osfmk/i386/commpage/bcopy_scalar.s

   1 /*
   2  * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22
  23 /*-
  24  * Copyright (c) 1990 The Regents of the University of California.
  25  * All rights reserved.
  26  *
  27  * This code is derived from locore.s.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 3. All advertising materials mentioning features or use of this software
  38  *    must display the following acknowledgement:
  39  *      This product includes software developed by the University of
  40  *      California, Berkeley and its contributors.
  41  * 4. Neither the name of the University nor the names of its contributors
  42  *    may be used to endorse or promote products derived from this software
  43  *    without specific prior written permission.
  44  *
  45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  55  * SUCH DAMAGE.
  56  */
  57
  58 #include <sys/appleapiopts.h>
  59 #include <machine/cpu_capabilities.h>
  60 #include <machine/commpage.h>
  61 #include <machine/asm.h>
  62
  63         /*
  64          * (ov)bcopy (src,dst,cnt)
  65          *  ws@tools.de     (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
  66          */
  67
  68 .text
  69 .align 5, 0x90
  70 Lbcopy_scalar:
  71         pushl   %esi
  72         pushl   %edi
  73         movl    12(%esp),%esi
  74         movl    16(%esp),%edi
  75         jmp     1f
  76 /*
  77 ** These need to be 32 bytes from Lbcopy_scalar
  78 */
  79 .align 5, 0x90
  80 Lmemcpy_scalar:
  81 Lmemmove_scalar:
  82         pushl   %esi
  83         pushl   %edi
  84         movl    12(%esp),%edi
  85         movl    16(%esp),%esi
  86         movl    %edi,%eax
  87 1:
  88         movl    20(%esp),%ecx
  89         movl    %edi,%edx
  90         subl    %esi,%edx
  91         cmpl    %ecx,%edx       /* overlapping? */
  92         jb      2f
  93         cld                     /* nope, copy forwards. */
  94         movl    %ecx,%edx
  95         shrl    $2,%ecx         /* copy by words */
  96         rep
  97         movsl
  98         movl    %edx,%ecx
  99         andl    $3,%ecx         /* any bytes left? */
 100         rep
 101         movsb
 102         popl    %edi
 103         popl    %esi
 104         ret
 105 2:
 106         addl    %ecx,%edi       /* copy backwards. */
 107         addl    %ecx,%esi
 108         std
 109         movl    %ecx,%edx
 110         andl    $3,%ecx         /* any fractional bytes? */
 111         decl    %edi
 112         decl    %esi
 113         rep
 114         movsb
 115         movl    %edx,%ecx       /* copy remainder by words */
 116         shrl    $2,%ecx
 117         subl    $3,%esi
 118         subl    $3,%edi
 119         rep
 120         movsl
 121         popl    %edi
 122         popl    %esi
 123         cld
 124         ret
 125
 126         COMMPAGE_DESCRIPTOR(bcopy_scalar,_COMM_PAGE_BCOPY,0,0)