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Back out Chris' last set of changes. This breaks 177.mesa and povray somehow.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30505 91177308-0d34-0410-b5e6-96231b3b80d8
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@ -5713,48 +5713,12 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) {
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return new CastInst(NotCond, SI.getType());
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}
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if (SetCondInst *IC = dyn_cast<SetCondInst>(SI.getCondition())) {
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// (x <s 0) ? -1 : 0 -> sra x, 31
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// (x >u 2147483647) ? -1 : 0 -> sra x, 31
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if (TrueValC->isAllOnesValue() && FalseValC->isNullValue())
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if (ConstantInt *CmpCst = dyn_cast<ConstantInt>(IC->getOperand(1))) {
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bool CanXForm = false;
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if (CmpCst->getType()->isSigned())
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CanXForm = CmpCst->isNullValue() &&
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IC->getOpcode() == Instruction::SetLT;
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else {
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unsigned Bits = CmpCst->getType()->getPrimitiveSizeInBits();
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CanXForm = (CmpCst->getRawValue() == ~0ULL >> (64-Bits+1)) &&
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IC->getOpcode() == Instruction::SetGT;
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}
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// The comparison constant and the result are not neccessarily the
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// same width. In any case, the first step to do is make sure that
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// X is signed.
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Value *X = IC->getOperand(0);
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if (!X->getType()->isSigned())
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X = InsertCastBefore(X, X->getType()->getSignedVersion(), SI);
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// Now that X is signed, we have to make the all ones value. Do
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// this by inserting a new SRA.
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unsigned Bits = X->getType()->getPrimitiveSizeInBits();
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Constant *ShAmt = ConstantUInt::get(Type::UByteTy, Bits-1);
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Instruction *SRA = new ShiftInst(Instruction::Shr, X, ShAmt,"ones");
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InsertNewInstBefore(SRA, SI);
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// Finally, convert to the type of the select RHS. If this is
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// smaller than the compare value, it will truncate the ones to fit.
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// If it is larger, it will sext the ones to fit.
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return new CastInst(SRA, SI.getType());
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}
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// If one of the constants is zero (we know they can't both be) and we
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// have a setcc instruction with zero, and we have an 'and' with the
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// non-constant value, eliminate this whole mess. This corresponds to
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// cases like this: ((X & 27) ? 27 : 0)
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if (TrueValC->isNullValue() || FalseValC->isNullValue())
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// If one of the constants is zero (we know they can't both be) and we
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// have a setcc instruction with zero, and we have an 'and' with the
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// non-constant value, eliminate this whole mess. This corresponds to
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// cases like this: ((X & 27) ? 27 : 0)
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if (TrueValC->isNullValue() || FalseValC->isNullValue())
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if (SetCondInst *IC = dyn_cast<SetCondInst>(SI.getCondition()))
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if (IC->isEquality() && isa<ConstantInt>(IC->getOperand(1)) &&
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cast<Constant>(IC->getOperand(1))->isNullValue())
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if (Instruction *ICA = dyn_cast<Instruction>(IC->getOperand(0)))
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@ -5774,7 +5738,6 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) {
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Instruction::Xor, V, ICA->getOperand(1)), SI);
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return ReplaceInstUsesWith(SI, V);
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}
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}
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}
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// See if we are selecting two values based on a comparison of the two values.
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