Add support for the new va_arg instruction

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@6029 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AsmParser/Lexer.l

@@ -221,6 +221,7 @@ call            { RET_TOK(OtherOpVal, Call, CALL); }
 cast            { RET_TOK(OtherOpVal, Cast, CAST); }
 shl             { RET_TOK(OtherOpVal, Shl, SHL); }
 shr             { RET_TOK(OtherOpVal, Shr, SHR); }
+va_arg          { RET_TOK(OtherOpVal, VarArg, VA_ARG); }
 
 ret             { RET_TOK(TermOpVal, Ret, RET); }
 br              { RET_TOK(TermOpVal, Br, BR); }

lib/AsmParser/llvmAsmParser.y

@@ -720,7 +720,7 @@ Module *RunVMAsmParser(const std::string &Filename, FILE *F) {
 
 // Other Operators
 %type  <OtherOpVal> ShiftOps
-%token <OtherOpVal> PHI CALL INVOKE CAST SHL SHR
+%token <OtherOpVal> PHI CALL INVOKE CAST SHL SHR VA_ARG
 
 %start Module
 %%
@@ -1614,6 +1614,10 @@ InstVal : ArithmeticOps Types ValueRef ',' ValueRef {
     $$ = new CastInst($2, *$4);
     delete $4;
   }
+  | VA_ARG ResolvedVal ',' Types {
+    $$ = new VarArgInst($2, *$4);
+    delete $4;
+  }
   | PHI PHIList {
     const Type *Ty = $2->front().first->getType();
     $$ = new PHINode(Ty);

lib/Bytecode/Reader/InstructionReader.cpp

@@ -130,11 +130,15 @@ bool BytecodeParser::ParseInstruction(const uchar *&Buf, const uchar *EndBuf,
 
   Value *V;
   switch (Raw.Opcode) {
+  case Instruction::VarArg:
   case Instruction::Cast: {
     V = getValue(Raw.Ty, Raw.Arg1);
     const Type *Ty = getType(Raw.Arg2);
     if (V == 0 || Ty == 0) { std::cerr << "Invalid cast!\n"; return true; }
+    if (Raw.Opcode == Instruction::Cast)
       Res = new CastInst(V, Ty);
+    else
+      Res = new VarArgInst(V, Ty);
     return false;
   }
   case Instruction::PHINode: {

lib/Bytecode/Writer/InstructionWriter.cpp

@@ -35,7 +35,7 @@ static void outputInstructionFormat0(const Instruction *I,
   output_vbr(Type, Out);                         // Result type
 
   unsigned NumArgs = I->getNumOperands();
-  output_vbr(NumArgs + isa<CastInst>(I), Out);
+  output_vbr(NumArgs + (isa<CastInst>(I) || isa<VarArgInst>(I)), Out);
 
   for (unsigned i = 0; i < NumArgs; ++i) {
     int Slot = Table.getValSlot(I->getOperand(i));
@@ -43,9 +43,9 @@ static void outputInstructionFormat0(const Instruction *I,
     output_vbr((unsigned)Slot, Out);
   }
 
-  if (isa<CastInst>(I)) {
+  if (isa<CastInst>(I) || isa<VarArgInst>(I)) {
     int Slot = Table.getValSlot(I->getType());
-    assert(Slot != -1 && "Cast return type unknown?");
+    assert(Slot != -1 && "Cast/VarArg return type unknown?");
     output_vbr((unsigned)Slot, Out);
   }
 
@@ -218,7 +218,7 @@ void BytecodeWriter::processInstruction(const Instruction &I) {
   if (Slot > MaxOpSlot) MaxOpSlot = Slot;
 
   // Handle the special case for cast...
-  if (isa<CastInst>(I)) {
+  if (isa<CastInst>(I) || isa<VarArgInst>(I)) {
     // Cast has to encode the destination type as the second argument in the
     // packet, or else we won't know what type to cast to!
     Slots[1] = Table.getValSlot(I.getType());

lib/VMCore/AsmWriter.cpp

@@ -3,8 +3,7 @@
 // This library implements the functionality defined in llvm/Assembly/Writer.h
 //
 // Note that these routines must be extremely tolerant of various errors in the
-// LLVM code, because of of the primary uses of it is for debugging
-// transformations.
+// LLVM code, because it can be used for debugging transformations.
 //
 //===----------------------------------------------------------------------===//
 
@@ -814,9 +813,13 @@ void AssemblyWriter::printInstruction(const Instruction &I) {
       writeOperand(AI->getArraySize(), true);
     }
   } else if (isa<CastInst>(I)) {
-    if (Operand) writeOperand(Operand, true);
+    writeOperand(Operand, true);
     Out << " to ";
     printType(I.getType());
+  } else if (isa<VarArgInst>(I)) {
+    writeOperand(Operand, true);
+    Out << ", ";
+    printType(I.getType());
   } else if (Operand) {   // Print the normal way...
 
     // PrintAllTypes - Instructions who have operands of all the same type 

lib/VMCore/Instruction.cpp

@@ -91,6 +91,7 @@ const char *Instruction::getOpcodeName(unsigned OpCode) {
   case Call:    return "call";
   case Shl:     return "shl";
   case Shr:     return "shr";
+  case VarArg:  return "va_arg";
 
   default: return "<Invalid operator> ";
   }

lib/VMCore/Verifier.cpp

@@ -130,6 +130,7 @@ namespace {  // Anonymous namespace for class
     void visitPHINode(PHINode &PN);
     void visitBinaryOperator(BinaryOperator &B);
     void visitShiftInst(ShiftInst &SI);
+    void visitVarArgInst(VarArgInst &VAI);
     void visitCallInst(CallInst &CI);
     void visitGetElementPtrInst(GetElementPtrInst &GEP);
     void visitLoadInst(LoadInst &LI);
@@ -402,7 +403,12 @@ void Verifier::visitShiftInst(ShiftInst &SI) {
   visitInstruction(SI);
 }
 
-
+void Verifier::visitVarArgInst(VarArgInst &VAI) {
+  Assert1(VAI.getParent()->getParent()->getFunctionType()->isVarArg(),
+          "va_arg instruction may only occur in function with variable args!",
+          &VAI);
+  visitInstruction(VAI);
+}
 
 void Verifier::visitGetElementPtrInst(GetElementPtrInst &GEP) {
   const Type *ElTy =