Disable Subzero IR generation for performance testing.

src/PNaClTranslator.cpp

 //===- subzero/src/PNaClTranslator.cpp - ICE from bitcode -----------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the PNaCl bitcode file to Ice, to machine code
@@ skipping 183 matching lines @@
   Module *getModule() const { return Mod.get(); }
 
   const DataLayout &getDataLayout() const { return DL; }
 
   /// Returns the number of bytes in the bitcode header.
   size_t getHeaderSize() const { return Header.getHeaderSize(); }
 
   /// Changes the size of the type list to the given size.
   void resizeTypeIDValues(unsigned NewSize) { TypeIDValues.resize(NewSize); }
 
+  bool disableIRGeneration() const {

[Jim Stichnoth, 2014/11/04 00:07:07]

Add comment for consistency with other methods?

More importantly, to me, the method name implies that calling it will have the
effect of disabling IR generation.  How about a name like isIRGenerationEnabled
(or isIRGenerationDisabled if you don't prefer not avoiding non-double
negatives)?

[Karl, 2014/11/04 20:37:21]

Done.

+    return Translator.getFlags().DisableIRGeneration;
+  }
+
   /// Returns the undefined type associated with type ID.
   /// Note: Returns extended type ready to be defined.
   ExtendedType *getTypeByIDForDefining(unsigned ID) {
     // Get corresponding element, verifying the value is still undefined
     // (and hence allowed to be defined).
     ExtendedType *Ty = getTypeByIDAsKind(ID, ExtendedType::Undefined);
     if (Ty)
       return Ty;
     if (ID >= TypeIDValues.size())
       TypeIDValues.resize(ID+1);
@@ skipping 63 matching lines @@
           FunctionDeclarationList.size() + VariableDeclarations.size();
       if (ID >= ExpectedSize)
         ExpectedSize = ID;
       ValueIDConstants.resize(ExpectedSize);
     } else {
       C = ValueIDConstants[ID];
     }
     if (C != nullptr)
       return C;
 
+    if (disableIRGeneration()) {

[Jim Stichnoth, 2014/11/04 00:07:07]

There's a vast number of disableIRGeneration() calls, so I have no idea if
you've caught them all.

How about adding an assert to the relevant ICE generation routines?

Asserting in the Cfg ctor would prevent CfgNode, Inst, and Variable from being
allocated.

For Constant, change GlobalContext where they are managed.  One possibility is
for the GlobalContext ctor to make ConstPool=NULL, and then any attempts to
access an ICE constant would segfault.  A gentler approach would be to assert in
TypePool::getOrAdd(), and maybe also UndefPool::getOrAdd() for completeness.

[Karl, 2014/11/04 20:37:21]

Done.

+      ValueIDConstants[ID] = nullptr;
+      return nullptr;
+    }
+
     // If reached, no such constant exists, create one.
     // TODO(kschimpf) Don't get addresses of intrinsic function declarations.
     Ice::GlobalDeclaration *Decl = nullptr;
     unsigned FcnIDSize = FunctionDeclarationList.size();
     if (ID < FcnIDSize) {
       Decl = FunctionDeclarationList[ID];
     } else if ((ID - FcnIDSize) < VariableDeclarations.size()) {
       Decl = VariableDeclarations[ID - FcnIDSize];
     }
     std::string Name;
@@ skipping 219 matching lines @@
   // Constructor for nested block parsers.
   BlockParserBaseClass(unsigned BlockID, BlockParserBaseClass *EnclosingParser)
       : NaClBitcodeParser(BlockID, EnclosingParser),
         Context(EnclosingParser->Context) {}
 
   // Gets the translator associated with the bitcode parser.
   Ice::Translator &getTranslator() const { return Context->getTranslator(); }
 
   const Ice::ClFlags &getFlags() const { return getTranslator().getFlags(); }
 
+  bool disableIRGeneration() const {
+    return getTranslator().getFlags().DisableIRGeneration;
+  }
+
   // Generates an error Message with the bit address prefixed to it.
   bool Error(const std::string &Message) override {
     uint64_t Bit = Record.GetStartBit() + Context->getHeaderSize() * 8;
     std::string Buffer;
     raw_string_ostream StrBuf(Buffer);
     StrBuf << "(" << format("%" PRIu64 ":%u", (Bit / 8),
                             static_cast<unsigned>(Bit % 8)) << ") " << Message;
     return Context->Error(StrBuf.str());
   }
 
