1 //===-- ValueLatticeUtils.cpp - Utils for solving lattices ------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements common functions useful for performing data-flow 10 // analyses that propagate values across function boundaries. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/Analysis/ValueLatticeUtils.h" 15 #include "llvm/IR/GlobalVariable.h" 16 #include "llvm/IR/Instructions.h" 17 using namespace llvm; 18 19 bool llvm::canTrackArgumentsInterprocedurally(Function *F) { 20 return F->hasLocalLinkage() && !F->hasAddressTaken(); 21 } 22 23 bool llvm::canTrackReturnsInterprocedurally(Function *F) { 24 return F->hasExactDefinition() && !F->hasFnAttribute(Attribute::Naked); 25 } 26 27 bool llvm::canTrackGlobalVariableInterprocedurally(GlobalVariable *GV) { 28 if (GV->isConstant() || !GV->hasLocalLinkage() || 29 !GV->hasDefinitiveInitializer()) 30 return false; 31 return all_of(GV->users(), [&](User *U) { 32 // Currently all users of a global variable have to be non-volatile loads 33 // or stores of the global type, and the global cannot be stored itself. 34 if (auto *Store = dyn_cast<StoreInst>(U)) 35 return Store->getValueOperand() != GV && !Store->isVolatile() && 36 Store->getValueOperand()->getType() == GV->getValueType(); 37 if (auto *Load = dyn_cast<LoadInst>(U)) 38 return !Load->isVolatile() && Load->getType() == GV->getValueType(); 39 40 return false; 41 }); 42 } 43