//===- 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
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/IPO.h"
-#include "llvm/iTerminators.h"
-#include "llvm/Module.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/LoopPass.h"
+#include "llvm/IR/Dominators.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Module.h"
#include "llvm/Pass.h"
-#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Support/CommandLine.h"
#include "llvm/Transforms/Scalar.h"
-#include "llvm/Transforms/Utils/FunctionUtils.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/CodeExtractor.h"
+#include <fstream>
+#include <set>
using namespace llvm;
+#define DEBUG_TYPE "loop-extract"
+
+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 LoopExtractor : public FunctionPass {
+ struct LoopExtractor : public LoopPass {
+ static char ID; // Pass identification, replacement for typeid
unsigned NumLoops;
- LoopExtractor(unsigned numLoops = ~0) : NumLoops(numLoops) {}
+ explicit LoopExtractor(unsigned numLoops = ~0)
+ : LoopPass(ID), NumLoops(numLoops) {
+ initializeLoopExtractorPass(*PassRegistry::getPassRegistry());
+ }
- virtual bool runOnFunction(Function &F);
-
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired<LoopInfo>();
+ bool runOnLoop(Loop *L, LPPassManager &LPM) override;
+
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
+ AU.addRequiredID(BreakCriticalEdgesID);
AU.addRequiredID(LoopSimplifyID);
+ AU.addRequired<DominatorTreeWrapperPass>();
}
};
+}
- RegisterOpt<LoopExtractor>
- X("loop-extract", "Extract loops into new functions");
+char LoopExtractor::ID = 0;
+INITIALIZE_PASS_BEGIN(LoopExtractor, "loop-extract",
+ "Extract loops into new functions", false, false)
+INITIALIZE_PASS_DEPENDENCY(BreakCriticalEdges)
+INITIALIZE_PASS_DEPENDENCY(LoopSimplify)
+INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
+INITIALIZE_PASS_END(LoopExtractor, "loop-extract",
+ "Extract loops into new functions", false, false)
+namespace {
/// SingleLoopExtractor - For bugpoint.
struct SingleLoopExtractor : public LoopExtractor {
+ static char ID; // Pass identification, replacement for typeid
SingleLoopExtractor() : LoopExtractor(1) {}
};
+} // End anonymous namespace
- RegisterOpt<SingleLoopExtractor>
- Y("loop-extract-single", "Extract at most one loop into a new function");
-} // End anonymous namespace
+char SingleLoopExtractor::ID = 0;
+INITIALIZE_PASS(SingleLoopExtractor, "loop-extract-single",
+ "Extract at most one loop into a new function", false, false)
-bool LoopExtractor::runOnFunction(Function &F) {
- LoopInfo &LI = getAnalysis<LoopInfo>();
+// createLoopExtractorPass - This pass extracts all natural loops from the
+// program into a function if it can.
+//
+Pass *llvm::createLoopExtractorPass() { return new LoopExtractor(); }
- // If this function has no loops, there is nothing to do.
- if (LI.begin() == LI.end())
+bool LoopExtractor::runOnLoop(Loop *L, LPPassManager &LPM) {
+ if (skipOptnoneFunction(L))
return false;
- // If there is more than one top-level loop in this function, extract all of
- // the loops.
+ // Only visit top-level loops.
+ if (L->getParentLoop())
+ return false;
+
+ // If LoopSimplify form is not available, stay out of trouble.
+ if (!L->isLoopSimplifyForm())
+ return false;
+
+ DominatorTree &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
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(*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<BranchInst>(EntryTI) ||
+ !cast<BranchInst>(EntryTI)->isUnconditional() ||
+ EntryTI->getSuccessor(0) != L->getHeader()) {
+ ShouldExtractLoop = true;
} 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.
- for (unsigned i = 0, e = TLL->getExitBlocks().size(); i != e; ++i)
- if (!isa<ReturnInst>(TLL->getExitBlocks()[i]->getTerminator())) {
- ShouldExtractLoop = true;
- break;
- }
- }
-
- if (ShouldExtractLoop) {
- if (NumLoops == 0) return Changed;
- --NumLoops;
- Changed |= (ExtractLoop(TLL) != 0);
- } 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(*i) != 0);
+ // Check to see if any exits from the loop are more than just return
+ // blocks.
