summaryrefslogtreecommitdiff
path: root/src/gc/env/gcenv.base.h
diff options
context:
space:
mode:
authorSteve MacLean <sdmaclea.qdt@qualcommdatacenter.com>2017-06-14 02:04:01 -0400
committerJan Kotas <jkotas@microsoft.com>2017-06-13 23:04:01 -0700
commitd23a2bc131eae32c473e39fcb3b640af1a95d244 (patch)
treee46b96cd6396676c2b010884c4834d3197917aaa /src/gc/env/gcenv.base.h
parentd2f9e21c69e70f1d0edac2392ff95d4670edff6e (diff)
downloadcoreclr-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/env/gcenv.base.h')
-rw-r--r--src/gc/env/gcenv.base.h29
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;