Use separate ValueList for metadata.

This fixes PR4666.

llvm-svn: 78056

5 files changed, 149 insertions, 44 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 81fdbd29afb..4ad97b12d62 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -34,6 +34,7 @@ void BitcodeReader::FreeState() {
   Buffer = 0;
   std::vector<PATypeHolder>().swap(TypeList);
   ValueList.clear();
+  MDValueList.clear();
   
   std::vector<AttrListPtr>().swap(MAttributes);
   std::vector<BasicBlock*>().swap(FunctionBBs);
@@ -312,6 +313,41 @@ void BitcodeReaderValueList::ResolveConstantForwardRefs() {
   }
 }
 
+void BitcodeReaderMDValueList::AssignValue(Value *V, unsigned Idx) {
+  if (Idx == size()) {
+    push_back(V);
+    return;
+  }
+  
+  if (Idx >= size())
+    resize(Idx+1);
+  
+  WeakVH &OldV = MDValuePtrs[Idx];
+  if (OldV == 0) {
+    OldV = V;
+    return;
+  }
+  
+  // If there was a forward reference to this value, replace it.
+  Value *PrevVal = OldV;
+  OldV->replaceAllUsesWith(V);
+  delete PrevVal;
+}
+
+Value *BitcodeReaderMDValueList::getValueFwdRef(unsigned Idx) {
+  if (Idx >= size())
+    resize(Idx + 1);
+  
+  if (Value *V = MDValuePtrs[Idx]) {
+    assert(V->getType() == Type::MetadataTy && "Type mismatch in value table!");
+    return V;
+  }
+  
+  // Create and return a placeholder, which will later be RAUW'd.
+  Value *V = new Argument(Type::MetadataTy);
+  MDValuePtrs[Idx] = V;
+  return V;
+}
 
 const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
   // If the TypeID is in range, return it.
@@ -700,7 +736,7 @@ bool BitcodeReader::ParseValueSymbolTable() {
 }
 
 bool BitcodeReader::ParseMetadata() {
-  unsigned NextValueNo = ValueList.size();
+  unsigned NextValueNo = MDValueList.size();
 
   if (Stream.EnterSubBlock(bitc::METADATA_BLOCK_ID))
     return Error("Malformed block record");
@@ -752,13 +788,13 @@ bool BitcodeReader::ParseMetadata() {
       unsigned Size = Record.size();
       SmallVector<MetadataBase*, 8> Elts;
       for (unsigned i = 0; i != Size; ++i) {
-        Value *MD = ValueList.getValueFwdRef(Record[i], Type::MetadataTy);
+        Value *MD = MDValueList.getValueFwdRef(Record[i]);
         if (MetadataBase *B = dyn_cast<MetadataBase>(MD))
         Elts.push_back(B);
       }
       Value *V = NamedMDNode::Create(Name.c_str(), Elts.data(), Elts.size(), 
                                      TheModule);
-      ValueList.AssignValue(V, NextValueNo++);
+      MDValueList.AssignValue(V, NextValueNo++);
       break;
     }
     case bitc::METADATA_NODE: {
@@ -769,13 +805,15 @@ bool BitcodeReader::ParseMetadata() {
       SmallVector<Value*, 8> Elts;
       for (unsigned i = 0; i != Size; i += 2) {
         const Type *Ty = getTypeByID(Record[i], false);
-        if (Ty != Type::VoidTy)
+        if (Ty == Type::MetadataTy)
+          Elts.push_back(MDValueList.getValueFwdRef(Record[i+1]));
+        else if (Ty != Type::VoidTy)
           Elts.push_back(ValueList.getValueFwdRef(Record[i+1], Ty));
         else
           Elts.push_back(NULL);
       }
       Value *V = MDNode::get(Context, &Elts[0], Elts.size());
-      ValueList.AssignValue(V, NextValueNo++);
+      MDValueList.AssignValue(V, NextValueNo++);
       break;
     }
     case bitc::METADATA_STRING: {
@@ -786,7 +824,7 @@ bool BitcodeReader::ParseMetadata() {
         String[i] = Record[i];
       Value *V = MDString::get(Context, 
                                StringRef(String.data(), String.size()));
-      ValueList.AssignValue(V, NextValueNo++);
+      MDValueList.AssignValue(V, NextValueNo++);
       break;
     }
     }
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.h b/llvm/lib/Bitcode/Reader/BitcodeReader.h
index 77dabdee2dc..bd048885a65 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.h
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.h
@@ -86,6 +86,41 @@ public:
   void ResolveConstantForwardRefs();
 };
 
