Landing: e754b70fe547

Project / Subsystem

gcc / x86

Date

2026-04-07

Author

H.J. Lu

Commit

e754b70fe5470b975d31887fa5647f1c92d6522d

Source

github

Perf win

No

Breaking

No

All attributes

project
gcc
subsystem
x86
patch_id
commit_hash
e754b70fe5470b975d31887fa5647f1c92d6522d
source_type
github
headline
x86: Rewrite stack alignment calculation
tldr
GCC rewrites x86 stack alignment calculation for better accuracy based on RTL points-to information.
author
H.J. Lu
outcome
committed
performance_win
false
breaking_change
false
series_id
series_parts
[]
tags
  • x86
  • stack
  • alignment
  • analysis
discussion_id_link
bugzilla_pr
date
2026-04-07T00:00:00.000Z

The ix86_find_max_used_stack_alignment function in GCC’s x86 backend has been significantly rewritten. The new implementation uses RTL points-to information, fallback mechanisms involving address decomposition and memory expression checks, to more accurately determine the maximum stack slot alignment. This change aims to improve stack frame handling and corrects issues related to stack usage analysis on x86.