osfmk/i386/bzero.s

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