Derive MDNode from MetadataBase instead of Constant. Emit MDNodes into METADATA_BLOCK...
[oota-llvm.git] / lib / Bitcode / Writer / BitcodeWriter.cpp
index 1937c7e26f151040ea54a20041cba9faecee9cb5..7d745ffd50d2d437718a1a4c38af95eb94bedfac 100644 (file)
 #include "llvm/DerivedTypes.h"
 #include "llvm/InlineAsm.h"
 #include "llvm/Instructions.h"
+#include "llvm/MDNode.h"
 #include "llvm/Module.h"
+#include "llvm/Operator.h"
 #include "llvm/TypeSymbolTable.h"
 #include "llvm/ValueSymbolTable.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/Streams.h"
 #include "llvm/Support/raw_ostream.h"
@@ -48,6 +51,7 @@ enum {
   // FUNCTION_BLOCK abbrev id's.
   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
   FUNCTION_INST_BINOP_ABBREV,
+  FUNCTION_INST_BINOP_FLAGS_ABBREV,
   FUNCTION_INST_CAST_ABBREV,
   FUNCTION_INST_RET_VOID_ABBREV,
   FUNCTION_INST_RET_VAL_ABBREV,
@@ -57,7 +61,7 @@ enum {
 
 static unsigned GetEncodedCastOpcode(unsigned Opcode) {
   switch (Opcode) {
-  default: assert(0 && "Unknown cast instruction!");
+  default: llvm_unreachable("Unknown cast instruction!");
   case Instruction::Trunc   : return bitc::CAST_TRUNC;
   case Instruction::ZExt    : return bitc::CAST_ZEXT;
   case Instruction::SExt    : return bitc::CAST_SEXT;
@@ -75,10 +79,13 @@ static unsigned GetEncodedCastOpcode(unsigned Opcode) {
 
 static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
   switch (Opcode) {
-  default: assert(0 && "Unknown binary instruction!");
-  case Instruction::Add:  return bitc::BINOP_ADD;
-  case Instruction::Sub:  return bitc::BINOP_SUB;
-  case Instruction::Mul:  return bitc::BINOP_MUL;
+  default: llvm_unreachable("Unknown binary instruction!");
+  case Instruction::Add:
+  case Instruction::FAdd: return bitc::BINOP_ADD;
+  case Instruction::Sub:
+  case Instruction::FSub: return bitc::BINOP_SUB;
+  case Instruction::Mul:
+  case Instruction::FMul: return bitc::BINOP_MUL;
   case Instruction::UDiv: return bitc::BINOP_UDIV;
   case Instruction::FDiv:
   case Instruction::SDiv: return bitc::BINOP_SDIV;
@@ -196,7 +203,7 @@ static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
     unsigned Code = 0;
     
     switch (T->getTypeID()) {
-    default: assert(0 && "Unknown type!");
+    default: llvm_unreachable("Unknown type!");
     case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
     case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
     case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
@@ -205,6 +212,7 @@ static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
     case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
     case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
+    case Type::MetadataTyID: Code = bitc::TYPE_CODE_METADATA; break;
     case Type::IntegerTyID:
       // INTEGER: [width]
       Code = bitc::TYPE_CODE_INTEGER;
@@ -273,27 +281,28 @@ static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 
 static unsigned getEncodedLinkage(const GlobalValue *GV) {
   switch (GV->getLinkage()) {
-  default: assert(0 && "Invalid linkage!");
+  default: llvm_unreachable("Invalid linkage!");
   case GlobalValue::GhostLinkage:  // Map ghost linkage onto external.
-  case GlobalValue::ExternalLinkage:     return 0;
-  case GlobalValue::WeakAnyLinkage:      return 1;
-  case GlobalValue::AppendingLinkage:    return 2;
-  case GlobalValue::InternalLinkage:     return 3;
-  case GlobalValue::LinkOnceAnyLinkage:  return 4;
-  case GlobalValue::DLLImportLinkage:    return 5;
-  case GlobalValue::DLLExportLinkage:    return 6;
-  case GlobalValue::ExternalWeakLinkage: return 7;
-  case GlobalValue::CommonLinkage:       return 8;
-  case GlobalValue::PrivateLinkage:      return 9;
-  case GlobalValue::WeakODRLinkage:      return 10;
-  case GlobalValue::LinkOnceODRLinkage:  return 11;
-  case GlobalValue::AvailableExternallyLinkage:  return 12;
+  case GlobalValue::ExternalLinkage:            return 0;
+  case GlobalValue::WeakAnyLinkage:             return 1;
+  case GlobalValue::AppendingLinkage:           return 2;
+  case GlobalValue::InternalLinkage:            return 3;
+  case GlobalValue::LinkOnceAnyLinkage:         return 4;
+  case GlobalValue::DLLImportLinkage:           return 5;
+  case GlobalValue::DLLExportLinkage:           return 6;
+  case GlobalValue::ExternalWeakLinkage:        return 7;
+  case GlobalValue::CommonLinkage:              return 8;
+  case GlobalValue::PrivateLinkage:             return 9;
+  case GlobalValue::WeakODRLinkage:             return 10;
+  case GlobalValue::LinkOnceODRLinkage:         return 11;
+  case GlobalValue::AvailableExternallyLinkage: return 12;
+  case GlobalValue::LinkerPrivateLinkage:       return 13;
   }
 }
 