@@ skipping 338 matching lines @@
       Error("Globals count record not first in block.");
       return;
     }
     Context->CreateGlobalVariables(Values[0]);
     return;
   case naclbitc::GLOBALVAR_VAR: {
     // VAR: [align, isconst]
     if (!isValidRecordSize(2, "Globals variable"))
       return;
     verifyNoMissingInitializers();
-    InitializersNeeded = 1;
-    CurGlobalVar = Context->getGlobalVariableByID(NextGlobalID);
-    CurGlobalVar->setAlignment((1 << Values[0]) >> 1);
-    CurGlobalVar->setIsConstant(Values[1] != 0);
+    if (!disableIRGeneration()) {
+      InitializersNeeded = 1;
+      CurGlobalVar = Context->getGlobalVariableByID(NextGlobalID);
+      CurGlobalVar->setAlignment((1 << Values[0]) >> 1);
+      CurGlobalVar->setIsConstant(Values[1] != 0);
+    }
     ++NextGlobalID;
     return;
   }
   case naclbitc::GLOBALVAR_COMPOUND:
     // COMPOUND: [size]
     if (!isValidRecordSize(1, "globals compound"))
       return;
     if (!CurGlobalVar->getInitializers().empty()) {
       Error("Globals compound record not first initializer");
       return;
     }
     if (Values[0] < 2) {
       std::string Buffer;
       raw_string_ostream StrBuf(Buffer);
       StrBuf << "Globals compound record size invalid. Found: " << Values[0];
       Error(StrBuf.str());
       return;
     }
+    if (disableIRGeneration())
+      return;
     InitializersNeeded = Values[0];
     return;
   case naclbitc::GLOBALVAR_ZEROFILL: {
     // ZEROFILL: [size]
     if (!isValidRecordSize(1, "Globals zerofill"))
       return;
+    if (disableIRGeneration())
+      return;
     CurGlobalVar->addInitializer(
         new Ice::VariableDeclaration::ZeroInitializer(Values[0]));
     return;
   }
   case naclbitc::GLOBALVAR_DATA: {
     // DATA: [b0, b1, ...]
     if (!isValidRecordSizeAtLeast(1, "Globals data"))
       return;
+    if (disableIRGeneration())
+      return;
     CurGlobalVar->addInitializer(
         new Ice::VariableDeclaration::DataInitializer(Values));
     return;
   }
   case naclbitc::GLOBALVAR_RELOC: {
     // RELOC: [val, [addend]]
     if (!isValidRecordSizeInRange(1, 2, "Globals reloc"))
       return;
+    if (disableIRGeneration())
+      return;
     unsigned Index = Values[0];
     Ice::SizeT Offset = 0;
     if (Values.size() == 2)
       Offset = Values[1];
     CurGlobalVar->addInitializer(new Ice::VariableDeclaration::RelocInitializer(
         Context->getGlobalDeclarationByID(Index), Offset));
     return;
   }
   default:
     BlockParserBaseClass::ProcessRecord();
@@ skipping 66 matching lines @@
 /// Parses function blocks in the bitcode file.
 class FunctionParser : public BlockParserBaseClass {
   FunctionParser(const FunctionParser &) = delete;
   FunctionParser &operator=(const FunctionParser &) = delete;
   friend class FunctionValuesymtabParser;
 
 public:
   FunctionParser(unsigned BlockID, BlockParserBaseClass *EnclosingParser)
       : BlockParserBaseClass(BlockID, EnclosingParser),
         Timer(Ice::TimerStack::TT_parseFunctions, getTranslator().getContext()),
-        Func(new Ice::Cfg(getTranslator().getContext())), CurrentBbIndex(0),
-        FcnId(Context->getNextFunctionBlockValueID()),
+        Func(disableIRGeneration()
+                 ? nullptr
+                 : new Ice::Cfg(getTranslator().getContext())),
+        CurrentBbIndex(0), FcnId(Context->getNextFunctionBlockValueID()),
         FuncDecl(Context->getFunctionByID(FcnId)),
         CachedNumGlobalValueIDs(Context->getNumGlobalIDs()),
         NextLocalInstIndex(Context->getNumGlobalIDs()),
         InstIsTerminating(false) {
-    Func->setFunctionName(FuncDecl->getName());
     if (getFlags().TimeEachFunction)
       getTranslator().getContext()->pushTimer(
           getTranslator().getContext()->getTimerID(
-              Ice::GlobalContext::TSK_Funcs, Func->getFunctionName()),
+              Ice::GlobalContext::TSK_Funcs, FuncDecl->getName()),
           Ice::GlobalContext::TSK_Funcs);
     // TODO(kschimpf) Clean up API to add a function signature to
     // a CFG.
     const Ice::FuncSigType &Signature = FuncDecl->getSignature();
-    Func->setReturnType(Signature.getReturnType());
-    Func->setInternal(FuncDecl->getLinkage() == GlobalValue::InternalLinkage);
-    CurrentNode = InstallNextBasicBlock();
-    Func->setEntryNode(CurrentNode);
-    for (Ice::Type ArgType : Signature.getArgList()) {
-      Func->addArg(getNextInstVar(ArgType));
+    if (disableIRGeneration()) {
+      CurrentNode = nullptr;
+      for (Ice::Type ArgType : Signature.getArgList()) {
+        (void)ArgType;
+        setNextLocalInstIndex(nullptr);
+      }
+    } else {
+      Func->setFunctionName(FuncDecl->getName());
+      Func->setReturnType(Signature.getReturnType());
+      Func->setInternal(FuncDecl->getLinkage() == GlobalValue::InternalLinkage);
+      CurrentNode = InstallNextBasicBlock();
+      Func->setEntryNode(CurrentNode);
+      for (Ice::Type ArgType : Signature.getArgList()) {
+        Func->addArg(getNextInstVar(ArgType));
+      }
     }
   }
 
   ~FunctionParser() override {};
 
