Landing: dc301f9b3da5

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Project / Subsystem

gcc / x86

Date

2026-09-22

Author

Matthias Kretz

Commit

dc301f9b3da5d0a367a0a6be394eba318d3f5b92

Source

github

Perf win

Yes

Breaking

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All attributes

project: gcc
subsystem: x86
patch_id: —
commit_hash: dc301f9b3da5d0a367a0a6be394eba318d3f5b92
source_type: github
headline: x86: Vectorize roundeven
tldr: Vectorizes the roundeven math operation on x86 using SSE and AVX instructions.
author: Matthias Kretz
outcome: committed
performance_win: true
breaking_change: false
series_id: —
series_parts: []
tags: • x86
• vectorization
• sse
• avx
• optimization
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/dc301f9b3da5d0a367a0a6be394eba318d3f5b92
date: 2026-09-22T00:00:00.000Z

This commit introduces vectorization for the roundeven math function on x86 architectures. It leverages SSE and AVX instructions, specifically (v)roundp[sd] and vrndscalep[hsd], to efficiently perform this operation on multiple data points simultaneously. The change includes new machine descriptions and test cases for various SSE and AVX instruction sets.