1 //===- RegionInfo.cpp - SESE region detection analysis --------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // Detects single entry single exit regions in the control flow graph. 10 //===----------------------------------------------------------------------===// 11 12 #include "llvm/Analysis/RegionInfo.h" 13 #include "llvm/ADT/PostOrderIterator.h" 14 #include "llvm/ADT/Statistic.h" 15 #include "llvm/Analysis/LoopInfo.h" 16 #include "llvm/Analysis/RegionInfoImpl.h" 17 #include "llvm/Analysis/RegionIterator.h" 18 #include "llvm/IR/PassManager.h" 19 #include "llvm/Support/CommandLine.h" 20 #include "llvm/Support/Debug.h" 21 #include "llvm/Support/ErrorHandling.h" 22 #ifndef NDEBUG 23 #include "llvm/Analysis/RegionPrinter.h" 24 #endif 25 26 using namespace llvm; 27 28 #define DEBUG_TYPE "region" 29 30 namespace llvm { 31 template class RegionBase<RegionTraits<Function>>; 32 template class RegionNodeBase<RegionTraits<Function>>; 33 template class RegionInfoBase<RegionTraits<Function>>; 34 } 35 36 STATISTIC(numRegions, "The # of regions"); 37 STATISTIC(numSimpleRegions, "The # of simple regions"); 38 39 // Always verify if expensive checking is enabled. 40 41 static cl::opt<bool,true> 42 VerifyRegionInfoX( 43 "verify-region-info", 44 cl::location(RegionInfoBase<RegionTraits<Function>>::VerifyRegionInfo), 45 cl::desc("Verify region info (time consuming)")); 46 47 48 static cl::opt<Region::PrintStyle, true> printStyleX("print-region-style", 49 cl::location(RegionInfo::printStyle), 50 cl::Hidden, 51 cl::desc("style of printing regions"), 52 cl::values( 53 clEnumValN(Region::PrintNone, "none", "print no details"), 54 clEnumValN(Region::PrintBB, "bb", 55 "print regions in detail with block_iterator"), 56 clEnumValN(Region::PrintRN, "rn", 57 "print regions in detail with element_iterator"), 58 clEnumValEnd)); 59 60 61 //===----------------------------------------------------------------------===// 62 // Region implementation 63 // 64 65 Region::Region(BasicBlock *Entry, BasicBlock *Exit, 66 RegionInfo* RI, 67 DominatorTree *DT, Region *Parent) : 68 RegionBase<RegionTraits<Function>>(Entry, Exit, RI, DT, Parent) { 69 70 } 71 72 Region::~Region() { } 73 74 //===----------------------------------------------------------------------===// 75 // RegionInfo implementation 76 // 77 78 RegionInfo::RegionInfo() : 79 RegionInfoBase<RegionTraits<Function>>() { 80 81 } 82 83 RegionInfo::~RegionInfo() { 84 85 } 86 87 void 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 95 void 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 108 void RegionInfo::view() { viewRegion(this); } 109 110 void RegionInfo::viewOnly() { viewRegionOnly(this); } 111 #endif 112 113 //===----------------------------------------------------------------------===// 114 // RegionInfoPass implementation 115 // 116 117 RegionInfoPass::RegionInfoPass() : FunctionPass(ID) { 118 initializeRegionInfoPassPass(*PassRegistry::getPassRegistry()); 119 } 120 121 RegionInfoPass::~RegionInfoPass() { 122 123 } 124 125 bool RegionInfoPass::runOnFunction(Function &F) { 126 releaseMemory(); 127 128 auto DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree(); 129 auto PDT = &getAnalysis<PostDominatorTreeWrapperPass>().getPostDomTree(); 130 auto DF = &getAnalysis<DominanceFrontierWrapperPass>().getDominanceFrontier(); 131 132 RI.recalculate(F, DT, PDT, DF); 133 return false; 134 } 135 136 void RegionInfoPass::releaseMemory() { 137 RI.releaseMemory(); 138 } 139 140 void RegionInfoPass::verifyAnalysis() const { 141 RI.verifyAnalysis(); 142 } 143 144 void RegionInfoPass::getAnalysisUsage(AnalysisUsage &AU) const { 145 AU.setPreservesAll(); 146 AU.addRequiredTransitive<DominatorTreeWrapperPass>(); 147 AU.addRequired<PostDominatorTreeWrapperPass>(); 148 AU.addRequired<DominanceFrontierWrapperPass>(); 149 } 150 151 void RegionInfoPass::print(raw_ostream &OS, const Module *) const { 152 RI.print(OS); 153 } 154 155 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 156 LLVM_DUMP_METHOD void RegionInfoPass::dump() const { 157 RI.dump(); 158 } 159 #endif 160 161 char RegionInfoPass::ID = 0; 162 163 INITIALIZE_PASS_BEGIN(RegionInfoPass, "regions", 164 "Detect single entry single exit regions", true, true) 165 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass) 166 INITIALIZE_PASS_DEPENDENCY(PostDominatorTreeWrapperPass) 167 INITIALIZE_PASS_DEPENDENCY(DominanceFrontierWrapperPass) 168 INITIALIZE_PASS_END(RegionInfoPass, "regions", 169 "Detect single entry single exit regions", true, true) 170 171 // Create methods available outside of this file, to use them 172 // "include/llvm/LinkAllPasses.h". Otherwise the pass would be deleted by 173 // the link time optimization. 174 175 namespace llvm { 176 FunctionPass *createRegionInfoPass() { 177 return new RegionInfoPass(); 178 } 179 } 180 181 //===----------------------------------------------------------------------===// 182 // RegionInfoAnalysis implementation 183 // 184 185 char RegionInfoAnalysis::PassID; 186 187 RegionInfo RegionInfoAnalysis::run(Function &F, AnalysisManager<Function> &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 } 196 197 RegionInfoPrinterPass::RegionInfoPrinterPass(raw_ostream &OS) 198 : OS(OS) {} 199 200 PreservedAnalyses 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 } 207 208 PreservedAnalyses RegionInfoVerifierPass::run(Function &F, 209 AnalysisManager<Function> &AM) { 210 AM.getResult<RegionInfoAnalysis>(F).verifyAnalysis(); 211 212 return PreservedAnalyses::all(); 213 } 214
