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| author | Craig Topper <craig.topper@intel.com> | 2017-08-05 23:35:54 +0000 |
|---|---|---|
| committer | Craig Topper <craig.topper@intel.com> | 2017-08-05 23:35:54 +0000 |
| commit | 9d8e9ff6206347ae56f242daf17d08160a184b2e (patch) | |
| tree | 9846a0807cce531e69e1bcf3528b37f0b61e068c /clang | |
| parent | 6bfa2aee78785d340ac185a30c666d22130fe018 (diff) | |
| download | bcm5719-llvm-9d8e9ff6206347ae56f242daf17d08160a184b2e.tar.gz bcm5719-llvm-9d8e9ff6206347ae56f242daf17d08160a184b2e.zip | |
[X86] Enable isel to use the PAUSE instruction even when SSE2 is disabled. Clang part
Summary:
On older processors this instruction encoding is treated as a NOP.
MSVC doesn't disable intrinsics based on features the way clang/gcc does. Because the PAUSE instruction encoding doesn't crash older processors, some software out there uses these intrinsics without checking for SSE2.
This change also seems to also be consistent with gcc behavior.
Fixes PR34079
Reviewers: RKSimon, zvi
Reviewed By: RKSimon
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D36362
llvm-svn: 310191
Diffstat (limited to 'clang')
| -rw-r--r-- | clang/include/clang/Basic/BuiltinsX86.def | 4 | ||||
| -rw-r--r-- | clang/test/CodeGen/pause.c | 11 |
2 files changed, 13 insertions, 2 deletions
diff --git a/clang/include/clang/Basic/BuiltinsX86.def b/clang/include/clang/Basic/BuiltinsX86.def index a516bf6bf06..6d3a478ac36 100644 --- a/clang/include/clang/Basic/BuiltinsX86.def +++ b/clang/include/clang/Basic/BuiltinsX86.def @@ -338,8 +338,8 @@ TARGET_BUILTIN(__builtin_ia32_lfence, "v", "", "sse2") TARGET_HEADER_BUILTIN(_mm_lfence, "v", "h", "emmintrin.h", ALL_LANGUAGES, "sse2") TARGET_BUILTIN(__builtin_ia32_mfence, "v", "", "sse2") TARGET_HEADER_BUILTIN(_mm_mfence, "v", "h", "emmintrin.h", ALL_LANGUAGES, "sse2") -TARGET_BUILTIN(__builtin_ia32_pause, "v", "", "sse2") -TARGET_HEADER_BUILTIN(_mm_pause, "v", "h", "emmintrin.h", ALL_LANGUAGES, "sse2") +TARGET_BUILTIN(__builtin_ia32_pause, "v", "", "") +TARGET_HEADER_BUILTIN(_mm_pause, "v", "h", "emmintrin.h", ALL_LANGUAGES, "") TARGET_BUILTIN(__builtin_ia32_pmuludq128, "V2LLiV4iV4i", "", "sse2") TARGET_BUILTIN(__builtin_ia32_psraw128, "V8sV8sV8s", "", "sse2") TARGET_BUILTIN(__builtin_ia32_psrad128, "V4iV4iV4i", "", "sse2") diff --git a/clang/test/CodeGen/pause.c b/clang/test/CodeGen/pause.c new file mode 100644 index 00000000000..1a8e10aec04 --- /dev/null +++ b/clang/test/CodeGen/pause.c @@ -0,0 +1,11 @@ +// RUN: %clang_cc1 -ffreestanding %s -triple=i386-pc-win32 -target-feature -sse2 -emit-llvm -o - -Wall -Werror | FileCheck %s +// RUN: %clang_cc1 -ffreestanding %s -triple=i386-pc-win32 -target-feature +sse2 -emit-llvm -o - -Wall -Werror | FileCheck %s + + +#include <x86intrin.h> + +void test_mm_pause() { + // CHECK-LABEL: test_mm_pause + // CHECK: call void @llvm.x86.sse2.pause() + return _mm_pause(); +} |
