Members/tobaru/cbc/CbC_llvm: lib/Analysis/RegionInfo.cpp comparison

comparison lib/Analysis/RegionInfo.cpp @ 0:95c75e76d11b

LLVM 3.4

author	Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
date	Thu, 12 Dec 2013 13:56:28 +0900
parents
children	54457678186b

comparison

equal deleted inserted replaced

--1:000000000000
+:95c75e76d11b
+//===- RegionInfo.cpp - SESE region detection analysis --------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// Detects single entry single exit regions in the control flow graph.
+//===----------------------------------------------------------------------===//
+#define DEBUG_TYPE "region"
+#include "llvm/Analysis/RegionInfo.h"
+#include "llvm/ADT/PostOrderIterator.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Analysis/RegionIterator.h"
+#include "llvm/Assembly/Writer.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/Debug.h"
+#include <algorithm>
+#include <set>
+using namespace llvm;
+// Always verify if expensive checking is enabled.
+#ifdef XDEBUG
+static bool VerifyRegionInfo = true;
+#else
+static bool VerifyRegionInfo = false;
+#endif
+static cl::opt<bool,true>
+VerifyRegionInfoX("verify-region-info", cl::location(VerifyRegionInfo),
+cl::desc("Verify region info (time consuming)"));
+STATISTIC(numRegions,       "The # of regions");
+STATISTIC(numSimpleRegions, "The # of simple regions");
+static cl::opt<enum Region::PrintStyle> printStyle("print-region-style",
+cl::Hidden,
+cl::desc("style of printing regions"),
+cl::values(
+clEnumValN(Region::PrintNone, "none",  "print no details"),
+clEnumValN(Region::PrintBB, "bb",
+"print regions in detail with block_iterator"),
+clEnumValN(Region::PrintRN, "rn",
+"print regions in detail with element_iterator"),
+clEnumValEnd));
+//===----------------------------------------------------------------------===//
+/// Region Implementation
+Region::Region(BasicBlock *Entry, BasicBlock *Exit, RegionInfo* RInfo,
+DominatorTree *dt, Region *Parent)
+: RegionNode(Parent, Entry, 1), RI(RInfo), DT(dt), exit(Exit) {}
+Region::~Region() {
+// Free the cached nodes.
+for (BBNodeMapT::iterator it = BBNodeMap.begin(),
+ie = BBNodeMap.end(); it != ie; ++it)
+delete it->second;
+// Only clean the cache for this Region. Caches of child Regions will be
+// cleaned when the child Regions are deleted.
+BBNodeMap.clear();
+for (iterator I = begin(), E = end(); I != E; ++I)
+delete *I;
+}
+void Region::replaceEntry(BasicBlock *BB) {
+entry.setPointer(BB);
+}
+void Region::replaceExit(BasicBlock *BB) {
+assert(exit && "No exit to replace!");
+exit = BB;
+}
+void Region::replaceEntryRecursive(BasicBlock *NewEntry) {
+std::vector<Region *> RegionQueue;
+BasicBlock *OldEntry = getEntry();
+RegionQueue.push_back(this);
+while (!RegionQueue.empty()) {
+Region *R = RegionQueue.back();
+RegionQueue.pop_back();
+R->replaceEntry(NewEntry);
+for (Region::const_iterator RI = R->begin(), RE = R->end(); RI != RE; ++RI)
+if ((*RI)->getEntry() == OldEntry)
+RegionQueue.push_back(*RI);
+}
+}
+void Region::replaceExitRecursive(BasicBlock *NewExit) {
+std::vector<Region *> RegionQueue;
+BasicBlock *OldExit = getExit();
+RegionQueue.push_back(this);
+while (!RegionQueue.empty()) {
+Region *R = RegionQueue.back();
+RegionQueue.pop_back();
+R->replaceExit(NewExit);
+for (Region::const_iterator RI = R->begin(), RE = R->end(); RI != RE; ++RI)
+if ((*RI)->getExit() == OldExit)
+RegionQueue.push_back(*RI);
+}
+}
+bool Region::contains(const BasicBlock *B) const {
+BasicBlock *BB = const_cast<BasicBlock*>(B);
+if (!DT->getNode(BB))
+return false;
+BasicBlock *entry = getEntry(), *exit = getExit();
+// Toplevel region.