 static unsigned getEncodedVisibility(const GlobalValue *GV) {
   switch (GV->getVisibility()) {
-  default: assert(0 && "Invalid visibility!");
+  default: llvm_unreachable("Invalid visibility!");
   case GlobalValue::DefaultVisibility:   return 0;
   case GlobalValue::HiddenVisibility:    return 1;
   case GlobalValue::ProtectedVisibility: return 2;
@@ -447,6 +456,75 @@ static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
   }
 }
 
+static uint64_t GetOptimizationFlags(const Value *V) {
+  uint64_t Flags = 0;
+
+  if (const OverflowingBinaryOperator *OBO =
+        dyn_cast<OverflowingBinaryOperator>(V)) {
+    if (OBO->hasNoSignedOverflow())
+      Flags |= 1 << bitc::OBO_NO_SIGNED_OVERFLOW;
+    if (OBO->hasNoUnsignedOverflow())
+      Flags |= 1 << bitc::OBO_NO_UNSIGNED_OVERFLOW;
+  } else if (const SDivOperator *Div = dyn_cast<SDivOperator>(V)) {
+    if (Div->isExact())
+      Flags |= 1 << bitc::SDIV_EXACT;
+  }
+
+  return Flags;
+}
+
+ static void WriteModuleMetadata(const ValueEnumerator &VE,
+                                 BitstreamWriter &Stream) {
+   const ValueEnumerator::ValueList &Vals = VE.getValues();
+   bool StartedMetadataBlock = false;
+   unsigned MDSAbbrev = 0;
+   SmallVector<uint64_t, 64> Record;
+   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
+
+     if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
+       if (!StartedMetadataBlock) {
+         Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
+         StartedMetadataBlock = true;
+       }
+      for (unsigned i = 0, e = N->getNumElements(); i != e; ++i) {
+        if (N->getElement(i)) {
+          Record.push_back(VE.getTypeID(N->getElement(i)->getType()));
+          Record.push_back(VE.getValueID(N->getElement(i)));
+        } else {
+          Record.push_back(VE.getTypeID(Type::VoidTy));
+          Record.push_back(0);
+        }
+      }
+      Stream.EmitRecord(bitc::METADATA_NODE, Record, 0);
+      Record.clear();
+     } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
+       if (!StartedMetadataBlock)  {
+        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
+
+        // Abbrev for METADATA_STRING.
+        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
+        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
+        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
+        MDSAbbrev = Stream.EmitAbbrev(Abbv);
+        StartedMetadataBlock = true;
+       }
+
+       // Code: [strchar x N]
+       const char *StrBegin = MDS->begin();
+       for (unsigned i = 0, e = MDS->size(); i != e; ++i)
+        Record.push_back(StrBegin[i]);
+    
+       // Emit the finished record.
+      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
+      Record.clear();
+     }
+   }
+
+   if (StartedMetadataBlock)
+     Stream.ExitBlock();    
+}
+
 
 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
                            const ValueEnumerator &VE,
@@ -459,8 +537,6 @@ static void WriteConstants(unsigned FirstVal, unsigned LastVal,
   unsigned String8Abbrev = 0;
   unsigned CString7Abbrev = 0;
   unsigned CString6Abbrev = 0;
-  unsigned MDString8Abbrev = 0;
-  unsigned MDString6Abbrev = 0;
   // If this is a constant pool for the module, emit module-specific abbrevs.
   if (isGlobal) {
     // Abbrev for CST_CODE_AGGREGATE.
@@ -488,19 +564,6 @@ static void WriteConstants(unsigned FirstVal, unsigned LastVal,
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
     CString6Abbrev = Stream.EmitAbbrev(Abbv);
-
-    // Abbrev for CST_CODE_MDSTRING.
-    Abbv = new BitCodeAbbrev();
-    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_MDSTRING));
-    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
-    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
-    MDString8Abbrev = Stream.EmitAbbrev(Abbv);
-    // Abbrev for CST_CODE_MDSTRING.
-    Abbv = new BitCodeAbbrev();
-    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_MDSTRING));
-    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
-    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
-    MDString6Abbrev = Stream.EmitAbbrev(Abbv);
   }  
   
