scoutos / prex-0.9.0 / usr / lib / libc / string / bcopy.c @ 03e9c04a
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1 | 03e9c04a | Brad Neuman | /*-
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2 | * Copyright (c) 1990, 1993
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3 | * The Regents of the University of California. All rights reserved.
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4 | *
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5 | * This code is derived from software contributed to Berkeley by
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6 | * Chris Torek.
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7 | *
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8 | * Redistribution and use in source and binary forms, with or without
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9 | * modification, are permitted provided that the following conditions
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10 | * are met:
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11 | * 1. Redistributions of source code must retain the above copyright
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12 | * notice, this list of conditions and the following disclaimer.
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13 | * 2. Redistributions in binary form must reproduce the above copyright
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14 | * notice, this list of conditions and the following disclaimer in the
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15 | * documentation and/or other materials provided with the distribution.
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16 | * 3. Neither the name of the University nor the names of its contributors
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17 | * may be used to endorse or promote products derived from this software
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18 | * without specific prior written permission.
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19 | *
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20 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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21 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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22 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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23 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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24 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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25 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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26 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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27 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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28 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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29 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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30 | * SUCH DAMAGE.
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31 | */
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32 | |||
33 | #include <sys/cdefs.h> |
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34 | #include <string.h> |
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35 | |||
36 | /*
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37 | * Copy a block of memory, handling overlap.
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38 | * This is the routine that actually implements
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39 | * (the portable versions of) bcopy, memcpy, and memmove.
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40 | */
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41 | #ifdef MEMCOPY
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42 | void *
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43 | memcpy(dst0, src0, length) |
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44 | #else
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45 | #ifdef MEMMOVE
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46 | void *
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47 | memmove(dst0, src0, length) |
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48 | #else
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49 | void
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50 | bcopy(src0, dst0, length) |
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51 | #endif
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52 | #endif
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53 | void *dst0;
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54 | const void *src0; |
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55 | size_t length; |
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56 | { |
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57 | char *dst = dst0;
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58 | const char *src = src0; |
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59 | |||
60 | if (length == 0 || dst == src) /* nothing to do */ |
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61 | goto done;
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62 | |||
63 | if (((unsigned long)dst < (unsigned long)src) && |
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64 | ((unsigned long)dst < (unsigned long)src + length)) { |
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65 | /* Copy backwards. */
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66 | src += length; |
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67 | dst += length; |
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68 | while (length--) {
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69 | *--dst = *--src; |
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70 | } |
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71 | } else {
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72 | while (length--) {
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73 | *dst++ = *src++; |
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74 | } |
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75 | } |
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76 | done:
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77 | #if defined(MEMCOPY) || defined(MEMMOVE)
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78 | return (dst0);
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79 | #else
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80 | return;
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81 | #endif
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82 | } |