[llvm-commits] CVS: llvm/lib/Transforms/Scalar/InstructionCombining.cpp

[Reid Spencer]

Changes in directory llvm/lib/Transforms/Scalar:

InstructionCombining.cpp updated: 1.569 -> 1.570
---
Log message:

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. 


---
Diffs of the changes:  (+17 -20)

 InstructionCombining.cpp |   37 +++++++++++++++++--------------------
 1 files changed, 17 insertions(+), 20 deletions(-)


Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.569 llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.570
--- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.569	Wed Dec 13 11:19:09 2006
+++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp	Wed Dec 13 12:21:21 2006
@@ -307,7 +307,7 @@
     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 @@
   // 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 @@
           // 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 @@
         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 @@
 /// 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 @@
   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 @@
   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 @@
     }
     
     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 @@
         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))