Landing: 44c89620f739

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Project / Subsystem

gcc / phiopt

Date

2026-08-29

Author

Andrea Pinski

Commit

44c89620f7390687a01045228d263845e6e311aa

Source

github

Perf win

Yes

Breaking

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All attributes

project: gcc
subsystem: phiopt
patch_id: —
commit_hash: 44c89620f7390687a01045228d263845e6e311aa
source_type: github
headline: Improve factoring and merging of operations involving certain builtins
tldr: PHI optimization pass now correctly handles factoring and merging of operations involving CRC, expect, object_size, clz, ctz, prefetch, and frame address built…
author: Andrea Pinski
outcome: committed
performance_win: true
breaking_change: false
series_id: —
series_parts: []
tags: • optimization
• phiopt
• builtins
• tree-optimization
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/44c89620f7390687a01045228d263845e6e311aa
date: 2026-08-29T00:00:00.000Z

The PHI optimization pass has been enhanced to correctly factor and merge operations involving several builtins that require constant arguments. Previously, operations like CRC builtins could not be factored out if their third argument differed, leading to errors. This change consolidates logic into a new factor_operation_ok function and extends its checks to cover CRC, expect, object_size, clz, ctz, prefetch, and frame address builtins, enabling better optimization while maintaining correctness.