Allow readonly functions to unwind exceptions.  Teach
the optimizers about this.  For example, a readonly
function with no uses cannot be removed unless it is
also marked nounwind.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71071 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/TailRecursionElimination.cpp b/lib/Transforms/Scalar/TailRecursionElimination.cpp
index e1234ef..682d069 100644
--- a/lib/Transforms/Scalar/TailRecursionElimination.cpp
+++ b/lib/Transforms/Scalar/TailRecursionElimination.cpp
@@ -201,7 +201,7 @@
 bool TailCallElim::CanMoveAboveCall(Instruction *I, CallInst *CI) {
   // FIXME: We can move load/store/call/free instructions above the call if the
   // call does not mod/ref the memory location being processed.
-  if (I->mayWriteToMemory() || isa<LoadInst>(I))
+  if (I->mayHaveSideEffects() || isa<LoadInst>(I))
     return false;
 
   // Otherwise, if this is a side-effect free instruction, check to make sure