diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp index 8a50d431282..6470fc2331d 100644 --- a/lib/Analysis/ScalarEvolution.cpp +++ b/lib/Analysis/ScalarEvolution.cpp @@ -7268,70 +7268,27 @@ bool ScalarEvolution::isKnownPredicateViaConstantRanges( // This code is split out from isKnownPredicate because it is called from // within isLoopEntryGuardedByCond. - switch (Pred) { - default: - llvm_unreachable("Unexpected ICmpInst::Predicate value!"); - case ICmpInst::ICMP_SGT: - std::swap(LHS, RHS); - case ICmpInst::ICMP_SLT: { - ConstantRange LHSRange = getSignedRange(LHS); - ConstantRange RHSRange = getSignedRange(RHS); - if (LHSRange.getSignedMax().slt(RHSRange.getSignedMin())) - return true; - if (LHSRange.getSignedMin().sge(RHSRange.getSignedMax())) - return false; - break; - } - case ICmpInst::ICMP_SGE: - std::swap(LHS, RHS); - case ICmpInst::ICMP_SLE: { - ConstantRange LHSRange = getSignedRange(LHS); - ConstantRange RHSRange = getSignedRange(RHS); - if (LHSRange.getSignedMax().sle(RHSRange.getSignedMin())) - return true; - if (LHSRange.getSignedMin().sgt(RHSRange.getSignedMax())) - return false; - break; - } - case ICmpInst::ICMP_UGT: - std::swap(LHS, RHS); - case ICmpInst::ICMP_ULT: { - ConstantRange LHSRange = getUnsignedRange(LHS); - ConstantRange RHSRange = getUnsignedRange(RHS); - if (LHSRange.getUnsignedMax().ult(RHSRange.getUnsignedMin())) - return true; - if (LHSRange.getUnsignedMin().uge(RHSRange.getUnsignedMax())) - return false; - break; - } - case ICmpInst::ICMP_UGE: - std::swap(LHS, RHS); - case ICmpInst::ICMP_ULE: { - ConstantRange LHSRange = getUnsignedRange(LHS); - ConstantRange RHSRange = getUnsignedRange(RHS); - if (LHSRange.getUnsignedMax().ule(RHSRange.getUnsignedMin())) - return true; - if (LHSRange.getUnsignedMin().ugt(RHSRange.getUnsignedMax())) - return false; - break; - } - case ICmpInst::ICMP_NE: { - if (getUnsignedRange(LHS).intersectWith(getUnsignedRange(RHS)).isEmptySet()) - return true; - if (getSignedRange(LHS).intersectWith(getSignedRange(RHS)).isEmptySet()) - return true; - const SCEV *Diff = getMinusSCEV(LHS, RHS); - if (isKnownNonZero(Diff)) - return true; - break; - } - case ICmpInst::ICMP_EQ: - // The check at the top of the function catches the case where - // the values are known to be equal. - break; - } - return false; + auto CheckRanges = + [&](const ConstantRange &RangeLHS, const ConstantRange &RangeRHS) { + return ConstantRange::makeSatisfyingICmpRegion(Pred, RangeRHS) + .contains(RangeLHS); + }; + + // The check at the top of the function catches the case where the values are + // known to be equal. + if (Pred == CmpInst::ICMP_EQ) + return false; + + if (Pred == CmpInst::ICMP_NE) + return CheckRanges(getSignedRange(LHS), getSignedRange(RHS)) || + CheckRanges(getUnsignedRange(LHS), getUnsignedRange(RHS)) || + isKnownNonZero(getMinusSCEV(LHS, RHS)); + + if (CmpInst::isSigned(Pred)) + return CheckRanges(getSignedRange(LHS), getSignedRange(RHS)); + + return CheckRanges(getUnsignedRange(LHS), getUnsignedRange(RHS)); } bool ScalarEvolution::isKnownPredicateViaNoOverflow(ICmpInst::Predicate Pred,