1//===- RegionInfo.cpp - SESE region detection analysis --------------------===// 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// Detects single entry single exit regions in the control flow graph. 9//===----------------------------------------------------------------------===// 10 11#include "llvm/Analysis/RegionInfo.h" 12#include "llvm/ADT/Statistic.h" 13#include "llvm/InitializePasses.h" 14#ifndef NDEBUG 15#include "llvm/Analysis/RegionPrinter.h" 16#endif 17#include "llvm/Analysis/RegionInfoImpl.h" 18#include "llvm/Config/llvm-config.h" 19#include "llvm/IR/Function.h" 20#include "llvm/Support/CommandLine.h" 21#include "llvm/Support/Compiler.h" 22 23using namespace llvm; 24 25#define DEBUG_TYPE "region" 26 27namespace llvm { 28 29template class RegionBase<RegionTraits<Function>>; 30template class RegionNodeBase<RegionTraits<Function>>; 31template class RegionInfoBase<RegionTraits<Function>>; 32 33} // end namespace llvm 34 35STATISTIC(numRegions, "The # of regions"); 36STATISTIC(numSimpleRegions, "The # of simple regions"); 37 38// Always verify if expensive checking is enabled. 39 40static cl::opt<bool,true> 41VerifyRegionInfoX( 42 "verify-region-info", 43 cl::location(RegionInfoBase<RegionTraits<Function>>::VerifyRegionInfo), 44 cl::desc("Verify region info (time consuming)")); 45 46static cl::opt<Region::PrintStyle, true> printStyleX("print-region-style", 47 cl::location(RegionInfo::printStyle), 48 cl::Hidden, 49 cl::desc("style of printing regions"), 50 cl::values( 51 clEnumValN(Region::PrintNone, "none", "print no details"), 52 clEnumValN(Region::PrintBB, "bb", 53 "print regions in detail with block_iterator"), 54 clEnumValN(Region::PrintRN, "rn", 55 "print regions in detail with element_iterator"))); 56 57//===----------------------------------------------------------------------===// 58// Region implementation 59// 60 61Region::Region(BasicBlock *Entry, BasicBlock *Exit, 62 RegionInfo* RI, 63 DominatorTree *DT, Region *Parent) : 64 RegionBase<RegionTraits<Function>>(Entry, Exit, RI, DT, Parent) { 65 66} 67 68Region::~Region() = default; 69 70//===----------------------------------------------------------------------===// 71// RegionInfo implementation 72// 73 74RegionInfo::RegionInfo() = default; 75 76RegionInfo::~RegionInfo() = default; 77 78bool RegionInfo::invalidate(Function &F, const PreservedAnalyses &PA, 79 FunctionAnalysisManager::Invalidator &) { 80 // Check whether the analysis, all analyses on functions, or the function's 81 // CFG has been preserved. 82 auto PAC = PA.getChecker<RegionInfoAnalysis>(); 83 return !(PAC.preserved() || PAC.preservedSet<AllAnalysesOn<Function>>() || 84 PAC.preservedSet<CFGAnalyses>()); 85} 86 87void RegionInfo::updateStatistics(Region *R) { 88 ++numRegions; 89 90 // TODO: Slow. Should only be enabled if -stats is used. 91 if (R->isSimple()) 92 ++numSimpleRegions; 93} 94 95void RegionInfo::recalculate(Function &F, DominatorTree *DT_, 96 PostDominatorTree *PDT_, DominanceFrontier *DF_) { 97 DT = DT_; 98 PDT = PDT_; 99 DF = DF_; 100 101 TopLevelRegion = new Region(&F.getEntryBlock(), nullptr, 102 this, DT, nullptr); 103 updateStatistics(TopLevelRegion); 104 calculate(F); 105} 106 107#ifndef NDEBUG 108void RegionInfo::view() { viewRegion(this); } 109 