/* 
 * Written by the Chair for Operating Systems, RWTH Aachen University
 * 
 * NO Copyright (C) 2010-2011, Stefan Lankes
 * consider these trivial functions to be public domain.
 * 
 * These functions are distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 */

#ifndef __ARCH_STRING_H__
#define __ARCH_STRING_H__

#include <metalsvm/stddef.h>
#include <asm/scc_memcpy.h>

#ifdef __cplusplus
extern "C" {
#endif

/* 
 * This function copies a physical page to its new physical destination.
 */
void copy_page_physical(void* dest, const void * src);

#ifdef HAVE_ARCH_MEMCPY
inline static void *memcpy(void* dest, const void *src, size_t count)
{
	int32_t i, j, k;

	if (BUILTIN_EXPECT(!dest || !src, 0))
		return dest;

	asm volatile (
		"cld; rep ; movsl\n\t"
		"movl %4, %%ecx\n\t" 
		"andl $3, %%ecx\n\t"
		"rep ; movsb\n\t" 
		: "=&c"(i), "=&D"(j), "=&S"(k) 
		: "0"(count/4), "g"(count), "1"(dest), "2"(src) : "memory");

	return dest;
}
#endif

#ifdef HAVE_ARCH_MEMSET
inline static void *memset(void* dest, int val, size_t count)
{
	int32_t i, j;

	if (BUILTIN_EXPECT(!dest, 0))
		return dest;

	asm volatile ("cld; rep ; stosb" 
		: "=&c"(i), "=&D"(j)
		: "a"(val), "1"(dest), "0"(count) : "memory");

	return dest;
}
#endif

#ifdef HAVE_ARCH_STRLEN
inline static size_t strlen(const char* str)
{
	size_t len = 0;
	uint32_t i, j;

	if (BUILTIN_EXPECT(!str, 0))
		return len;

	asm volatile("not %%ecx; cld; repne ; scasb; not %%ecx; dec %%ecx"
		: "=&c"(len), "=&D"(i), "=&a"(j)
		: "2"(0), "1"(str), "0"(len)
		: "memory");

	return len;
}
#endif

#ifdef HAVE_ARCH_STRNCPY
char* strncpy(char* dest, const char* src, size_t n);
#endif

#ifdef HAVE_ARCH_STRCPY
char* strcpy(char* dest, const char* src);
#endif

#ifdef __cplusplus
}
#endif

#endif