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-rw-r--r--lib/Transforms/Utils/BasicBlockUtils.cpp29
1 files changed, 18 insertions, 11 deletions
diff --git a/lib/Transforms/Utils/BasicBlockUtils.cpp b/lib/Transforms/Utils/BasicBlockUtils.cpp
index 7bc4fcdf36..1f62dabb20 100644
--- a/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ b/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -274,24 +274,31 @@ void llvm::RemoveSuccessor(TerminatorInst *TI, unsigned SuccNum) {
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;
+/// GetSuccessorNumber - 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::GetSuccessorNumber(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 = GetSuccessorNumber(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