/*
	This C language subroutine converts an upper
	case letter to lowercase.

	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 tolower(int c);			<Prototype>
*/

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

.SEGMENT/CODE	Code_Space_Name;
.FILE 		RTL_FILENAME;

.GLOBAL	    	_tolower;

_tolower:	R12=90;			/* 90 = ASC('Z')	*/
		R8=65;			/* 65 = ASC('A')	*/
		R2=32;			/* Caps mask		*/

		COMP(R4,R12), R0=R4;	/* Test for <= Z	*/
		IF GT R2=R2-R2;		/* Zero caps mask	*/
		COMP(R4,R8), FETCH_RETURN /* Test for >= A	*/
		IF GE R0=R4 OR R2;	/* If so, mask in caps	*/

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