+  void setNextLocalInstIndex(Ice::Operand *Op) {
+    setOperand(NextLocalInstIndex++, Op);
+  }
+
   // Set the next constant ID to the given constant C.
-  void setNextConstantID(Ice::Constant *C) {
-    setOperand(NextLocalInstIndex++, C);
-  }
+  void setNextConstantID(Ice::Constant *C) { setNextLocalInstIndex(C); }
 
 private:
   Ice::TimerMarker Timer;
   // The corresponding ICE function defined by the function block.
   Ice::Cfg *Func;
   // The index to the current basic block being built.
   uint32_t CurrentBbIndex;
   // The basic block being built.
   Ice::CfgNode *CurrentNode;
   // The ID for the function.
   unsigned FcnId;
   // The corresponding function declaration.
   Ice::FunctionDeclaration *FuncDecl;
   // Holds the dividing point between local and global absolute value indices.
   uint32_t CachedNumGlobalValueIDs;
   // Holds operands local to the function block, based on indices
   // defined in the bitcode file.
   std::vector<Ice::Operand *> LocalOperands;
   // Holds the index within LocalOperands corresponding to the next
   // instruction that generates a value.
   uint32_t NextLocalInstIndex;
   // True if the last processed instruction was a terminating
   // instruction.
   bool InstIsTerminating;
   // Upper limit of alignment power allowed by LLVM
   static const uint64_t AlignPowerLimit = 29;
 
+  void popTimerIfTimingEachFunction() const {
+    if (getFlags().TimeEachFunction)
+      getTranslator().getContext()->popTimer(
+          getTranslator().getContext()->getTimerID(
+              Ice::GlobalContext::TSK_Funcs, Func->getFunctionName()),
+          Ice::GlobalContext::TSK_Funcs);
+  }
+
   // Extracts the corresponding Alignment to use, given the AlignPower
   // (i.e. 2**AlignPower, or 0 if AlignPower == 0). InstName is the
   // name of the instruction the alignment appears in.
   void extractAlignment(const char *InstName, uint64_t AlignPower,
                         unsigned &Alignment) {
     if (AlignPower <= AlignPowerLimit) {
       Alignment = (1 << static_cast<unsigned>(AlignPower)) >> 1;
       return;
     }
     std::string Buffer;
     raw_string_ostream StrBuf(Buffer);
     StrBuf << InstName << " alignment greater than 2**" << AlignPowerLimit
            << ". Found: 2**" << AlignPower;
     Error(StrBuf.str());
     // Error recover with value that is always acceptable.
     Alignment = 1;
   }
 
   bool ParseBlock(unsigned BlockID) override;
 
   void ProcessRecord() override;
 
   void ExitBlock() override;
 
   // Creates and appends a new basic block to the list of basic blocks.
-  Ice::CfgNode *InstallNextBasicBlock() { return Func->makeNode(); }
+  Ice::CfgNode *InstallNextBasicBlock() {
+    assert(!disableIRGeneration());
+    return Func->makeNode();
+  }
 
   // Returns the Index-th basic block in the list of basic blocks.
   Ice::CfgNode *getBasicBlock(uint32_t Index) {
+    assert(!disableIRGeneration());
     const Ice::NodeList &Nodes = Func->getNodes();
     if (Index >= Nodes.size()) {
       std::string Buffer;
       raw_string_ostream StrBuf(Buffer);
       StrBuf << "Reference to basic block " << Index
              << " not found. Must be less than " << Nodes.size();
       Error(StrBuf.str());
       // TODO(kschimpf) Remove error recovery once implementation complete.
       Index = 0;
     }
     return Nodes[Index];
   }
 
   // Returns the Index-th basic block in the list of basic blocks.
   // Assumes Index corresponds to a branch instruction. Hence, if
   // the branch references the entry block, it also generates a
   // corresponding error.
   Ice::CfgNode *getBranchBasicBlock(uint32_t Index) {
+    assert(!disableIRGeneration());
     if (Index == 0) {
       Error("Branch to entry block not allowed");
       // TODO(kschimpf) Remove error recovery once implementation complete.
     }
     return getBasicBlock(Index);
   }
 
   // Generate an instruction variable with type Ty.
   Ice::Variable *createInstVar(Ice::Type Ty) {
+    assert(!disableIRGeneration());
     if (Ty == Ice::IceType_void) {
       Error("Can't define instruction value using type void");
       // Recover since we can't throw an exception.
       Ty = Ice::IceType_i32;
     }
     return Func->makeVariable(Ty);
   }
 
   // Generates the next available local variable using the given type.
   Ice::Variable *getNextInstVar(Ice::Type Ty) {
+    assert(!disableIRGeneration());
     assert(NextLocalInstIndex >= CachedNumGlobalValueIDs);
     // Before creating one, see if a forwardtyperef has already defined it.
     uint32_t LocalIndex = NextLocalInstIndex - CachedNumGlobalValueIDs;
     if (LocalIndex < LocalOperands.size()) {
       Ice::Operand *Op = LocalOperands[LocalIndex];
       if (Op != nullptr) {
         if (Ice::Variable *Var = dyn_cast<Ice::Variable>(Op)) {
           if (Var->getType() == Ty) {
             ++NextLocalInstIndex;
             return Var;
@@ skipping 37 matching lines @@
     uint32_t LocalIndex = Index - CachedNumGlobalValueIDs;
     if (LocalIndex >= LocalOperands.size()) {
       std::string Buffer;
       raw_string_ostream StrBuf(Buffer);
       StrBuf << "Value index " << Index << " not defined!";
       Error(StrBuf.str());
       report_fatal_error("Unable to continue");
     }
     Ice::Operand *Op = LocalOperands[LocalIndex];
     if (Op == nullptr) {
+      if (disableIRGeneration())
+        return nullptr;
       std::string Buffer;
       raw_string_ostream StrBuf(Buffer);
       StrBuf << "Value index " << Index << " not defined!";
       Error(StrBuf.str());
       report_fatal_error("Unable to continue");
     }
     return Op;
   }
 
