Landing: 55867c37ec0d

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Project / Subsystem

gcc / gcc

Date

2026-09-27

Author

Jeff Law

Commit

55867c37ec0dd0c4f1872183a6e43ea7dc16d479

Source

github

Perf win

Yes

Breaking

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project: gcc
subsystem: gcc
patch_id: —
commit_hash: 55867c37ec0dd0c4f1872183a6e43ea7dc16d479
source_type: github
headline: Reassociation optimization correctly handles int128 and BitInt for rotate+xor
tldr: Reassociation optimization now correctly handles 128-bit integers and BitInt types for rotate+xor sequences.
author: Jeff Law
outcome: committed
performance_win: true
breaking_change: false
series_id: —
series_parts: []
tags: • optimization
• integer types
• performance
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/55867c37ec0dd0c4f1872183a6e43ea7dc16d479
date: 2026-09-27T00:00:00.000Z

A previous reassociation optimization that exposed rotate+xor sequences has been fixed to correctly handle int128 and BitInt types. The change replaces HOST_WIDE_INT interfaces with wi:: interfaces, resolving code generation issues on architectures like AArch64 and enabling the optimization for BitInt.