X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTransforms%2FIPO%2FLoopExtractor.cpp;h=cb813303facb9de95a7df8b993d63bfddbfcc96d;hb=03e896bd6073efc4523d8bcd0239d6ed62126db7;hp=480f0f7c03d79bf818c4aebd0d377c5ab57880a1;hpb=efddcfa0df921ebca3e316120480df7df3e6e405;p=oota-llvm.git diff --git a/lib/Transforms/IPO/LoopExtractor.cpp b/lib/Transforms/IPO/LoopExtractor.cpp index 480f0f7c03d..cb813303fac 100644 --- a/lib/Transforms/IPO/LoopExtractor.cpp +++ b/lib/Transforms/IPO/LoopExtractor.cpp @@ -1,10 +1,10 @@ //===- 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. -// +// This file 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 @@ -14,56 +14,229 @@ // //===----------------------------------------------------------------------===// +#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/LoopInfo.h" +#include "llvm/Analysis/Dominators.h" +#include "llvm/Analysis/LoopPass.h" +#include "llvm/Support/CommandLine.h" #include "llvm/Transforms/Scalar.h" #include "llvm/Transforms/Utils/FunctionUtils.h" -#include +#include "llvm/ADT/Statistic.h" +#include +#include using namespace llvm; +STATISTIC(NumExtracted, "Number of loops extracted"); + namespace { - // FIXME: PassManager should allow Module passes to require FunctionPasses - struct LoopExtractor : public FunctionPass { - virtual bool run(Module &M); - virtual bool runOnFunction(Function &F); - + struct LoopExtractor : public LoopPass { + static char ID; // Pass identification, replacement for typeid + unsigned NumLoops; + + explicit LoopExtractor(unsigned numLoops = ~0) + : LoopPass(&ID), NumLoops(numLoops) {} + + virtual bool runOnLoop(Loop *L, LPPassManager &LPM); + virtual void getAnalysisUsage(AnalysisUsage &AU) const { - AU.addRequired(); + AU.addRequiredID(BreakCriticalEdgesID); + AU.addRequiredID(LoopSimplifyID); + AU.addRequired(); } }; +} - RegisterOpt - X("loop-extract", "Extract loops into new functions"); -} // End anonymous namespace +char LoopExtractor::ID = 0; +static RegisterPass +X("loop-extract", "Extract loops into new functions"); -bool LoopExtractor::run(Module &M) { - bool Changed = false; - for (Module::iterator i = M.begin(), e = M.end(); i != e; ++i) - Changed |= runOnFunction(*i); - return Changed; -} +namespace { + /// SingleLoopExtractor - For bugpoint. + struct SingleLoopExtractor : public LoopExtractor { + static char ID; // Pass identification, replacement for typeid + SingleLoopExtractor() : LoopExtractor(1) {} + }; +} // End anonymous namespace -bool LoopExtractor::runOnFunction(Function &F) { - std::cerr << F.getName() << "\n"; +char SingleLoopExtractor::ID = 0; +static RegisterPass +Y("loop-extract-single", "Extract at most one loop into a new function"); - LoopInfo &LI = getAnalysis(); +// createLoopExtractorPass - This pass extracts all natural loops from the +// program into a function if it can. +// +Pass *llvm::createLoopExtractorPass() { return new LoopExtractor(); } + +bool LoopExtractor::runOnLoop(Loop *L, LPPassManager &LPM) { + // Only visit top-level loops. + if (L->getParentLoop()) + return false; - // We don't want to keep extracting the only loop of a function into a new one - if (LI.begin() == LI.end() || LI.begin() + 1 == LI.end()) + // If LoopSimplify form is not available, stay out of trouble. + if (!L->isLoopSimplifyForm()) return false; + DominatorTree &DT = getAnalysis(); bool Changed = false; - // Try to move each loop out of the code into separate function - for (LoopInfo::iterator i = LI.begin(), e = LI.end(); i != e; ++i) - Changed |= (ExtractLoop(*i) != 0); + // If there is more than one top-level loop in this function, extract all of + // the loops. Otherwise there is exactly one top-level loop; in this case if + // this function is more than a minimal wrapper around the loop, extract + // the loop. + bool ShouldExtractLoop = false; + + // Extract the loop if the entry block doesn't branch to the loop header. + TerminatorInst *EntryTI = + L->getHeader()->getParent()->getEntryBlock().getTerminator(); + if (!isa(EntryTI) || + !cast(EntryTI)->isUnconditional() || + EntryTI->getSuccessor(0) != L->getHeader()) + ShouldExtractLoop = true; + else { + // Check to see if any exits from the loop are more than just return + // blocks. + SmallVector ExitBlocks; + L->getExitBlocks(ExitBlocks); + for (unsigned i = 0, e = ExitBlocks.size(); i != e; ++i) + if (!isa(ExitBlocks[i]->getTerminator())) { + ShouldExtractLoop = true; + break; + } + } + if (ShouldExtractLoop) { + if (NumLoops == 0) return Changed; + --NumLoops; + if (ExtractLoop(DT, L) != 0) { + Changed = true; + // After extraction, the loop is replaced by a function call, so + // we shouldn't try to run any more loop passes on it. + LPM.deleteLoopFromQueue(L); + } + ++NumExtracted; + } return Changed; } -/// createLoopExtractorPass -/// -FunctionPass* llvm::createLoopExtractorPass() { - return new LoopExtractor(); +// createSingleLoopExtractorPass - This pass extracts one natural loop from the +// program into a function if it can. This is used by bugpoint. +// +Pass *llvm::createSingleLoopExtractorPass() { + return new SingleLoopExtractor(); +} + + +// BlockFile - A file which contains a list of blocks that should not be +// extracted. +static cl::opt +BlockFile("extract-blocks-file", cl::value_desc("filename"), + cl::desc("A file containing list of basic blocks to not extract"), + cl::Hidden); + +namespace { + /// 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 BlocksToNotExtract; + std::vector > BlocksToNotExtractByName; + public: + static char ID; // Pass identification, replacement for typeid + explicit BlockExtractorPass(const std::vector &B) + : ModulePass(&ID), BlocksToNotExtract(B) { + if (!BlockFile.empty()) + LoadFile(BlockFile.c_str()); + } + BlockExtractorPass() : ModulePass(&ID) {} + + bool runOnModule(Module &M); + }; +} + +char BlockExtractorPass::ID = 0; +static RegisterPass +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 &BTNE) +{ + return new BlockExtractorPass(BTNE); +} + +void BlockExtractorPass::LoadFile(const char *Filename) { + // Load the BlockFile... + std::ifstream In(Filename); + if (!In.good()) { + errs() << "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 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 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(); }