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96a74c4527
Fix typo pointed out by Roman Divacky. There should be no functional change, as the rest of the code will return nullptr for undef anyway. The condition is just there for clarity.
77 lines
2.7 KiB
C++
77 lines
2.7 KiB
C++
//===- ValueLattice.cpp - Value constraint analysis -------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Analysis/ValueLattice.h"
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#include "llvm/Analysis/ConstantFolding.h"
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namespace llvm {
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Constant *
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ValueLatticeElement::getCompare(CmpInst::Predicate Pred, Type *Ty,
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const ValueLatticeElement &Other,
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const DataLayout &DL) const {
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// Not yet resolved.
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if (isUnknown() || Other.isUnknown())
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return nullptr;
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// TODO: Can be made more precise, but always returning undef would be
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// incorrect.
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if (isUndef() || Other.isUndef())
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return nullptr;
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if (isConstant() && Other.isConstant())
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return ConstantFoldCompareInstOperands(Pred, getConstant(),
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Other.getConstant(), DL);
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if (ICmpInst::isEquality(Pred)) {
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// not(C) != C => true, not(C) == C => false.
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if ((isNotConstant() && Other.isConstant() &&
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getNotConstant() == Other.getConstant()) ||
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(isConstant() && Other.isNotConstant() &&
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getConstant() == Other.getNotConstant()))
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return Pred == ICmpInst::ICMP_NE ? ConstantInt::getTrue(Ty)
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: ConstantInt::getFalse(Ty);
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}
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// Integer constants are represented as ConstantRanges with single
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// elements.
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if (!isConstantRange() || !Other.isConstantRange())
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return nullptr;
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const auto &CR = getConstantRange();
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const auto &OtherCR = Other.getConstantRange();
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if (CR.icmp(Pred, OtherCR))
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return ConstantInt::getTrue(Ty);
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if (CR.icmp(CmpInst::getInversePredicate(Pred), OtherCR))
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return ConstantInt::getFalse(Ty);
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return nullptr;
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}
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raw_ostream &operator<<(raw_ostream &OS, const ValueLatticeElement &Val) {
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if (Val.isUnknown())
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return OS << "unknown";
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if (Val.isUndef())
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return OS << "undef";
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if (Val.isOverdefined())
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return OS << "overdefined";
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if (Val.isNotConstant())
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return OS << "notconstant<" << *Val.getNotConstant() << ">";
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if (Val.isConstantRangeIncludingUndef())
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return OS << "constantrange incl. undef <"
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<< Val.getConstantRange(true).getLower() << ", "
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<< Val.getConstantRange(true).getUpper() << ">";
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if (Val.isConstantRange())
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return OS << "constantrange<" << Val.getConstantRange().getLower() << ", "
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<< Val.getConstantRange().getUpper() << ">";
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return OS << "constant<" << *Val.getConstant() << ">";
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}
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} // end namespace llvm
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