Landing: 791386dc22c9

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Project / Subsystem

gcc / tree-optimization

Date

2026-10-02

Author

Yongqiang Tian

Commit

791386dc22c978e374863d459c378c64cb6d8f26

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: tree-optimization
patch_id: —
commit_hash: 791386dc22c978e374863d459c378c64cb6d8f26
source_type: github
headline: Skip GIMPLE_DEBUG stmts before assigning UIDs
tldr: GCC now skips GIMPLE_DEBUG statements before assigning UIDs, preventing them from disrupting VEC_PERM simplification and ensuring consistent optimization regar…
author: Yongqiang Tian
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • optimization
• bugfix
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/791386dc22c978e374863d459c378c64cb6d8f26
date: 2026-10-02T00:00:00.000Z

This commit fixes a bug where GIMPLE_DEBUG statements interfered with optimization passes by consuming Unique Identifiers (UIDs) prematurely. This consumption caused pending VEC_PERM simplify sequences to be flushed, making optimization results dependent on the presence of debug information. The fix ensures that debug statements are skipped before UID assignment and processing of ordinary statements, leading to more consistent optimization.