/*      $NetBSD: memcpy.S,v 1.4 2014/03/22 19:38:46 jakllsch Exp $      */

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from locore.s.
 * Optimised by David Laight 2003
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 */

#ifdef __HAIKU__
#include <asm_defs.h>
#endif

        /*
         * (ov)bcopy (src,dst,cnt)
         *  ws@tools.de     (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
         */

#ifdef BCOPY
ENTRY(bcopy)
#else
#ifdef MEMMOVE
ENTRY(memmove)
#else
#define MEMCPY
#define NO_OVERLAP
.align 4
FUNCTION(memcpy):
#endif
#endif
        push    %esi
        mov     %edi,%edx
#if defined(MEMCPY) || defined(MEMMOVE)
        movl    8(%esp),%edi
        movl    12(%esp),%esi
#else
        movl    8(%esp),%esi
        movl    12(%esp),%edi
#endif
        movl    16(%esp),%ecx
#if defined(NO_OVERLAP)
        movl    %ecx,%eax
#else
        movl    %edi,%eax
        subl    %esi,%eax
        cmpl    %ecx,%eax       /* overlapping? */
        movl    %ecx,%eax
        jb      .Lbackwards
#endif
        /* nope, copy forwards. */
        shrl    $2,%ecx         /* copy by words */
        rep
        movsl
        and     $3,%eax         /* any bytes left? */
        jnz     .Ltrailing
.Ldone:
#if defined(MEMCPY) || defined(MEMMOVE)
        movl    8(%esp),%eax
#endif
        mov     %edx,%edi
        pop     %esi
        ret

.Ltrailing:
        cmp     $2,%eax
        jb      1f
        movw    (%esi),%ax
        movw    %ax,(%edi)
        je      .Ldone
        movb    2(%esi),%al
        movb    %al,2(%edi)
        jmp     .Ldone
1:      movb    (%esi),%al
        movb    %al,(%edi)
        jmp     .Ldone

#if !defined(NO_OVERLAP)
.Lbackwards:
        addl    %ecx,%edi       /* copy backwards. */
        addl    %ecx,%esi
        and     $3,%eax         /* any fractional bytes? */
        jnz     .Lback_align
.Lback_aligned:
        shrl    $2,%ecx
        subl    $4,%esi
        subl    $4,%edi
        std
        rep
        movsl
        cld
        jmp     .Ldone

.Lback_align:
        sub     %eax,%esi
        sub     %eax,%edi
        cmp     $2,%eax
        jb      1f
        je      2f
        movb    2(%esi),%al
        movb    %al,2(%edi)
2:      movw    (%esi),%ax
        movw    %ax,(%edi)
        jmp     .Lback_aligned
1:      movb    (%esi),%al
        movb    %al,(%edi)
        jmp     .Lback_aligned
#endif

#ifdef BCOPY
END(bcopy)
#else
#ifdef MEMMOVE
END(memmove)
#else
FUNCTION_END(memcpy)
SYMBOL(memcpy_end):
#endif
#endif