Landing: 568e1b4823b0

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Project / Subsystem

gcc / doc

Date

2026-05-12

Author

Alex Coplan

Commit

568e1b4823b076235497e8fc790ded7629e472a4

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: doc
patch_id: —
commit_hash: 568e1b4823b076235497e8fc790ded7629e472a4
source_type: github
headline: Document GET_MODE_MASK limit using HOST_BITS_PER_WIDE_INT.
tldr: The documentation for GET_MODE_MASK is updated to reflect its actual behavior regarding mode sizes.
author: Alex Coplan
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • documentation
• gcc
• machine modes
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/568e1b4823b076235497e8fc790ded7629e472a4
date: 2026-05-12T00:00:00.000Z

The GCC internals manual incorrectly stated that the GET_MODE_MASK macro, used to get a bitmask for a given machine mode, only worked for modes with sizes up to HOST_BITS_PER_INT. This commit corrects the documentation to reflect that it works for modes up to HOST_BITS_PER_WIDE_INT, aligning the documentation with the code.