Landing: 579349b0f126

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Project / Subsystem

gcc / gcc

Date

2026-08-20

Author

Roger Sayle

Commit

579349b0f12681ffcbfd14eafe6efdc8da67a1f2

Source

github

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Breaking

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project: gcc
subsystem: gcc
patch_id: —
commit_hash: 579349b0f12681ffcbfd14eafe6efdc8da67a1f2
source_type: github
headline: Fix ICE optimizing 0.0 - x with -ffinite-math-only
tldr: Corrects an integer compiler error (ICE) when optimizing floating-point expressions involving negative zero under the -ffinite-math-only flag.
author: Roger Sayle
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • optimization
• floating-point
• compiler-bug
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/579349b0f12681ffcbfd14eafe6efdc8da67a1f2
date: 2026-08-20T00:00:00.000Z

An Integer Compiler Error (ICE) occurring when optimizing expressions like (T)0.0 - x with the -ffinite-math-only flag has been resolved. The issue stemmed from an incorrect assumption about how GCC handles negative zero in floating-point constants. A new predicate, real_negzerop, has been introduced to robustly identify negative zero across various constant types (real, vector, complex) and prevent the ICE.