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| author | Steve MacLean <sdmaclea.qdt@qualcommdatacenter.com> | 2017-06-14 02:04:01 -0400 |
|---|---|---|
| committer | Jan Kotas <jkotas@microsoft.com> | 2017-06-13 23:04:01 -0700 |
| commit | d23a2bc131eae32c473e39fcb3b640af1a95d244 (patch) | |
| tree | e46b96cd6396676c2b010884c4834d3197917aaa /src/gc | |
| parent | d2f9e21c69e70f1d0edac2392ff95d4670edff6e (diff) | |
| download | coreclr-d23a2bc131eae32c473e39fcb3b640af1a95d244.tar.gz coreclr-d23a2bc131eae32c473e39fcb3b640af1a95d244.tar.bz2 coreclr-d23a2bc131eae32c473e39fcb3b640af1a95d244.zip | |
[Arn64/Unix] Revise Volatile.T barriers (#12156)
* [Arm64] Revise Volatile<T> barriers
* Remove VolateStore from CopyValueClassUnchecked
* Replace MemoryBarrier() in CopyValueClassUnchecked
Diffstat (limited to 'src/gc')
| -rw-r--r-- | src/gc/env/gcenv.base.h | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/src/gc/env/gcenv.base.h b/src/gc/env/gcenv.base.h index af1a3cd9f0..1e9406c296 100644 --- a/src/gc/env/gcenv.base.h +++ b/src/gc/env/gcenv.base.h @@ -351,7 +351,7 @@ typedef PTR_PTR_Object PTR_UNCHECKED_OBJECTREF; #if defined(__clang__) #if defined(_ARM_) || defined(_ARM64_) // This is functionally equivalent to the MemoryBarrier() macro used on ARM on Windows. -#define VOLATILE_MEMORY_BARRIER() asm volatile ("dmb sy" : : : "memory") +#define VOLATILE_MEMORY_BARRIER() asm volatile ("dmb ish" : : : "memory") #else // // For Clang, we prevent reordering by the compiler by inserting the following after a volatile @@ -392,8 +392,22 @@ template<typename T> inline T VolatileLoad(T const * pt) { +#if defined(_ARM64_) && defined(__clang__) + T val; + static const unsigned lockFreeAtomicSizeMask = (1 << 1) | (1 << 2) | (1 << 4) | (1 << 8); + if((1 << sizeof(T)) & lockFreeAtomicSizeMask) + { + __atomic_load((T volatile const *)pt, &val, __ATOMIC_ACQUIRE); + } + else + { + val = *(T volatile const *)pt; + asm volatile ("dmb ishld" : : : "memory"); + } +#else T val = *(T volatile const *)pt; VOLATILE_MEMORY_BARRIER(); +#endif return val; } @@ -420,8 +434,21 @@ template<typename T> inline void VolatileStore(T* pt, T val) { +#if defined(_ARM64_) && defined(__clang__) + static const unsigned lockFreeAtomicSizeMask = (1 << 1) | (1 << 2) | (1 << 4) | (1 << 8); + if((1 << sizeof(T)) & lockFreeAtomicSizeMask) + { + __atomic_store((T volatile *)pt, &val, __ATOMIC_RELEASE); + } + else + { + VOLATILE_MEMORY_BARRIER(); + *(T volatile *)pt = val; + } +#else VOLATILE_MEMORY_BARRIER(); *(T volatile *)pt = val; +#endif } extern GCSystemInfo g_SystemInfo; |