Landing: 9c8aa6038770

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Project / Subsystem

gcc / aarch64

Date

2026-08-11

Author

Kyrylo Tkachov

Commit

9c8aa60387702aedd5fd619064c16609b40fa476

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: aarch64
patch_id: —
commit_hash: 9c8aa60387702aedd5fd619064c16609b40fa476
source_type: github
headline: aarch64: Prevent trapping FP comparisons from becoming conditional.
tldr: Ensures floating-point comparisons that can trap (e.g., with NaNs) remain unconditional on AArch64.
author: Kyrylo Tkachov
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • aarch64
• floating-point
• exceptions
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/9c8aa60387702aedd5fd619064c16609b40fa476
date: 2026-08-11T00:00:00.000Z

On AArch64, conditional floating-point comparisons can mask exceptions, such as those raised by quiet NaNs. This commit modifies the code generation to prevent such trapping comparisons from becoming conditional, preserving the expected exception behavior. It ensures that operations like (a < b) & (c < d) correctly raise exceptions if c or d is a quiet NaN when a < b is false. New tests are added to verify this behavior.