lib/Analysis/ValueLatticeUtils.cpp

   1 //===-- ValueLatticeUtils.cpp - Utils for solving lattices ------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file implements common functions useful for performing data-flow
  11 // analyses that propagate values across function boundaries.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "llvm/Analysis/ValueLatticeUtils.h"
  16 #include "llvm/IR/GlobalVariable.h"
  17 #include "llvm/IR/Instructions.h"
  18 using namespace llvm;
  19
  20 bool llvm::canTrackArgumentsInterprocedurally(Function *F) {
  21   return F->hasLocalLinkage() && !F->hasAddressTaken();
  22 }
  23
  24 bool llvm::canTrackReturnsInterprocedurally(Function *F) {
  25   return F->hasExactDefinition() && !F->hasFnAttribute(Attribute::Naked);
  26 }
  27
  28 bool llvm::canTrackGlobalVariableInterprocedurally(GlobalVariable *GV) {
  29   if (GV->isConstant() || !GV->hasLocalLinkage() ||
  30       !GV->hasDefinitiveInitializer())
  31     return false;
  32   return !any_of(GV->users(), [&](User *U) {
  33     if (auto *Store = dyn_cast<StoreInst>(U)) {
  34       if (Store->getValueOperand() == GV || Store->isVolatile())
  35         return true;
  36     } else if (auto *Load = dyn_cast<LoadInst>(U)) {
  37       if (Load->isVolatile())
  38         return true;
  39     } else {
  40       return true;
  41     }
  42     return false;
  43   });
  44 }