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Annotation of XNU/osfmk/i386/bzero.s, revision 1.1.1.1

1.1       root        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  [email protected]
                     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

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