osfmk/i386/bzero.s

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25  /*
  26  * @OSF_COPYRIGHT@
  27  */
  28 /*
  29  * Mach Operating System
  30  * Copyright (c) 1991,1990 Carnegie Mellon University
  31  * All Rights Reserved.
  32  *
  33  * Permission to use, copy, modify and distribute this software and its
  34  * documentation is hereby granted, provided that both the copyright
  35  * notice and this permission notice appear in all copies of the
  36  * software, derivative works or modified versions, and any portions
  37  * thereof, and that both notices appear in supporting documentation.
  38  *
  39  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  40  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  41  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  42  *
  43  * Carnegie Mellon requests users of this software to return to
  44  *
  45  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  46  *  School of Computer Science
  47  *  Carnegie Mellon University
  48  *  Pittsburgh PA 15213-3890
  49  *
  50  * any improvements or extensions that they make and grant Carnegie Mellon
  51  * the rights to redistribute these changes.
  52  */
  53 /*
  54  */
  55
  56 #include <i386/asm.h>
  57
  58 /*
  59  * void *memset(void * addr, int pattern, size_t length)
  60  */
  61
  62 ENTRY(memset)
  63         pushl   %edi
  64         movl    4+ 4(%esp),%edi         /* addr */
  65         movb    4+ 8(%esp),%al          /* pattern */
  66         movl    4+ 12(%esp),%edx        /* length */
  67         movb    %al,%ah
  68         movw    %ax,%cx
  69         shll    $16,%eax
  70         movw    %cx,%ax
  71         cld
  72 /* zero longs */
  73         movl    %edx,%ecx
  74         shrl    $2,%ecx
  75         rep
  76         stosl
  77 /* zero bytes */
  78         movl    %edx,%ecx
  79         andl    $3,%ecx
  80         rep
  81         stosb
  82         movl    4+ 4(%esp),%eax         /* returns its first argument */
  83         popl    %edi
  84         ret
  85
  86 /*
  87  * void bzero(char * addr, unsigned int length)
  88  */
  89 Entry(blkclr)
  90 ENTRY(bzero)
  91         pushl   %edi
  92         movl    4+ 4(%esp),%edi         /* addr */
  93         movl    4+ 8(%esp),%edx         /* length */
  94         xorl    %eax,%eax
  95         cld
  96 /* zero longs */
  97         movl    %edx,%ecx
  98         shrl    $2,%ecx
  99         rep
 100         stosl
 101 /* zero bytes */
 102         movl    %edx,%ecx
 103         andl    $3,%ecx
 104         rep
 105         stosb
 106         popl    %edi
 107         ret