110void RegionInfo::viewOnly() { viewRegionOnly(this); } 111#endif 112 113//===----------------------------------------------------------------------===// 114// RegionInfoPass implementation 115// 116 117RegionInfoPass::RegionInfoPass() : FunctionPass(ID) { 118 initializeRegionInfoPassPass(*PassRegistry::getPassRegistry()); 119} 120 121RegionInfoPass::~RegionInfoPass() = default; 122 123bool RegionInfoPass::runOnFunction(Function &F) { 124 releaseMemory(); 125 126 auto DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree(); 127 auto PDT = &getAnalysis<PostDominatorTreeWrapperPass>().getPostDomTree(); 128 auto DF = &getAnalysis<DominanceFrontierWrapperPass>().getDominanceFrontier(); 129 130 RI.recalculate(F, DT, PDT, DF); 131 return false; 132} 133 134void RegionInfoPass::releaseMemory() { 135 RI.releaseMemory(); 136} 137 138void RegionInfoPass::verifyAnalysis() const { 139 RI.verifyAnalysis(); 140} 141 142void RegionInfoPass::getAnalysisUsage(AnalysisUsage &AU) const { 143 AU.setPreservesAll(); 144 AU.addRequiredTransitive<DominatorTreeWrapperPass>(); 145 AU.addRequired<PostDominatorTreeWrapperPass>(); 146 AU.addRequired<DominanceFrontierWrapperPass>(); 147} 148 149void RegionInfoPass::print(raw_ostream &OS, const Module *) const { 150 RI.print(OS); 151} 152 153#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 154LLVM_DUMP_METHOD void RegionInfoPass::dump() const { 155 RI.dump(); 156} 157#endif 158 159char RegionInfoPass::ID = 0; 160 161INITIALIZE_PASS_BEGIN(RegionInfoPass, "regions", 162 "Detect single entry single exit regions", true, true) 163INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass) 164INITIALIZE_PASS_DEPENDENCY(PostDominatorTreeWrapperPass) 165INITIALIZE_PASS_DEPENDENCY(DominanceFrontierWrapperPass) 166INITIALIZE_PASS_END(RegionInfoPass, "regions", 167 "Detect single entry single exit regions", true, true) 168 169// Create methods available outside of this file, to use them 170// "include/llvm/LinkAllPasses.h". Otherwise the pass would be deleted by 171// the link time optimization. 172 173namespace llvm { 174 175 FunctionPass *createRegionInfoPass() { 176 return new RegionInfoPass(); 177 } 178 179} // end namespace llvm 180 181//===----------------------------------------------------------------------===// 182// RegionInfoAnalysis implementation 183// 184 185AnalysisKey RegionInfoAnalysis::Key; 186 187RegionInfo RegionInfoAnalysis::run(Function &F, FunctionAnalysisManager &AM) { 188 RegionInfo RI; 189 auto *DT = &AM.getResult<DominatorTreeAnalysis>(F); 190 auto *PDT = &AM.getResult<PostDominatorTreeAnalysis>(F); 191 auto *DF = &AM.getResult<DominanceFrontierAnalysis>(F); 192 193 RI.recalculate(F, DT, PDT, DF); 194 return RI; 195} 196 197RegionInfoPrinterPass::RegionInfoPrinterPass(raw_ostream &OS) 198 : OS(OS) {} 199 200PreservedAnalyses RegionInfoPrinterPass::run(Function &F, 201 FunctionAnalysisManager &AM) { 202 OS << "Region Tree for function: " << F.getName() << "\n"; 203 AM.getResult<RegionInfoAnalysis>(F).print(OS); 204 205 return PreservedAnalyses::all(); 206} 207 208PreservedAnalyses RegionInfoVerifierPass::run(Function &F, 209 FunctionAnalysisManager &AM) { 210 AM.getResult<RegionInfoAnalysis>(F).verifyAnalysis(); 211 212 return PreservedAnalyses::all(); 213} 214