   // Sets element Index (in the local operands list) to Op.
   void setOperand(uint32_t Index, Ice::Operand *Op) {
-    assert(Op);
+    assert(Op || disableIRGeneration());
     // Check if simple push works.
     uint32_t LocalIndex = Index - CachedNumGlobalValueIDs;
     if (LocalIndex == LocalOperands.size()) {
       LocalOperands.push_back(Op);
       return;
     }
 
     // Must be forward reference, expand vector to accommodate.
     if (LocalIndex >= LocalOperands.size())
       LocalOperands.resize(LocalIndex + 1);
 
     // If element not defined, set it.
     Ice::Operand *OldOp = LocalOperands[LocalIndex];
     if (OldOp == nullptr) {
+      if (disableIRGeneration())
+        return;
       LocalOperands[LocalIndex] = Op;
       return;
     }
 
     // See if forward reference matches.
     if (OldOp == Op)
       return;
 
     // Error has occurred.
     std::string Buffer;
@@ skipping 396 matching lines @@
 };
 
 void FunctionParser::ReportInvalidBinopOpcode(unsigned Opcode, Ice::Type Ty) {
   std::string Buffer;
   raw_string_ostream StrBuf(Buffer);
   StrBuf << "Binary opcode " << Opcode << "not understood for type " << Ty;
   Error(StrBuf.str());
 }
 
 void FunctionParser::ExitBlock() {
+  if (disableIRGeneration()) {
+    popTimerIfTimingEachFunction();
+    return;
+  }
   // Before translating, check for blocks without instructions, and
   // insert unreachable. This shouldn't happen, but be safe.
   unsigned Index = 0;
   for (Ice::CfgNode *Node : Func->getNodes()) {
     if (Node->getInsts().size() == 0) {
       std::string Buffer;
       raw_string_ostream StrBuf(Buffer);
       StrBuf << "Basic block " << Index << " contains no instructions";
       Error(StrBuf.str());
       // TODO(kschimpf) Remove error recovery once implementation complete.
       Node->appendInst(Ice::InstUnreachable::create(Func));
     }
     ++Index;
   }
   Func->computePredecessors();
   // Note: Once any errors have been found, we turn off all
   // translation of all remaining functions. This allows use to see
   // multiple errors, without adding extra checks to the translator
   // for such parsing errors.
   if (Context->getNumErrors() == 0)
     getTranslator().translateFcn(Func);
-  if (getFlags().TimeEachFunction)
-    getTranslator().getContext()->popTimer(
-        getTranslator().getContext()->getTimerID(Ice::GlobalContext::TSK_Funcs,
-                                                 Func->getFunctionName()),
-        Ice::GlobalContext::TSK_Funcs);
+  popTimerIfTimingEachFunction();
 }
 
 void FunctionParser::ReportInvalidBinaryOp(Ice::InstArithmetic::OpKind Op,
                                            Ice::Type OpTy) {
   std::string Buffer;
   raw_string_ostream StrBuf(Buffer);
   StrBuf << "Invalid operator type for " << Ice::InstArithmetic::getOpName(Op)
          << ". Found " << OpTy;
   Error(StrBuf.str());
 }
 
 void FunctionParser::ProcessRecord() {
   const NaClBitcodeRecord::RecordVector &Values = Record.GetValues();
   if (InstIsTerminating) {
     InstIsTerminating = false;
-    CurrentNode = getBasicBlock(++CurrentBbIndex);
+    if (!disableIRGeneration())
+      CurrentNode = getBasicBlock(++CurrentBbIndex);
   }
   // The base index for relative indexing.
   int32_t BaseIndex = getNextInstIndex();
   switch (Record.GetCode()) {
   case naclbitc::FUNC_CODE_DECLAREBLOCKS: {
     // DECLAREBLOCKS: [n]
     if (!isValidRecordSize(1, "function block count"))
       return;
+    if (disableIRGeneration())
+      return;
     if (Func->getNodes().size() != 1) {
       Error("Duplicate function block count record");
       return;
     }
     uint32_t NumBbs = Values[0];
     if (NumBbs == 0) {
       Error("Functions must contain at least one basic block.");
       // TODO(kschimpf) Remove error recovery once implementation complete.
       NumBbs = 1;
     }
     // Install the basic blocks, skipping bb0 which was created in the
     // constructor.
     for (size_t i = 1; i < NumBbs; ++i)
       InstallNextBasicBlock();
     return;
   }
   case naclbitc::FUNC_CODE_INST_BINOP: {
     // BINOP: [opval, opval, opcode]
     if (!isValidRecordSize(3, "function block binop"))
       return;
+    if (disableIRGeneration()) {
+      setNextLocalInstIndex(nullptr);
+      return;
+    }
     Ice::Operand *Op1 = getRelativeOperand(Values[0], BaseIndex);
     Ice::Operand *Op2 = getRelativeOperand(Values[1], BaseIndex);
     Ice::Type Type1 = Op1->getType();
     Ice::Type Type2 = Op2->getType();
     if (Type1 != Type2) {
       std::string Buffer;
       raw_string_ostream StrBuf(Buffer);
       StrBuf << "Binop argument types differ: " << Type1 << " and " << Type2;
       Error(StrBuf.str());
       appendErrorInstruction(Type1);
       return;
     }
 
