osfmk/i386/bzero.s

   1 /*
   2  * Copyright (c) 2000 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  * @OSF_COPYRIGHT@
  24  */
  25 /*
  26  * Mach Operating System
  27  * Copyright (c) 1991,1990 Carnegie Mellon University
  28  * All Rights Reserved.
  29  *
  30  * Permission to use, copy, modify and distribute this software and its
  31  * documentation is hereby granted, provided that both the copyright
  32  * notice and this permission notice appear in all copies of the
  33  * software, derivative works or modified versions, and any portions
  34  * thereof, and that both notices appear in supporting documentation.
  35  *
  36  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  37  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  38  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  39  *
  40  * Carnegie Mellon requests users of this software to return to
  41  *
  42  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  43  *  School of Computer Science
  44  *  Carnegie Mellon University
  45  *  Pittsburgh PA 15213-3890
  46  *
  47  * any improvements or extensions that they make and grant Carnegie Mellon
  48  * the rights to redistribute these changes.
  49  */
  50 /*
  51  */
  52
  53 #include <i386/asm.h>
  54
  55 /*
  56  * void *memset(void * addr, int pattern, size_t length)
  57  */
  58
  59 ENTRY(memset)
  60         pushl   %edi
  61         movl    4+ 4(%esp),%edi         /* addr */
  62         movb    4+ 8(%esp),%al          /* pattern */
  63         movl    4+ 12(%esp),%edx        /* length */
  64         movb    %al,%ah
  65         movw    %ax,%cx
  66         shll    $16,%eax
  67         movw    %cx,%ax
  68         cld
  69 /* zero longs */
  70         movl    %edx,%ecx
  71         shrl    $2,%ecx
  72         rep
  73         stosl
  74 /* zero bytes */
  75         movl    %edx,%ecx
  76         andl    $3,%ecx
  77         rep
  78         stosb
  79         movl    4+ 4(%esp),%eax         /* returns its first argument */
  80         popl    %edi
  81         ret
  82
  83 /*
  84  * void bzero(char * addr, unsigned int length)
  85  */
  86 Entry(blkclr)
  87 ENTRY(bzero)
  88         pushl   %edi
  89         movl    4+ 4(%esp),%edi         /* addr */
  90         movl    4+ 8(%esp),%edx         /* length */
  91         xorl    %eax,%eax
  92         cld
  93 /* zero longs */
  94         movl    %edx,%ecx
  95         shrl    $2,%ecx
  96         rep
  97         stosl
  98 /* zero bytes */
  99         movl    %edx,%ecx
 100         andl    $3,%ecx
 101         rep
 102         stosb
 103         popl    %edi
 104         ret