1 //===- RegionPass.cpp - Region Pass and Region Pass Manager ---------------===// 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 // 10 // This file implements RegionPass and RGPassManager. All region optimization 11 // and transformation passes are derived from RegionPass. RGPassManager is 12 // responsible for managing RegionPasses. 13 // most of these codes are COPY from LoopPass.cpp 14 // 15 //===----------------------------------------------------------------------===// 16 #include "llvm/Analysis/RegionPass.h" 17 #include "llvm/Analysis/RegionIterator.h" 18 #include "llvm/Support/Debug.h" 19 #include "llvm/Support/Timer.h" 20 #include "llvm/Support/raw_ostream.h" 21 using namespace llvm; 22 23 #define DEBUG_TYPE "regionpassmgr" 24 25 //===----------------------------------------------------------------------===// 26 // RGPassManager 27 // 28 29 char RGPassManager::ID = 0; 30 31 RGPassManager::RGPassManager() 32 : FunctionPass(ID), PMDataManager() { 33 skipThisRegion = false; 34 redoThisRegion = false; 35 RI = nullptr; 36 CurrentRegion = nullptr; 37 } 38 39 // Recurse through all subregions and all regions into RQ. 40 static void addRegionIntoQueue(Region &R, std::deque<Region *> &RQ) { 41 RQ.push_back(&R); 42 for (const auto &E : R) 43 addRegionIntoQueue(*E, RQ); 44 } 45 46 /// Pass Manager itself does not invalidate any analysis info. 47 void RGPassManager::getAnalysisUsage(AnalysisUsage &Info) const { 48 Info.addRequired<RegionInfoPass>(); 49 Info.setPreservesAll(); 50 } 51 52 /// run - Execute all of the passes scheduled for execution. Keep track of 53 /// whether any of the passes modifies the function, and if so, return true. 54 bool RGPassManager::runOnFunction(Function &F) { 55 RI = &getAnalysis<RegionInfoPass>().getRegionInfo(); 56 bool Changed = false; 57 58 // Collect inherited analysis from Module level pass manager. 59 populateInheritedAnalysis(TPM->activeStack); 60 61 addRegionIntoQueue(*RI->getTopLevelRegion(), RQ); 62 63 if (RQ.empty()) // No regions, skip calling finalizers 64 return false; 65 66 // Initialization 67 for (std::deque<Region *>::const_iterator I = RQ.begin(), E = RQ.end(); 68 I != E; ++I) { 69 Region *R = *I; 70 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) { 71 RegionPass *RP = (RegionPass *)getContainedPass(Index); 72 Changed |= RP->doInitialization(R, *this); 73 } 74 } 75 76 // Walk Regions 77 while (!RQ.empty()) { 78 79 CurrentRegion = RQ.back(); 80 skipThisRegion = false; 81 redoThisRegion = false; 82 83 // Run all passes on the current Region. 84 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) { 85 RegionPass *P = (RegionPass*)getContainedPass(Index); 86 87 if (isPassDebuggingExecutionsOrMore()) { 88 dumpPassInfo(P, EXECUTION_MSG, ON_REGION_MSG, 89 CurrentRegion->getNameStr()); 90 dumpRequiredSet(P); 91 } 92 93 initializeAnalysisImpl(P); 94 95 { 96 PassManagerPrettyStackEntry X(P, *CurrentRegion->getEntry()); 97 98 TimeRegion PassTimer(getPassTimer(P)); 99 Changed |= P->runOnRegion(CurrentRegion, *this); 100 } 101 102 if (isPassDebuggingExecutionsOrMore()) { 103 if (Changed) 104 dumpPassInfo(P, MODIFICATION_MSG, ON_REGION_MSG, 105 skipThisRegion ? "<deleted>" : 106 CurrentRegion->getNameStr()); 107 dumpPreservedSet(P); 108 } 109 110 if (!skipThisRegion) { 111 // Manually check that this region is still healthy. This is done 112 // instead of relying on RegionInfo::verifyRegion since RegionInfo 113 // is a function pass and it's really expensive to verify every 114 // Region in the function every time. That level of checking can be 115 // enabled with the -verify-region-info option. 116 { 117 TimeRegion PassTimer(getPassTimer(P)); 118 CurrentRegion->verifyRegion(); 119 } 120 121 // Then call the regular verifyAnalysis functions. 122 verifyPreservedAnalysis(P); 123 } 124 125 removeNotPreservedAnalysis(P); 126 recordAvailableAnalysis(P); 127 removeDeadPasses(P, 128 (!isPassDebuggingExecutionsOrMore() || skipThisRegion) ? 129 "<deleted>" : CurrentRegion->getNameStr(), 130 ON_REGION_MSG); 131 132 if (skipThisRegion) 133 // Do not run other passes on this region. 