Fix PR284: [indvars] Induction variable analysis violates LLVM invariants
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12275 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/InductionVariable.cpp b/lib/Analysis/InductionVariable.cpp
index b602529..8f62297 100644
--- a/lib/Analysis/InductionVariable.cpp
+++ b/lib/Analysis/InductionVariable.cpp
@@ -136,10 +136,14 @@
if (Constant *CV = dyn_cast<Constant>(V))
Step = ConstantExpr::get(Instruction::Sub, Zero, CV);
else if (Instruction *I = dyn_cast<Instruction>(V)) {
+ BasicBlock::iterator InsertPt = I;
+ for (++InsertPt; isa<PHINode>(InsertPt); ++InsertPt)
+ /*empty*/;
Step = BinaryOperator::create(Instruction::Sub, Zero, V,
- V->getName()+".neg", I->getNext());
+ V->getName()+".neg", InsertPt);
} else {
+ // Must be loop invariant
Step = BinaryOperator::create(Instruction::Sub, Zero, V,
V->getName()+".neg",
Phi->getParent()->getParent()->begin()->begin());