     Ice::InstArithmetic::OpKind Opcode;
     if (!convertBinopOpcode(Values[2], Type1, Opcode))
       return;
     CurrentNode->appendInst(Ice::InstArithmetic::create(
         Func, Opcode, getNextInstVar(Type1), Op1, Op2));
     return;
   }
   case naclbitc::FUNC_CODE_INST_CAST: {
     // CAST: [opval, destty, castopc]
     if (!isValidRecordSize(3, "function block cast"))
       return;
+    if (disableIRGeneration()) {
+      setNextLocalInstIndex(nullptr);
+      return;
+    }
     Ice::Operand *Src = getRelativeOperand(Values[0], BaseIndex);
     Ice::Type CastType = Context->getSimpleTypeByID(Values[1]);
     Instruction::CastOps LLVMCastOp;
     Ice::InstCast::OpKind CastKind;
     if (!naclbitc::DecodeCastOpcode(Values[2], LLVMCastOp) ||
         !convertLLVMCastOpToIceOp(LLVMCastOp, CastKind)) {
       std::string Buffer;
       raw_string_ostream StrBuf(Buffer);
       StrBuf << "Cast opcode not understood: " << Values[2];
       Error(StrBuf.str());
@@ skipping 10 matching lines @@
       Error(StrBuf.str());
       appendErrorInstruction(CastType);
       return;
     }
     CurrentNode->appendInst(
         Ice::InstCast::create(Func, CastKind, getNextInstVar(CastType), Src));
     return;
   }
   case naclbitc::FUNC_CODE_INST_VSELECT: {
     // VSELECT: [opval, opval, pred]
+    if (!isValidRecordSize(3, "function block select"))
+      return;
+    if (disableIRGeneration()) {
+      setNextLocalInstIndex(nullptr);
+      return;
+    }
     Ice::Operand *ThenVal = getRelativeOperand(Values[0], BaseIndex);
     Ice::Type ThenType = ThenVal->getType();
     Ice::Operand *ElseVal = getRelativeOperand(Values[1], BaseIndex);
     Ice::Type ElseType = ElseVal->getType();
     if (ThenType != ElseType) {
       std::string Buffer;
       raw_string_ostream StrBuf(Buffer);
       StrBuf << "Select operands not same type. Found " << ThenType << " and "
              << ElseType;
       Error(StrBuf.str());
@@ skipping 24 matching lines @@
       return;
     }
     CurrentNode->appendInst(Ice::InstSelect::create(
         Func, getNextInstVar(ThenType), CondVal, ThenVal, ElseVal));
     return;
   }
   case naclbitc::FUNC_CODE_INST_EXTRACTELT: {
     // EXTRACTELT: [opval, opval]
     if (!isValidRecordSize(2, "function block extract element"))
       return;
+    if (disableIRGeneration()) {
+      setNextLocalInstIndex(nullptr);
+      return;
+    }
     Ice::Operand *Vec = getRelativeOperand(Values[0], BaseIndex);
     Ice::Type VecType = Vec->getType();
     Ice::Operand *Index = getRelativeOperand(Values[1], BaseIndex);
     VectorIndexCheckValue IndexCheckValue = validateVectorIndex(Vec, Index);
     if (IndexCheckValue != VectorIndexValid) {
       std::string Buffer;
       raw_string_ostream StrBuf(Buffer);
       dumpVectorIndexCheckValue(StrBuf, IndexCheckValue);
       StrBuf << ": extractelement " << VecType << " " << *Vec << ", "
              << Index->getType() << " " << *Index;
       Error(StrBuf.str());
       appendErrorInstruction(VecType);
       return;
     }
     CurrentNode->appendInst(Ice::InstExtractElement::create(
         Func, getNextInstVar(typeElementType(VecType)), Vec, Index));
     return;
   }
   case naclbitc::FUNC_CODE_INST_INSERTELT: {
     // INSERTELT: [opval, opval, opval]
     if (!isValidRecordSize(3, "function block insert element"))
       return;
+    if (disableIRGeneration()) {
+      setNextLocalInstIndex(nullptr);
+      return;
+    }
     Ice::Operand *Vec = getRelativeOperand(Values[0], BaseIndex);
     Ice::Type VecType = Vec->getType();
     Ice::Operand *Elt = getRelativeOperand(Values[1], BaseIndex);
     Ice::Operand *Index = getRelativeOperand(Values[2], BaseIndex);
     VectorIndexCheckValue IndexCheckValue = validateVectorIndex(Vec, Index);
     if (IndexCheckValue != VectorIndexValid) {
       std::string Buffer;
       raw_string_ostream StrBuf(Buffer);
       dumpVectorIndexCheckValue(StrBuf, IndexCheckValue);
       StrBuf << ": insertelement " << VecType << " " << *Vec << ", "
              << Elt->getType() << " " << *Elt << ", " << Index->getType() << " "
              << *Index;
       Error(StrBuf.str());
       appendErrorInstruction(Elt->getType());
       return;
     }
     CurrentNode->appendInst(Ice::InstInsertElement::create(
         Func, getNextInstVar(VecType), Vec, Elt, Index));
     return;
   }
   case naclbitc::FUNC_CODE_INST_CMP2: {
     // CMP2: [opval, opval, pred]
     if (!isValidRecordSize(3, "function block compare"))
       return;
+    if (disableIRGeneration()) {
+      setNextLocalInstIndex(nullptr);
+      return;
+    }
     Ice::Operand *Op1 = getRelativeOperand(Values[0], BaseIndex);
     Ice::Operand *Op2 = getRelativeOperand(Values[1], BaseIndex);
     Ice::Type Op1Type = Op1->getType();
     Ice::Type Op2Type = Op2->getType();
     Ice::Type DestType = getCompareResultType(Op1Type);
     if (Op1Type != Op2Type) {
       std::string Buffer;
       raw_string_ostream StrBuf(Buffer);
       StrBuf << "Compare argument types differ: " << Op1Type
              << " and " << Op2Type;
@@ skipping 41 matching lines @@
       Error(StrBuf.str());
       appendErrorInstruction(DestType);
       return;
     }
     return;
   }
   case naclbitc::FUNC_CODE_INST_RET: {
     // RET: [opval?]
     if (!isValidRecordSizeInRange(0, 1, "function block ret"))
       return;
+    if (disableIRGeneration()) {
+      setNextLocalInstIndex(nullptr);
+      return;
+    }
     if (Values.size() == 0) {
       CurrentNode->appendInst(Ice::InstRet::create(Func));
     } else {
       CurrentNode->appendInst(
           Ice::InstRet::create(Func, getRelativeOperand(Values[0], BaseIndex)));
     }
     InstIsTerminating = true;
     return;
   }
   case naclbitc::FUNC_CODE_INST_BR: {
     if (Values.size() == 1) {
       // BR: [bb#]
+      if (disableIRGeneration())
+        return;
       Ice::CfgNode *Block = getBranchBasicBlock(Values[0]);
       if (Block == nullptr)
         return;
       CurrentNode->appendInst(Ice::InstBr::create(Func, Block));
     } else {
       // BR: [bb#, bb#, opval]
       if (!isValidRecordSize(3, "function block branch"))
         return;
+      if (disableIRGeneration())