+if (!exit)
+return true;
+return (DT->dominates(entry, BB)
+&& !(DT->dominates(exit, BB) && DT->dominates(entry, exit)));
+}
+bool Region::contains(const Loop *L) const {
+// BBs that are not part of any loop are element of the Loop
+// described by the NULL pointer. This loop is not part of any region,
+// except if the region describes the whole function.
+if (L == 0)
+return getExit() == 0;
+if (!contains(L->getHeader()))
+return false;
+SmallVector<BasicBlock *, 8> ExitingBlocks;
+L->getExitingBlocks(ExitingBlocks);
+for (SmallVectorImpl<BasicBlock*>::iterator BI = ExitingBlocks.begin(),
+BE = ExitingBlocks.end(); BI != BE; ++BI)
+if (!contains(*BI))
+return false;
+return true;
+}
+Loop *Region::outermostLoopInRegion(Loop *L) const {
+if (!contains(L))
+return 0;
+while (L && contains(L->getParentLoop())) {
+L = L->getParentLoop();
+}
+return L;
+}
+Loop *Region::outermostLoopInRegion(LoopInfo *LI, BasicBlock* BB) const {
+assert(LI && BB && "LI and BB cannot be null!");
+Loop *L = LI->getLoopFor(BB);
+return outermostLoopInRegion(L);
+}
+BasicBlock *Region::getEnteringBlock() const {
+BasicBlock *entry = getEntry();
+BasicBlock *Pred;
+BasicBlock *enteringBlock = 0;
+for (pred_iterator PI = pred_begin(entry), PE = pred_end(entry); PI != PE;
+++PI) {
+Pred = *PI;
+if (DT->getNode(Pred) && !contains(Pred)) {
+if (enteringBlock)
+return 0;
+enteringBlock = Pred;
+}
+}
+return enteringBlock;
+}
+BasicBlock *Region::getExitingBlock() const {
+BasicBlock *exit = getExit();
+BasicBlock *Pred;
+BasicBlock *exitingBlock = 0;
+if (!exit)
+return 0;
+for (pred_iterator PI = pred_begin(exit), PE = pred_end(exit); PI != PE;
+++PI) {
+Pred = *PI;
+if (contains(Pred)) {
+if (exitingBlock)
+return 0;
+exitingBlock = Pred;
+}
+}
+return exitingBlock;
+}
+bool Region::isSimple() const {
+return !isTopLevelRegion() && getEnteringBlock() && getExitingBlock();
+}
+std::string Region::getNameStr() const {
+std::string exitName;
+std::string entryName;
+if (getEntry()->getName().empty()) {
+raw_string_ostream OS(entryName);
+WriteAsOperand(OS, getEntry(), false);
+} else
+entryName = getEntry()->getName();
+if (getExit()) {
+if (getExit()->getName().empty()) {
+raw_string_ostream OS(exitName);
+WriteAsOperand(OS, getExit(), false);
+} else
+exitName = getExit()->getName();
+} else
+exitName = "<Function Return>";
+return entryName + " => " + exitName;
+}
+void Region::verifyBBInRegion(BasicBlock *BB) const {
+if (!contains(BB))
+llvm_unreachable("Broken region found!");
+BasicBlock *entry = getEntry(), *exit = getExit();
+for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB); SI != SE; ++SI)
+if (!contains(*SI) && exit != *SI)
+llvm_unreachable("Broken region found!");
+if (entry != BB)
+for (pred_iterator SI = pred_begin(BB), SE = pred_end(BB); SI != SE; ++SI)
+if (!contains(*SI))
+llvm_unreachable("Broken region found!");
+}
+void Region::verifyWalk(BasicBlock *BB, std::set<BasicBlock*> *visited) const {
+BasicBlock *exit = getExit();
+visited->insert(BB);
+verifyBBInRegion(BB);
+for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB); SI != SE; ++SI)
+if (*SI != exit && visited->find(*SI) == visited->end())
+verifyWalk(*SI, visited);
+}
+void Region::verifyRegion() const {
+// Only do verification when user wants to, otherwise this expensive
+// check will be invoked by PassManager.
