/*
* Copyright (C) 2005 Sergey Bondari
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef __amd64_MEMSTR_H__
#define __amd64_MEMSTR_H__
/** Copy memory
*
* Copy a given number of bytes (3rd argument)
* from the memory location defined by 2nd argument
* to the memory location defined by 1st argument.
* The memory areas cannot overlap.
*
* @param dst Destination
* @param src Source
* @param cnt Number of bytes
* @return Destination
*/
static inline void * memcpy(void * dst, const void * src, size_t cnt)
{
__native d0, d1, d2;
__asm__ __volatile__(
"rep movsq\n\t"
"movq %4, %%rcx\n\t"
"andq $7, %%rcx\n\t"
"jz 1f\n\t"
"rep movsb\n\t"
"1:\n"
: "=&c" (d0), "=&D" (d1), "=&S" (d2)
: "0" ((__native)(cnt / 8)), "g" ((__native)cnt), "1" ((__native) dst), "2" ((__native) src)
: "memory");
return dst;
}
/** Compare memory regions for equality
*
* Compare a given number of bytes (3rd argument)
* at memory locations defined by 1st and 2nd argument
* for equality. If bytes are equal function returns 0.
*
* @param src Region 1
* @param dst Region 2
* @param cnt Number of bytes
* @return Zero if bytes are equal, non-zero otherwise
*/
static inline int memcmp(const void * src, const void * dst, size_t cnt)
{
__native d0, d1, d2;
__native ret;
__asm__ (
"repe cmpsb\n\t"
"je 1f\n\t"
"movq %3, %0\n\t"
"addq $1, %0\n\t"
"1:\n"
: "=a" (ret), "=%S" (d0), "=&D" (d1), "=&c" (d2)
: "0" (0), "1" (src), "2" (dst), "3" ((__native)cnt)
);
return ret;
}
/** Fill memory with words
* Fill a given number of words (2nd argument)
* at memory defined by 1st argument with the
* word value defined by 3rd argument.
*
* @param dst Destination
* @param cnt Number of words
* @param x Value to fill
*/
static inline void memsetw(__address dst, size_t cnt, __u16 x)
{
__native d0, d1;
__asm__ __volatile__ (
"rep stosw\n\t"
: "=&D" (d0), "=&c" (d1), "=a" (x)
: "0" (dst), "1" ((__native)cnt), "2" (x)
: "memory"
);
}
/** Fill memory with bytes
* Fill a given number of bytes (2nd argument)
* at memory defined by 1st argument with the
* word value defined by 3rd argument.
*
* @param dst Destination
* @param cnt Number of bytes
* @param x Value to fill
*/
static inline void memsetb(__address dst, size_t cnt, __u8 x)
{
__native d0, d1;
__asm__ __volatile__ (
"rep stosb\n\t"
: "=&D" (d0), "=&c" (d1), "=a" (x)
: "0" (dst), "1" ((__native)cnt), "2" (x)
: "memory"
);
}
#endif