134 break; 135 } 136 137 // If the region was deleted, release all the region passes. This frees up 138 // some memory, and avoids trouble with the pass manager trying to call 139 // verifyAnalysis on them. 140 if (skipThisRegion) 141 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) { 142 Pass *P = getContainedPass(Index); 143 freePass(P, "<deleted>", ON_REGION_MSG); 144 } 145 146 // Pop the region from queue after running all passes. 147 RQ.pop_back(); 148 149 if (redoThisRegion) 150 RQ.push_back(CurrentRegion); 151 152 // Free all region nodes created in region passes. 153 RI->clearNodeCache(); 154 } 155 156 // Finalization 157 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) { 158 RegionPass *P = (RegionPass*)getContainedPass(Index); 159 Changed |= P->doFinalization(); 160 } 161 162 // Print the region tree after all pass. 163 DEBUG( 164 dbgs() << "\nRegion tree of function " << F.getName() 165 << " after all region Pass:\n"; 166 RI->dump(); 167 dbgs() << "\n"; 168 ); 169 170 return Changed; 171 } 172 173 /// Print passes managed by this manager 174 void RGPassManager::dumpPassStructure(unsigned Offset) { 175 errs().indent(Offset*2) << "Region Pass Manager\n"; 176 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) { 177 Pass *P = getContainedPass(Index); 178 P->dumpPassStructure(Offset + 1); 179 dumpLastUses(P, Offset+1); 180 } 181 } 182 183 namespace { 184 //===----------------------------------------------------------------------===// 185 // PrintRegionPass 186 class PrintRegionPass : public RegionPass { 187 private: 188 std::string Banner; 189 raw_ostream &Out; // raw_ostream to print on. 190 191 public: 192 static char ID; 193 PrintRegionPass(const std::string &B, raw_ostream &o) 194 : RegionPass(ID), Banner(B), Out(o) {} 195 196 void getAnalysisUsage(AnalysisUsage &AU) const override { 197 AU.setPreservesAll(); 198 } 199 200 bool runOnRegion(Region *R, RGPassManager &RGM) override { 201 Out << Banner; 202 for (const auto *BB : R->blocks()) { 203 if (BB) 204 BB->print(Out); 205 else 206 Out << "Printing <null> Block"; 207 } 208 209 return false; 210 } 211 }; 212 213 char PrintRegionPass::ID = 0; 214 } //end anonymous namespace 215 216 //===----------------------------------------------------------------------===// 217 // RegionPass 218 219 // Check if this pass is suitable for the current RGPassManager, if 220 // available. This pass P is not suitable for a RGPassManager if P 221 // is not preserving higher level analysis info used by other 222 // RGPassManager passes. In such case, pop RGPassManager from the 223 // stack. This will force assignPassManager() to create new 224 // LPPassManger as expected. 225 void RegionPass::preparePassManager(PMStack &PMS) { 226 227 // Find RGPassManager 228 while (!PMS.empty() && 229 PMS.top()->getPassManagerType() > PMT_RegionPassManager) 230 PMS.pop(); 231 232 233 // If this pass is destroying high level information that is used 234 // by other passes that are managed by LPM then do not insert 235 // this pass in current LPM. Use new RGPassManager. 236 if (PMS.top()->getPassManagerType() == PMT_RegionPassManager && 237 !PMS.top()->preserveHigherLevelAnalysis(this)) 238 PMS.pop(); 239 } 240 241 /// Assign pass manager to manage this pass. 242 void RegionPass::assignPassManager(PMStack &PMS, 243 PassManagerType PreferredType) { 244 // Find RGPassManager 245 while (!PMS.empty() && 246 PMS.top()->getPassManagerType() > PMT_RegionPassManager) 247 PMS.pop(); 248 249 RGPassManager *RGPM; 250 251 // Create new Region Pass Manager if it does not exist. 252 if (PMS.top()->getPassManagerType() == PMT_RegionPassManager) 253 RGPM = (RGPassManager*)PMS.top(); 254 else { 255 256 assert (!PMS.empty() && "Unable to create Region Pass Manager"); 257 PMDataManager *PMD = PMS.top(); 258 259 // [1] Create new Region Pass Manager 260 RGPM = new RGPassManager(); 261 RGPM->populateInheritedAnalysis(PMS); 262 263 // [2] Set up new manager's top level manager 264 PMTopLevelManager *TPM = PMD->getTopLevelManager(); 265 TPM->addIndirectPassManager(RGPM); 266 267 // [3] Assign manager to manage this new manager. This may create 268 // and push new managers into PMS 269 TPM->schedulePass(RGPM); 270 271 // [4] Push new manager into PMS 272 PMS.push(RGPM); 273 } 274 275 RGPM->add(this); 276 } 277 278 /// Get the printer pass 279 Pass *RegionPass::createPrinterPass(raw_ostream &O, 280 const std::string &Banner) const { 281 return new PrintRegionPass(Banner, O); 282 } 283