1 //===- RegionPass.cpp - Region Pass and Region Pass Manager ---------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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
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"
22 #define DEBUG_TYPE "regionpassmgr"
24 //===----------------------------------------------------------------------===//
28 char RGPassManager::ID = 0;
30 RGPassManager::RGPassManager()
31 : FunctionPass(ID), PMDataManager() {
32 skipThisRegion = false;
33 redoThisRegion = false;
35 CurrentRegion = nullptr;
38 // Recurse through all subregions and all regions into RQ.
39 static void addRegionIntoQueue(Region &R, std::deque<Region *> &RQ) {
41 for (const auto &E : R)
42 addRegionIntoQueue(*E, RQ);
45 /// Pass Manager itself does not invalidate any analysis info.
46 void RGPassManager::getAnalysisUsage(AnalysisUsage &Info) const {
47 Info.addRequired<RegionInfoPass>();
48 Info.setPreservesAll();
51 /// run - Execute all of the passes scheduled for execution. Keep track of
52 /// whether any of the passes modifies the function, and if so, return true.
53 bool RGPassManager::runOnFunction(Function &F) {
54 RI = &getAnalysis<RegionInfoPass>().getRegionInfo();
57 // Collect inherited analysis from Module level pass manager.
58 populateInheritedAnalysis(TPM->activeStack);
60 addRegionIntoQueue(*RI->getTopLevelRegion(), RQ);
62 if (RQ.empty()) // No regions, skip calling finalizers
66 for (std::deque<Region *>::const_iterator I = RQ.begin(), E = RQ.end();
69 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
70 RegionPass *RP = (RegionPass *)getContainedPass(Index);
71 Changed |= RP->doInitialization(R, *this);
78 CurrentRegion = RQ.back();
79 skipThisRegion = false;
80 redoThisRegion = false;
82 // Run all passes on the current Region.
83 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
84 RegionPass *P = (RegionPass*)getContainedPass(Index);
86 if (isPassDebuggingExecutionsOrMore()) {
87 dumpPassInfo(P, EXECUTION_MSG, ON_REGION_MSG,
88 CurrentRegion->getNameStr());
92 initializeAnalysisImpl(P);
95 PassManagerPrettyStackEntry X(P, *CurrentRegion->getEntry());
97 TimeRegion PassTimer(getPassTimer(P));
98 Changed |= P->runOnRegion(CurrentRegion, *this);
101 if (isPassDebuggingExecutionsOrMore()) {
103 dumpPassInfo(P, MODIFICATION_MSG, ON_REGION_MSG,
104 skipThisRegion ? "<deleted>" :
105 CurrentRegion->getNameStr());
109 if (!skipThisRegion) {
110 // Manually check that this region is still healthy. This is done
111 // instead of relying on RegionInfo::verifyRegion since RegionInfo
112 // is a function pass and it's really expensive to verify every
113 // Region in the function every time. That level of checking can be
114 // enabled with the -verify-region-info option.
116 TimeRegion PassTimer(getPassTimer(P));
117 CurrentRegion->verifyRegion();
120 // Then call the regular verifyAnalysis functions.
121 verifyPreservedAnalysis(P);
124 removeNotPreservedAnalysis(P);
125 recordAvailableAnalysis(P);
127 (!isPassDebuggingExecutionsOrMore() || skipThisRegion) ?
128 "<deleted>" : CurrentRegion->getNameStr(),
132 // Do not run other passes on this region.
136 // If the region was deleted, release all the region passes. This frees up
137 // some memory, and avoids trouble with the pass manager trying to call
138 // verifyAnalysis on them.
140 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
141 Pass *P = getContainedPass(Index);
142 freePass(P, "<deleted>", ON_REGION_MSG);
145 // Pop the region from queue after running all passes.
149 RQ.push_back(CurrentRegion);
151 // Free all region nodes created in region passes.
152 RI->clearNodeCache();
156 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
157 RegionPass *P = (RegionPass*)getContainedPass(Index);
158 Changed |= P->doFinalization();
161 // Print the region tree after all pass.
163 dbgs() << "\nRegion tree of function " << F.getName()
164 << " after all region Pass:\n";
172 /// Print passes managed by this manager
173 void RGPassManager::dumpPassStructure(unsigned Offset) {
174 errs().indent(Offset*2) << "Region Pass Manager\n";
175 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
176 Pass *P = getContainedPass(Index);
177 P->dumpPassStructure(Offset + 1);
178 dumpLastUses(P, Offset+1);
183 //===----------------------------------------------------------------------===//
185 class PrintRegionPass : public RegionPass {
188 raw_ostream &Out; // raw_ostream to print on.
192 PrintRegionPass(const std::string &B, raw_ostream &o)
193 : RegionPass(ID), Banner(B), Out(o) {}
195 void getAnalysisUsage(AnalysisUsage &AU) const override {
196 AU.setPreservesAll();
199 bool runOnRegion(Region *R, RGPassManager &RGM) override {
201 for (const auto &BB : R->blocks()) {
205 Out << "Printing <null> Block";
212 char PrintRegionPass::ID = 0;
213 } //end anonymous namespace
215 //===----------------------------------------------------------------------===//
218 // Check if this pass is suitable for the current RGPassManager, if
219 // available. This pass P is not suitable for a RGPassManager if P
220 // is not preserving higher level analysis info used by other
221 // RGPassManager passes. In such case, pop RGPassManager from the
222 // stack. This will force assignPassManager() to create new
223 // LPPassManger as expected.
224 void RegionPass::preparePassManager(PMStack &PMS) {
226 // Find RGPassManager
227 while (!PMS.empty() &&
228 PMS.top()->getPassManagerType() > PMT_RegionPassManager)
232 // If this pass is destroying high level information that is used
233 // by other passes that are managed by LPM then do not insert
234 // this pass in current LPM. Use new RGPassManager.
235 if (PMS.top()->getPassManagerType() == PMT_RegionPassManager &&
236 !PMS.top()->preserveHigherLevelAnalysis(this))
240 /// Assign pass manager to manage this pass.
241 void RegionPass::assignPassManager(PMStack &PMS,
242 PassManagerType PreferredType) {
243 // Find RGPassManager
244 while (!PMS.empty() &&
245 PMS.top()->getPassManagerType() > PMT_RegionPassManager)
250 // Create new Region Pass Manager if it does not exist.
251 if (PMS.top()->getPassManagerType() == PMT_RegionPassManager)
252 RGPM = (RGPassManager*)PMS.top();
255 assert (!PMS.empty() && "Unable to create Region Pass Manager");
256 PMDataManager *PMD = PMS.top();
258 // [1] Create new Region Pass Manager
259 RGPM = new RGPassManager();
260 RGPM->populateInheritedAnalysis(PMS);
262 // [2] Set up new manager's top level manager
263 PMTopLevelManager *TPM = PMD->getTopLevelManager();
264 TPM->addIndirectPassManager(RGPM);
266 // [3] Assign manager to manage this new manager. This may create
267 // and push new managers into PMS
268 TPM->schedulePass(RGPM);
270 // [4] Push new manager into PMS
277 /// Get the printer pass
278 Pass *RegionPass::createPrinterPass(raw_ostream &O,
279 const std::string &Banner) const {
280 return new PrintRegionPass(Banner, O);