Landing: a33f80c6ed06

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Project / Subsystem

gcc / combine

Date

2026-05-11

Author

Boudewijn van der Heide

Commit

a33f80c6ed06037bd1d31680ae3152e362931f51

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: combine
patch_id: —
commit_hash: a33f80c6ed06037bd1d31680ae3152e362931f51
source_type: github
headline: Combine pass checks for CLOBBER in `make_compound_operation_int`.
tldr: This commit prevents an ICE in the combine pass by checking for CLOBBER instructions before calling `simplify_subreg`.
author: Boudewijn van der Heide
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • combine
• bugfix
• rtl-optimization
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/a33f80c6ed06037bd1d31680ae3152e362931f51
date: 2026-05-11T00:00:00.000Z

The combine pass was triggering a gcc_assert failure when make_compound_operation_int received a CLOBBER instruction and then called simplify_subreg with an invalid mode. This commit fixes the issue by checking for CLOBBER instructions before calling simplify_subreg and returning NULL_RTX if one is encountered, preventing the ICE.