/*
	This C language subroutine counts the number of 
	zero crossing in an array.
	
	The Run Time Library for the C Language.

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

	Created on 6/24/90
	Updated on 5/94 by AS
	Updated on 3/95 by AS - separated polymorphic functions

	#include <stats.h>				<Header>
	int izero_cross(fract in[], int length);	<Prototype>
	int xzero_cross(fract in[], int length);	<Prototype>
	int zero_cross(float in[], int length);		<Prototype>
*/

#include "lib_glob.h"
#include "sts_glob.h"

.SEGMENT/CODE	Code_Space_Name;
.FILE 		RTL_FILENAME;

.GLOBAL	    	_izero_cross, _zero_cross;
.GLOBAL		___izero_crossD, ___zero_crossD;


_zero_cross:
_xzero_cross:
_izero_cross:	
___izero_crossD:
___xzero_crossD:
___zero_crossD:	R0=R0-R0, dm_ptr=R4;		/* Clear count, set ptr	*/

		R8=R8-1, R12=DM(dm_ptr,dm_1);	/* Fetch first point	*/
		R8=R8-1, R4=DM(dm_ptr,dm_1);	/* Fetch second point	*/
		IF LE JUMP (PC, finishedd);	/* Small array		*/
						/* rm'ed rev 0 silicon fix 'nop'*/
		LCNTR=R8, DO count_xzcsd UNTIL LCE;
			R2=R4 XOR R12, R4=DM(dm_ptr,dm_1);	
count_xzcsd:		IF LT R0=R0+1, R12=R4;
finishedd:	
		R2=R4 XOR R12, FETCH_RETURN 
		IF LT R0=R0+1;

restore_state:	RETURN (DB);
		RESTORE_STACK
		RESTORE_FRAME

.ENDSEG;