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| author | Reid Kleckner <reid@kleckner.net> | 2013-10-17 01:29:48 +0000 |
|---|---|---|
| committer | Reid Kleckner <reid@kleckner.net> | 2013-10-17 01:29:48 +0000 |
| commit | 0b327d323db4bbd93a4b91ed98ee9ab243290f4e (patch) | |
| tree | a1ef5c95ba39e90a52317ce5984e223543086a26 /lib/Headers | |
| parent | b5b3f816d3c2543e11fb4f0b235041beafd81a1e (diff) | |
| download | clang-0b327d323db4bbd93a4b91ed98ee9ab243290f4e.tar.gz | |
Add implementations of the MSVC barrier intrinsics
Summary:
These are deprecated in VS 2012 according to MSDN. They don't actually
compile down to any code. They prevent the compiler from reordering
memory accesses across the barrier, which is what a memory-clobbering
volatile asm does.
Reviewers: echristo
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1954
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192860 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Headers')
| -rw-r--r-- | lib/Headers/Intrin.h | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/lib/Headers/Intrin.h b/lib/Headers/Intrin.h index 5b00e3c8fe..437646471d 100644 --- a/lib/Headers/Intrin.h +++ b/lib/Headers/Intrin.h @@ -243,7 +243,9 @@ static __inline__ unsigned long __cdecl _lrotr(unsigned long, int); static __inline__ unsigned int _lzcnt_u32(unsigned int); +static __inline__ void _ReadBarrier(void); +static __inline__ void _ReadWriteBarrier(void); static __inline__ void *_ReturnAddress(void); @@ -280,6 +282,7 @@ unsigned int _t1mskc_u32(unsigned int); unsigned int _tzcnt_u32(unsigned int); unsigned int _tzcnt_u32(unsigned int); unsigned int _tzmsk_u32(unsigned int); +static __inline__ void _WriteBarrier(void); void _xabort(const unsigned int imm); unsigned __int32 xbegin(void); @@ -744,6 +747,24 @@ _InterlockedCompareExchange64(__int64 volatile *_Destination, } #endif /*----------------------------------------------------------------------------*\ +|* Barriers +\*----------------------------------------------------------------------------*/ +static __inline__ void __attribute__((__always_inline__, __nodebug__)) +__attribute__((deprecated("use other intrinsics or C++11 atomics instead"))) +_ReadWriteBarrier(void) { + __asm__ volatile ("" : : : "memory"); +} +static __inline__ void __attribute__((__always_inline__, __nodebug__)) +__attribute__((deprecated("use other intrinsics or C++11 atomics instead"))) +_ReadBarrier(void) { + __asm__ volatile ("" : : : "memory"); +} +static __inline__ void __attribute__((__always_inline__, __nodebug__)) +__attribute__((deprecated("use other intrinsics or C++11 atomics instead"))) +_WriteBarrier(void) { + __asm__ volatile ("" : : : "memory"); +} +/*----------------------------------------------------------------------------*\ |* Misc \*----------------------------------------------------------------------------*/ static __inline__ void * __attribute__((__always_inline__, __nodebug__)) |