Add a comment to describe why vector shuffles are legalized to custom DAG nodes.

[oota-llvm.git] / lib / VMCore / Metadata.cpp

diff --git a/lib/VMCore/Metadata.cpp b/lib/VMCore/Metadata.cpp
index bf0611f9e468c67c3165710daa5bcce12393a7a8..4762a1055507829a9ebbc28fad30db0a946791e1 100644 (file)
--- a/lib/VMCore/Metadata.cpp
+++ b/lib/VMCore/Metadata.cpp
@@ -18,6 +18,34 @@
 #include "SymbolTableListTraitsImpl.h"
 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
 //
@@ -38,37 +66,43 @@ MDString *MDString::get(LLVMContext &Context, const StringRef &Str) {
 //
 MDNode::MDNode(Value*const* Vals, unsigned NumVals)
   : MetadataBase(Type::MetadataTy, Value::MDNodeVal) {
-  for (unsigned i = 0; i != NumVals; ++i)
+  NumOperands = 0;
+  resizeOperands(NumVals);
+  for (unsigned i = 0; i != NumVals; ++i) {
+    // Only record metadata uses.
+    if (MetadataBase *MB = dyn_cast_or_null<MetadataBase>(Vals[i]))
+      OperandList[NumOperands++] = MB;
     Node.push_back(WeakVH(Vals[i]));
-}
-
-void MDNode::Profile(FoldingSetNodeID &ID) const {
-  for (const_elem_iterator I = elem_begin(), E = elem_end(); I != E; ++I)
-    ID.AddPointer(*I);
+  }
 }
 
 MDNode *MDNode::get(LLVMContext &Context, Value*const* Vals, unsigned NumVals) {
   LLVMContextImpl *pImpl = Context.pImpl;
-  FoldingSetNodeID ID;
-  for (unsigned i = 0; i != NumVals; ++i)
-    ID.AddPointer(Vals[i]);
-
-  pImpl->ConstantsLock.reader_acquire();
-  void *InsertPoint;
-  MDNode *N = pImpl->MDNodeSet.FindNodeOrInsertPos(ID, InsertPoint);
-  pImpl->ConstantsLock.reader_release();
+  std::vector<Value*> V;
+  V.reserve(NumVals);
+  for (unsigned i = 0; i < NumVals; ++i)
+    V.push_back(Vals[i]);
   
-  if (!N) {
-    sys::SmartScopedWriter<true> Writer(pImpl->ConstantsLock);
-    N = pImpl->MDNodeSet.FindNodeOrInsertPos(ID, InsertPoint);
-    if (!N) {
-      // InsertPoint will have been set by the FindNodeOrInsertPos call.
-      N = new MDNode(Vals, NumVals);
-      pImpl->MDNodeSet.InsertNode(N, InsertPoint);
-    }
-  }
+  return pImpl->MDNodes.getOrCreate(Type::MetadataTy, V);
+}
+
+/// dropAllReferences - Remove all uses and clear node vector.
+void MDNode::dropAllReferences() {
+  User::dropAllReferences();
+  Node.clear();
+}
 
-  return N;
+static std::vector<Value*> getValType(MDNode *N) {
+  std::vector<Value*> Elements;
+  Elements.reserve(N->getNumElements());
+  for (unsigned i = 0, e = N->getNumElements(); i != e; ++i)
+    Elements.push_back(N->getElement(i));
+  return Elements;
+}
+
+MDNode::~MDNode() {
+  dropAllReferences();
+  getType()->getContext().pImpl->MDNodes.remove(this);
 }
 
 //===----------------------------------------------------------------------===//
@@ -78,8 +112,38 @@ NamedMDNode::NamedMDNode(const Twine &N, MetadataBase*const* MDs,
                          unsigned NumMDs, Module *ParentModule)
   : MetadataBase(Type::MetadataTy, Value::NamedMDNodeVal), Parent(0) {
   setName(N);
-  for (unsigned i = 0; i != NumMDs; ++i)
+  NumOperands = 0;
+  resizeOperands(NumMDs);
+
+  for (unsigned i = 0; i != NumMDs; ++i) {
+    if (MDs[i])
+      OperandList[NumOperands++] = MDs[i];
     Node.push_back(WeakMetadataVH(MDs[i]));
+  }
   if (ParentModule)
     ParentModule->getNamedMDList().push_back(this);
 }
+
+NamedMDNode *NamedMDNode::Create(const NamedMDNode *NMD, Module *M) {
+  assert (NMD && "Invalid source NamedMDNode!");
+  SmallVector<MetadataBase *, 4> Elems;
+  for (unsigned i = 0, e = NMD->getNumElements(); i != e; ++i)
+    Elems.push_back(NMD->getElement(i));
+  return new NamedMDNode(NMD->getName().data(), Elems.data(), Elems.size(), M);
+}
+
+/// eraseFromParent - Drop all references and remove the node from parent
+/// module.
+void NamedMDNode::eraseFromParent() {
+  getParent()->getNamedMDList().erase(this);
+}
+
+/// dropAllReferences - Remove all uses and clear node vector.
+void NamedMDNode::dropAllReferences() {
+  User::dropAllReferences();
+  Node.clear();
+}
+
+NamedMDNode::~NamedMDNode() {
+  dropAllReferences();
+}