osfmk/i386/bzero.s

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