switch UndefValue and ConstantPointerNull over to DenseMap's for uniquing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148693 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 35 insertions, 4 deletions

diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp
index d04298f149..f2d8794284 100644
--- a/lib/VMCore/Constants.cpp
+++ b/lib/VMCore/Constants.cpp
@@ -1127,13 +1127,29 @@ Constant *ConstantVector::getSplatValue() const {
 //
 
 ConstantPointerNull *ConstantPointerNull::get(PointerType *Ty) {
-  return Ty->getContext().pImpl->NullPtrConstants.getOrCreate(Ty, 0);
+  OwningPtr<ConstantPointerNull> &Entry =
+    Ty->getContext().pImpl->CPNConstants[Ty];
+  if (Entry == 0)
+    Entry.reset(new ConstantPointerNull(Ty));
+  
+  return Entry.get();
 }
 
 // destroyConstant - Remove the constant from the constant table...
 //
 void ConstantPointerNull::destroyConstant() {
-  getType()->getContext().pImpl->NullPtrConstants.remove(this);
+  // Drop ownership of the CPN object before removing the entry so that it
+  // doesn't get double deleted.
+  LLVMContextImpl::CPNMapTy &CPNConstants = getContext().pImpl->CPNConstants;
+  LLVMContextImpl::CPNMapTy::iterator I = CPNConstants.find(getType());
+  assert(I != CPNConstants.end() && "CPN object not in uniquing map");
+  I->second.take();
+  
+  // Actually remove the entry from the DenseMap now, which won't free the
+  // constant.
+  CPNConstants.erase(I);
+  
+  // Free the constant and any dangling references to it.
   destroyConstantImpl();
 }
 
@@ -1142,13 +1158,28 @@ void ConstantPointerNull::destroyConstant() {
 //
 
 UndefValue *UndefValue::get(Type *Ty) {
-  return Ty->getContext().pImpl->UndefValueConstants.getOrCreate(Ty, 0);
+  OwningPtr<UndefValue> &Entry = Ty->getContext().pImpl->UVConstants[Ty];
+  if (Entry == 0)
+    Entry.reset(new UndefValue(Ty));
+  
+  return Entry.get();
 }
 
 // destroyConstant - Remove the constant from the constant table.
 //
 void UndefValue::destroyConstant() {
-  getType()->getContext().pImpl->UndefValueConstants.remove(this);
+  // Drop ownership of the object before removing the entry so that it
+  // doesn't get double deleted.
+  LLVMContextImpl::UVMapTy &UVConstants = getContext().pImpl->UVConstants;
+  LLVMContextImpl::UVMapTy::iterator I = UVConstants.find(getType());
+  assert(I != UVConstants.end() && "UV object not in uniquing map");
+  I->second.take();
+  
+  // Actually remove the entry from the DenseMap now, which won't free the
+  // constant.
+  UVConstants.erase(I);
+  
+  // Free the constant and any dangling references to it.
   destroyConstantImpl();
 }