#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Support/CFG.h"
+#include "llvm/Support/Debug.h"
#include "llvm/ADT/SetOperations.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/Statistic.h"
// Delete each unique out-of-loop (and thus dead) predecessor.
for (SmallPtrSet<BasicBlock *, 4>::iterator I = BadPreds.begin(),
E = BadPreds.end(); I != E; ++I) {
+
+ DEBUG(dbgs() << "LoopSimplify: Deleting edge from dead predecessor ";
+ WriteAsOperand(dbgs(), *I, false);
+ dbgs() << "\n");
+
// Inform each successor of each dead pred.
for (succ_iterator SI = succ_begin(*I), SE = succ_end(*I); SI != SE; ++SI)
(*SI)->removePredecessor(*I);
if (BranchInst *BI = dyn_cast<BranchInst>((*I)->getTerminator()))
if (BI->isConditional()) {
if (UndefValue *Cond = dyn_cast<UndefValue>(BI->getCondition())) {
+
+ DEBUG(dbgs() << "LoopSimplify: Resolving \"br i1 undef\" to exit in ";
+ WriteAsOperand(dbgs(), *I, false);
+ dbgs() << "\n");
+
BI->setCondition(ConstantInt::get(Cond->getType(),
!L->contains(BI->getSuccessor(0))));
Changed = true;
// Success. The block is now dead, so remove it from the loop,
// update the dominator tree and dominance frontier, and delete it.
+
+ DEBUG(dbgs() << "LoopSimplify: Eliminating exiting block ";
+ WriteAsOperand(dbgs(), ExitingBlock, false);
+ dbgs() << "\n");
+
assert(pred_begin(ExitingBlock) == pred_end(ExitingBlock));
Changed = true;
LI->removeBlock(ExitingBlock);
SplitBlockPredecessors(Header, &OutsideBlocks[0], OutsideBlocks.size(),
".preheader", this);
+ DEBUG(dbgs() << "LoopSimplify: Creating pre-header ";
+ WriteAsOperand(dbgs(), NewBB, false);
+ dbgs() << "\n");
+
// Make sure that NewBB is put someplace intelligent, which doesn't mess up
// code layout too horribly.
PlaceSplitBlockCarefully(NewBB, OutsideBlocks, L);
LoopBlocks.size(), ".loopexit",
this);
+ DEBUG(dbgs() << "LoopSimplify: Creating dedicated exit block ";
+ WriteAsOperand(dbgs(), NewBB, false);
+ dbgs() << "\n");
+
return NewBB;
}
OuterLoopPreds.push_back(PN->getIncomingBlock(i));
}
+ DEBUG(dbgs() << "LoopSimplify: Splitting out a new outer loop\n");
+
BasicBlock *Header = L->getHeader();
BasicBlock *NewBB = SplitBlockPredecessors(Header, &OuterLoopPreds[0],
OuterLoopPreds.size(),
Header->getName()+".backedge", F);
BranchInst *BETerminator = BranchInst::Create(Header, BEBlock);
+ DEBUG(dbgs() << "LoopSimplify: Inserting unique backedge block ";
+ WriteAsOperand(dbgs(), BEBlock, false);
+ dbgs() << "\n");
+
// Move the new backedge block to right after the last backedge block.
Function::iterator InsertPos = BackedgeBlocks.back(); ++InsertPos;
F->getBasicBlockList().splice(InsertPos, F->getBasicBlockList(), BEBlock);