Landing: 19378ecd3851

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Project / Subsystem

gcc / vect

Date

2026-09-27

Author

wangjue

Commit

19378ecd3851564bb168dd7779cb52c79193cb2d

Source

github

Perf win

Yes

Breaking

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All attributes

project: gcc
subsystem: vect
patch_id: —
commit_hash: 19378ecd3851564bb168dd7779cb52c79193cb2d
source_type: github
headline: Vectorizer avoids redundant widen-narrow sequence for SAT_TRUNC.
tldr: Vectorizer optimization avoids redundant widen-then-narrow operations for SAT_TRUNC.
author: wangjue
outcome: committed
performance_win: true
breaking_change: false
series_id: —
series_parts: []
tags: • vectorization
• optimization
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/19378ecd3851564bb168dd7779cb52c79193cb2d
date: 2026-09-27T00:00:00.000Z

The vectorizer now looks through promotions to avoid a redundant widen-and-narrow sequence when SAT_TRUNC is supported for narrower types. This optimization targets the tree-vect-patterns.cc file and introduces new test cases for SAT_TRUNC promotion.