3681be876f
GCC 7 introduced -fprofile-update={atomic,prefer-atomic} (prefer-atomic is for
best efforts (some targets do not support atomics)) to increment counters
atomically, which is exactly what we have done with -fprofile-instr-generate
(D50867) and -fprofile-arcs (b5ef137c11b1cc6ae839ee75b49233825772bdd0).
This patch adds the option to clang to surface the internal options at driver level.
GCC 7 also turned on -fprofile-update=prefer-atomic when -pthread is specified,
but it has performance regression
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89307). So we don't follow suit.
Differential Revision: https://reviews.llvm.org/D87737
7 lines
195 B
C
7 lines
195 B
C
// RUN: %clang_cc1 %s -emit-llvm -fprofile-instrument=clang -fprofile-update=atomic -o - | FileCheck %s
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// CHECK: define {{.*}}@foo
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// CHECK-NOT: load {{.*}}foo
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// CHECK: ret void
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void foo() {}
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