Landing: de8bbe994812

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Project / Subsystem

gcc / gcc

Date

2026-08-21

Author

Richard Biener

Commit

de8bbe99481216b1b44ae9cbbbd5057ed5a62506

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: gcc
patch_id: —
commit_hash: de8bbe99481216b1b44ae9cbbbd5057ed5a62506
source_type: github
headline: Add FIXME comments to vectorization code.
tldr: Adds comments to vectorization code highlighting imprecise heuristics.
author: Richard Biener
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • optimization
• vectorization
• maintenance
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/de8bbe99481216b1b44ae9cbbbd5057ed5a62506
date: 2026-08-21T00:00:00.000Z

This commit adds FIXME comments to tree-vect-slp.cc, pointing out that the vect_slp_node_weight and containing_loop functions use imprecise heuristics when selecting the fallback basic block (bbs[0]). These comments alert developers to potential areas for improvement in the SLP (Superword Level Parallelism) vectorization pass.