+if (!VerifyRegionInfo) return;
+std::set<BasicBlock*> visited;
+verifyWalk(getEntry(), &visited);
+}
+void Region::verifyRegionNest() const {
+for (Region::const_iterator RI = begin(), RE = end(); RI != RE; ++RI)
+(*RI)->verifyRegionNest();
+verifyRegion();
+}
+Region::element_iterator Region::element_begin() {
+return GraphTraits<Region*>::nodes_begin(this);
+}
+Region::element_iterator Region::element_end() {
+return GraphTraits<Region*>::nodes_end(this);
+}
+Region::const_element_iterator Region::element_begin() const {
+return GraphTraits<const Region*>::nodes_begin(this);
+}
+Region::const_element_iterator Region::element_end() const {
+return GraphTraits<const Region*>::nodes_end(this);
+}
+Region* Region::getSubRegionNode(BasicBlock *BB) const {
+Region *R = RI->getRegionFor(BB);
+if (!R || R == this)
+return 0;
+// If we pass the BB out of this region, that means our code is broken.
+assert(contains(R) && "BB not in current region!");
+while (contains(R->getParent()) && R->getParent() != this)
+R = R->getParent();
+if (R->getEntry() != BB)
+return 0;
+return R;
+}
+RegionNode* Region::getBBNode(BasicBlock *BB) const {
+assert(contains(BB) && "Can get BB node out of this region!");
+BBNodeMapT::const_iterator at = BBNodeMap.find(BB);
+if (at != BBNodeMap.end())
+return at->second;
+RegionNode *NewNode = new RegionNode(const_cast<Region*>(this), BB);
+BBNodeMap.insert(std::make_pair(BB, NewNode));
+return NewNode;
+}
+RegionNode* Region::getNode(BasicBlock *BB) const {
+assert(contains(BB) && "Can get BB node out of this region!");
+if (Region* Child = getSubRegionNode(BB))
+return Child->getNode();
+return getBBNode(BB);
+}
+void Region::transferChildrenTo(Region *To) {
+for (iterator I = begin(), E = end(); I != E; ++I) {
+(*I)->parent = To;
+To->children.push_back(*I);
+}
+children.clear();
+}
+void Region::addSubRegion(Region *SubRegion, bool moveChildren) {
+assert(SubRegion->parent == 0 && "SubRegion already has a parent!");
+assert(std::find(begin(), end(), SubRegion) == children.end()
+&& "Subregion already exists!");
+SubRegion->parent = this;
+children.push_back(SubRegion);
+if (!moveChildren)
+return;
+assert(SubRegion->children.size() == 0
+&& "SubRegions that contain children are not supported");
+for (element_iterator I = element_begin(), E = element_end(); I != E; ++I)
+if (!(*I)->isSubRegion()) {
+BasicBlock *BB = (*I)->getNodeAs<BasicBlock>();
+if (SubRegion->contains(BB))
+RI->setRegionFor(BB, SubRegion);
+}
+std::vector<Region*> Keep;
+for (iterator I = begin(), E = end(); I != E; ++I)
+if (SubRegion->contains(*I) && *I != SubRegion) {
+SubRegion->children.push_back(*I);
+(*I)->parent = SubRegion;
+} else
+Keep.push_back(*I);
+children.clear();
+children.insert(children.begin(), Keep.begin(), Keep.end());
+}
+Region *Region::removeSubRegion(Region *Child) {
+assert(Child->parent == this && "Child is not a child of this region!");
+Child->parent = 0;
+RegionSet::iterator I = std::find(children.begin(), children.end(), Child);
+assert(I != children.end() && "Region does not exit. Unable to remove.");
