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

[Zhou Sheng]

Changes in directory llvm/lib/Transforms/Scalar:

InstructionCombining.cpp updated: 1.650 -> 1.651
---
Log message:

Fix a bug in APIntified ComputeMaskedBits().


---
Diffs of the changes:  (+4 -8)

 InstructionCombining.cpp |   12 ++++--------
 1 files changed, 4 insertions(+), 8 deletions(-)


Index: llvm/lib/Transforms/Scalar/InstructionCombining.cpp
diff -u llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.650 
llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.651
--- llvm/lib/Transforms/Scalar/InstructionCombining.cpp:1.650   Wed Mar  7 
19:52:58 2007
+++ llvm/lib/Transforms/Scalar/InstructionCombining.cpp Wed Mar  7 23:42:00 2007
@@ -675,11 +675,9 @@
   case Instruction::ZExt:  {
     // Compute the bits in the result that are not present in the input.
     const IntegerType *SrcTy = cast<IntegerType>(I->getOperand(0)->getType());
-    APInt NotIn(~SrcTy->getMask());
-    APInt NewBits = APInt::getAllOnesValue(BitWidth) & 
-                    NotIn.zext(BitWidth);
+    APInt NewBits(APInt::getAllOnesValue(BitWidth).shl(SrcTy->getBitWidth()));
       
-    Mask &= ~NotIn;
+    Mask &= SrcTy->getMask().zext(BitWidth);
     ComputeMaskedBits(I->getOperand(0), Mask, KnownZero, KnownOne, Depth+1);
     assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 
     // The top bits are known to be zero.
@@ -689,11 +687,9 @@
   case Instruction::SExt: {
     // Compute the bits in the result that are not present in the input.
     const IntegerType *SrcTy = cast<IntegerType>(I->getOperand(0)->getType());
-    APInt NotIn(~SrcTy->getMask());
-    APInt NewBits = APInt::getAllOnesValue(BitWidth) & 
-                    NotIn.zext(BitWidth);
+    APInt NewBits(APInt::getAllOnesValue(BitWidth).shl(SrcTy->getBitWidth()));
       
-    Mask &= ~NotIn;
+    Mask &= SrcTy->getMask().zext(BitWidth);
     ComputeMaskedBits(I->getOperand(0), Mask, KnownZero, KnownOne, Depth+1);
     assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?"); 
 



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