+ SmallVector<BasicBlock*, 8> ExitBlocks;
+ L->getExitBlocks(ExitBlocks);
+ for (unsigned i = 0, e = ExitBlocks.size(); i != e; ++i)
+ if (!isa<ReturnInst>(ExitBlocks[i]->getTerminator())) {
+ ShouldExtractLoop = true;
+ break;
+ }
+ }
+
+ if (ShouldExtractLoop) {
+ // We must omit landing pads. Landing pads must accompany the invoke
+ // instruction. But this would result in a loop in the extracted
+ // function. An infinite cycle occurs when it tries to extract that loop as
+ // well.
+ SmallVector<BasicBlock*, 8> ExitBlocks;
+ L->getExitBlocks(ExitBlocks);
+ for (unsigned i = 0, e = ExitBlocks.size(); i != e; ++i)
+ if (ExitBlocks[i]->isLandingPad()) {
+ ShouldExtractLoop = false;
+ break;
}
+ }
+
+ if (ShouldExtractLoop) {
+ if (NumLoops == 0) return Changed;
+ --NumLoops;
+ CodeExtractor Extractor(DT, *L);
+ if (Extractor.extractCodeRegion() != nullptr) {
+ 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;
Pass *llvm::createSingleLoopExtractorPass() {
return new SingleLoopExtractor();
}
+
+
+// BlockFile - A file which contains a list of blocks that should not be
+// extracted.
+static 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);
+
+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);
+ void SplitLandingPadPreds(Function *F);
+
+ std::vector<BasicBlock*> BlocksToNotExtract;
+ std::vector<std::pair<std::string, std::string> > BlocksToNotExtractByName;
+ public:
+ static char ID; // Pass identification, replacement for typeid
+ BlockExtractorPass() : ModulePass(ID) {
+ if (!BlockFile.empty())
+ LoadFile(BlockFile.c_str());
+ }
+
+ bool runOnModule(Module &M) override;
+ };
+}
+
+char BlockExtractorPass::ID = 0;
+INITIALIZE_PASS(BlockExtractorPass, "extract-blocks",
+ "Extract Basic Blocks From Module (for bugpoint use)",
+ false, false)
+
+// createBlockExtractorPass - This pass extracts all blocks (except those
+// specified in the argument list) from the functions in the module.
+//
+ModulePass *llvm::createBlockExtractorPass() {
+ return new BlockExtractorPass();
+}
+
+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));
+ }
+}
+
+/// SplitLandingPadPreds - The landing pad needs to be extracted with the invoke
+/// instruction. The critical edge breaker will refuse to break critical edges
+/// to a landing pad. So do them here. After this method runs, all landing pads
+/// should have only one predecessor.
+void BlockExtractorPass::SplitLandingPadPreds(Function *F) {
+ for (Function::iterator I = F->begin(), E = F->end(); I != E; ++I) {
+ InvokeInst *II = dyn_cast<InvokeInst>(I);
+ if (!II) continue;
+ BasicBlock *Parent = II->getParent();
+ BasicBlock *LPad = II->getUnwindDest();
+
+ // Look through the landing pad's predecessors. If one of them ends in an
+ // 'invoke', then we want to split the landing pad.
+ bool Split = false;
+ for (pred_iterator
+ PI = pred_begin(LPad), PE = pred_end(LPad); PI != PE; ++PI) {
+ BasicBlock *BB = *PI;
+ if (BB->isLandingPad() && BB != Parent &&
+ isa<InvokeInst>(Parent->getTerminator())) {
+ Split = true;
+ break;
+ }
+ }
+
+ if (!Split) continue;
+
+ SmallVector<BasicBlock*, 2> NewBBs;
+ SplitLandingPadPredecessors(LPad, Parent, ".1", ".2", NewBBs);
+ }
+}
+
+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) {
+ SplitLandingPadPreds(&*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) {
+ SmallVector<BasicBlock*, 2> BlocksToExtractVec;
+ BlocksToExtractVec.push_back(BlocksToExtract[i]);
+ if (const InvokeInst *II =
+ dyn_cast<InvokeInst>(BlocksToExtract[i]->getTerminator()))
+ BlocksToExtractVec.push_back(II->getUnwindDest());
+ CodeExtractor(BlocksToExtractVec).extractCodeRegion();
+ }
+
+ return !BlocksToExtract.empty();
+}
projects / oota-llvm.git / blobdiff