+children.erase(children.begin()+(I-begin()));
+return Child;
+}
+unsigned Region::getDepth() const {
+unsigned Depth = 0;
+for (Region *R = parent; R != 0; R = R->parent)
+++Depth;
+return Depth;
+}
+Region *Region::getExpandedRegion() const {
+unsigned NumSuccessors = exit->getTerminator()->getNumSuccessors();
+if (NumSuccessors == 0)
+return NULL;
+for (pred_iterator PI = pred_begin(getExit()), PE = pred_end(getExit());
+PI != PE; ++PI)
+if (!DT->dominates(getEntry(), *PI))
+return NULL;
+Region *R = RI->getRegionFor(exit);
+if (R->getEntry() != exit) {
+if (exit->getTerminator()->getNumSuccessors() == 1)
+return new Region(getEntry(), *succ_begin(exit), RI, DT);
+else
+return NULL;
+}
+while (R->getParent() && R->getParent()->getEntry() == exit)
+R = R->getParent();
+if (!DT->dominates(getEntry(), R->getExit()))
+for (pred_iterator PI = pred_begin(getExit()), PE = pred_end(getExit());
+PI != PE; ++PI)
+if (!DT->dominates(R->getExit(), *PI))
+return NULL;
+return new Region(getEntry(), R->getExit(), RI, DT);
+}
+void Region::print(raw_ostream &OS, bool print_tree, unsigned level,
+enum PrintStyle Style) const {
+if (print_tree)
+OS.indent(level*2) << "[" << level << "] " << getNameStr();
+else
+OS.indent(level*2) << getNameStr();
+OS << "\n";
+if (Style != PrintNone) {
+OS.indent(level*2) << "{\n";
+OS.indent(level*2 + 2);
+if (Style == PrintBB) {
+for (const_block_iterator I = block_begin(), E = block_end(); I != E; ++I)
+OS << (*I)->getName() << ", "; // TODO: remove the last ","
+} else if (Style == PrintRN) {
+for (const_element_iterator I = element_begin(), E = element_end(); I!=E; ++I)
+OS << **I << ", "; // TODO: remove the last ",
+}
+OS << "\n";
+}
+if (print_tree)
+for (const_iterator RI = begin(), RE = end(); RI != RE; ++RI)
+(*RI)->print(OS, print_tree, level+1, Style);
+if (Style != PrintNone)
+OS.indent(level*2) << "} \n";
+}
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+void Region::dump() const {
+print(dbgs(), true, getDepth(), printStyle.getValue());
+}
+#endif
+void Region::clearNodeCache() {
+// Free the cached nodes.
+for (BBNodeMapT::iterator I = BBNodeMap.begin(),
+IE = BBNodeMap.end(); I != IE; ++I)
+delete I->second;
+BBNodeMap.clear();
+for (Region::iterator RI = begin(), RE = end(); RI != RE; ++RI)
+(*RI)->clearNodeCache();
+}
+//===----------------------------------------------------------------------===//
+// RegionInfo implementation
+//
+bool RegionInfo::isCommonDomFrontier(BasicBlock *BB, BasicBlock *entry,
+BasicBlock *exit) const {
+for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB); PI != PE; ++PI) {
+BasicBlock *P = *PI;
+if (DT->dominates(entry, P) && !DT->dominates(exit, P))
+return false;
+}
+return true;
+}
+bool RegionInfo::isRegion(BasicBlock *entry, BasicBlock *exit) const {
+assert(entry && exit && "entry and exit must not be null!");
+typedef DominanceFrontier::DomSetType DST;
+DST *entrySuccs = &DF->find(entry)->second;
+// Exit is the header of a loop that contains the entry. In this case,
+// the dominance frontier must only contain the exit.
