Author: ctopper Date: Sat Aug 5 16:35:54 2017 New Revision: 310191 URL: http://llvm.org/viewvc/llvm-project?rev=310191&view=rev Log: [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 Added: cfe/trunk/test/CodeGen/pause.c Modified: cfe/trunk/include/clang/Basic/BuiltinsX86.def Modified: cfe/trunk/include/clang/Basic/BuiltinsX86.def URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/BuiltinsX86.def?rev=310191&r1=310190&r2=310191&view=diff ============================================================================== --- cfe/trunk/include/clang/Basic/BuiltinsX86.def (original) +++ cfe/trunk/include/clang/Basic/BuiltinsX86.def Sat Aug 5 16:35:54 2017 @@ -338,8 +338,8 @@ TARGET_BUILTIN(__builtin_ia32_lfence, "v 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") Added: cfe/trunk/test/CodeGen/pause.c URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/pause.c?rev=310191&view=auto ============================================================================== --- cfe/trunk/test/CodeGen/pause.c (added) +++ cfe/trunk/test/CodeGen/pause.c Sat Aug 5 16:35:54 2017 @@ -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(); +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
