| //===- ValueLattice.cpp - Value constraint analysis -------------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Analysis/ValueLattice.h" |
| #include "llvm/Analysis/ConstantFolding.h" |
| |
| namespace llvm { |
| Constant * |
| ValueLatticeElement::getCompare(CmpInst::Predicate Pred, Type *Ty, |
| const ValueLatticeElement &Other, |
| const DataLayout &DL) const { |
| // Not yet resolved. |
| if (isUnknown() || Other.isUnknown()) |
| return nullptr; |
| |
| // TODO: Can be made more precise, but always returning undef would be |
| // incorrect. |
| if (isUndef() || Other.isUndef()) |
| return nullptr; |
| |
| if (isConstant() && Other.isConstant()) |
| return ConstantFoldCompareInstOperands(Pred, getConstant(), |
| Other.getConstant(), DL); |
| |
| if (ICmpInst::isEquality(Pred)) { |
| // not(C) != C => true, not(C) == C => false. |
| if ((isNotConstant() && Other.isConstant() && |
| getNotConstant() == Other.getConstant()) || |
| (isConstant() && Other.isNotConstant() && |
| getConstant() == Other.getNotConstant())) |
| return Pred == ICmpInst::ICMP_NE ? ConstantInt::getTrue(Ty) |
| : ConstantInt::getFalse(Ty); |
| } |
| |
| // Integer constants are represented as ConstantRanges with single |
| // elements. |
| if (!isConstantRange() || !Other.isConstantRange()) |
| return nullptr; |
| |
| const auto &CR = getConstantRange(); |
| const auto &OtherCR = Other.getConstantRange(); |
| if (CR.icmp(Pred, OtherCR)) |
| return ConstantInt::getTrue(Ty); |
| if (CR.icmp(CmpInst::getInversePredicate(Pred), OtherCR)) |
| return ConstantInt::getFalse(Ty); |
| |
| return nullptr; |
| } |
| |
| raw_ostream &operator<<(raw_ostream &OS, const ValueLatticeElement &Val) { |
| if (Val.isUnknown()) |
| return OS << "unknown"; |
| if (Val.isUndef()) |
| return OS << "undef"; |
| if (Val.isOverdefined()) |
| return OS << "overdefined"; |
| |
| if (Val.isNotConstant()) |
| return OS << "notconstant<" << *Val.getNotConstant() << ">"; |
| |
| if (Val.isConstantRangeIncludingUndef()) |
| return OS << "constantrange incl. undef <" |
| << Val.getConstantRange(true).getLower() << ", " |
| << Val.getConstantRange(true).getUpper() << ">"; |
| |
| if (Val.isConstantRange()) |
| return OS << "constantrange<" << Val.getConstantRange().getLower() << ", " |
| << Val.getConstantRange().getUpper() << ">"; |
| return OS << "constant<" << *Val.getConstant() << ">"; |
| } |
| } // end namespace llvm |