maybe_set_first_label_num can take an rtx_code_label *

The function maybe_set_first_label_num acts on a CODE_LABEL; we can
capture that in the type system.

gcc/ChangeLog:
	* emit-rtl.c (maybe_set_first_label_num): Strengthen param from
	rtx to rtx_code_label *.
	* rtl.h (maybe_set_first_label_num): Likewise.

From-SVN: r235525

gcc/ChangeLog

 2016-04-27  David Malcolm  <dmalcolm@redhat.com>
 
+	* emit-rtl.c (maybe_set_first_label_num): Strengthen param from
+	rtx to rtx_code_label *.
+	* rtl.h (maybe_set_first_label_num): Likewise.
+
+2016-04-27  David Malcolm  <dmalcolm@redhat.com>
+
 	* df-core.c (df_add_problem): Make the problem param be const.
 	(df_remove_problem): Make local "problem" be const.
 	* df-problems.c (problem_RD): Make const.

gcc/emit-rtl.c

@@ -1355,7 +1355,7 @@ get_first_label_num (void)
    Fix this now so that array indices work later.  */
 
 void
-maybe_set_first_label_num (rtx x)
+maybe_set_first_label_num (rtx_code_label *x)
 {
   if (CODE_LABEL_NUMBER (x) < first_label_num)
     first_label_num = CODE_LABEL_NUMBER (x);

gcc/rtl.h

@@ -3508,7 +3508,7 @@ extern int condjump_in_parallel_p (const rtx_insn *);
 extern int max_reg_num (void);
 extern int max_label_num (void);
 extern int get_first_label_num (void);
-extern void maybe_set_first_label_num (rtx);
+extern void maybe_set_first_label_num (rtx_code_label *);
 extern void delete_insns_since (rtx_insn *);
 extern void mark_reg_pointer (rtx, int);
 extern void mark_user_reg (rtx);