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Fix for bugzilla https://bugs.llvm.org/show_bug.cgi?id=39137.
ClosedPublic

Authored by AndreyChurbanov on Nov 9 2018, 5:50 AM.

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Details

Reviewers

hbae
tlwilmar
jlpeyton

Commits

rG82318c6f14e1: Fix for bugzilla https://bugs.llvm.org/show_bug.cgi?id=39137.
rOMP346862: Fix for bugzilla https://bugs.llvm.org/show_bug.cgi?id=39137.
rL346862: Fix for bugzilla https://bugs.llvm.org/show_bug.cgi?id=39137.

Summary

Exit earlier from omp_set_num_threads in case requested number of threads is equal to num_threads ICV (internal control variable), in order to avoid unnecessary write.

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Event Timeline

AndreyChurbanov created this revision.Nov 9 2018, 5:50 AM

Herald added a subscriber: openmp-commits. · View Herald TranscriptNov 9 2018, 5:50 AM

LGTM.

This revision is now accepted and ready to land.Nov 9 2018, 8:51 AM

Closed by commit rL346862: Fix for bugzilla https://bugs.llvm.org/show_bug.cgi?id=39137. (authored by achurbanov). · Explain WhyNov 14 2018, 5:52 AM

This revision was automatically updated to reflect the committed changes.

Herald added a subscriber: llvm-commits. · View Herald TranscriptNov 14 2018, 5:52 AM

Revision Contents

Path

Size

runtime/

src/

kmp_runtime.cpp

2 lines

Diff 173307

runtime/src/kmp_runtime.cpp

This file is larger than 256 KB, so syntax highlighting is disabled by default.

Show First 20 Lines • Show All 2,643 Lines • ▼ Show 20 Lines	void __kmp_set_num_threads(int new_nth, int gtid) {

if (new_nth < 1)		if (new_nth < 1)
new_nth = 1;		new_nth = 1;
else if (new_nth > __kmp_max_nth)		else if (new_nth > __kmp_max_nth)
new_nth = __kmp_max_nth;		new_nth = __kmp_max_nth;

KMP_COUNT_VALUE(OMP_set_numthreads, new_nth);		KMP_COUNT_VALUE(OMP_set_numthreads, new_nth);
thread = __kmp_threads[gtid];		thread = __kmp_threads[gtid];
		if (thread->th.th_current_task->td_icvs.nproc == new_nth)
		return; // nothing to do

__kmp_save_internal_controls(thread);		__kmp_save_internal_controls(thread);

set__nproc(thread, new_nth);		set__nproc(thread, new_nth);

// If this omp_set_num_threads() call will cause the hot team size to be		// If this omp_set_num_threads() call will cause the hot team size to be
// reduced (in the absence of a num_threads clause), then reduce it now,		// reduced (in the absence of a num_threads clause), then reduce it now,
// rather than waiting for the next parallel region.		// rather than waiting for the next parallel region.
▲ Show 20 Lines • Show All 5,125 Lines • Show Last 20 Lines