--- hw/mpcore.c
+++ hw/mpcore.c
@@ -106,6 +106,7 @@
     case 12: /* Interrupt status.  */
         return s->status;
     }
+    return 0;
 }
 
 static void mpcore_timer_write(mpcore_timer_state *s, int offset,
--- target-m68k/translate.c
+++ target-m68k/translate.c
@@ -452,6 +452,7 @@
     default:
         qemu_assert(0, "bad operand size");
     }
+    return 0;
 }
 
 /* Assign value to a register.  If the width is less than the register width