   SmallVector<uint64_t, 64> Record;
@@ -509,6 +572,8 @@ 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<MDString>(V) || isa<MDNode>(V))
+      continue;
     // If we need to switch types, do so now.
     if (V->getType() != LastTy) {
       LastTy = V->getType();
@@ -634,6 +699,9 @@ static void WriteConstants(unsigned FirstVal, unsigned LastVal,
           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
           Record.push_back(VE.getValueID(C->getOperand(0)));
           Record.push_back(VE.getValueID(C->getOperand(1)));
+          uint64_t Flags = GetOptimizationFlags(CE);
+          if (Flags != 0)
+            Record.push_back(Flags);
         }
         break;
       case Instruction::GetElementPtr:
@@ -678,40 +746,15 @@ static void WriteConstants(unsigned FirstVal, unsigned LastVal,
         break;
       case Instruction::ICmp:
       case Instruction::FCmp:
-      case Instruction::VICmp:
-      case Instruction::VFCmp:
-        if (isa<VectorType>(C->getOperand(0)->getType())
-            && (CE->getOpcode() == Instruction::ICmp
-                || CE->getOpcode() == Instruction::FCmp)) {
-          // compare returning vector of Int1Ty
-          assert(0 && "Unsupported constant!");
-        } else {
-          Code = bitc::CST_CODE_CE_CMP;
-        }
+        Code = bitc::CST_CODE_CE_CMP;
         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
         Record.push_back(VE.getValueID(C->getOperand(0)));
         Record.push_back(VE.getValueID(C->getOperand(1)));
         Record.push_back(CE->getPredicate());
         break;
       }
-    } else if (const MDString *S = dyn_cast<MDString>(C)) {
-      Code = bitc::CST_CODE_MDSTRING;
-      AbbrevToUse = MDString6Abbrev;
-      for (unsigned i = 0, e = S->size(); i != e; ++i) {
-        char V = S->begin()[i];
-        Record.push_back(V);
-
-        if (!BitCodeAbbrevOp::isChar6(V))
-          AbbrevToUse = MDString8Abbrev;
-      }
-    } else if (const MDNode *N = dyn_cast<MDNode>(C)) {
-      Code = bitc::CST_CODE_MDNODE;
-      for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
-        Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
-        Record.push_back(VE.getValueID(N->getOperand(i)));
-      }
     } else {
-      assert(0 && "Unknown constant!");
+      llvm_unreachable("Unknown constant!");
     }
     Stream.EmitRecord(Code, Record, AbbrevToUse);
     Record.clear();
@@ -775,6 +818,12 @@ static void WriteInstruction(const Instruction &I, unsigned InstID,
         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
       Vals.push_back(VE.getValueID(I.getOperand(1)));
       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
+      uint64_t Flags = GetOptimizationFlags(&I);
+      if (Flags != 0) {
+        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
+          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
+        Vals.push_back(Flags);
+      }
     }
     break;
 
@@ -825,15 +874,8 @@ static void WriteInstruction(const Instruction &I, unsigned InstID,
     break;
   case Instruction::ICmp:
   case Instruction::FCmp:
-  case Instruction::VICmp:
-  case Instruction::VFCmp:
-    if (I.getOpcode() == Instruction::ICmp
-        || I.getOpcode() == Instruction::FCmp) {
-      // compare returning Int1Ty or vector of Int1Ty
-      Code = bitc::FUNC_CODE_INST_CMP2;
-    } else {
-      Code = bitc::FUNC_CODE_INST_CMP;
-    }
+    // compare returning Int1Ty or vector of Int1Ty
+    Code = bitc::FUNC_CODE_INST_CMP2;
     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
     Vals.push_back(VE.getValueID(I.getOperand(1)));
     Vals.push_back(cast<CmpInst>(I).getPredicate());
@@ -1132,7 +1174,7 @@ static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID, 
                                    Abbv) != VST_ENTRY_8_ABBREV)
-      assert(0 && "Unexpected abbrev ordering!");
+      llvm_unreachable("Unexpected abbrev ordering!");
   }
   
