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Fix InstCombine/2006-11-10-ashr-miscompile.ll a miscompilation introduced 

by the shr -> [al]shr patch.  This was reduced from 176.gcc.

llvm-svn: 31653
This commit is contained in:
Chris Lattner 2006-11-10 23:38:52 +00:00
parent d530a503da
commit d4dee405cb
1 changed files with 3 additions and 3 deletions
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6
llvm/lib/Transforms/Scalar/InstructionCombining.cpp
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@ -5082,10 +5082,10 @@ Instruction *InstCombiner::visitShiftInst(ShiftInst &I) {
return ReplaceInstUsesWith(I, Op0); // X >>s undef -> X
}
// shr int -1, X = -1 (for any arithmetic shift rights of ~0)
if (!isLeftShift)
// ashr int -1, X = -1 (for any arithmetic shift rights of ~0)
if (I.getOpcode() == Instruction::AShr)
if (ConstantInt *CSI = dyn_cast<ConstantInt>(Op0))
if (CSI->isAllOnesValue() && Op0->getType()->isSigned())
if (CSI->isAllOnesValue())
return ReplaceInstUsesWith(I, CSI);
// Try to fold constant and into select arguments.