It's not necessary to do rounding for alloca operations when the requested

alignment is equal to the stack alignment.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 201 insertions, 0 deletions

diff --git a/lib/Transforms/IPO/LoopExtractor.cpp b/lib/Transforms/IPO/LoopExtractor.cpp
new file mode 100644
index 0000000..7b14ce0
--- /dev/null
+++ b/lib/Transforms/IPO/LoopExtractor.cpp
@@ -0,0 +1,201 @@
+//===- 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/Compiler.h"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Utils/FunctionUtils.h"
+#include "llvm/ADT/Statistic.h"
+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;
+
+    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.
+      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(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 {
+  /// 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 {
+    std::vector<BasicBlock*> BlocksToNotExtract;
+  public:
+    static char ID; // Pass identification, replacement for typeid
+    BlockExtractorPass(std::vector<BasicBlock*> &B) 
+      : ModulePass((intptr_t)&ID), BlocksToNotExtract(B) {}
+    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(std::vector<BasicBlock*> &BTNE) {
+  return new BlockExtractorPass(BTNE);
+}
+
+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);
+  }
+
+  // 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();
+}