llvm/llvm/lib/Analysis/ScopedNoAliasAA.cpp

//===- ScopedNoAliasAA.cpp - Scoped No-Alias Alias Analysis ---------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file defines the ScopedNoAlias alias-analysis pass, which implements
// metadata-based scoped no-alias support.
//
// Alias-analysis scopes are defined by an id (which can be a string or some
// other metadata node), a domain node, and an optional descriptive string.
// A domain is defined by an id (which can be a string or some other metadata
// node), and an optional descriptive string.
//
// !dom0 =   metadata !{ metadata !"domain of foo()" }
// !scope1 = metadata !{ metadata !scope1, metadata !dom0, metadata !"scope 1" }
// !scope2 = metadata !{ metadata !scope2, metadata !dom0, metadata !"scope 2" }
//
// Loads and stores can be tagged with an alias-analysis scope, and also, with
// a noalias tag for a specific scope:
//
// ... = load %ptr1, !alias.scope !{ !scope1 }
// ... = load %ptr2, !alias.scope !{ !scope1, !scope2 }, !noalias !{ !scope1 }
//
// When evaluating an aliasing query, if one of the instructions is associated
// has a set of noalias scopes in some domain that is a superset of the alias
// scopes in that domain of some other instruction, then the two memory
// accesses are assumed not to alias.
//
//===----------------------------------------------------------------------===//

#include "llvm/Analysis/ScopedNoAliasAA.h"
#include "llvm/ADT/SetOperations.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/Analysis/MemoryLocation.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Metadata.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"

usingnamespacellvm;

// A handy option for disabling scoped no-alias functionality. The same effect
// can also be achieved by stripping the associated metadata tags from IR, but
// this option is sometimes more convenient.
static cl::opt<bool> EnableScopedNoAlias("enable-scoped-noalias",
                                         cl::init(true), cl::Hidden);

AliasResult ScopedNoAliasAAResult::alias(const MemoryLocation &LocA,
                                         const MemoryLocation &LocB,
                                         AAQueryInfo &AAQI,
                                         const Instruction *) { … }

ModRefInfo ScopedNoAliasAAResult::getModRefInfo(const CallBase *Call,
                                                const MemoryLocation &Loc,
                                                AAQueryInfo &AAQI) { … }

ModRefInfo ScopedNoAliasAAResult::getModRefInfo(const CallBase *Call1,
                                                const CallBase *Call2,
                                                AAQueryInfo &AAQI) { … }

static void collectMDInDomain(const MDNode *List, const MDNode *Domain,
                              SmallPtrSetImpl<const MDNode *> &Nodes) { … }

bool ScopedNoAliasAAResult::mayAliasInScopes(const MDNode *Scopes,
                                             const MDNode *NoAlias) const { … }

AnalysisKey ScopedNoAliasAA::Key;

ScopedNoAliasAAResult ScopedNoAliasAA::run(Function &F,
                                           FunctionAnalysisManager &AM) { … }

char ScopedNoAliasAAWrapperPass::ID = …;

INITIALIZE_PASS(…)

ImmutablePass *llvm::createScopedNoAliasAAWrapperPass() { … }

ScopedNoAliasAAWrapperPass::ScopedNoAliasAAWrapperPass() : … { … }

bool ScopedNoAliasAAWrapperPass::doInitialization(Module &M) { … }

bool ScopedNoAliasAAWrapperPass::doFinalization(Module &M) { … }

void ScopedNoAliasAAWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const { … }