Add some debug output to LoopSimplify.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97458 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2010-03-01 17:55:27 +00:00
parent c235a0c388
commit c5e49c64d1

View File

@ -51,6 +51,7 @@
#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"
@ -147,6 +148,11 @@ ReprocessLoop:
// 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);
@ -169,6 +175,11 @@ ReprocessLoop:
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;
@ -296,6 +307,11 @@ ReprocessLoop:
// 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);
@ -349,6 +365,10 @@ BasicBlock *LoopSimplify::InsertPreheaderForLoop(Loop *L) {
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);
@ -374,6 +394,10 @@ BasicBlock *LoopSimplify::RewriteLoopExitBlock(Loop *L, BasicBlock *Exit) {
LoopBlocks.size(), ".loopexit",
this);
DEBUG(dbgs() << "LoopSimplify: Creating dedicated exit block ";
WriteAsOperand(dbgs(), NewBB, false);
dbgs() << "\n");
return NewBB;
}
@ -494,6 +518,8 @@ Loop *LoopSimplify::SeparateNestedLoop(Loop *L, LPPassManager &LPM) {
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(),
@ -588,6 +614,10 @@ LoopSimplify::InsertUniqueBackedgeBlock(Loop *L, BasicBlock *Preheader) {
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);