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  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 /*-
  25  * Copyright (c) 1990 The Regents of the University of California.
  26  * All rights reserved.
  27  *
  28  * This code is derived from locore.s.
  29  *
  30  * Redistribution and use in source and binary forms, with or without
  31  * modification, are permitted provided that the following conditions
  32  * are met:
  33  * 1. Redistributions of source code must retain the above copyright
  34  *    notice, this list of conditions and the following disclaimer.
  35  * 2. Redistributions in binary form must reproduce the above copyright
  36  *    notice, this list of conditions and the following disclaimer in the
  37  *    documentation and/or other materials provided with the distribution.
  38  * 3. All advertising materials mentioning features or use of this software
  39  *    must display the following acknowledgement:
  40  *      This product includes software developed by the University of
  41  *      California, Berkeley and its contributors.
  42  * 4. Neither the name of the University nor the names of its contributors
  43  *    may be used to endorse or promote products derived from this software
  44  *    without specific prior written permission.
  45  *
  46  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  47  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  48  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  49  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  50  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  51  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  52  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  53  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  54  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  55  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  56  * SUCH DAMAGE.
  57  */
  58
  59 #include <sys/appleapiopts.h>
  60 #include <machine/cpu_capabilities.h>
  61 #include <machine/commpage.h>
  62 #include <machine/asm.h>
  63
  64         /*
  65          * (ov)bcopy (src,dst,cnt)
  66          *  ws@tools.de     (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
  67          */
  68
  69 .text
  70 .align 5, 0x90
  71 Lbcopy_scalar:
  72         pushl   %esi
  73         pushl   %edi
  74         movl    12(%esp),%esi
  75         movl    16(%esp),%edi
  76         jmp     1f
  77 /*
  78 ** These need to be 32 bytes from Lbcopy_scalar
  79 */
  80 .align 5, 0x90
  81 Lmemcpy_scalar:
  82 Lmemmove_scalar:
  83         pushl   %esi
  84         pushl   %edi
  85         movl    12(%esp),%edi
  86         movl    16(%esp),%esi
  87         movl    %edi,%eax
  88 1:
  89         movl    20(%esp),%ecx
  90         movl    %edi,%edx
  91         subl    %esi,%edx
  92         cmpl    %ecx,%edx       /* overlapping? */
  93         jb      2f
  94         cld                     /* nope, copy forwards. */
  95         movl    %ecx,%edx
  96         shrl    $2,%ecx         /* copy by words */
  97         rep
  98         movsl
  99         movl    %edx,%ecx
 100         andl    $3,%ecx         /* any bytes left? */
 101         rep
 102         movsb
 103         popl    %edi
 104         popl    %esi
 105         ret
 106 2:
 107         addl    %ecx,%edi       /* copy backwards. */
 108         addl    %ecx,%esi
 109         std
 110         movl    %ecx,%edx
 111         andl    $3,%ecx         /* any fractional bytes? */
 112         decl    %edi
 113         decl    %esi
 114         rep
 115         movsb
 116         movl    %edx,%ecx       /* copy remainder by words */
 117         shrl    $2,%ecx
 118         subl    $3,%esi
 119         subl    $3,%edi
 120         rep
 121         movsl
 122         popl    %edi
 123         popl    %esi
 124         cld
 125         ret
 126
 127         COMMPAGE_DESCRIPTOR(bcopy_scalar,_COMM_PAGE_BCOPY,0,0)