170 lines · cpp
1//===- MemoryModelRelaxationAnnotations.cpp ---------------------*- 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-exception6//7//===----------------------------------------------------------------------===//8 9#include "llvm/IR/MemoryModelRelaxationAnnotations.h"10#include "llvm/IR/Instructions.h"11#include "llvm/IR/Metadata.h"12#include "llvm/Support/Debug.h"13#include "llvm/Support/raw_ostream.h"14 15using namespace llvm;16 17//===- MMRAMetadata -------------------------------------------------------===//18 19MMRAMetadata::MMRAMetadata(const Instruction &I)20 : MMRAMetadata(I.getMetadata(LLVMContext::MD_mmra)) {}21 22MMRAMetadata::MMRAMetadata(MDNode *MD) {23 if (!MD)24 return;25 26 // TODO: Split this into a "tryParse" function that can return an err.27 // CTor can use the tryParse & just fatal on err.28 29 MDTuple *Tuple = dyn_cast<MDTuple>(MD);30 assert(Tuple && "Invalid MMRA structure");31 32 const auto HandleTagMD = [this](MDNode *TagMD) {33 Tags.insert({cast<MDString>(TagMD->getOperand(0))->getString(),34 cast<MDString>(TagMD->getOperand(1))->getString()});35 };36 37 if (isTagMD(Tuple)) {38 HandleTagMD(Tuple);39 return;40 }41 42 for (const MDOperand &Op : Tuple->operands()) {43 MDNode *MDOp = cast<MDNode>(Op.get());44 assert(isTagMD(MDOp));45 HandleTagMD(MDOp);46 }47}48 49bool MMRAMetadata::isTagMD(const Metadata *MD) {50 if (auto *Tuple = dyn_cast<MDTuple>(MD)) {51 return Tuple->getNumOperands() == 2 &&52 isa<MDString>(Tuple->getOperand(0)) &&53 isa<MDString>(Tuple->getOperand(1));54 }55 return false;56}57 58MDTuple *MMRAMetadata::getTagMD(LLVMContext &Ctx, StringRef Prefix,59 StringRef Suffix) {60 return MDTuple::get(Ctx,61 {MDString::get(Ctx, Prefix), MDString::get(Ctx, Suffix)});62}63 64MDTuple *MMRAMetadata::getMD(LLVMContext &Ctx,65 ArrayRef<MMRAMetadata::TagT> Tags) {66 if (Tags.empty())67 return nullptr;68 69 if (Tags.size() == 1)70 return getTagMD(Ctx, Tags.front());71 72 SmallVector<Metadata *> MMRAs;73 for (const auto &Tag : Tags)74 MMRAs.push_back(getTagMD(Ctx, Tag));75 return MDTuple::get(Ctx, MMRAs);76}77 78MDNode *MMRAMetadata::combine(LLVMContext &Ctx, const MMRAMetadata &A,79 const MMRAMetadata &B) {80 // Let A and B be two tags set, and U be the prefix-wise union of A and B.81 // For every unique tag prefix P present in A or B:82 // * If either A or B has no tags with prefix P, no tags with prefix83 // P are added to U.84 // * If both A and B have at least one tag with prefix P, all tags with prefix85 // P from both sets are added to U.86 87 SmallVector<Metadata *> Result;88 89 for (const auto &[P, S] : A) {90 if (B.hasTagWithPrefix(P))91 Result.push_back(getTagMD(Ctx, P, S));92 }93 for (const auto &[P, S] : B) {94 if (A.hasTagWithPrefix(P))95 Result.push_back(getTagMD(Ctx, P, S));96 }97 98 return MDTuple::get(Ctx, Result);99}100 101bool MMRAMetadata::hasTag(StringRef Prefix, StringRef Suffix) const {102 return Tags.count({Prefix, Suffix});103}104 105bool MMRAMetadata::isCompatibleWith(const MMRAMetadata &Other) const {106 // Two sets of tags are compatible iff, for every unique tag prefix P107 // present in at least one set:108 // - the other set contains no tag with prefix P, or109 // - at least one tag with prefix P is common to both sets.110 111 StringMap<bool> PrefixStatuses;112 for (const auto &[P, S] : Tags)113 PrefixStatuses[P] |= (Other.hasTag(P, S) || !Other.hasTagWithPrefix(P));114 for (const auto &[P, S] : Other)115 PrefixStatuses[P] |= (hasTag(P, S) || !hasTagWithPrefix(P));116 117 for (auto &[Prefix, Status] : PrefixStatuses) {118 if (!Status)119 return false;120 }121 122 return true;123}124 125bool MMRAMetadata::hasTagWithPrefix(StringRef Prefix) const {126 for (const auto &[P, S] : Tags)127 if (P == Prefix)128 return true;129 return false;130}131 132MMRAMetadata::const_iterator MMRAMetadata::begin() const {133 return Tags.begin();134}135 136MMRAMetadata::const_iterator MMRAMetadata::end() const { return Tags.end(); }137 138bool MMRAMetadata::empty() const { return Tags.empty(); }139 140unsigned MMRAMetadata::size() const { return Tags.size(); }141 142void MMRAMetadata::print(raw_ostream &OS) const {143 bool IsFirst = true;144 // TODO: use map_iter + join145 for (const auto &[P, S] : Tags) {146 if (IsFirst)147 IsFirst = false;148 else149 OS << ", ";150 OS << P << ":" << S;151 }152}153 154LLVM_DUMP_METHOD155void MMRAMetadata::dump() const { print(dbgs()); }156 157//===- Helpers ------------------------------------------------------------===//158 159static bool isReadWriteMemCall(const Instruction &I) {160 if (const auto *C = dyn_cast<CallBase>(&I))161 return C->mayReadOrWriteMemory() ||162 !C->getMemoryEffects().doesNotAccessMemory();163 return false;164}165 166bool llvm::canInstructionHaveMMRAs(const Instruction &I) {167 return isa<LoadInst>(I) || isa<StoreInst>(I) || isa<AtomicCmpXchgInst>(I) ||168 isa<AtomicRMWInst>(I) || isa<FenceInst>(I) || isReadWriteMemCall(I);169}170