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Fix PR577 and testcase InstCombine/2005-06-15-ShiftSetCCCrash.ll.
Do not perform undefined out of range shifts. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22217 91177308-0d34-0410-b5e6-96231b3b80d8
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@ -2560,6 +2560,14 @@ Instruction *InstCombiner::visitSetCondInst(SetCondInst &I) {
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default: break;
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case Instruction::SetEQ:
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case Instruction::SetNE: {
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unsigned TypeBits = CI->getType()->getPrimitiveSizeInBits();
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// Check that the shift amount is in range. If not, don't perform
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// undefined shifts. When the shift is visited it will be
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// simplified.
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if (ShAmt->getValue() >= TypeBits)
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break;
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// If we are comparing against bits always shifted out, the
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// comparison cannot succeed.
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Constant *Comp =
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@ -2573,7 +2581,6 @@ Instruction *InstCombiner::visitSetCondInst(SetCondInst &I) {
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if (LHSI->hasOneUse()) {
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// Otherwise strength reduce the shift into an and.
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unsigned ShAmtVal = (unsigned)ShAmt->getValue();
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unsigned TypeBits = CI->getType()->getPrimitiveSizeInBits();
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uint64_t Val = (1ULL << (TypeBits-ShAmtVal))-1;
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Constant *Mask;
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@ -2603,6 +2610,14 @@ Instruction *InstCombiner::visitSetCondInst(SetCondInst &I) {
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default: break;
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case Instruction::SetEQ:
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case Instruction::SetNE: {
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// Check that the shift amount is in range. If not, don't perform
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// undefined shifts. When the shift is visited it will be
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// simplified.
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unsigned TypeBits = ShAmt->getType()->getPrimitiveSizeInBits();
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if (ShAmt->getValue() >= TypeBits)
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break;
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// If we are comparing against bits always shifted out, the
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// comparison cannot succeed.
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Constant *Comp =
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@ -2623,7 +2638,6 @@ Instruction *InstCombiner::visitSetCondInst(SetCondInst &I) {
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Constant *Mask;
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if (CI->getType()->isUnsigned()) {
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unsigned TypeBits = CI->getType()->getPrimitiveSizeInBits();
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Val &= ~0ULL >> (64-TypeBits);
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Mask = ConstantUInt::get(CI->getType(), Val);
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} else {
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