mc8051fun/long_mul__.c

#include "mc8051fun.h"

/*
 * val0,val1 = r0,r1
 * r2 = result
 * r7 = len of val0,val1
 */
void long_mul__()  __naked
{

	__asm
	.globl	long_mul

long_mul:
	push	AR0
	push 	AR7
	mov	r0,AR2
	lcall	long_fill_zero
	pop	AR7
	pop	AR0
	
	mov	r6,#8
	mov	a,@r1
000$:
	rrc	a
	jnc	001$

	push	ACC
	push	AR0
	push	AR1
	push	AR7
	mov	r1,AR0
	mov	r0,AR2
	lcall	long_add
	pop	AR7
	pop	AR1
	pop	AR0
	pop	ACC	

001$:
	push	ACC
	push	AR7
	push	AR0
	clr	c
	lcall	long_rlc
	pop	AR0
	pop	AR7
	pop	ACC

	djnz	r6,000$
	ret	
	__endasm;
}