processStore may delete the instruction, avoid
using dyn_cast<> on already freed memory.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50618 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/lib/Transforms/Scalar/MemCpyOptimizer.cpp
index d6e5f39..8036bf8 100644
--- a/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -718,8 +718,7 @@
       
       if (StoreInst *SI = dyn_cast<StoreInst>(I))
         changed_function |= processStore(SI, BI);
-
-      if (MemCpyInst* M = dyn_cast<MemCpyInst>(I)) {
+      else if (MemCpyInst* M = dyn_cast<MemCpyInst>(I)) {
         changed_function |= processMemCpy(M);
       }
     }