Landing: c31cb1362859

Project / Subsystem

gcc / gcc/tree-optimization

Date

2026-07-08

Author

Richard Biener

Commit

c31cb13628593fc57779419a806170b6ef2c3b81

Source

github

Perf win

No

Breaking

No

All attributes

project
gcc
subsystem
gcc/tree-optimization
patch_id
commit_hash
c31cb13628593fc57779419a806170b6ef2c3b81
source_type
github
headline
tree-optimization/126159 - Handle unions in data dependence analysis
tldr
Improves data dependence analysis to handle non-aggregate union field accesses.
author
Richard Biener
outcome
committed
performance_win
false
breaking_change
false
series_id
series_parts
[]
tags
  • optimization
  • dataflow analysis
discussion_id_link
bugzilla_pr
date
2026-07-08T00:00:00.000Z

This commit enhances GCC’s data dependence analysis pass to correctly handle accesses to non-aggregate fields within unions. Previously, such accesses could be misinterpreted, potentially leading to incorrect optimization decisions. The changes ensure that accesses to union members, particularly when subsetting is not applied, are properly accounted for, improving the accuracy of data flow analysis.