   { // 7-bit fixed width VST_ENTRY strings.
@@ -1143,7 +1185,7 @@ static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
                                    Abbv) != VST_ENTRY_7_ABBREV)
-      assert(0 && "Unexpected abbrev ordering!");
+      llvm_unreachable("Unexpected abbrev ordering!");
   }
   { // 6-bit char6 VST_ENTRY strings.
     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
@@ -1153,7 +1195,7 @@ static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
                                    Abbv) != VST_ENTRY_6_ABBREV)
-      assert(0 && "Unexpected abbrev ordering!");
+      llvm_unreachable("Unexpected abbrev ordering!");
   }
   { // 6-bit char6 VST_BBENTRY strings.
     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
@@ -1163,7 +1205,7 @@ static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
                                    Abbv) != VST_BBENTRY_6_ABBREV)
-      assert(0 && "Unexpected abbrev ordering!");
+      llvm_unreachable("Unexpected abbrev ordering!");
   }
   
   
@@ -1175,7 +1217,7 @@ static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
                               Log2_32_Ceil(VE.getTypes().size()+1)));
     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
-      assert(0 && "Unexpected abbrev ordering!");
+      llvm_unreachable("Unexpected abbrev ordering!");
   }
   
   { // INTEGER abbrev for CONSTANTS_BLOCK.
@@ -1184,7 +1226,7 @@ static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
-      assert(0 && "Unexpected abbrev ordering!");
+      llvm_unreachable("Unexpected abbrev ordering!");
   }
   
   { // CE_CAST abbrev for CONSTANTS_BLOCK.
@@ -1197,14 +1239,14 @@ static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 
     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
-      assert(0 && "Unexpected abbrev ordering!");
+      llvm_unreachable("Unexpected abbrev ordering!");
   }
   { // NULL abbrev for CONSTANTS_BLOCK.
     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
                                    Abbv) != CONSTANTS_NULL_Abbrev)
-      assert(0 && "Unexpected abbrev ordering!");
+      llvm_unreachable("Unexpected abbrev ordering!");
   }
   
   // FIXME: This should only use space for first class types!
@@ -1217,7 +1259,7 @@ static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
-      assert(0 && "Unexpected abbrev ordering!");
+      llvm_unreachable("Unexpected abbrev ordering!");
   }
   { // INST_BINOP abbrev for FUNCTION_BLOCK.
     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
@@ -1227,7 +1269,18 @@ static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
-      assert(0 && "Unexpected abbrev ordering!");
+      llvm_unreachable("Unexpected abbrev ordering!");
+  }
+  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
+    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
+    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
+    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
+    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
+                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
+      llvm_unreachable("Unexpected abbrev ordering!");
   }
   { // INST_CAST abbrev for FUNCTION_BLOCK.
     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
@@ -1238,7 +1291,7 @@ static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
-      assert(0 && "Unexpected abbrev ordering!");
+      llvm_unreachable("Unexpected abbrev ordering!");
   }
   
   { // INST_RET abbrev for FUNCTION_BLOCK.
@@ -1246,7 +1299,7 @@ static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
-      assert(0 && "Unexpected abbrev ordering!");
+      llvm_unreachable("Unexpected abbrev ordering!");
   }
   { // INST_RET abbrev for FUNCTION_BLOCK.
     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
@@ -1254,14 +1307,14 @@ static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
-      assert(0 && "Unexpected abbrev ordering!");
+      llvm_unreachable("Unexpected abbrev ordering!");
   }
   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
-      assert(0 && "Unexpected abbrev ordering!");
+      llvm_unreachable("Unexpected abbrev ordering!");
   }
   
   Stream.ExitBlock();
@@ -1294,20 +1347,13 @@ static void WriteModule(const Module *M, BitstreamWriter &Stream) {
   // Emit top-level description of module, including target triple, inline asm,
   // descriptors for global variables, and function prototype info.
   WriteModuleInfo(M, VE, Stream);
-  
+
   // Emit constants.
   WriteModuleConstants(VE, Stream);
-  
-  // If we have any aggregate values in the value table, purge them - these can
-  // only be used to initialize global variables.  Doing so makes the value
-  // namespace smaller for code in functions.
-  int NumNonAggregates = VE.PurgeAggregateValues();
-  if (NumNonAggregates != -1) {
-    SmallVector<unsigned, 1> Vals;
-    Vals.push_back(NumNonAggregates);
-    Stream.EmitRecord(bitc::MODULE_CODE_PURGEVALS, Vals);
-  }
-  
+
+  // Emit metadata.
+  WriteModuleMetadata(VE, Stream);
+
   // Emit function bodies.
   for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
     if (!I->isDeclaration())