Reapply r79708 with the appropriate fix for the case that still requires locking.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79731 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson 2009-08-22 06:32:36 +00:00
parent 022fc3e70a
commit 02b10347bb

View File

@ -5022,12 +5022,16 @@ static ManagedStatic<sys::SmartMutex<true> > VTMutex;
/// getValueTypeList - Return a pointer to the specified value type.
///
const EVT *SDNode::getValueTypeList(EVT VT) {
sys::SmartScopedLock<true> Lock(*VTMutex);
if (VT.isExtended()) {
sys::SmartScopedLock<true> Lock(*VTMutex);
return &(*EVTs->insert(VT).first);
} else {
// All writes to this location will have the same value, so it's ok
// to race on it. We only need to ensure that at least one write has
// succeeded before we return the pointer into the array.
VTs[VT.getSimpleVT().SimpleTy] = VT;
return &VTs[VT.getSimpleVT().SimpleTy];
sys::MemoryFence();
return VTs + VT.getSimpleVT().SimpleTy;
}
}