Index: lib/Transforms/InstCombine/InstructionCombining.cpp
===================================================================
--- lib/Transforms/InstCombine/InstructionCombining.cpp
+++ lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -1348,6 +1348,11 @@
         // normalized.
         if (SO1->getType() != GO1->getType())
           return nullptr;
+          
+        // Is it worth summing the offsets?
+        if (!isa<ConstantInt>(SO1))
+        	return nullptr;
+        
         Sum = Builder->CreateAdd(SO1, GO1, PtrOp->getName()+".sum");
       }