Landing: bbb4d0073162

← All landings

Project / Subsystem

gcc / gcc

Date

2026-03-05

Author

Richard Biener

Commit

bbb4d007316269bea3a72c2a77cad75945f2433f

Source

github

Perf win

Yes

Breaking

View on GitHub →

All attributes

project: gcc
subsystem: gcc
patch_id: —
commit_hash: bbb4d007316269bea3a72c2a77cad75945f2433f
source_type: github
headline: Avoid live code-generation for stmts kept as scalars
tldr: GCC now avoids unnecessary live code generation for scalar statements used in SLP graph leafs, simplifying the vectorization process.
author: Richard Biener
outcome: committed
performance_win: true
breaking_change: false
series_id: —
series_parts: []
tags: • optimization
• vectorization
• slp
• code generation
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/bbb4d007316269bea3a72c2a77cad75945f2433f
date: 2026-03-05T00:00:00.000Z

This commit optimizes the SLP (Superword Level Parallelism) vectorization pass in GCC by avoiding live code generation for scalar definitions that are kept in scalar form because they are used as external inputs in SLP graph leafs. This change resolves specific cases where workarounds were needed during live code generation, streamlining the vectorization process and potentially improving performance.