Landing: 5dfe1056b85f

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Project / Subsystem

gcc / i386

Date

2026-05-14

Author

Uros Bizjak

Commit

5dfe1056b85f249e7b4ad454a59f2951c716191e

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: i386
patch_id: —
commit_hash: 5dfe1056b85f249e7b4ad454a59f2951c716191e
source_type: github
headline: i386: Remove TARGET_SHIFT1 Tuning Feature
tldr: The `TARGET_SHIFT1` tuning feature for i386 is removed, simplifying shift instruction encoding.
author: Uros Bizjak
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • i386
• optimization
• assembler
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/5dfe1056b85f249e7b4ad454a59f2951c716191e
date: 2026-05-14T00:00:00.000Z

The TARGET_SHIFT1 tuning feature for i386 is now removed. GNU as now automatically encodes “sal $1, reg” using the shorter implicit-count-1 form. The compiler-side TARGET_SHIFT1 / X86_TUNE_SHIFT1 logic is redundant. Affected shift instruction patterns will emit the explicit-immediate form, and rely on the assembler to produce the optimal encoding.