| //===- LoopExtractor.cpp - Extract each loop into a new function ----------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file was developed by the LLVM research group and is distributed under |
| // the University of Illinois Open Source License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // A pass wrapper around the ExtractLoop() scalar transformation to extract each |
| // top-level loop into its own new function. If the loop is the ONLY loop in a |
| // given function, it is not touched. This is a pass most useful for debugging |
| // via bugpoint. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #define DEBUG_TYPE "loop-extract" |
| #include "llvm/Transforms/IPO.h" |
| #include "llvm/Instructions.h" |
| #include "llvm/Module.h" |
| #include "llvm/Pass.h" |
| #include "llvm/Analysis/Dominators.h" |
| #include "llvm/Analysis/LoopInfo.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Support/Compiler.h" |
| #include "llvm/Transforms/Scalar.h" |
| #include "llvm/Transforms/Utils/FunctionUtils.h" |
| #include "llvm/ADT/Statistic.h" |
| #include <fstream> |
| #include <set> |
| using namespace llvm; |
| |
| STATISTIC(NumExtracted, "Number of loops extracted"); |
| |
| namespace { |
| // FIXME: This is not a function pass, but the PassManager doesn't allow |
| // Module passes to require FunctionPasses, so we can't get loop info if we're |
| // not a function pass. |
| struct VISIBILITY_HIDDEN LoopExtractor : public FunctionPass { |
| static char ID; // Pass identification, replacement for typeid |
| unsigned NumLoops; |
| |
| explicit LoopExtractor(unsigned numLoops = ~0) |
| : FunctionPass((intptr_t)&ID), NumLoops(numLoops) {} |
| |
| virtual bool runOnFunction(Function &F); |
| |
| virtual void getAnalysisUsage(AnalysisUsage &AU) const { |
| AU.addRequiredID(BreakCriticalEdgesID); |
| AU.addRequiredID(LoopSimplifyID); |
| AU.addRequired<DominatorTree>(); |
| AU.addRequired<LoopInfo>(); |
| } |
| }; |
| |
| char LoopExtractor::ID = 0; |
| RegisterPass<LoopExtractor> |
| X("loop-extract", "Extract loops into new functions"); |
| |
| /// SingleLoopExtractor - For bugpoint. |
| struct SingleLoopExtractor : public LoopExtractor { |
| static char ID; // Pass identification, replacement for typeid |
| SingleLoopExtractor() : LoopExtractor(1) {} |
| }; |
| |
| char SingleLoopExtractor::ID = 0; |
| RegisterPass<SingleLoopExtractor> |
| Y("loop-extract-single", "Extract at most one loop into a new function"); |
| } // End anonymous namespace |
| |
| // createLoopExtractorPass - This pass extracts all natural loops from the |
| // program into a function if it can. |
| // |
| FunctionPass *llvm::createLoopExtractorPass() { return new LoopExtractor(); } |
| |
| bool LoopExtractor::runOnFunction(Function &F) { |
| LoopInfo &LI = getAnalysis<LoopInfo>(); |
| |
| // If this function has no loops, there is nothing to do. |
| if (LI.begin() == LI.end()) |
| return false; |
| |
| DominatorTree &DT = getAnalysis<DominatorTree>(); |
| |
| // If there is more than one top-level loop in this function, extract all of |
| // the loops. |
| bool Changed = false; |
| if (LI.end()-LI.begin() > 1) { |
| for (LoopInfo::iterator i = LI.begin(), e = LI.end(); i != e; ++i) { |
| if (NumLoops == 0) return Changed; |
| --NumLoops; |
| Changed |= ExtractLoop(DT, *i) != 0; |
| ++NumExtracted; |
| } |
| } else { |
| // Otherwise there is exactly one top-level loop. If this function is more |
| // than a minimal wrapper around the loop, extract the loop. |
| Loop *TLL = *LI.begin(); |
| bool ShouldExtractLoop = false; |
| |
| // Extract the loop if the entry block doesn't branch to the loop header. |
| TerminatorInst *EntryTI = F.getEntryBlock().getTerminator(); |
| if (!isa<BranchInst>(EntryTI) || |
| !cast<BranchInst>(EntryTI)->isUnconditional() || |
| EntryTI->getSuccessor(0) != TLL->getHeader()) |
| ShouldExtractLoop = true; |
| else { |
| // Check to see if any exits from the loop are more than just return |
| // blocks. |
| SmallVector<BasicBlock*, 8> ExitBlocks; |
| TLL->getExitBlocks(ExitBlocks); |
| for (unsigned i = 0, e = ExitBlocks.size(); i != e; ++i) |
| if (!isa<ReturnInst>(ExitBlocks[i]->getTerminator())) { |
| ShouldExtractLoop = true; |
| break; |
| } |
| } |
| |
| if (ShouldExtractLoop) { |
| if (NumLoops == 0) return Changed; |
| --NumLoops; |
| Changed |= ExtractLoop(DT, TLL) != 0; |
| ++NumExtracted; |
| } else { |
| // Okay, this function is a minimal container around the specified loop. |
| // If we extract the loop, we will continue to just keep extracting it |
| // infinitely... so don't extract it. However, if the loop contains any |