+        return;
       Ice::Operand *Cond = getRelativeOperand(Values[2], BaseIndex);
       if (Cond->getType() != Ice::IceType_i1) {
         std::string Buffer;
         raw_string_ostream StrBuf(Buffer);
         StrBuf << "Branch condition " << *Cond << " not i1. Found: "
                << Cond->getType();
         Error(StrBuf.str());
         return;
       }
       Ice::CfgNode *ThenBlock = getBranchBasicBlock(Values[0]);
@@ skipping 10 matching lines @@
     // SWITCH: [Condty, Cond, BbIndex, NumCases Case ...]
     // where Case = [1, 1, Value, BbIndex].
     //
     // Note: Unlike most instructions, we don't infer the type of
     // Cond, but provide it as a separate field. There are also
     // unnecesary data fields (i.e. constants 1).  These were not
     // cleaned up in PNaCl bitcode because the bitcode format was
     // already frozen when the problem was noticed.
     if (!isValidRecordSizeAtLeast(4, "function block switch"))
       return;
+    if (disableIRGeneration())
+      return;
     Ice::Type CondTy = Context->getSimpleTypeByID(Values[0]);
     if (!Ice::isScalarIntegerType(CondTy)) {
       std::string Buffer;
       raw_string_ostream StrBuf(Buffer);
       StrBuf << "Case condition must be non-wide integer. Found: " << CondTy;
       Error(StrBuf.str());
       return;
     }
     Ice::SizeT BitWidth = Ice::getScalarIntBitWidth(CondTy);
     Ice::Operand *Cond = getRelativeOperand(Values[1], BaseIndex);
@@ skipping 31 matching lines @@
       Switch->addBranch(CaseIndex, Value.getSExtValue(), Label);
     }
     CurrentNode->appendInst(Switch);
     InstIsTerminating = true;
     return;
   }
   case naclbitc::FUNC_CODE_INST_UNREACHABLE: {
     // UNREACHABLE: []
     if (!isValidRecordSize(0, "function block unreachable"))
       return;
+    if (disableIRGeneration())
+      return;
     CurrentNode->appendInst(
         Ice::InstUnreachable::create(Func));
     InstIsTerminating = true;
     return;
   }
   case naclbitc::FUNC_CODE_INST_PHI: {
     // PHI: [ty, val1, bb1, ..., valN, bbN] for n >= 2.
     if (!isValidRecordSizeAtLeast(3, "function block phi"))
       return;
     Ice::Type Ty = Context->getSimpleTypeByID(Values[0]);
     if ((Values.size() & 0x1) == 0) {
       // Not an odd number of values.
       std::string Buffer;
       raw_string_ostream StrBuf(Buffer);
       StrBuf << "function block phi record size not valid: " << Values.size();
       Error(StrBuf.str());
       appendErrorInstruction(Ty);
       return;
     }
     if (Ty == Ice::IceType_void) {
       Error("Phi record using type void not allowed");
       return;
     }
+    if (disableIRGeneration()) {
+      setNextLocalInstIndex(nullptr);
+      return;
+    }
     Ice::Variable *Dest = getNextInstVar(Ty);
     Ice::InstPhi *Phi = Ice::InstPhi::create(Func, Values.size() >> 1, Dest);
     for (unsigned i = 1; i < Values.size(); i += 2) {
       Ice::Operand *Op =
           getRelativeOperand(NaClDecodeSignRotatedValue(Values[i]), BaseIndex);
       if (Op->getType() != Ty) {
         std::string Buffer;
         raw_string_ostream StrBuf(Buffer);
         StrBuf << "Value " << *Op << " not type " << Ty
                << " in phi instruction. Found: " << Op->getType();
         Error(StrBuf.str());
         appendErrorInstruction(Ty);
         return;
       }
       Phi->addArgument(Op, getBasicBlock(Values[i + 1]));
     }
     CurrentNode->appendInst(Phi);
     return;
   }
   case naclbitc::FUNC_CODE_INST_ALLOCA: {
     // ALLOCA: [Size, align]
     if (!isValidRecordSize(2, "function block alloca"))
       return;
+    if (disableIRGeneration()) {
+      setNextLocalInstIndex(nullptr);
+      return;
+    }
     Ice::Operand *ByteCount = getRelativeOperand(Values[0], BaseIndex);
     Ice::Type PtrTy = Context->getIcePointerType();
     if (ByteCount->getType() != Ice::IceType_i32) {
       std::string Buffer;
       raw_string_ostream StrBuf(Buffer);
       StrBuf << "Alloca on non-i32 value. Found: " << *ByteCount;
       Error(StrBuf.str());
       appendErrorInstruction(PtrTy);
       return;
     }
     unsigned Alignment;
     extractAlignment("Alloca", Values[1], Alignment);
     CurrentNode->appendInst(Ice::InstAlloca::create(Func, ByteCount, Alignment,
                                                     getNextInstVar(PtrTy)));
     return;
   }
   case naclbitc::FUNC_CODE_INST_LOAD: {
     // LOAD: [address, align, ty]
     if (!isValidRecordSize(3, "function block load"))
       return;
+    if (disableIRGeneration()) {
+      setNextLocalInstIndex(nullptr);
+      return;
+    }
     Ice::Operand *Address = getRelativeOperand(Values[0], BaseIndex);
     Ice::Type Ty = Context->getSimpleTypeByID(Values[2]);
     if (!isValidPointerType(Address, "Load")) {
       appendErrorInstruction(Ty);
       return;
     }
     unsigned Alignment;
     extractAlignment("Load", Values[1], Alignment);
     if (!isValidLoadStoreAlignment(Alignment, Ty, "Load")) {
       appendErrorInstruction(Ty);
       return;
     }
     CurrentNode->appendInst(
         Ice::InstLoad::create(Func, getNextInstVar(Ty), Address, Alignment));
     return;
   }
   case naclbitc::FUNC_CODE_INST_STORE: {
     // STORE: [address, value, align]
     if (!isValidRecordSize(3, "function block store"))
       return;
+    if (disableIRGeneration())
+      return;
     Ice::Operand *Address = getRelativeOperand(Values[0], BaseIndex);
     if (!isValidPointerType(Address, "Store"))
       return;
     Ice::Operand *Value = getRelativeOperand(Values[1], BaseIndex);
     unsigned Alignment;
     extractAlignment("Store", Values[2], Alignment);
     if (!isValidLoadStoreAlignment(Alignment, Value->getType(), "Store"))
       return;
     CurrentNode->appendInst(
         Ice::InstStore::create(Func, Value, Address, Alignment));
@@ skipping 58 matching lines @@
       std::string Buffer;
       raw_string_ostream StrBuf(Buffer);
       StrBuf << "Function call calling convention value " << (CCInfo >> 1)
              << " not understood.";
       Error(StrBuf.str());
       appendErrorInstruction(ReturnType);
       return;
     }
     bool IsTailCall = static_cast<bool>(CCInfo & 1);
 
