Landing: da3b0463f663

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Project / Subsystem

gcc / tree-optimization

Date

2026-08-31

Author

Kyrylo Tkachov

Commit

da3b0463f66312c9e93a027bae73bf17c24a8833

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: tree-optimization
patch_id: —
commit_hash: da3b0463f66312c9e93a027bae73bf17c24a8833
source_type: github
headline: Canonicalize conditional signed narrow clips to fix RISC-V saturation patterns.
tldr: Canonicalizes conditional signed narrow clips to ensure correct saturation behavior for RISC-V targets.
author: Kyrylo Tkachov
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • optimization
• risc-v
• compiler
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/da3b0463f66312c9e93a027bae73bf17c24a8833
date: 2026-08-31T00:00:00.000Z

This change canonicalizes conditional signed narrow clip operations before loop if-conversion. The original form could lead to undefined behavior with signed minimum values and was being incorrectly transformed into saturating truncations. The new form ensures that the original overflow semantics are preserved when specific conditions like -fwrapv or sanitization are in effect, restoring correct saturation patterns for RISC-V tests.