Landing: a430011e1c2b

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Project / Subsystem

gcc / gcc/value-range

Date

2026-07-14

Author

Aldy Hernandez

Commit

a430011e1c2b75ff7a2cd82b118c69ffc168127a

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: gcc/value-range
patch_id: —
commit_hash: a430011e1c2b75ff7a2cd82b118c69ffc168127a
source_type: github
headline: Floating-point range analysis now represents and handles inverse constant ranges.
tldr: GCC's floating-point range analysis can now represent intervals that exclude specific values, improving precision.
author: Aldy Hernandez
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • optimization
• floating-point
• compiler internals
• range analysis
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/a430011e1c2b75ff7a2cd82b118c69ffc168127a
date: 2026-07-14T00:00:00.000Z

This commit enhances GCC’s floating-point range analysis (frange) to correctly represent the inverse of a constant range. Previously, attempts to exclude a value were lost, turning into a generic ‘varying’ range. The update allows frange to store intervals like x != C by representing them as two sub-ranges, bringing it to parity with other analysis methods and improving the compiler’s ability to optimize code involving inequalities.