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These rountines are now available as part of basic block utilities. 

llvm-svn: 37955
This commit is contained in:
Devang Patel 2007-07-06 22:03:47 +00:00
parent 86d0ea973d
commit 12358b4827
1 changed files with 5 additions and 66 deletions
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71
llvm/lib/Transforms/Scalar/LoopUnswitch.cpp
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@ -106,8 +106,6 @@ namespace {
void UnswitchTrivialCondition(Loop *L, Value *Cond, Constant *Val,
BasicBlock *ExitBlock);
void UnswitchNontrivialCondition(Value *LIC, Constant *OnVal, Loop *L);
BasicBlock *SplitEdge(BasicBlock *From, BasicBlock *To);
BasicBlock *SplitBlock(BasicBlock *Old, Instruction *SplitPt);
void RewriteLoopBodyWithConditionConstant(Loop *L, Value *LIC,
Constant *Val, bool isEqual);
@ -399,65 +397,6 @@ bool LoopUnswitch::UnswitchIfProfitable(Value *LoopCond, Constant *Val,Loop *L){
return true;
}
/// SplitBlock - Split the specified block at the specified instruction - every
/// thing before SplitPt stays in Old and everything starting with SplitPt moves
/// to a new block. The two blocks are joined by an unconditional branch and
/// the loop info is updated.
///
BasicBlock *LoopUnswitch::SplitBlock(BasicBlock *Old, Instruction *SplitPt) {
BasicBlock::iterator SplitIt = SplitPt;
while (isa<PHINode>(SplitIt))
++SplitIt;
BasicBlock *New = Old->splitBasicBlock(SplitIt, Old->getName()+".split");
// The new block lives in whichever loop the old one did.
if (Loop *L = LI->getLoopFor(Old))
L->addBasicBlockToLoop(New, *LI);
if (DominatorTree *DT = getAnalysisToUpdate<DominatorTree>())
DT->addNewBlock(New, Old);
if (DominanceFrontier *DF = getAnalysisToUpdate<DominanceFrontier>())
DF->splitBlock(Old);
return New;
}
BasicBlock *LoopUnswitch::SplitEdge(BasicBlock *BB, BasicBlock *Succ) {
TerminatorInst *LatchTerm = BB->getTerminator();
unsigned SuccNum = 0;
for (unsigned i = 0, e = LatchTerm->getNumSuccessors(); ; ++i) {
assert(i != e && "Didn't find edge?");
if (LatchTerm->getSuccessor(i) == Succ) {
SuccNum = i;
break;
}
}
// If this is a critical edge, let SplitCriticalEdge do it.
if (SplitCriticalEdge(BB->getTerminator(), SuccNum, this))
return LatchTerm->getSuccessor(SuccNum);
// If the edge isn't critical, then BB has a single successor or Succ has a
// single pred. Split the block.
BasicBlock::iterator SplitPoint;
if (BasicBlock *SP = Succ->getSinglePredecessor()) {
// If the successor only has a single pred, split the top of the successor
// block.
assert(SP == BB && "CFG broken");
return SplitBlock(Succ, Succ->begin());
} else {
// Otherwise, if BB has a single successor, split it at the bottom of the
// block.
assert(BB->getTerminator()->getNumSuccessors() == 1 &&
"Should have a single succ!");
return SplitBlock(BB, BB->getTerminator());
}
}
// RemapInstruction - Convert the instruction operands from referencing the
// current values into those specified by ValueMap.
//
@ -581,7 +520,7 @@ void LoopUnswitch::UnswitchTrivialCondition(Loop *L, Value *Cond,
// to insert the conditional branch. We will change 'OrigPH' to have a
// conditional branch on Cond.
BasicBlock *OrigPH = L->getLoopPreheader();
BasicBlock *NewPH = SplitEdge(OrigPH, L->getHeader());
BasicBlock *NewPH = SplitEdge(OrigPH, L->getHeader(), this);
// Now that we have a place to insert the conditional branch, create a place
// to branch to: this is the exit block out of the loop that we should
@ -592,7 +531,7 @@ void LoopUnswitch::UnswitchTrivialCondition(Loop *L, Value *Cond,
// without actually branching to it (the exit block should be dominated by the
// loop header, not the preheader).
assert(!L->contains(ExitBlock) && "Exit block is in the loop?");
BasicBlock *NewExit = SplitBlock(ExitBlock, ExitBlock->begin());
BasicBlock *NewExit = SplitBlock(ExitBlock, ExitBlock->begin(), this);
// Okay, now we have a position to branch from and a position to branch to,
// insert the new conditional branch.
@ -629,7 +568,7 @@ void LoopUnswitch::UnswitchNontrivialCondition(Value *LIC, Constant *Val,
// First step, split the preheader and exit blocks, and add these blocks to
// the LoopBlocks list.
BasicBlock *OrigPreheader = L->getLoopPreheader();
LoopBlocks.push_back(SplitEdge(OrigPreheader, L->getHeader()));
LoopBlocks.push_back(SplitEdge(OrigPreheader, L->getHeader(), this));
// We want the loop to come after the preheader, but before the exit blocks.
LoopBlocks.insert(LoopBlocks.end(), L->block_begin(), L->block_end());
@ -644,7 +583,7 @@ void LoopUnswitch::UnswitchNontrivialCondition(Value *LIC, Constant *Val,
std::vector<BasicBlock*> Preds(pred_begin(ExitBlock), pred_end(ExitBlock));
for (unsigned j = 0, e = Preds.size(); j != e; ++j) {
BasicBlock* MiddleBlock = SplitEdge(Preds[j], ExitBlock);
BasicBlock* MiddleBlock = SplitEdge(Preds[j], ExitBlock, this);
BasicBlock* StartBlock = Preds[j];
BasicBlock* EndBlock;
if (MiddleBlock->getSinglePredecessor() == ExitBlock) {
@ -985,7 +924,7 @@ void LoopUnswitch::RewriteLoopBodyWithConditionConstant(Loop *L, Value *LIC,
// loop structure and put the block on an dead code path.
BasicBlock* Old = SI->getParent();
BasicBlock* Split = SplitBlock(Old, SI);
BasicBlock* Split = SplitBlock(Old, SI, this);
Instruction* OldTerm = Old->getTerminator();
new BranchInst(Split, SI->getSuccessor(i),