Derive metadata hierarchy from Value instead of User.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84801 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 7 insertions, 99 deletions

diff --git a/lib/VMCore/LLVMContext.cpp b/lib/VMCore/LLVMContext.cpp
index 39ed7ed..3b4a1a3 100644
--- a/lib/VMCore/LLVMContext.cpp
+++ b/lib/VMCore/LLVMContext.cpp
@@ -45,32 +45,6 @@ GetElementPtrConstantExpr::GetElementPtrConstantExpr
     OperandList[i+1] = IdxList[i];
 }
 
-bool LLVMContext::RemoveDeadMetadata() {
-  std::vector<WeakVH> DeadMDNodes;
-  bool Changed = false;
-  while (1) {
-
-    for (FoldingSet<MDNode>::iterator 
-           I = pImpl->MDNodeSet.begin(),
-           E = pImpl->MDNodeSet.end(); I != E; ++I) {
-      MDNode *N = &(*I);
-      if (N->use_empty()) 
-        DeadMDNodes.push_back(WeakVH(N));
-    }
-    
-    if (DeadMDNodes.empty())
-      return Changed;
-
-    while (!DeadMDNodes.empty()) {
-      Value *V = DeadMDNodes.back(); DeadMDNodes.pop_back();
-      if (const MDNode *N = dyn_cast_or_null<MDNode>(V))
-        if (N->use_empty())
-          delete N;
-    }
-  }
-  return Changed;
-}
-
 MetadataContext &LLVMContext::getMetadata() {
   return pImpl->TheMetadata;
 }
diff --git a/lib/VMCore/LLVMContextImpl.h b/lib/VMCore/LLVMContextImpl.h
index 58e8870..84902d5 100644
--- a/lib/VMCore/LLVMContextImpl.h
+++ b/lib/VMCore/LLVMContextImpl.h
@@ -203,9 +203,6 @@ public:
     AggZeroConstants.freeConstants();
     NullPtrConstants.freeConstants();
     UndefValueConstants.freeConstants();
-    for (FoldingSet<MDNode>::iterator I = MDNodeSet.begin(), 
-           E = MDNodeSet.end(); I != E; ++I)
-      I->dropAllReferences();
     for (IntMapTy::iterator I = IntConstants.begin(), E = IntConstants.end(); 
          I != E; ++I) {
       if (I->second->use_empty())
@@ -216,6 +213,7 @@ public:
       if (I->second->use_empty())
         delete I->second;
     }
+    MDNodeSet.clear();
   }
 };
 
diff --git a/lib/VMCore/Metadata.cpp b/lib/VMCore/Metadata.cpp
index 365fe8b..faf79fd 100644
--- a/lib/VMCore/Metadata.cpp
+++ b/lib/VMCore/Metadata.cpp
@@ -23,30 +23,6 @@ using namespace llvm;
 // MetadataBase implementation.
 //
 
-/// resizeOperands - Metadata keeps track of other metadata uses using 
-/// OperandList. Resize this list to hold anticipated number of metadata
-/// operands.
-void MetadataBase::resizeOperands(unsigned NumOps) {
-  unsigned e = getNumOperands();
-  if (NumOps == 0) {
-    NumOps = e*2;
-    if (NumOps < 2) NumOps = 2;  
-  } else if (NumOps > NumOperands) {
-    // No resize needed.
-    if (ReservedSpace >= NumOps) return;
-  } else if (NumOps == NumOperands) {
-    if (ReservedSpace == NumOps) return;
-  } else {
-    return;
-  }
-
-  ReservedSpace = NumOps;
-  Use *OldOps = OperandList;
-  Use *NewOps = allocHungoffUses(NumOps);
-  std::copy(OldOps, OldOps + e, NewOps);
-  OperandList = NewOps;
-  if (OldOps) Use::zap(OldOps, OldOps + e, true);
-}
 //===----------------------------------------------------------------------===//
 // MDString implementation.
 //
@@ -65,20 +41,11 @@ MDString *MDString::get(LLVMContext &Context, const StringRef &Str) {
 //
 MDNode::MDNode(LLVMContext &C, Value *const *Vals, unsigned NumVals)
   : MetadataBase(Type::getMetadataTy(C), Value::MDNodeVal) {
-  NumOperands = 0;
-  resizeOperands(NumVals);
   NodeSize = NumVals;
   Node = new ElementVH[NodeSize];
   ElementVH *Ptr = Node;
-  for (unsigned i = 0; i != NumVals; ++i) {
-    // Only record metadata uses.
-    if (MetadataBase *MB = dyn_cast_or_null<MetadataBase>(Vals[i]))
-      OperandList[NumOperands++] = MB;
-    else if(Vals[i] && 
-            Vals[i]->getType()->getTypeID() == Type::MetadataTyID)
-      OperandList[NumOperands++] = Vals[i];
+  for (unsigned i = 0; i != NumVals; ++i) 
     *Ptr++ = ElementVH(Vals[i], this);
-  }
 }
 
