/* 
 * Copyright 2010 Stefan Lankes, Chair for Operating Systems,
 *                               RWTH Aachen University
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * This file is part of MetalSVM.
 */

#ifndef __ARCH_STRING_H__
#define __ARCH_STRING_H__

#include <metalsvm/stddef.h>

#ifdef __cplusplus
extern "C" {
#endif

#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