+    if (disableIRGeneration()) {
+      if (ReturnType != Ice::IceType_void)
+        setNextLocalInstIndex(nullptr);
+      return;
+    }
+
     // Create the call instruction.
     Ice::Variable *Dest = (ReturnType == Ice::IceType_void)
                               ? nullptr
                               : getNextInstVar(ReturnType);
     Ice::SizeT NumParams = Values.size() - ParamsStartIndex;
     Ice::InstCall *Inst = nullptr;
     if (IntrinsicInfo) {
       Inst =
           Ice::InstIntrinsicCall::create(Func, NumParams, Dest, Callee,
                                          IntrinsicInfo->Info);
@@ skipping 49 matching lines @@
       }
     }
 
     CurrentNode->appendInst(Inst);
     return;
   }
   case naclbitc::FUNC_CODE_INST_FORWARDTYPEREF: {
     // FORWARDTYPEREF: [opval, ty]
     if (!isValidRecordSize(2, "function block forward type ref"))
       return;
-    setOperand(Values[0], createInstVar(Context->getSimpleTypeByID(Values[1])));
+    if (disableIRGeneration()) {
+      setOperand(Values[0], nullptr);
+    } else {
+      setOperand(Values[0],
+                 createInstVar(Context->getSimpleTypeByID(Values[1])));
+    }
     return;
   }
   default:
     // Generate error message!
     BlockParserBaseClass::ProcessRecord();
     return;
   }
 }
 