+
+//===----------------------------------------------------------------------===//
+//                          BitcodeReaderMDValueList Class
+//===----------------------------------------------------------------------===//
+
+class BitcodeReaderMDValueList {
+  std::vector<WeakVH> MDValuePtrs;
+  
+  LLVMContext& Context;
+public:
+  BitcodeReaderMDValueList(LLVMContext& C) : Context(C) {}
+
+  // vector compatibility methods
+  unsigned size() const       { return MDValuePtrs.size(); }
+  void resize(unsigned N)     { MDValuePtrs.resize(N); }
+  void push_back(Value *V)    { MDValuePtrs.push_back(V);  }
+  void clear()                { MDValuePtrs.clear();  }
+  Value *back() const         { return MDValuePtrs.back(); }
+  void pop_back()             { MDValuePtrs.pop_back(); }
+  bool empty() const          { return MDValuePtrs.empty(); }
+  
+  Value *operator[](unsigned i) const {
+    assert(i < MDValuePtrs.size());
+    return MDValuePtrs[i];
+  }
+  
+  void shrinkTo(unsigned N) {
+    assert(N <= size() && "Invalid shrinkTo request!");
+    MDValuePtrs.resize(N);
+  }
+
+  Value *getValueFwdRef(unsigned Idx);
+  void AssignValue(Value *V, unsigned Idx);
+};
+
 class BitcodeReader : public ModuleProvider {
   LLVMContext& Context;
   MemoryBuffer *Buffer;
@@ -96,6 +131,7 @@ class BitcodeReader : public ModuleProvider {
   
   std::vector<PATypeHolder> TypeList;
   BitcodeReaderValueList ValueList;
+  BitcodeReaderMDValueList MDValueList;
   std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInits;
   std::vector<std::pair<GlobalAlias*, unsigned> > AliasInits;
   
@@ -127,7 +163,7 @@ class BitcodeReader : public ModuleProvider {
   DenseMap<Function*, std::pair<uint64_t, unsigned> > DeferredFunctionInfo;
 public:
   explicit BitcodeReader(MemoryBuffer *buffer, LLVMContext& C)
-      : Context(C), Buffer(buffer), ErrorString(0), ValueList(C) {
+    : Context(C), Buffer(buffer), ErrorString(0), ValueList(C), MDValueList(C) {
     HasReversedFunctionsWithBodies = false;
   }
   ~BitcodeReader() {
@@ -160,7 +196,10 @@ public:
 private:
   const Type *getTypeByID(unsigned ID, bool isTypeTable = false);
   Value *getFnValueByID(unsigned ID, const Type *Ty) {
-    return ValueList.getValueFwdRef(ID, Ty);
+    if (Ty == Type::MetadataTy)
+      return MDValueList.getValueFwdRef(ID);
+    else
+      return ValueList.getValueFwdRef(ID, Ty);
   }
   BasicBlock *getBasicBlock(unsigned ID) const {
     if (ID >= FunctionBBs.size()) return 0; // Invalid ID
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index 6bd40ba0e5b..a5c28fcc763 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -492,7 +492,7 @@ static void WriteMDNode(const MDNode *N,
 
 static void WriteModuleMetadata(const ValueEnumerator &VE,
                                 BitstreamWriter &Stream) {
-  const ValueEnumerator::ValueList &Vals = VE.getValues();
+  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
   bool StartedMetadataBlock = false;
   unsigned MDSAbbrev = 0;
   SmallVector<uint64_t, 64> Record;
@@ -601,8 +601,6 @@ static void WriteConstants(unsigned FirstVal, unsigned LastVal,
   const Type *LastTy = 0;
   for (unsigned i = FirstVal; i != LastVal; ++i) {
     const Value *V = Vals[i].first;
-    if (isa<MetadataBase>(V))
-      continue;
     // If we need to switch types, do so now.
     if (V->getType() != LastTy) {
       LastTy = V->getType();
diff --git a/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp b/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
index 7583bb96c9e..4712dea7629 100644
--- a/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
+++ b/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
@@ -114,6 +114,18 @@ ValueEnumerator::ValueEnumerator(const Module *M) {
     TypeMap[Types[i].first] = i+1;
 }
 
+unsigned ValueEnumerator::getValueID(const Value *V) const {
+  if (isa<MetadataBase>(V)) {
+    ValueMapType::const_iterator I = MDValueMap.find(V);
+    assert(I != MDValueMap.end() && "Value not in slotcalculator!");
+    return I->second-1;
+  }
+  
+  ValueMapType::const_iterator I = ValueMap.find(V);
+  assert(I != ValueMap.end() && "Value not in slotcalculator!");
+  return I->second-1;
+}
+  
 // Optimize constant ordering.
 namespace {
   struct CstSortPredicate {
@@ -165,9 +177,51 @@ void ValueEnumerator::EnumerateValueSymbolTable(const ValueSymbolTable &VST) {
     EnumerateValue(VI->getValue());
 }
 
