//
void RemoveSuccessor(TerminatorInst *TI, unsigned SuccNum);
+/// SuccessorNumber - Search for the specified successor of basic block BB and
+/// return its position in the terminator instruction's list of successors.
+/// It is an error to call this with a block that is not a successor.
+unsigned SuccessorNumber(BasicBlock *BB, BasicBlock *Succ);
+
/// isCriticalEdge - Return true if the specified edge is a critical edge.
/// Critical edges are edges from a block with multiple successors to a block
/// with multiple predecessors.
// We can't do PRE safely on a critical edge, so instead we schedule
// the edge to be split and perform the PRE the next time we iterate
// on the function.
- unsigned SuccNum = 0;
- for (unsigned i = 0, e = PREPred->getTerminator()->getNumSuccessors();
- i != e; ++i)
- if (PREPred->getTerminator()->getSuccessor(i) == CurrentBlock) {
- SuccNum = i;
- break;
- }
-
+ unsigned SuccNum = SuccessorNumber(PREPred, CurrentBlock);
if (isCriticalEdge(PREPred->getTerminator(), SuccNum)) {
toSplit.push_back(std::make_pair(PREPred->getTerminator(), SuccNum));
continue;
ReplaceInstWithInst(TI, NewTI);
}
-/// SplitEdge - Split the edge connecting specified block. Pass P must
-/// not be NULL.
-BasicBlock *llvm::SplitEdge(BasicBlock *BB, BasicBlock *Succ, Pass *P) {
- TerminatorInst *LatchTerm = BB->getTerminator();
- unsigned SuccNum = 0;
+/// SuccessorNumber - Search for the specified successor of basic block BB and
+/// return its position in the terminator instruction's list of successors.
+/// It is an error to call this with a block that is not a successor.
+unsigned llvm::SuccessorNumber(BasicBlock *BB, BasicBlock *Succ) {
+ TerminatorInst *Term = BB->getTerminator();
#ifndef NDEBUG
- unsigned e = LatchTerm->getNumSuccessors();
+ unsigned e = Term->getNumSuccessors();
#endif
for (unsigned i = 0; ; ++i) {
assert(i != e && "Didn't find edge?");
- if (LatchTerm->getSuccessor(i) == Succ) {
- SuccNum = i;
- break;
- }
+ if (Term->getSuccessor(i) == Succ)
+ return i;
}
+ return 0;
+}
+
+/// SplitEdge - Split the edge connecting specified block. Pass P must
+/// not be NULL.
+BasicBlock *llvm::SplitEdge(BasicBlock *BB, BasicBlock *Succ, Pass *P) {
+ unsigned SuccNum = SuccessorNumber(BB, Succ);
// If this is a critical edge, let SplitCriticalEdge do it.
- if (SplitCriticalEdge(BB->getTerminator(), SuccNum, P))
+ TerminatorInst *LatchTerm = BB->getTerminator();
+ if (SplitCriticalEdge(LatchTerm, SuccNum, P))
return LatchTerm->getSuccessor(SuccNum);
// If the edge isn't critical, then BB has a single successor or Succ has a