/*
	This C language subroutine returns non-zero
	if the input is a control character, zero otherwise.

	The Run Time Library for the C Language.

	Gordon A. Sterling	(617) 461 - 3076
	DSP Development Tools Engineering

	Updated on 5/94 by AS

	#include <ctype.h>			<Header>
	int iscntrl(int c);			<Prototype>
*/

#include "lib_glob.h"
#include "cty_glob.h"

.SEGMENT/CODE	Code_Space_Name;
.FILE 		RTL_FILENAME;

.GLOBAL	    	_iscntrl;

_iscntrl:	R4=PASS R4, R0=dm_1;	/* Test for EOF, set ret*/
		IF LT R0=R0-R0;		/* If EOF return 0	*/

		R2=127;			/* Test for del		*/
		COMP(R4,R2), FETCH_RETURN /* If ch != del return 0*/

/* If ch == del, (from above) this test is not done		*/
		R2=31;			/* Upper bound on cntrl	*/
		IF NE COMP(R4,R2);	/* Is ch <= 31		*/

		IF GT R0=R0-R0;		/* Clear return		*/

restore_state:	RETURN (DB);
		RESTORE_STACK
		RESTORE_FRAME
.ENDSEG;