Landing: f7a75a1506d9

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Project / Subsystem

gcc / gcc/fold-mem-offsets

Date

2025-06-14

Author

Konstantinos Eleftheriou

Commit

f7a75a1506d91fcc76890732a0f720952e01e8fa

Source

github

Perf win

Yes

Breaking

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All attributes

project: gcc
subsystem: gcc/fold-mem-offsets
patch_id: —
commit_hash: f7a75a1506d91fcc76890732a0f720952e01e8fa
source_type: github
headline: Convert fold-mem-offsets pass to use RTL-SSA
tldr: The fold-mem-offsets optimization pass is rewritten to use RTL-SSA, improving efficiency by processing instructions in a single pass.
author: Konstantinos Eleftheriou
outcome: committed
performance_win: true
breaking_change: false
series_id: —
series_parts: []
tags: • optimization
• rtl-ssa
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/f7a75a1506d91fcc76890732a0f720952e01e8fa
date: 2025-06-14T00:00:00.000Z

The fold-mem-offsets optimization pass has been converted from using DF (Data Flow) to RTL-SSA (Register Transfer Language Static Single Assignment). This rewrite significantly alters how the pass collects information, now processing each instruction only once. It introduces single-USE and multi-USE modes for identifying foldable memory offsets, with performance varying based on code complexity and optimization level.