//===----------------------------------------------------------------------===//
#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/Transforms/Scalar.h"
#include "llvm/Transforms/Utils/FunctionUtils.h"
+#include "llvm/ADT/Statistic.h"
using namespace llvm;
namespace {
+ Statistic<> NumExtracted("loop-extract", "Number of loops extracted");
+
// 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.
virtual bool runOnFunction(Function &F);
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired<LoopInfo>();
+ AU.addRequiredID(BreakCriticalEdgesID);
AU.addRequiredID(LoopSimplifyID);
+ AU.addRequired<DominatorSet>();
+ AU.addRequired<LoopInfo>();
}
};
bool LoopExtractor::runOnFunction(Function &F) {
LoopInfo &LI = getAnalysis<LoopInfo>();
- // 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 this function has no loops, there is nothing to do.
+ if (LI.begin() == LI.end())
return false;
- bool Changed = false;
+ DominatorSet &DS = getAnalysis<DominatorSet>();
- // Try to move each loop out of the code into separate function
- 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.
+ 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(DS, *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.
+ std::vector<BasicBlock*> 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(DS, 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(DS, *i) != 0;
+ ++NumExtracted;
+ }
+ }
}
return Changed;
Pass *llvm::createSingleLoopExtractorPass() {
return new SingleLoopExtractor();
}
+
+
+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 Pass {
+ std::vector<BasicBlock*> BlocksToNotExtract;
+ public:
+ BlockExtractorPass(std::vector<BasicBlock*> &B) : BlocksToNotExtract(B) {}
+ BlockExtractorPass() {}
+
+ bool run(Module &M);
+ };
+ RegisterOpt<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.
+//
+Pass *llvm::createBlockExtractorPass(std::vector<BasicBlock*> &BTNE) {
+ return new BlockExtractorPass(BTNE);
+}
+
+bool BlockExtractorPass::run(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(), F->getFunctionType());
+
+ // 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);
+ }
+
+ // 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();
+}
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