Landing: 76b8869f08a6

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Project / Subsystem

gcc / tree-optimization

Date

2026-02-25

Author

Richard Biener

Commit

76b8869f08a6ca99c72596e481dd91b2d545643a

Source

github

Perf win

Yes

Breaking

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All attributes

project: gcc
subsystem: tree-optimization
patch_id: —
commit_hash: 76b8869f08a6ca99c72596e481dd91b2d545643a
source_type: github
headline: tree-optimization/124222 - rewrite BB SLP costing scalar coverage
tldr: GCC now uses vector coverage indicated by `SLP_TREE_TYPE` to improve and simplify basic block vector scalar costing, handling SLP patterns correctly.
author: Richard Biener
outcome: committed
performance_win: true
breaking_change: false
series_id: —
series_parts: []
tags: • optimization
• vectorization
• slp
• cost modeling
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/76b8869f08a6ca99c72596e481dd91b2d545643a
date: 2026-02-25T00:00:00.000Z

This commit rewrites the basic block (BB) SLP (Superword Level Parallelism) costing for scalar coverage in GCC. By utilizing the vector coverage indicated by SLP_TREE_TYPE, the compiler can now more accurately and efficiently assess the cost of vectorizing scalar operations within SLP patterns. This improvement simplifies the costing process and enables better vectorization decisions.