 /// Parses constants within a function block.
@@ skipping 41 matching lines @@
     if (NextConstantType == Ice::IceType_void)
       Error("constants block set type not allowed for void type");
     return;
   }
   case naclbitc::CST_CODE_UNDEF: {
     // UNDEF
     if (!isValidRecordSize(0, "constants block undef"))
       return;
     if (!isValidNextConstantType())
       return;
+    if (disableIRGeneration()) {
+      FuncParser->setNextConstantID(nullptr);
+      return;
+    }
     FuncParser->setNextConstantID(
         getContext()->getConstantUndef(NextConstantType));
     return;
   }
   case naclbitc::CST_CODE_INTEGER: {
     // INTEGER: [intval]
     if (!isValidRecordSize(1, "constants block integer"))
       return;
     if (!isValidNextConstantType())
       return;
     if (IntegerType *IType = dyn_cast<IntegerType>(
             Context->convertToLLVMType(NextConstantType))) {
       APInt Value(IType->getBitWidth(), NaClDecodeSignRotatedValue(Values[0]));
       Ice::Constant *C = (NextConstantType == Ice::IceType_i64)
                              ? getContext()->getConstantInt64(
                                    NextConstantType, Value.getSExtValue())
                              : getContext()->getConstantInt32(
                                    NextConstantType, Value.getSExtValue());
-      FuncParser->setNextConstantID(C);
+      if (disableIRGeneration()) {
+        FuncParser->setNextConstantID(nullptr);
+      } else {
+        FuncParser->setNextConstantID(C);
+      }
       return;
     }
     std::string Buffer;
     raw_string_ostream StrBuf(Buffer);
     StrBuf << "constant block integer record for non-integer type "
            << NextConstantType;
     Error(StrBuf.str());
     return;
   }
   case naclbitc::CST_CODE_FLOAT: {
     // FLOAT: [fpval]
     if (!isValidRecordSize(1, "constants block float"))
       return;
     if (!isValidNextConstantType())
       return;
+    if (disableIRGeneration()) {
+      FuncParser->setNextConstantID(nullptr);
+      return;
+    }
     switch (NextConstantType) {
     case Ice::IceType_f32: {
       APFloat Value(APFloat::IEEEsingle,
                     APInt(32, static_cast<uint32_t>(Values[0])));
       FuncParser->setNextConstantID(
           getContext()->getConstantFloat(Value.convertToFloat()));
       return;
     }
     case Ice::IceType_f64: {
       APFloat Value(APFloat::IEEEdouble, APInt(64, Values[0]));
-      FuncParser->setNextConstantID(
-          getContext()->getConstantDouble(Value.convertToDouble()));
+      if (disableIRGeneration()) {
+        FuncParser->setNextConstantID(nullptr);
+      } else {
+        FuncParser->setNextConstantID(
+            getContext()->getConstantDouble(Value.convertToDouble()));
+      }
       return;
     }
     default: {
       std::string Buffer;
       raw_string_ostream StrBuf(Buffer);
       StrBuf << "constant block float record for non-floating type "
              << NextConstantType;
       Error(StrBuf.str());
       return;
     }
@@ skipping 40 matching lines @@
 };
 
 void FunctionValuesymtabParser::setValueName(uint64_t Index, StringType &Name) {
   // Note: We check when Index is too small, so that we can error recover
   // (FP->getOperand will create fatal error).
   if (Index < getFunctionParser()->CachedNumGlobalValueIDs) {
     reportUnableToAssign("instruction", Index, Name);
     // TODO(kschimpf) Remove error recovery once implementation complete.
     return;
   }
+  if (disableIRGeneration())
+    return;
   Ice::Operand *Op = getFunctionParser()->getOperand(Index);
   if (Ice::Variable *V = dyn_cast<Ice::Variable>(Op)) {
     std::string Nm(Name.data(), Name.size());
     V->setName(Nm);
   } else {
     reportUnableToAssign("variable", Index, Name);
   }
 }
 
 void FunctionValuesymtabParser::setBbName(uint64_t Index, StringType &Name) {
+  if (disableIRGeneration())
+    return;
   if (Index >= getFunctionParser()->Func->getNumNodes()) {
     reportUnableToAssign("block", Index, Name);
     return;
   }
   std::string Nm(Name.data(), Name.size());
   getFunctionParser()->Func->getNodes()[Index]->setName(Nm);
 }
 
 bool FunctionParser::ParseBlock(unsigned BlockID) {
   switch (BlockID) {
@@ skipping 249 matching lines @@
 
   if (TopLevelBlocks != 1) {
     errs() << IRFilename
            << ": Contains more than one module. Found: " << TopLevelBlocks
            << "\n";
     ErrorStatus = true;
   }
 }
 
 } // end of namespace Ice