 void MDNode::Profile(FoldingSetNodeID &ID) const {
@@ -109,19 +76,14 @@ MDNode *MDNode::get(LLVMContext &Context, Value*const* Vals, unsigned NumVals) {
   return N;
 }
 
-/// dropAllReferences - Remove all uses and clear node vector.
-void MDNode::dropAllReferences() {
-  User::dropAllReferences();
-  delete [] Node;
-  Node = NULL;
-}
-
+/// ~MDNode - Destroy MDNode.
 MDNode::~MDNode() {
   {
     LLVMContextImpl *pImpl = getType()->getContext().pImpl;
     pImpl->MDNodeSet.RemoveNode(this);
   }
-  dropAllReferences();
+  delete [] Node;
+  Node = NULL;
 }
 
 // Replace value from this node's element list.
@@ -148,27 +110,6 @@ void MDNode::replaceElement(Value *From, Value *To) {
   // Remove "this" from the context map. 
   pImpl->MDNodeSet.RemoveNode(this);
 
-  // MDNode only lists metadata elements in operand list, because MDNode
-  // used by MDNode is considered a valid use. However on the side, MDNode
-  // using a non-metadata value is not considered a "use" of non-metadata
-  // value.
-  SmallVector<unsigned, 4> OpIndexes;
-  unsigned OpIndex = 0;
-  for (User::op_iterator OI = op_begin(), OE = op_end();
-       OI != OE; ++OI, OpIndex++) {
-    if (*OI == From)
-      OpIndexes.push_back(OpIndex);
-  }
-  if (MetadataBase *MDTo = dyn_cast_or_null<MetadataBase>(To)) {
-    for (SmallVector<unsigned, 4>::iterator OI = OpIndexes.begin(),
-           OE = OpIndexes.end(); OI != OE; ++OI)
-      setOperand(*OI, MDTo);
-  } else {
-    for (SmallVector<unsigned, 4>::iterator OI = OpIndexes.begin(),
-           OE = OpIndexes.end(); OI != OE; ++OI)
-      setOperand(*OI, 0);
-  }
-
   // Replace From element(s) in place.
   for (SmallVector<unsigned, 4>::iterator I = Indexes.begin(), E = Indexes.end(); 
        I != E; ++I) {
@@ -207,14 +148,10 @@ NamedMDNode::NamedMDNode(LLVMContext &C, const Twine &N,
                          unsigned NumMDs, Module *ParentModule)
   : MetadataBase(Type::getMetadataTy(C), Value::NamedMDNodeVal), Parent(0) {
   setName(N);
-  NumOperands = 0;
-  resizeOperands(NumMDs);
 
-  for (unsigned i = 0; i != NumMDs; ++i) {
-    if (MDs[i])
-      OperandList[NumOperands++] = MDs[i];
+  for (unsigned i = 0; i != NumMDs; ++i)
     Node.push_back(WeakMetadataVH(MDs[i]));
-  }
+
   if (ParentModule)
     ParentModule->getNamedMDList().push_back(this);
 }
@@ -236,7 +173,6 @@ void NamedMDNode::eraseFromParent() {
 
 /// dropAllReferences - Remove all uses and clear node vector.
 void NamedMDNode::dropAllReferences() {
-  User::dropAllReferences();
   Node.clear();
 }