+void ValueEnumerator::EnumerateMetadata(const MetadataBase *MD) {
+  // Check to see if it's already in!
+  unsigned &MDValueID = MDValueMap[MD];
+  if (MDValueID) {
+    // Increment use count.
+    MDValues[MDValueID-1].second++;
+    return;
+  }
+
+  // Enumerate the type of this value.
+  EnumerateType(MD->getType());
+
+  if (const MDNode *N = dyn_cast<MDNode>(MD)) {
+    MDValues.push_back(std::make_pair(MD, 1U));
+    MDValueMap[MD] = MDValues.size();
+    MDValueID = MDValues.size();
+    for (MDNode::const_elem_iterator I = N->elem_begin(), E = N->elem_end();
+         I != E; ++I) {
+      if (*I)
+        EnumerateValue(*I);
+      else
+        EnumerateType(Type::VoidTy);
+    }
+    return;
+  } else if (const NamedMDNode *N = dyn_cast<NamedMDNode>(MD)) {
+    for(NamedMDNode::const_elem_iterator I = N->elem_begin(),
+          E = N->elem_end(); I != E; ++I) {
+      MetadataBase *M = *I;
+      EnumerateValue(M);
+    }
+    MDValues.push_back(std::make_pair(MD, 1U));
+    MDValueMap[MD] = Values.size();
+    return;
+  }
+
+  // Add the value.
+  MDValues.push_back(std::make_pair(MD, 1U));
+  MDValueID = MDValues.size();
+}
+
 void ValueEnumerator::EnumerateValue(const Value *V) {
   assert(V->getType() != Type::VoidTy && "Can't insert void values!");
-  
+  if (const MetadataBase *MB = dyn_cast<MetadataBase>(V))
+    return EnumerateMetadata(MB);
+
   // Check to see if it's already in!
   unsigned &ValueID = ValueMap[V];
   if (ValueID) {
@@ -207,31 +261,6 @@ void ValueEnumerator::EnumerateValue(const Value *V) {
     }
   }
 
-  if (const MDNode *N = dyn_cast<MDNode>(V)) {
-    Values.push_back(std::make_pair(V, 1U));
-    ValueMap[V] = Values.size();
-    ValueID = Values.size();
-    for (MDNode::const_elem_iterator I = N->elem_begin(), E = N->elem_end();
-         I != E; ++I) {
-      if (*I)
-        EnumerateValue(*I);
-      else
-        EnumerateType(Type::VoidTy);
-    }
-    return;
-  }
-
-  if (const NamedMDNode *N = dyn_cast<NamedMDNode>(V)) {
-    for(NamedMDNode::const_elem_iterator I = N->elem_begin(),
-          E = N->elem_end(); I != E; ++I) {
-      MetadataBase *M = *I;
-      EnumerateValue(M);
-    }
-    Values.push_back(std::make_pair(V, 1U));
-    ValueMap[V] = Values.size();
-    return;
-  }
-
   // Add the value.
   Values.push_back(std::make_pair(V, 1U));
   ValueID = Values.size();
diff --git a/llvm/lib/Bitcode/Writer/ValueEnumerator.h b/llvm/lib/Bitcode/Writer/ValueEnumerator.h
index 40eeabb2b6a..b5106f0809f 100644
--- a/llvm/lib/Bitcode/Writer/ValueEnumerator.h
+++ b/llvm/lib/Bitcode/Writer/ValueEnumerator.h
@@ -25,6 +25,7 @@ class Value;
 class BasicBlock;
 class Function;
 class Module;
+class MetadataBase;
 class AttrListPtr;
 class TypeSymbolTable;
 class ValueSymbolTable;
@@ -44,7 +45,9 @@ private:
   typedef DenseMap<const Value*, unsigned> ValueMapType;
   ValueMapType ValueMap;
   ValueList Values;
-  
+  ValueList MDValues;
+  ValueMapType MDValueMap;
+
   typedef DenseMap<void*, unsigned> AttributeMapType;
   AttributeMapType AttributeMap;
   std::vector<AttrListPtr> Attributes;
@@ -64,12 +67,8 @@ private:
 public:
   ValueEnumerator(const Module *M);
 
-  unsigned getValueID(const Value *V) const {
-    ValueMapType::const_iterator I = ValueMap.find(V);
-    assert(I != ValueMap.end() && "Value not in slotcalculator!");
-    return I->second-1;
-  }
-  
+  unsigned getValueID(const Value *V) const;
+
   unsigned getTypeID(const Type *T) const {
     TypeMapType::const_iterator I = TypeMap.find(T);
     assert(I != TypeMap.end() && "Type not in ValueEnumerator!");
@@ -91,6 +90,7 @@ public:
   }
   
   const ValueList &getValues() const { return Values; }
+  const ValueList &getMDValues() const { return MDValues; }
   const TypeList &getTypes() const { return Types; }
   const std::vector<const BasicBlock*> &getBasicBlocks() const {
     return BasicBlocks; 
@@ -108,6 +108,7 @@ public:
 private:
   void OptimizeConstants(unsigned CstStart, unsigned CstEnd);
     
+  void EnumerateMetadata(const MetadataBase *MD);
   void EnumerateValue(const Value *V);
   void EnumerateType(const Type *T);
   void EnumerateOperandType(const Value *V);