Do not erase induction variable increment if it is used outside the loop.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51280 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopIndexSplit.cpp b/lib/Transforms/Scalar/LoopIndexSplit.cpp
index 8b55444..5faec97 100644
--- a/lib/Transforms/Scalar/LoopIndexSplit.cpp
+++ b/lib/Transforms/Scalar/LoopIndexSplit.cpp
@@ -596,11 +596,27 @@
if (isa<PHINode>(I) || I == LTerminator)
continue;
- if (I == IndVarIncrement)
- I->replaceAllUsesWith(ExitValue);
- else
+ if (I == IndVarIncrement) {
+ // Replace induction variable increment if it is not used outside
+ // the loop.
+ bool UsedOutsideLoop = false;
+ for (Value::use_iterator UI = I->use_begin(), E = I->use_end();
+ UI != E; ++UI) {
+ if (Instruction *Use = dyn_cast<Instruction>(UI))
+ if (!L->contains(Use->getParent())) {
+ UsedOutsideLoop = true;
+ break;
+ }
+ }
+ if (!UsedOutsideLoop) {
+ I->replaceAllUsesWith(ExitValue);
+ I->eraseFromParent();
+ }
+ }
+ else {
I->replaceAllUsesWith(UndefValue::get(I->getType()));
- I->eraseFromParent();
+ I->eraseFromParent();
+ }
}
LPM->deleteLoopFromQueue(L);