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Use compiler barrier instead of memory barrier for release/acquire atomic operations on mac.

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BUG=
R=jarin@chromium.org

Review URL: https://codereview.chromium.org/694703003

Cr-Commit-Position: refs/heads/master@{#25147}
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25147 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
hpayer@chromium.org 2014-11-05 12:35:19 +00:00
parent 858a5e5319
commit 66430307b5
1 changed files with 17 additions and 6 deletions
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23
src/base/atomicops_internals_mac.h
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@ -12,6 +12,20 @@
namespace v8 {
namespace base {
#define ATOMICOPS_COMPILER_BARRIER() __asm__ __volatile__("" : : : "memory")
inline void MemoryBarrier() { OSMemoryBarrier(); }
inline void AcquireMemoryBarrier() {
// On x86 processors, loads already have acquire semantics, so
// there is no need to put a full barrier here.
#if V8_HOST_ARCH_IA32 || V8_HOST_ARCH_X64
ATOMICOPS_COMPILER_BARRIER();
#else
MemoryBarrier();
#endif
}
inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32* ptr,
Atomic32 old_value,
Atomic32 new_value) {
@ -46,10 +60,6 @@ inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32* ptr,
return OSAtomicAdd32Barrier(increment, const_cast<Atomic32*>(ptr));
}
inline void MemoryBarrier() {
OSMemoryBarrier();
}
inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr,
Atomic32 old_value,
Atomic32 new_value) {
@ -98,7 +108,7 @@ inline Atomic32 NoBarrier_Load(volatile const Atomic32* ptr) {
inline Atomic32 Acquire_Load(volatile const Atomic32* ptr) {
Atomic32 value = *ptr;
MemoryBarrier();
AcquireMemoryBarrier();
return value;
}
@ -188,7 +198,7 @@ inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) {
inline Atomic64 Acquire_Load(volatile const Atomic64* ptr) {
Atomic64 value = *ptr;
MemoryBarrier();
AcquireMemoryBarrier();
return value;
}
@ -199,6 +209,7 @@ inline Atomic64 Release_Load(volatile const Atomic64* ptr) {
#endif // defined(__LP64__)
#undef ATOMICOPS_COMPILER_BARRIER
} } // namespace v8::base
#endif // V8_BASE_ATOMICOPS_INTERNALS_MAC_H_