+if (!DT->dominates(entry, exit)) {
+for (DST::iterator SI = entrySuccs->begin(), SE = entrySuccs->end();
+SI != SE; ++SI)
+if (*SI != exit && *SI != entry)
+return false;
+return true;
+}
+DST *exitSuccs = &DF->find(exit)->second;
+// Do not allow edges leaving the region.
+for (DST::iterator SI = entrySuccs->begin(), SE = entrySuccs->end();
+SI != SE; ++SI) {
+if (*SI == exit || *SI == entry)
+continue;
+if (exitSuccs->find(*SI) == exitSuccs->end())
+return false;
+if (!isCommonDomFrontier(*SI, entry, exit))
+return false;
+}
+// Do not allow edges pointing into the region.
+for (DST::iterator SI = exitSuccs->begin(), SE = exitSuccs->end();
+SI != SE; ++SI)
+if (DT->properlyDominates(entry, *SI) && *SI != exit)
+return false;
+return true;
+}
+void RegionInfo::insertShortCut(BasicBlock *entry, BasicBlock *exit,
+BBtoBBMap *ShortCut) const {
+assert(entry && exit && "entry and exit must not be null!");
+BBtoBBMap::iterator e = ShortCut->find(exit);
+if (e == ShortCut->end())
+// No further region at exit available.
+(*ShortCut)[entry] = exit;
+else {
+// We found a region e that starts at exit. Therefore (entry, e->second)
+// is also a region, that is larger than (entry, exit). Insert the
+// larger one.
+BasicBlock *BB = e->second;
+(*ShortCut)[entry] = BB;
+}
+}
+DomTreeNode* RegionInfo::getNextPostDom(DomTreeNode* N,
+BBtoBBMap *ShortCut) const {
+BBtoBBMap::iterator e = ShortCut->find(N->getBlock());
+if (e == ShortCut->end())
+return N->getIDom();
+return PDT->getNode(e->second)->getIDom();
+}
+bool RegionInfo::isTrivialRegion(BasicBlock *entry, BasicBlock *exit) const {
+assert(entry && exit && "entry and exit must not be null!");
+unsigned num_successors = succ_end(entry) - succ_begin(entry);
+if (num_successors <= 1 && exit == *(succ_begin(entry)))
+return true;
+return false;
+}
+void RegionInfo::updateStatistics(Region *R) {
+++numRegions;
+// TODO: Slow. Should only be enabled if -stats is used.
+if (R->isSimple()) ++numSimpleRegions;
+}
+Region *RegionInfo::createRegion(BasicBlock *entry, BasicBlock *exit) {
+assert(entry && exit && "entry and exit must not be null!");
+if (isTrivialRegion(entry, exit))
+return 0;
+Region *region = new Region(entry, exit, this, DT);
+BBtoRegion.insert(std::make_pair(entry, region));
+#ifdef XDEBUG
+region->verifyRegion();
+#else
+DEBUG(region->verifyRegion());
+#endif
+updateStatistics(region);
+return region;
+}
+void RegionInfo::findRegionsWithEntry(BasicBlock *entry, BBtoBBMap *ShortCut) {
+assert(entry);
+DomTreeNode *N = PDT->getNode(entry);
+if (!N)
+return;
+Region *lastRegion= 0;
+BasicBlock *lastExit = entry;
+// As only a BasicBlock that postdominates entry can finish a region, walk the
+// post dominance tree upwards.
+while ((N = getNextPostDom(N, ShortCut))) {
+BasicBlock *exit = N->getBlock();
+if (!exit)
+break;
+if (isRegion(entry, exit)) {
+Region *newRegion = createRegion(entry, exit);
+if (lastRegion)
+newRegion->addSubRegion(lastRegion);
+lastRegion = newRegion;
+lastExit = exit;
+}
+// This can never be a region, so stop the search.
+if (!DT->dominates(entry, exit))
+break;
+}
+// Tried to create regions from entry to lastExit.  Next time take a
+// shortcut from entry to lastExit.
