RegionPass.cpp revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f
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/Timer.h" 19 20#include "llvm/Support/Debug.h" 21using namespace llvm; 22 23#define DEBUG_TYPE "regionpassmgr" 24 25//===----------------------------------------------------------------------===// 26// RGPassManager 27// 28 29char RGPassManager::ID = 0; 30 31RGPassManager::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. 40static 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. 47void RGPassManager::getAnalysisUsage(AnalysisUsage &Info) const { 48 Info.addRequired<RegionInfo>(); 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. 54bool RGPassManager::runOnFunction(Function &F) { 55 RI = &getAnalysis<RegionInfo>(); 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 dumpPassInfo(P, EXECUTION_MSG, ON_REGION_MSG, 88 CurrentRegion->getNameStr()); 89 dumpRequiredSet(P); 90 91 initializeAnalysisImpl(P); 92 93 { 94 PassManagerPrettyStackEntry X(P, *CurrentRegion->getEntry()); 95 96 TimeRegion PassTimer(getPassTimer(P)); 97 Changed |= P->runOnRegion(CurrentRegion, *this); 98 } 99 100 if (Changed) 101 dumpPassInfo(P, MODIFICATION_MSG, ON_REGION_MSG, 102 skipThisRegion ? "<deleted>" : 103 CurrentRegion->getNameStr()); 104 dumpPreservedSet(P); 105 106 if (!skipThisRegion) { 107 // Manually check that this region is still healthy. This is done 108 // instead of relying on RegionInfo::verifyRegion since RegionInfo 109 // is a function pass and it's really expensive to verify every 110 // Region in the function every time. That level of checking can be 111 // enabled with the -verify-region-info option. 112 { 113 TimeRegion PassTimer(getPassTimer(P)); 114 CurrentRegion->verifyRegion(); 115 } 116 117 // Then call the regular verifyAnalysis functions. 118 verifyPreservedAnalysis(P); 119 } 120 121 removeNotPreservedAnalysis(P); 122 recordAvailableAnalysis(P); 123 removeDeadPasses(P, 124 skipThisRegion ? "<deleted>" : 125 CurrentRegion->getNameStr(), 126 ON_REGION_MSG); 127 128 if (skipThisRegion) 129 // Do not run other passes on this region. 130 break; 131 } 132 133 // If the region was deleted, release all the region passes. This frees up 134 // some memory, and avoids trouble with the pass manager trying to call 135 // verifyAnalysis on them. 136 if (skipThisRegion) 137 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) { 138 Pass *P = getContainedPass(Index); 139 freePass(P, "<deleted>", ON_REGION_MSG); 140 } 141 142 // Pop the region from queue after running all passes. 143 RQ.pop_back(); 144 145 if (redoThisRegion) 146 RQ.push_back(CurrentRegion); 147 148 // Free all region nodes created in region passes. 149 RI->clearNodeCache(); 150 } 151 152 // Finalization 153 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) { 154 RegionPass *P = (RegionPass*)getContainedPass(Index); 155 Changed |= P->doFinalization(); 156 } 157 158 // Print the region tree after all pass. 159 DEBUG( 160 dbgs() << "\nRegion tree of function " << F.getName() 161 << " after all region Pass:\n"; 162 RI->dump(); 163 dbgs() << "\n"; 164 ); 165 166 return Changed; 167} 168 169/// Print passes managed by this manager 170void RGPassManager::dumpPassStructure(unsigned Offset) { 171 errs().indent(Offset*2) << "Region Pass Manager\n"; 172 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) { 173 Pass *P = getContainedPass(Index); 174 P->dumpPassStructure(Offset + 1); 175 dumpLastUses(P, Offset+1); 176 } 177} 178 179namespace { 180//===----------------------------------------------------------------------===// 181// PrintRegionPass 182class PrintRegionPass : public RegionPass { 183private: 184 std::string Banner; 185 raw_ostream &Out; // raw_ostream to print on. 186 187public: 188 static char ID; 189 PrintRegionPass(const std::string &B, raw_ostream &o) 190 : RegionPass(ID), Banner(B), Out(o) {} 191 192 void getAnalysisUsage(AnalysisUsage &AU) const override { 193 AU.setPreservesAll(); 194 } 195 196 bool runOnRegion(Region *R, RGPassManager &RGM) override { 197 Out << Banner; 198 for (const auto &BB : R->blocks()) 199 BB->print(Out); 200 201 return false; 202 } 203}; 204 205char PrintRegionPass::ID = 0; 206} //end anonymous namespace 207 208//===----------------------------------------------------------------------===// 209// RegionPass 210 211// Check if this pass is suitable for the current RGPassManager, if 212// available. This pass P is not suitable for a RGPassManager if P 213// is not preserving higher level analysis info used by other 214// RGPassManager passes. In such case, pop RGPassManager from the 215// stack. This will force assignPassManager() to create new 216// LPPassManger as expected. 217void RegionPass::preparePassManager(PMStack &PMS) { 218 219 // Find RGPassManager 220 while (!PMS.empty() && 221 PMS.top()->getPassManagerType() > PMT_RegionPassManager) 222 PMS.pop(); 223 224 225 // If this pass is destroying high level information that is used 226 // by other passes that are managed by LPM then do not insert 227 // this pass in current LPM. Use new RGPassManager. 228 if (PMS.top()->getPassManagerType() == PMT_RegionPassManager && 229 !PMS.top()->preserveHigherLevelAnalysis(this)) 230 PMS.pop(); 231} 232 233/// Assign pass manager to manage this pass. 234void RegionPass::assignPassManager(PMStack &PMS, 235 PassManagerType PreferredType) { 236 // Find RGPassManager 237 while (!PMS.empty() && 238 PMS.top()->getPassManagerType() > PMT_RegionPassManager) 239 PMS.pop(); 240 241 RGPassManager *RGPM; 242 243 // Create new Region Pass Manager if it does not exist. 244 if (PMS.top()->getPassManagerType() == PMT_RegionPassManager) 245 RGPM = (RGPassManager*)PMS.top(); 246 else { 247 248 assert (!PMS.empty() && "Unable to create Region Pass Manager"); 249 PMDataManager *PMD = PMS.top(); 250 251 // [1] Create new Region Pass Manager 252 RGPM = new RGPassManager(); 253 RGPM->populateInheritedAnalysis(PMS); 254 255 // [2] Set up new manager's top level manager 256 PMTopLevelManager *TPM = PMD->getTopLevelManager(); 257 TPM->addIndirectPassManager(RGPM); 258 259 // [3] Assign manager to manage this new manager. This may create 260 // and push new managers into PMS 261 TPM->schedulePass(RGPM); 262 263 // [4] Push new manager into PMS 264 PMS.push(RGPM); 265 } 266 267 RGPM->add(this); 268} 269 270/// Get the printer pass 271Pass *RegionPass::createPrinterPass(raw_ostream &O, 272 const std::string &Banner) const { 273 return new PrintRegionPass(Banner, O); 274} 275