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Fix PR1014 and InstCombine/2006-11-27-XorBug.ll.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31941 91177308-0d34-0410-b5e6-96231b3b80d8
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@ -939,17 +939,15 @@ bool InstCombiner::SimplifyDemandedBits(Value *V, uint64_t DemandedMask,
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// Output known-1 are known to be set if set in only one of the LHS, RHS.
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uint64_t KnownOneOut = (KnownZero & KnownOne2) | (KnownOne & KnownZero2);
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// If all of the unknown bits are known to be zero on one side or the other
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// (but not both) turn this into an *inclusive* or.
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// If all of the demanded bits are known to be zero on one side or the
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// other, turn this into an *inclusive* or.
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// e.g. (A & C1)^(B & C2) -> (A & C1)|(B & C2) iff C1&C2 == 0
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if (uint64_t UnknownBits = DemandedMask & ~(KnownZeroOut|KnownOneOut)) {
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if ((UnknownBits & (KnownZero|KnownZero2)) == UnknownBits) {
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Instruction *Or =
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BinaryOperator::createOr(I->getOperand(0), I->getOperand(1),
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I->getName());
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InsertNewInstBefore(Or, *I);
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return UpdateValueUsesWith(I, Or);
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}
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if ((DemandedMask & ~KnownZero & ~KnownZero2) == 0) {
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Instruction *Or =
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BinaryOperator::createOr(I->getOperand(0), I->getOperand(1),
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I->getName());
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InsertNewInstBefore(Or, *I);
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return UpdateValueUsesWith(I, Or);
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}
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// If all of the demanded bits on one side are known, and all of the set
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