+if (lastExit != entry)
+insertShortCut(entry, lastExit, ShortCut);
+}
+void RegionInfo::scanForRegions(Function &F, BBtoBBMap *ShortCut) {
+BasicBlock *entry = &(F.getEntryBlock());
+DomTreeNode *N = DT->getNode(entry);
+// Iterate over the dominance tree in post order to start with the small
+// regions from the bottom of the dominance tree.  If the small regions are
+// detected first, detection of bigger regions is faster, as we can jump
+// over the small regions.
+for (po_iterator<DomTreeNode*> FI = po_begin(N), FE = po_end(N); FI != FE;
+++FI) {
+findRegionsWithEntry(FI->getBlock(), ShortCut);
+}
+}
+Region *RegionInfo::getTopMostParent(Region *region) {
+while (region->parent)
+region = region->getParent();
+return region;
+}
+void RegionInfo::buildRegionsTree(DomTreeNode *N, Region *region) {
+BasicBlock *BB = N->getBlock();
+// Passed region exit
+while (BB == region->getExit())
+region = region->getParent();
+BBtoRegionMap::iterator it = BBtoRegion.find(BB);
+// This basic block is a start block of a region. It is already in the
+// BBtoRegion relation. Only the child basic blocks have to be updated.
+if (it != BBtoRegion.end()) {
+Region *newRegion = it->second;
+region->addSubRegion(getTopMostParent(newRegion));
+region = newRegion;
+} else {
+BBtoRegion[BB] = region;
+}
+for (DomTreeNode::iterator CI = N->begin(), CE = N->end(); CI != CE; ++CI)
+buildRegionsTree(*CI, region);
+}
+void RegionInfo::releaseMemory() {
+BBtoRegion.clear();
+if (TopLevelRegion)
+delete TopLevelRegion;
+TopLevelRegion = 0;
+}
+RegionInfo::RegionInfo() : FunctionPass(ID) {
+initializeRegionInfoPass(*PassRegistry::getPassRegistry());
+TopLevelRegion = 0;
+}
+RegionInfo::~RegionInfo() {
+releaseMemory();
+}
+void RegionInfo::Calculate(Function &F) {
+// ShortCut a function where for every BB the exit of the largest region
+// starting with BB is stored. These regions can be threated as single BBS.
+// This improves performance on linear CFGs.
+BBtoBBMap ShortCut;
+scanForRegions(F, &ShortCut);
+BasicBlock *BB = &F.getEntryBlock();
+buildRegionsTree(DT->getNode(BB), TopLevelRegion);
+}
+bool RegionInfo::runOnFunction(Function &F) {
+releaseMemory();
+DT = &getAnalysis<DominatorTree>();
+PDT = &getAnalysis<PostDominatorTree>();
+DF = &getAnalysis<DominanceFrontier>();
+TopLevelRegion = new Region(&F.getEntryBlock(), 0, this, DT, 0);
+updateStatistics(TopLevelRegion);
+Calculate(F);
+return false;
+}
+void RegionInfo::getAnalysisUsage(AnalysisUsage &AU) const {
+AU.setPreservesAll();
+AU.addRequiredTransitive<DominatorTree>();
+AU.addRequired<PostDominatorTree>();
+AU.addRequired<DominanceFrontier>();
+}
+void RegionInfo::print(raw_ostream &OS, const Module *) const {
+OS << "Region tree:\n";
+TopLevelRegion->print(OS, true, 0, printStyle.getValue());
+OS << "End region tree\n";
+}
+void RegionInfo::verifyAnalysis() const {
+// Only do verification when user wants to, otherwise this expensive check
+// will be invoked by PMDataManager::verifyPreservedAnalysis when
+// a regionpass (marked PreservedAll) finish.
+if (!VerifyRegionInfo) return;
+TopLevelRegion->verifyRegionNest();
+}
+// Region pass manager support.
