__builtin_align_down: Cast value to __uintptr_t in the fallback
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Authored by jhb on Feb 7 2026, 3:46 PM.

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Reviewers

jrtc27
arichardson
kib
ngie

Commits

rGd46ff9d8389b: __builtin_align_down: Cast value to __uintptr_t in the fallback
rG5faceb84142f: __builtin_align_down: Cast value to __uintptr_t in the fallback

Summary

This matches the behavior of the fallbacks for builtin_align_up
and builtin_is_aligned.

Diff Detail

Repository

rG FreeBSD src repository

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Build Status

Buildable 70497
Build 67380: arc lint + arc unit

Event Timeline

jhb created this revision.Feb 7 2026, 3:46 PM

Herald added a subscriber: imp. · View Herald TranscriptFeb 7 2026, 3:46 PM

jhb requested review of this revision.Feb 7 2026, 3:46 PM

jhb added a parent revision: D55160: arm64: Explicitly use movz.

jhb added a child revision: D55162: arm bcm2835: Appease a warning from GCC.

Harbormaster completed remote builds in B70497: Diff 171415.Feb 7 2026, 3:47 PM

I worry that this was intentionally left out to avoid breaking there use of rounddown() on integer types larger than uintptr_t? (E.g. vm_paddr_t on i386)

If that is really a worry, maybe we use _Generic (including the fallback for pre-C11) that maps pointer types to versions that use uintptr_t and otherwise doesn't use the cast?

kib accepted this revision.Feb 17 2026, 9:10 PM

This revision is now accepted and ready to land.Feb 17 2026, 9:10 PM

ngie accepted this revision.Feb 18 2026, 12:20 AM

Almost certainly an accidental omission

Closed by commit rG5faceb84142f: __builtin_align_down: Cast value to __uintptr_t in the fallback (authored by jhb). · Explain WhyFeb 24 2026, 8:24 PM

This revision was automatically updated to reflect the committed changes.

jhb added a commit: rG5faceb84142f: __builtin_align_down: Cast value to __uintptr_t in the fallback.

jhb added a commit: rGd46ff9d8389b: __builtin_align_down: Cast value to __uintptr_t in the fallback.Fri, Apr 24, 5:56 PM