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 this code has been COPIED from LoopPass.cpp
15 //===----------------------------------------------------------------------===//
16 #include "llvm/Analysis/RegionPass.h"
17 #include "llvm/IR/OptBisect.h"
18 #include "llvm/Support/Debug.h"
19 #include "llvm/Support/Timer.h"
20 #include "llvm/Support/raw_ostream.h"
23 #define DEBUG_TYPE "regionpassmgr"
25 //===----------------------------------------------------------------------===//
29 char RGPassManager::ID = 0;
31 RGPassManager::RGPassManager()
32 : FunctionPass(ID), PMDataManager() {
33 skipThisRegion = false;
34 redoThisRegion = false;
36 CurrentRegion = nullptr;
39 // Recurse through all subregions and all regions into RQ.
40 static void addRegionIntoQueue(Region &R, std::deque<Region *> &RQ) {
42 for (const auto &E : R)
43 addRegionIntoQueue(*E, RQ);
46 /// Pass Manager itself does not invalidate any analysis info.
47 void RGPassManager::getAnalysisUsage(AnalysisUsage &Info) const {
48 Info.addRequired<RegionInfoPass>();
49 Info.setPreservesAll();
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();
58 // Collect inherited analysis from Module level pass manager.
59 populateInheritedAnalysis(TPM->activeStack);
61 addRegionIntoQueue(*RI->getTopLevelRegion(), RQ);
63 if (RQ.empty()) // No regions, skip calling finalizers
67 for (Region *R : RQ) {
68 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
69 RegionPass *RP = (RegionPass *)getContainedPass(Index);
70 Changed |= RP->doInitialization(R, *this);
77 CurrentRegion = RQ.back();
78 skipThisRegion = false;
79 redoThisRegion = false;
81 // Run all passes on the current Region.
82 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
83 RegionPass *P = (RegionPass*)getContainedPass(Index);
85 if (isPassDebuggingExecutionsOrMore()) {
86 dumpPassInfo(P, EXECUTION_MSG, ON_REGION_MSG,
87 CurrentRegion->getNameStr());
91 initializeAnalysisImpl(P);
94 PassManagerPrettyStackEntry X(P, *CurrentRegion->getEntry());
96 TimeRegion PassTimer(getPassTimer(P));
97 Changed |= P->runOnRegion(CurrentRegion, *this);
100 if (isPassDebuggingExecutionsOrMore()) {
102 dumpPassInfo(P, MODIFICATION_MSG, ON_REGION_MSG,
103 skipThisRegion ? "<deleted>" :
104 CurrentRegion->getNameStr());
108 if (!skipThisRegion) {
109 // Manually check that this region is still healthy. This is done
110 // instead of relying on RegionInfo::verifyRegion since RegionInfo
111 // is a function pass and it's really expensive to verify every
112 // Region in the function every time. That level of checking can be
113 // enabled with the -verify-region-info option.
115 TimeRegion PassTimer(getPassTimer(P));
116 CurrentRegion->verifyRegion();
119 // Then call the regular verifyAnalysis functions.
120 verifyPreservedAnalysis(P);
123 removeNotPreservedAnalysis(P);
124 recordAvailableAnalysis(P);
126 (!isPassDebuggingExecutionsOrMore() || skipThisRegion) ?
127 "<deleted>" : CurrentRegion->getNameStr(),
131 // Do not run other passes on this region.
135 // If the region was deleted, release all the region passes. This frees up
136 // some memory, and avoids trouble with the pass manager trying to call
137 // verifyAnalysis on them.
139 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
140 Pass *P = getContainedPass(Index);
141 freePass(P, "<deleted>", ON_REGION_MSG);
144 // Pop the region from queue after running all passes.
148 RQ.push_back(CurrentRegion);
150 // Free all region nodes created in region passes.
151 RI->clearNodeCache();
155 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
156 RegionPass *P = (RegionPass*)getContainedPass(Index);
157 Changed |= P->doFinalization();
160 // Print the region tree after all pass.
162 dbgs() << "\nRegion tree of function " << F.getName()
163 << " after all region Pass:\n";
171 /// Print passes managed by this manager
172 void RGPassManager::dumpPassStructure(unsigned Offset) {
173 errs().indent(Offset*2) << "Region Pass Manager\n";
174 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
175 Pass *P = getContainedPass(Index);
176 P->dumpPassStructure(Offset + 1);
177 dumpLastUses(P, Offset+1);
182 //===----------------------------------------------------------------------===//
184 class PrintRegionPass : public RegionPass {
187 raw_ostream &Out; // raw_ostream to print on.
191 PrintRegionPass(const std::string &B, raw_ostream &o)
192 : RegionPass(ID), Banner(B), Out(o) {}
194 void getAnalysisUsage(AnalysisUsage &AU) const override {
195 AU.setPreservesAll();
198 bool runOnRegion(Region *R, RGPassManager &RGM) override {
200 for (const auto *BB : R->blocks()) {
204 Out << "Printing <null> Block";
210 StringRef getPassName() const override { return "Print Region IR"; }
213 char PrintRegionPass::ID = 0;
214 } //end anonymous namespace
216 //===----------------------------------------------------------------------===//
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) {
227 // Find RGPassManager
228 while (!PMS.empty() &&
229 PMS.top()->getPassManagerType() > PMT_RegionPassManager)
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))
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)
251 // Create new Region Pass Manager if it does not exist.
252 if (PMS.top()->getPassManagerType() == PMT_RegionPassManager)
253 RGPM = (RGPassManager*)PMS.top();
256 assert (!PMS.empty() && "Unable to create Region Pass Manager");
257 PMDataManager *PMD = PMS.top();
259 // [1] Create new Region Pass Manager
260 RGPM = new RGPassManager();
261 RGPM->populateInheritedAnalysis(PMS);
263 // [2] Set up new manager's top level manager
264 PMTopLevelManager *TPM = PMD->getTopLevelManager();
265 TPM->addIndirectPassManager(RGPM);
267 // [3] Assign manager to manage this new manager. This may create
268 // and push new managers into PMS
269 TPM->schedulePass(RGPM);
271 // [4] Push new manager into PMS
278 /// Get the printer pass
279 Pass *RegionPass::createPrinterPass(raw_ostream &O,
280 const std::string &Banner) const {
281 return new PrintRegionPass(Banner, O);
284 bool RegionPass::skipRegion(Region &R) const {
285 Function &F = *R.getEntry()->getParent();
286 if (!F.getContext().getOptBisect().shouldRunPass(this, R))
289 if (F.hasFnAttribute(Attribute::OptimizeNone)) {
290 // Report this only once per function.
291 if (R.getEntry() == &F.getEntryBlock())
292 DEBUG(dbgs() << "Skipping pass '" << getPassName()
293 << "' on function " << F.getName() << "\n");