Fix a bug in EvaluateInDifferentType. The type of operand should not be

used to determine whether a ZExt or SExt cast is performed. Instead, pass
an "isSigned" bool to the function and determine its value from the opcode
of the cast involved.
Also, clean up some cruft from previous patches.

llvm-svn: 32548

1 files changed, 17 insertions, 20 deletions

diff --git a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
index 43cf48ae132..c63bfcb8c23 100644
--- a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -307,7 +307,7 @@ namespace {
     Instruction *PromoteCastOfAllocation(CastInst &CI, AllocationInst &AI);
     Instruction *MatchBSwap(BinaryOperator &I);
 
-    Value *EvaluateInDifferentType(Value *V, const Type *Ty);
+    Value *EvaluateInDifferentType(Value *V, const Type *Ty, bool isSigned);
   };
 
   RegisterPass<InstCombiner> X("instcombine", "Combine redundant instructions");
@@ -2171,14 +2171,12 @@ Instruction *InstCombiner::visitMul(BinaryOperator &I) {
   // See if we can simplify things based on how the boolean was originally
   // formed.
   CastInst *BoolCast = 0;
-  if (CastInst *CI = dyn_cast<CastInst>(I.getOperand(0)))
-    if (CI->getOperand(0)->getType() == Type::BoolTy &&
-        CI->getOpcode() == Instruction::ZExt)
+  if (ZExtInst *CI = dyn_cast<ZExtInst>(I.getOperand(0)))
+    if (CI->getOperand(0)->getType() == Type::BoolTy)
       BoolCast = CI;
   if (!BoolCast)
-    if (CastInst *CI = dyn_cast<CastInst>(I.getOperand(1)))
-      if (CI->getOperand(0)->getType() == Type::BoolTy &&
-        CI->getOpcode() == Instruction::ZExt)
+    if (ZExtInst *CI = dyn_cast<ZExtInst>(I.getOperand(1)))
+      if (CI->getOperand(0)->getType() == Type::BoolTy)
         BoolCast = CI;
   if (BoolCast) {
     if (SetCondInst *SCI = dyn_cast<SetCondInst>(BoolCast->getOperand(0))) {
@@ -4333,8 +4331,7 @@ Instruction *InstCombiner::visitSetCondInst(SetCondInst &I) {
           // Check to see if there is a noop-cast between the shift and the and.
           if (!Shift) {
             if (CastInst *CI = dyn_cast<CastInst>(LHSI->getOperand(0)))
-              if (CI->getOpcode() == Instruction::BitCast && 
-                  CI->getType()->isIntegral())
+              if (CI->getOpcode() == Instruction::BitCast)
                 Shift = dyn_cast<ShiftInst>(CI->getOperand(0));
           }
 
@@ -5375,10 +5372,8 @@ Instruction *InstCombiner::FoldShiftByConstant(Value *Op0, ConstantInt *Op1,
         Amt = Op0->getType()->getPrimitiveSizeInBits();
       
       Value *Op = ShiftOp->getOperand(0);
-      if (isShiftOfSignedShift != isSignedShift)
-        Op = InsertNewInstBefore(new BitCastInst(Op, I.getType(), "tmp"), I);
       ShiftInst *ShiftResult = new ShiftInst(I.getOpcode(), Op,
-                           ConstantInt::get(Type::UByteTy, Amt));
+                                          ConstantInt::get(Type::UByteTy, Amt));
       if (I.getType() == ShiftResult->getType())
         return ShiftResult;
       InsertNewInstBefore(ShiftResult, I);
@@ -5658,9 +5653,10 @@ static bool CanEvaluateInDifferentType(Value *V, const Type *Ty,
 /// EvaluateInDifferentType - Given an expression that 
 /// CanEvaluateInDifferentType returns true for, actually insert the code to
 /// evaluate the expression.
-Value *InstCombiner::EvaluateInDifferentType(Value *V, const Type *Ty) {
+Value *InstCombiner::EvaluateInDifferentType(Value *V, const Type *Ty, 
+                                             bool isSigned ) {
   if (Constant *C = dyn_cast<Constant>(V))
-    return ConstantExpr::getIntegerCast(C, Ty, C->getType()->isSigned());
+    return ConstantExpr::getIntegerCast(C, Ty, isSigned /*Sext or ZExt*/);
 
   // Otherwise, it must be an instruction.
   Instruction *I = cast<Instruction>(V);
@@ -5669,8 +5665,8 @@ Value *InstCombiner::EvaluateInDifferentType(Value *V, const Type *Ty) {
   case Instruction::And:
   case Instruction::Or:
   case Instruction::Xor: {
-    Value *LHS = EvaluateInDifferentType(I->getOperand(0), Ty);
-    Value *RHS = EvaluateInDifferentType(I->getOperand(1), Ty);
+    Value *LHS = EvaluateInDifferentType(I->getOperand(0), Ty, isSigned);
+    Value *RHS = EvaluateInDifferentType(I->getOperand(1), Ty, isSigned);
     Res = BinaryOperator::create((Instruction::BinaryOps)I->getOpcode(),
                                  LHS, RHS, I->getName());
     break;
@@ -5678,7 +5674,7 @@ Value *InstCombiner::EvaluateInDifferentType(Value *V, const Type *Ty) {
   case Instruction::AShr:
   case Instruction::LShr:
   case Instruction::Shl: {
-    Value *LHS = EvaluateInDifferentType(I->getOperand(0), Ty);
+    Value *LHS = EvaluateInDifferentType(I->getOperand(0), Ty, isSigned);
     Res = new ShiftInst((Instruction::OtherOps)I->getOpcode(), LHS,
                         I->getOperand(1), I->getName());
     break;
@@ -5824,7 +5820,8 @@ Instruction *InstCombiner::commonIntCastTransforms(CastInst &CI) {
     }
     
     if (DoXForm) {
-      Value *Res = EvaluateInDifferentType(SrcI, DestTy);
+      Value *Res = EvaluateInDifferentType(SrcI, DestTy, 
+                                           CI.getOpcode() == Instruction::SExt);
       assert(Res->getType() == DestTy);
       switch (CI.getOpcode()) {
       default: assert(0 && "Unknown cast type!");
@@ -7920,11 +7917,11 @@ static Instruction *InstCombineStoreToCast(InstCombiner &IC, StoreInst &SI) {
         Value *NewCast;
         Instruction::CastOps opcode = Instruction::BitCast;
         Value *SIOp0 = SI.getOperand(0);
-        if (SrcPTy->getTypeID() == Type::PointerTyID) {
+        if (isa<PointerType>(SrcPTy)) {
           if (SIOp0->getType()->isIntegral())
             opcode = Instruction::IntToPtr;
         } else if (SrcPTy->isIntegral()) {
-          if (SIOp0->getType()->getTypeID() == Type::PointerTyID)
+          if (isa<PointerType>(SIOp0->getType()))
             opcode = Instruction::PtrToInt;
         }
         if (Constant *C = dyn_cast<Constant>(SIOp0))