lib/Analysis/ValueLatticeUtils.cpp

   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 !any_of(GV->users(), [&](User *U) {
  32     if (auto *Store = dyn_cast<StoreInst>(U)) {
  33       if (Store->getValueOperand() == GV || Store->isVolatile())
  34         return true;
  35     } else if (auto *Load = dyn_cast<LoadInst>(U)) {
  36       if (Load->isVolatile())
  37         return true;
  38     } else {
  39       return true;
  40     }
  41     return false;
  42   });
  43 }