Mark fallthrough cases with gcc_fallthrough.

	* gcc/combine.c (simplify_compare_const): Add gcc_fallthrough.

From-SVN: r241744

gcc/ChangeLog

+2016-11-01  Fritz Reese  <fritzoreese@gmail.com>
+
+	* gcc/combine.c (simplify_compare_const): Add gcc_fallthrough.
+
 2016-11-01  Bilyan Borisov  <bilyan.borisov@arm.com>
 	    Tamar Christina <tamar.christina@arm.com>
 

gcc/combine.c

@@ -11414,6 +11414,7 @@ simplify_compare_const (enum rtx_code code, machine_mode mode,
 	  const_op -= 1;
 	  code = LE;
 	  /* ... fall through to LE case below.  */
+	  gcc_fallthrough ();
 	}
       else
 	break;
@@ -11443,6 +11444,7 @@ simplify_compare_const (enum rtx_code code, machine_mode mode,
 	  const_op -= 1;
 	  code = GT;
 	  /* ... fall through to GT below.  */
+	  gcc_fallthrough ();
 	}
       else
 	break;