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Differential D126710

Allow build without __c11_atomic_fetch_nand
ClosedPublic

Authored by brooks on May 31 2022, 10:29 AM.

Details

Reviewers
lkail
theraven
compnerd
efriedma
jyknight
Commits
rG18efa420da5f: compiler-rt: Allow build without __c11_atomic_fetch_nand
Summary

Don't build atomic fetch nand libcall functions when the required
compiler builtin isn't available. Without this compiler-rt can't be
built with LLVM 13 or earlier.

Not building the libcall functions isn't optimal, but aligns with the
usecase in FreeBSD where compiler-rt from LLVM 14 is built with an LLVM
13 clang and no LLVM 14 clang is built.

Diff Detail

Event Timeline

brooks created this revision.May 31 2022, 10:29 AM
Herald added a project: Restricted Project. · View Herald TranscriptMay 31 2022, 10:29 AM
Herald added subscribers: Enna1, krytarowski, arichardson, emaste. · View Herald Transcript
brooks requested review of this revision.May 31 2022, 10:29 AM
Herald added a project: Restricted Project. · View Herald TranscriptMay 31 2022, 10:29 AM
Herald added a subscriber: Restricted Project. · View Herald Transcript
brooks mentioned this in D126395: Allow build without __c11_atomic_fetch_nand.May 31 2022, 10:29 AM
emaste added a comment.May 31 2022, 10:29 AM

Fine with me from a FreeBSD perspective

Harbormaster completed remote builds in B167079: Diff 433133.May 31 2022, 11:07 AM
efriedma accepted this revision.May 31 2022, 4:45 PM

Maybe leave a short note explaining that this is a temporary hack to allow building compiler-rt with older versions of clang.

Otherwise LGTM

This revision is now accepted and ready to land.May 31 2022, 4:45 PM
brooks updated this revision to Diff 433228.May 31 2022, 4:53 PM
  • Add an explanatory comment
Harbormaster completed remote builds in B167153: Diff 433228.May 31 2022, 4:54 PM
brooks updated this revision to Diff 433229.May 31 2022, 4:54 PM
  • Hopefully use arc correctly
efriedma accepted this revision.May 31 2022, 4:56 PM
Harbormaster completed remote builds in B167154: Diff 433229.May 31 2022, 5:34 PM
Closed by commit rG18efa420da5f: compiler-rt: Allow build without __c11_atomic_fetch_nand (authored by brooks, committed by emaste). · Explain WhyJun 1 2022, 9:58 AM
This revision was automatically updated to reflect the committed changes.
emaste added a commit: rG18efa420da5f: compiler-rt: Allow build without __c11_atomic_fetch_nand.

Revision Contents

PathSize
compiler-rt/
lib/
builtins/
3 lines

Diff 433441

compiler-rt/lib/builtins/atomic.c

Show First 20 Lines • Show All 359 Lines • ▼ Show 20 Lines
OPTIMISED_CASES OPTIMISED_CASES
#undef OPTIMISED_CASE #undef OPTIMISED_CASE
#define OPTIMISED_CASE(n, lockfree, type) ATOMIC_RMW(n, lockfree, type, or, |) #define OPTIMISED_CASE(n, lockfree, type) ATOMIC_RMW(n, lockfree, type, or, |)
OPTIMISED_CASES OPTIMISED_CASES
#undef OPTIMISED_CASE #undef OPTIMISED_CASE
#define OPTIMISED_CASE(n, lockfree, type) ATOMIC_RMW(n, lockfree, type, xor, ^) #define OPTIMISED_CASE(n, lockfree, type) ATOMIC_RMW(n, lockfree, type, xor, ^)
OPTIMISED_CASES OPTIMISED_CASES
#undef OPTIMISED_CASE #undef OPTIMISED_CASE
// Allow build with clang without __c11_atomic_fetch_nand builtin (pre-14)
#if __has_builtin(__c11_atomic_fetch_nand)
#define OPTIMISED_CASE(n, lockfree, type) ATOMIC_RMW_NAND(n, lockfree, type) #define OPTIMISED_CASE(n, lockfree, type) ATOMIC_RMW_NAND(n, lockfree, type)
OPTIMISED_CASES OPTIMISED_CASES
#undef OPTIMISED_CASE #undef OPTIMISED_CASE
#endif