This is an archive of the discontinued LLVM Phabricator instance.

Differential D154704

[libc] Enable aliasing on AMDGPU targets
ClosedPublic

Authored by jhuber6 on Jul 7 2023, 4:47 AM.

Details

Reviewers
sivachandra
lntue
michaelrj
Commits
rGc012eb79e233: [libc] Enable aliasing on AMDGPU targets
Summary

AMDGPU supports aliases now, so we can drop this case and leave it only
for the NVPTX target. Unfortunately it's unlikely that NVPTX will be
able to support this in the future due to their PTX language being very
limited.

Diff Detail

Event Timeline

jhuber6 created this revision.Jul 7 2023, 4:47 AM
Herald added projects: Restricted Project, Restricted Project. · View Herald TranscriptJul 7 2023, 4:47 AM
Herald added subscribers: libc-commits, jeroen.dobbelaere, tpr and 3 others. · View Herald Transcript
jhuber6 requested review of this revision.Jul 7 2023, 4:47 AM
Herald added subscribers: wangpc, wdng. · View Herald TranscriptJul 7 2023, 4:47 AM
Harbormaster completed remote builds in B243736: Diff 538084.Jul 7 2023, 4:54 AM
lntue accepted this revision.Jul 7 2023, 8:50 AM
This revision is now accepted and ready to land.Jul 7 2023, 8:50 AM
Closed by commit rGc012eb79e233: [libc] Enable aliasing on AMDGPU targets (authored by jhuber6). · Explain WhyJul 7 2023, 9:49 AM
This revision was automatically updated to reflect the committed changes.
jhuber6 added a commit: rGc012eb79e233: [libc] Enable aliasing on AMDGPU targets.
tra added a subscriber: tra.Jul 10 2023, 10:10 AM
tra added inline comments.
libc/src/__support/common.h
19

PTX did add support for aliases a while back, but we indeed don't use it at the moment.

jhuber6 added inline comments.Jul 10 2023, 10:12 AM
libc/src/__support/common.h
19

Ah, probably should've checked the PTX reference. Now if they just made .section work outside of debug mode I'd be a happy camper. Guessing this just requires some effort in the backend to support it? Might be worthwhile.

Revision Contents

PathSize
libc/
src/
__support/
4 lines

Diff 538178

libc/src/__support/common.h

Show All 10 Lines
#include "src/__support/macros/attributes.h" #include "src/__support/macros/attributes.h"
#include "src/__support/macros/properties/architectures.h" #include "src/__support/macros/properties/architectures.h"
#ifndef LLVM_LIBC_FUNCTION_ATTR #ifndef LLVM_LIBC_FUNCTION_ATTR
#define LLVM_LIBC_FUNCTION_ATTR #define LLVM_LIBC_FUNCTION_ATTR
#endif #endif
// GPU targets do not support aliasing. // The NVPTX target does not support aliasing.
traUnsubmitted
Not Done
ReplyInline Actions

PTX did add support for aliases a while back, but we indeed don't use it at the moment.

tra: PTX did add support for aliases a while back, but we indeed don't use it at the moment.
jhuber6AuthorUnsubmitted
Done
ReplyInline Actions

Ah, probably should've checked the PTX reference. Now if they just made .section work outside of debug mode I'd be a happy camper. Guessing this just requires some effort in the backend to support it? Might be worthwhile.

jhuber6: Ah, probably should've checked the PTX reference. Now if they just made `.section` work outside…
#if defined(LIBC_COPT_PUBLIC_PACKAGING) && defined(LIBC_TARGET_ARCH_IS_GPU) #if defined(LIBC_COPT_PUBLIC_PACKAGING) && defined(LIBC_TARGET_ARCH_IS_NVPTX)
#define LLVM_LIBC_FUNCTION_IMPL(type, name, arglist) \ #define LLVM_LIBC_FUNCTION_IMPL(type, name, arglist) \
LLVM_LIBC_FUNCTION_ATTR decltype(__llvm_libc::name) \ LLVM_LIBC_FUNCTION_ATTR decltype(__llvm_libc::name) \
__##name##_impl__ __asm__(#name); \ __##name##_impl__ __asm__(#name); \
type __##name##_impl__ arglist type __##name##_impl__ arglist
// MacOS needs to be excluded because it does not support aliasing. // MacOS needs to be excluded because it does not support aliasing.
#elif defined(LIBC_COPT_PUBLIC_PACKAGING) && (!defined(__APPLE__)) #elif defined(LIBC_COPT_PUBLIC_PACKAGING) && (!defined(__APPLE__))
#define LLVM_LIBC_FUNCTION_IMPL(type, name, arglist) \ #define LLVM_LIBC_FUNCTION_IMPL(type, name, arglist) \
LLVM_LIBC_FUNCTION_ATTR decltype(__llvm_libc::name) \ LLVM_LIBC_FUNCTION_ATTR decltype(__llvm_libc::name) \
Show All 35 Lines