efficiency and compatibility of layer-wise PTQ pipelines. Across diverse LLM architectures and bit-widths, LPCD-based submodule quantization consistently enhances both layer-wise PTQ methods and existing submodule approaches.
title LPCD: Unified Framework from Layer-Wise to Submodule Quantization
topic Machine Learning
Artificial Intelligence
Computation and Language
url https://arxiv.org/abs/2512.01546