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"
17using namespace llvm;
18
19bool llvm::canTrackArgumentsInterprocedurally(Function *F) {
20 return F->hasLocalLinkage() && !F->hasAddressTaken();
21}
22
23bool llvm::canTrackReturnsInterprocedurally(Function *F) {
24 return F->hasExactDefinition() && !F->hasFnAttribute(Kind: Attribute::Naked);
25}
26
27bool llvm::canTrackGlobalVariableInterprocedurally(GlobalVariable *GV) {
28 if (GV->isConstant() || !GV->hasLocalLinkage() ||
29 !GV->hasDefinitiveInitializer())
30 return false;
31 return all_of(Range: GV->users(), P: [&](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>(Val: U))
35 return Store->getValueOperand() != GV && !Store->isVolatile() &&
36 Store->getValueOperand()->getType() == GV->getValueType();
37 if (auto *Load = dyn_cast<LoadInst>(Val: U))
38 return !Load->isVolatile() && Load->getType() == GV->getValueType();
39
40 return false;
41 });
42}
43