Index: lib/Target/X86/X86InstrArithmetic.td
===================================================================
--- lib/Target/X86/X86InstrArithmetic.td
+++ lib/Target/X86/X86InstrArithmetic.td
@@ -989,10 +989,12 @@
       }
     } // Constraints = "$src1 = $dst"
 
-    def NAME#8mr    : BinOpMR_RMW<BaseOpc, mnemonic, Xi8 , opnode>;
-    def NAME#16mr   : BinOpMR_RMW<BaseOpc, mnemonic, Xi16, opnode>;
-    def NAME#32mr   : BinOpMR_RMW<BaseOpc, mnemonic, Xi32, opnode>;
-    def NAME#64mr   : BinOpMR_RMW<BaseOpc, mnemonic, Xi64, opnode>;
+    let mayLoad = 1, mayStore = 1 in {
+      def NAME#8mr    : BinOpMR_RMW<BaseOpc, mnemonic, Xi8 , opnode>;
+      def NAME#16mr   : BinOpMR_RMW<BaseOpc, mnemonic, Xi16, opnode>;
+      def NAME#32mr   : BinOpMR_RMW<BaseOpc, mnemonic, Xi32, opnode>;
+      def NAME#64mr   : BinOpMR_RMW<BaseOpc, mnemonic, Xi64, opnode>;
+    }
 
     // NOTE: These are order specific, we want the mi8 forms to be listed
     // first so that they are slightly preferred to the mi forms.