SCEV: Handle a corner case reducing AddRecExpr * AddRecExpr
If integer overflow causes one of the terms to reach zero, that can
force the entire expression to zero.
Fixes PR12929: cast<Ty>() argument of incompatible type
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157673 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 59f441e..8781441 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -2088,9 +2088,12 @@
const SCEV *NewAddRec = getAddRecExpr(AddRecOps, AddRec->getLoop(),
SCEV::FlagAnyWrap);
if (Ops.size() == 2) return NewAddRec;
- Ops[Idx] = AddRec = cast<SCEVAddRecExpr>(NewAddRec);
+ Ops[Idx] = NewAddRec;
Ops.erase(Ops.begin() + OtherIdx); --OtherIdx;
OpsModified = true;
+ AddRec = dyn_cast<SCEVAddRecExpr>(NewAddRec);
+ if (!AddRec)
+ break;
}
}
if (OpsModified)