Landing: 7ca53f9d86ef

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Project / Subsystem

gcc / tree-ssa-ccp

Date

2026-05-16

Author

Jakub Jelinek

Commit

7ca53f9d86ef5f4c6a49f414f3cdd88d2b8a0bad

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: tree-ssa-ccp
patch_id: —
commit_hash: 7ca53f9d86ef5f4c6a49f414f3cdd88d2b8a0bad
source_type: github
headline: tree-ssa-ccp: Correctly handle __builtin_bitreverse*.
tldr: Fixes bitwise constant propagation (CCP) for `__builtin_bitreverse*` intrinsics.
author: Jakub Jelinek
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • optimization
• bitreverse
• constant propagation
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/7ca53f9d86ef5f4c6a49f414f3cdd88d2b8a0bad
date: 2026-05-16T00:00:00.000Z

This commit corrects the handling of __builtin_bitreverse* builtins in the tree-ssa-ccp pass. It ensures that bitwise constant propagation (CCP) correctly handles bit reversal, which requires bit-reversing the value and mask constants, unlike byte swapping where the value and mask are bswapped.