+Region *RegionInfo::getRegionFor(BasicBlock *BB) const {
+BBtoRegionMap::const_iterator I=
+BBtoRegion.find(BB);
+return I != BBtoRegion.end() ? I->second : 0;
+}
+void RegionInfo::setRegionFor(BasicBlock *BB, Region *R) {
+BBtoRegion[BB] = R;
+}
+Region *RegionInfo::operator[](BasicBlock *BB) const {
+return getRegionFor(BB);
+}
+BasicBlock *RegionInfo::getMaxRegionExit(BasicBlock *BB) const {
+BasicBlock *Exit = NULL;
+while (true) {
+// Get largest region that starts at BB.
+Region *R = getRegionFor(BB);
+while (R && R->getParent() && R->getParent()->getEntry() == BB)
+R = R->getParent();
+// Get the single exit of BB.
+if (R && R->getEntry() == BB)
+Exit = R->getExit();
+else if (++succ_begin(BB) == succ_end(BB))
+Exit = *succ_begin(BB);
+else // No single exit exists.
+return Exit;
+// Get largest region that starts at Exit.
+Region *ExitR = getRegionFor(Exit);
+while (ExitR && ExitR->getParent()
+&& ExitR->getParent()->getEntry() == Exit)
+ExitR = ExitR->getParent();
+for (pred_iterator PI = pred_begin(Exit), PE = pred_end(Exit); PI != PE;
+++PI)
+if (!R->contains(*PI) && !ExitR->contains(*PI))
+break;
+// This stops infinite cycles.
+if (DT->dominates(Exit, BB))
+break;
+BB = Exit;
+}
+return Exit;
+}
+Region*
+RegionInfo::getCommonRegion(Region *A, Region *B) const {
+assert (A && B && "One of the Regions is NULL");
+if (A->contains(B)) return A;
+while (!B->contains(A))
+B = B->getParent();
+return B;
+}
+Region*
+RegionInfo::getCommonRegion(SmallVectorImpl<Region*> &Regions) const {
+Region* ret = Regions.back();
+Regions.pop_back();
+for (SmallVectorImpl<Region*>::const_iterator I = Regions.begin(),
+E = Regions.end(); I != E; ++I)
+ret = getCommonRegion(ret, *I);
+return ret;
+}
+Region*
+RegionInfo::getCommonRegion(SmallVectorImpl<BasicBlock*> &BBs) const {
+Region* ret = getRegionFor(BBs.back());
+BBs.pop_back();
+for (SmallVectorImpl<BasicBlock*>::const_iterator I = BBs.begin(),
+E = BBs.end(); I != E; ++I)
+ret = getCommonRegion(ret, getRegionFor(*I));
+return ret;
+}
+void RegionInfo::splitBlock(BasicBlock* NewBB, BasicBlock *OldBB)
+{
+Region *R = getRegionFor(OldBB);
+setRegionFor(NewBB, R);
+while (R->getEntry() == OldBB && !R->isTopLevelRegion()) {
+R->replaceEntry(NewBB);
+R = R->getParent();
+}
+setRegionFor(OldBB, R);
+}
+char RegionInfo::ID = 0;
+INITIALIZE_PASS_BEGIN(RegionInfo, "regions",
+"Detect single entry single exit regions", true, true)
+INITIALIZE_PASS_DEPENDENCY(DominatorTree)
+INITIALIZE_PASS_DEPENDENCY(PostDominatorTree)
+INITIALIZE_PASS_DEPENDENCY(DominanceFrontier)
+INITIALIZE_PASS_END(RegionInfo, "regions",
+"Detect single entry single exit regions", true, true)
+// Create methods available outside of this file, to use them
+// "include/llvm/LinkAllPasses.h". Otherwise the pass would be deleted by
+// the link time optimization.
+namespace llvm {
+FunctionPass *createRegionInfoPass() {
+return new RegionInfo();
+}
+}

Mercurial > hg > Members > tobaru > cbc > CbC_llvm

comparison lib/Analysis/RegionInfo.cpp @ 0:95c75e76d11b