| // subloops, extract them. |
| for (Loop::iterator i = TLL->begin(), e = TLL->end(); i != e; ++i) { |
| if (NumLoops == 0) return Changed; |
| --NumLoops; |
| Changed |= ExtractLoop(DT, *i) != 0; |
| ++NumExtracted; |
| } |
| } |
| } |
| |
| return Changed; |
| } |
| |
| // createSingleLoopExtractorPass - This pass extracts one natural loop from the |
| // program into a function if it can. This is used by bugpoint. |
| // |
| FunctionPass *llvm::createSingleLoopExtractorPass() { |
| return new SingleLoopExtractor(); |
| } |
| |
| |
| namespace { |
| // BlockFile - A file which contains a list of blocks that should not be |
| // extracted. |
| cl::opt<std::string> |
| BlockFile("extract-blocks-file", cl::value_desc("filename"), |
| cl::desc("A file containing list of basic blocks to not extract"), |
| cl::Hidden); |
| |
| /// BlockExtractorPass - This pass is used by bugpoint to extract all blocks |
| /// from the module into their own functions except for those specified by the |
| /// BlocksToNotExtract list. |
| class BlockExtractorPass : public ModulePass { |
| void LoadFile(const char *Filename); |
| |
| std::vector<BasicBlock*> BlocksToNotExtract; |
| std::vector<std::pair<std::string, std::string> > BlocksToNotExtractByName; |
| public: |
| static char ID; // Pass identification, replacement for typeid |
| explicit BlockExtractorPass(const std::vector<BasicBlock*> &B) |
| : ModulePass((intptr_t)&ID), BlocksToNotExtract(B) { |
| if (!BlockFile.empty()) |
| LoadFile(BlockFile.c_str()); |
| } |
| BlockExtractorPass() : ModulePass((intptr_t)&ID) {} |
| |
| bool runOnModule(Module &M); |
| }; |
| |
| char BlockExtractorPass::ID = 0; |
| RegisterPass<BlockExtractorPass> |
| XX("extract-blocks", "Extract Basic Blocks From Module (for bugpoint use)"); |
| } |
| |
| // createBlockExtractorPass - This pass extracts all blocks (except those |
| // specified in the argument list) from the functions in the module. |
| // |
| ModulePass *llvm::createBlockExtractorPass(const std::vector<BasicBlock*> &BTNE) |
| { |
| return new BlockExtractorPass(BTNE); |
| } |
| |
| void BlockExtractorPass::LoadFile(const char *Filename) { |
| // Load the BlockFile... |
| std::ifstream In(Filename); |
| if (!In.good()) { |
| cerr << "WARNING: BlockExtractor couldn't load file '" << Filename |
| << "'!\n"; |
| return; |
| } |
| while (In) { |
| std::string FunctionName, BlockName; |
| In >> FunctionName; |
| In >> BlockName; |
| if (!BlockName.empty()) |
| BlocksToNotExtractByName.push_back( |
| std::make_pair(FunctionName, BlockName)); |
| } |
| } |
| |
| bool BlockExtractorPass::runOnModule(Module &M) { |
| std::set<BasicBlock*> TranslatedBlocksToNotExtract; |
| for (unsigned i = 0, e = BlocksToNotExtract.size(); i != e; ++i) { |
| BasicBlock *BB = BlocksToNotExtract[i]; |
| Function *F = BB->getParent(); |
| |
| // Map the corresponding function in this module. |
| Function *MF = M.getFunction(F->getName()); |
| assert(MF->getFunctionType() == F->getFunctionType() && "Wrong function?"); |
| |
| // Figure out which index the basic block is in its function. |
| Function::iterator BBI = MF->begin(); |
| std::advance(BBI, std::distance(F->begin(), Function::iterator(BB))); |
| TranslatedBlocksToNotExtract.insert(BBI); |
| } |
| |
| while (!BlocksToNotExtractByName.empty()) { |
| // There's no way to find BBs by name without looking at every BB inside |
| // every Function. Fortunately, this is always empty except when used by |
| // bugpoint in which case correctness is more important than performance. |
| |
| std::string &FuncName = BlocksToNotExtractByName.back().first; |
| std::string &BlockName = BlocksToNotExtractByName.back().second; |
| |
| for (Module::iterator FI = M.begin(), FE = M.end(); FI != FE; ++FI) { |
| Function &F = *FI; |
| if (F.getName() != FuncName) continue; |
| |
| for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE; ++BI) { |
| BasicBlock &BB = *BI; |
| if (BB.getName() != BlockName) continue; |
| |
| TranslatedBlocksToNotExtract.insert(BI); |
| } |
| } |
| |
| BlocksToNotExtractByName.pop_back(); |
| } |
| |
| // Now that we know which blocks to not extract, figure out which ones we WANT |
| // to extract. |
| std::vector<BasicBlock*> BlocksToExtract; |
| for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) |
| for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) |
| if (!TranslatedBlocksToNotExtract.count(BB)) |
| BlocksToExtract.push_back(BB); |
| |
| for (unsigned i = 0, e = BlocksToExtract.size(); i != e; ++i) |
| ExtractBasicBlock(BlocksToExtract[i]); |
| |
| return !BlocksToExtract.empty(); |
| } |