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  * 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  *  mem.c - Standard memory functions.
  24  *
  25  *  Copyright (c) 1998-2002 Apple Computer, Inc.
  26  *
  27  *  DRI: Josh de Cesare
  28  */
  29
  30 #import <libclite.h>
  31 #import <ci.h>
  32
  33
  34 void *memcpy(void *dst, const void *src, size_t len)
  35 {
  36   const char *s = src;
  37   char       *d = dst;
  38   int        pos = 0, dir = 1;
  39
  40   if (d > s) {
  41     dir = -1;
  42     pos = len - 1;
  43   }
  44
  45   while (len--) {
  46     d[pos] = s[pos];
  47     pos += dir;
  48   }
  49
  50   return dst;
  51 }
  52
  53
  54 void *memset(void *dst, int ch, size_t len)
  55 {
  56   long tmp = 0x01010101 * (ch & 0x000000FF);
  57
  58   if (len < 32) while (len--) *(((char *)dst)++) = ch;
  59   else {
  60     // do the front chunk as chars
  61     while ((long)dst & 3) {
  62       len--;
  63       *(((char *)dst)++) = ch;
  64     }
  65
  66     // do the middle chunk as longs
  67     while (len > 3) {
  68       len -= 4;
  69       *(((long *)dst)++) = tmp;
  70     }
  71
  72     // do the last chunk as chars
  73     while (len--) *(((char *)dst)++) = ch;
  74   }
  75
  76   return dst;
  77 }
  78
  79 void *bcopy(void *src, void *dst, int len)
  80 {
  81   return memcpy(dst, src, len);
  82 }
  83
  84 void bzero(void *dst, int len)
  85 {
  86   memset(dst, 0, len);
  87 }
  88