Add back a couple checks removed by r129128; the fact that an intitializer

is an array of structures doesn't imply it's a ConstantArray of
ConstantStruct.

llvm-svn: 129207

llvm/lib/Transforms/IPO/GlobalOpt.cpp

@@ -1954,11 +1954,13 @@ GlobalVariable *GlobalOpt::FindGlobalCtors(Module &M) {
   // only allowed to optimize the initializer if it is unique.
   if (!GV->hasUniqueInitializer()) return 0;
   
-  ConstantArray *CA = cast<ConstantArray>(GV->getInitializer());
-  
+  ConstantArray *CA = dyn_cast<ConstantArray>(GV->getInitializer());
+  if (!CA) return 0;
+
   for (User::op_iterator i = CA->op_begin(), e = CA->op_end(); i != e; ++i) {
-    ConstantStruct *CS = cast<ConstantStruct>(*i);
-    
+    ConstantStruct *CS = dyn_cast<ConstantStruct>(*i);
+    if (!CS) return 0;
+
     if (isa<ConstantPointerNull>(CS->getOperand(1)))
       continue;
 

llvm/test/Transforms/GlobalOpt/2011-04-09-EmptyGlobalCtors.ll

@@ -0,0 +1,5 @@
+; RUN: opt < %s -globalopt -disable-output
+
+%0 = type { i32, void ()* }
+@llvm.global_ctors = appending global [0 x %0] zeroinitializer
+