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/Analysis/DominanceFrontier.h" 14#include "llvm/InitializePasses.h" 15#ifndef NDEBUG 16#include "llvm/Analysis/RegionPrinter.h" 17#endif 18#include "llvm/Analysis/RegionInfoImpl.h" 19#include "llvm/Config/llvm-config.h" 20#include "llvm/IR/Function.h" 21#include "llvm/Support/CommandLine.h" 22#include "llvm/Support/Compiler.h" 23 24using namespace llvm; 25 26#define DEBUG_TYPE "region" 27 28namespace llvm { 29 30template class RegionBase<RegionTraits<Function>>; 31template class RegionNodeBase<RegionTraits<Function>>; 32template class RegionInfoBase<RegionTraits<Function>>; 33 34} // end namespace llvm 35 36STATISTIC(numRegions, "The # of regions"); 37STATISTIC(numSimpleRegions, "The # of simple regions"); 38 39// Always verify if expensive checking is enabled. 40 41static cl::opt<bool,true> 42VerifyRegionInfoX( 43 "verify-region-info", 44 cl::location(RegionInfoBase<RegionTraits<Function>>::VerifyRegionInfo), 45 cl::desc("Verify region info (time consuming)")); 46 47static cl::opt<Region::PrintStyle, true> printStyleX("print-region-style", 48 cl::location(RegionInfo::printStyle), 49 cl::Hidden, 50 cl::desc("style of printing regions"), 51 cl::values( 52 clEnumValN(Region::PrintNone, "none", "print no details"), 53 clEnumValN(Region::PrintBB, "bb", 54 "print regions in detail with block_iterator"), 55 clEnumValN(Region::PrintRN, "rn", 56 "print regions in detail with element_iterator"))); 57 58//===----------------------------------------------------------------------===// 59// Region implementation 60// 61 62Region::Region(BasicBlock *Entry, BasicBlock *Exit, 63 RegionInfo* RI, 64 DominatorTree *DT, Region *Parent) : 65 RegionBase<RegionTraits<Function>>(Entry, Exit, RI, DT, Parent) { 66 67} 68 69Region::~Region() = default; 70 71//===----------------------------------------------------------------------===// 72// RegionInfo implementation 73// 74 75RegionInfo::RegionInfo() = default; 76 77RegionInfo::~RegionInfo() = default; 78 79bool RegionInfo::invalidate(Function &F, const PreservedAnalyses &PA, 80 FunctionAnalysisManager::Invalidator &) { 81 // Check whether the analysis, all analyses on functions, or the function's 82 // CFG has been preserved. 83 auto PAC = PA.getChecker<RegionInfoAnalysis>(); 84 return !(PAC.preserved() || PAC.preservedSet<AllAnalysesOn<Function>>() || 85 PAC.preservedSet<CFGAnalyses>()); 86} 87 88void RegionInfo::updateStatistics(Region *R) { 89 ++numRegions; 90 91 // TODO: Slow. Should only be enabled if -stats is used. 92 if (R->isSimple()) 93 ++numSimpleRegions; 94} 95 96void RegionInfo::recalculate(Function &F, DominatorTree *DT_, 97 PostDominatorTree *PDT_, DominanceFrontier *DF_) { 98 DT = DT_; 99 PDT = PDT_; 100 DF = DF_; 101 102 TopLevelRegion = new Region(&F.getEntryBlock(), nullptr, 103 this, DT, nullptr); 104 updateStatistics(TopLevelRegion); 105 calculate(F); 106} 107 108#ifndef NDEBUG 109void RegionInfo::view() { viewRegion(this); } 110 111void RegionInfo::viewOnly() { viewRegionOnly(this); } 112#endif 113 114//===----------------------------------------------------------------------===// 115// RegionInfoPass implementation 116// 117 118RegionInfoPass::RegionInfoPass() : FunctionPass(ID) { 119 initializeRegionInfoPassPass(*PassRegistry::getPassRegistry()); 120} 121 122RegionInfoPass::~RegionInfoPass() = default; 123 124bool RegionInfoPass::runOnFunction(Function &F) { 125 releaseMemory(); 126 127 auto DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree(); 128 auto PDT = &getAnalysis<PostDominatorTreeWrapperPass>().getPostDomTree(); 129 auto DF = &getAnalysis<DominanceFrontierWrapperPass>().getDominanceFrontier(); 130 131 RI.recalculate(F, DT, PDT, DF); 132 return false; 133} 134 135void RegionInfoPass::releaseMemory() { 136 RI.releaseMemory(); 137} 138 139void RegionInfoPass::verifyAnalysis() const { 140 RI.verifyAnalysis(); 141} 142 143void RegionInfoPass::getAnalysisUsage(AnalysisUsage &AU) const { 144 AU.setPreservesAll(); 145 AU.addRequiredTransitive<DominatorTreeWrapperPass>(); 146 AU.addRequired<PostDominatorTreeWrapperPass>(); 147 AU.addRequired<DominanceFrontierWrapperPass>(); 148} 149 150void RegionInfoPass::print(raw_ostream &OS, const Module *) const { 151 RI.print(OS); 152} 153 154#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 155LLVM_DUMP_METHOD void RegionInfoPass::dump() const { 156 RI.dump(); 157} 158#endif 159 160char RegionInfoPass::ID = 0; 161 162INITIALIZE_PASS_BEGIN(RegionInfoPass, "regions", 163 "Detect single entry single exit regions", true, true) 164INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass) 165INITIALIZE_PASS_DEPENDENCY(PostDominatorTreeWrapperPass) 166INITIALIZE_PASS_DEPENDENCY(DominanceFrontierWrapperPass) 167INITIALIZE_PASS_END(RegionInfoPass, "regions", 168 "Detect single entry single exit regions", true, true) 169 170// Create methods available outside of this file, to use them 171// "include/llvm/LinkAllPasses.h". Otherwise the pass would be deleted by 172// the link time optimization. 173 174namespace llvm { 175 176 FunctionPass *createRegionInfoPass() { 177 return new RegionInfoPass(); 178 } 179 180} // end namespace llvm 181 182//===----------------------------------------------------------------------===// 183// RegionInfoAnalysis implementation 184// 185 186AnalysisKey RegionInfoAnalysis::Key; 187 188RegionInfo RegionInfoAnalysis::run(Function &F, FunctionAnalysisManager &AM) { 189 RegionInfo RI; 190 auto *DT = &AM.getResult<DominatorTreeAnalysis>(F); 191 auto *PDT = &AM.getResult<PostDominatorTreeAnalysis>(F); 192 auto *DF = &AM.getResult<DominanceFrontierAnalysis>(F); 193 194 RI.recalculate(F, DT, PDT, DF); 195 return RI; 196} 197 198RegionInfoPrinterPass::RegionInfoPrinterPass(raw_ostream &OS) 199 : OS(OS) {} 200 201PreservedAnalyses RegionInfoPrinterPass::run(Function &F, 202 FunctionAnalysisManager &AM) { 203 OS << "Region Tree for function: " << F.getName() << "\n"; 204 AM.getResult<RegionInfoAnalysis>(F).print(OS); 205 206 return PreservedAnalyses::all(); 207} 208 209PreservedAnalyses RegionInfoVerifierPass::run(Function &F, 210 FunctionAnalysisManager &AM) { 211 AM.getResult<RegionInfoAnalysis>(F).verifyAnalysis(); 212 213 return PreservedAnalyses::all(); 214} 215