bootx.tproj/libclite.subproj/mem.c

   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  *  mem.c - Standard memory functions.
  27  *
  28  *  Copyright (c) 1998-2002 Apple Computer, Inc.
  29  *
  30  *  DRI: Josh de Cesare
  31  */
  32
  33 #import <libclite.h>
  34 #import <ci.h>
  35
  36
  37 void *memcpy(void *dst, const void *src, size_t len)
  38 {
  39   const char *s = src;
  40   char       *d = dst;
  41   int        pos = 0, dir = 1;
  42
  43   if (d > s) {
  44     dir = -1;
  45     pos = len - 1;
  46   }
  47
  48   while (len--) {
  49     d[pos] = s[pos];
  50     pos += dir;
  51   }
  52
  53   return dst;
  54 }
  55
  56
  57 void *memset(void *dst, int ch, size_t len)
  58 {
  59   long tmp = 0x01010101 * (ch & 0x000000FF);
  60
  61   if (len < 32) while (len--) *(((char *)dst)++) = ch;
  62   else {
  63     // do the front chunk as chars
  64     while ((long)dst & 3) {
  65       len--;
  66       *(((char *)dst)++) = ch;
  67     }
  68
  69     // do the middle chunk as longs
  70     while (len > 3) {
  71       len -= 4;
  72       *(((long *)dst)++) = tmp;
  73     }
  74
  75     // do the last chunk as chars
  76     while (len--) *(((char *)dst)++) = ch;
  77   }
  78
  79   return dst;
  80 }
  81
  82 void bcopy(const void *src, void *dst, size_t len)
  83 {
  84   memcpy(dst, src, len);
  85 }
  86
  87 void bzero(void *dst, int len)
  88 {
  89   memset(dst, 0, len);
  90 }
  91