#include "string.h"

#if 1

char * strcpy(char * dst, const char * src)
{
	__asm 
	{
		lda dst
		sta accu
		lda dst + 1
		sta accu + 1

		ldy #0
	L1:	lda (src), y
		sta (dst), y
		beq W1
		iny
		lda (src), y
		sta (dst), y
		beq W1
		iny
		bne L1
		inc src + 1
		inc dst + 1
		bne L1
	W1:

	}
}

#else
char * strcpy(char * dst, const char * src)
{
	char * d = dst;
	const char * s = src;

	do {} while (*d++ = *s++);
	
	return dst;
}
#endif

#pragma native(strcpy)

#if 1

int strcmp(const char * ptr1, const char * ptr2)
{
	__asm 
	{
		ldy #0
		sty accu + 1
	L1: lda (ptr1), y
		beq W1
		cmp (ptr2), y
		bne W2
		iny
		lda (ptr1), y
		beq W1
		cmp (ptr2), y
		bne W2
		iny
		bne L1
		inc ptr1 + 1
		inc ptr2 + 1
		bne L1

	W1:	cmp (ptr2), y
		beq E

	W2:	bcs W3

		lda #$ff
		sta accu + 1
		bmi E

	W3: lda #$01

	E:
		sta accu
	}
}

#else
int strcmp(const char * ptr1, const char * ptr2)
{
	const char	*	p = ptr1, * q = ptr2;
	char		c, d;
	while ((c = *p++) == (d = *q++))
	{
		if (!c)
			return 0;
	}
	if (c < d)
		return -1;
	else
		return 1;
}
#endif

#pragma native(strcmp)

int strlen(const char * str)
{
	const char	*	s = str;
	
	int i = 0;
	while (s[i])
		i++;
	return i;
}

#pragma native(strlen)

char * strcat(char * dst, const char * src)
{
	char * d = dst;
	const char * s = src;

	while (*d)
		d++;
	
	do {} while (*d++ = *s++);
	
	return dst;
}	

#pragma native(strcat)

char * cpycat(char * dst, const char * src)
{
	do {} while (*dst++ = *src++);
	
	return dst;	
}

#pragma native(cpycat)

void * memset(void * dst, int value, int size)
{
	__asm
	{
			lda	value

			ldx	size + 1
			beq	_w1
			ldy	#0
	_loop1:
			sta (dst), y
			iny
			bne	_loop1
			inc dst + 1
			dex
			bne	_loop1
	_w1:
			ldy	size
			beq	_w2
	_loop2:
			dey
			sta (dst), y
			bne _loop2
	_w2:
	}
	return dst;
}
	

void * memclr(void * dst, int size)
{
	char	*	d = dst;
	while (size--)
		*d++ = 0;
	return dst;
}	

void * memcpy(void * dst, const void * src, int size)
{
	__asm
	{
			ldx	size + 1
			beq	_w1
			ldy	#0
	_loop1:
			lda (src), y
			sta (dst), y
			iny
			bne	_loop1
			inc src + 1
			inc dst + 1
			dex
			bne	_loop1
	_w1:
			ldy	size
			beq	_w2
			dey
			beq	_w3
	_loop2:
			lda (src), y
			sta (dst), y
			dey
			bne _loop2
	_w3:
			lda (src), y
			sta (dst), y
	_w2:
	}
	return dst;
#if 0

	char	*	d = dst, * s = src;
	while (size--)
		*d++ = *s++;
	return dst;
#endif
}

#pragma native(memcpy)

void * memmove(void * dst, const void * src, int size)
{	
	int	sz = size;
	if (sz > 0)
	{
		char	*	d = dst, * s = src;
		if (d < s)
		{
			do {
				*d++ = *s++;				
			} while (--sz);
		}
		else if (d > s)
		{
			d += sz;
			s += sz;
			do {
				*--d = *--s;
			} while (--sz);
		}	
	}
	return dst;
}

int memcmp(const void * ptr1, const void * ptr2, int size)
{
	char	*	p = ptr1, * q = ptr2;
	char		c, d;

	while (size--)
	{
		c = *p++;
		d = *q++;
		if (c < d)
			return -1;
		else if (c > d)
			return 1;
	}
	
	return 0;
}