| 1 | /* Copyright (C) 1998 Free Software Foundation, Inc. | 
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| 2 |  | 
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| 3 | This program is free software; you can redistribute it and/or modify it | 
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| 4 | under the terms of the GNU General Public License as published by the | 
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| 5 | Free Software Foundation; either version 2, or (at your option) any | 
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| 6 | later version. | 
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| 7 |  | 
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| 8 | This program is distributed in the hope that it will be useful, | 
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| 9 | but WITHOUT ANY WARRANTY; without even the implied warranty of | 
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| 10 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the | 
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| 11 | GNU General Public License for more details. | 
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| 12 |  | 
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| 13 | You should have received a copy of the GNU General Public License | 
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| 14 | along with this program; if not, write to the Free Software | 
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| 15 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, | 
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| 16 | USA.  */ | 
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| 17 |  | 
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| 18 | /* Last ditch effort to support memmove: if user doesn't have | 
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| 19 | memmove or bcopy, we offer this sluggish implementation. */ | 
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| 20 |  | 
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| 21 | #include "config.h" | 
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| 22 | #ifndef HAVE_MEMMOVE | 
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| 23 |  | 
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| 24 | #include <sys/types.h> | 
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| 25 | #ifdef HAVE_MEMORY_H | 
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| 26 | # include <memory.h> | 
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| 27 | #endif | 
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| 28 |  | 
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| 29 | #ifndef VOID | 
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| 30 | # define VOID void | 
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| 31 | #endif | 
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| 32 |  | 
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| 33 | VOID * | 
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| 34 | memmove(dest, src, len) | 
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| 35 | VOID *dest; | 
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| 36 | const VOID *src; | 
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| 37 | size_t len; | 
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| 38 | { | 
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| 39 | #ifdef HAVE_BCOPY | 
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| 40 | bcopy(src, dest, len); | 
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| 41 |  | 
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| 42 | #else /*!HAVE_BCOPY*/ | 
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| 43 | char *dp = dest; | 
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| 44 | const char *sp = src; | 
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| 45 |  | 
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| 46 | # ifdef HAVE_MEMCPY | 
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| 47 | /* A special-case for non-overlapping regions, on the assumption | 
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| 48 | that there is some hope that the sytem's memcpy() implementaion | 
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| 49 | is better than our dumb fall-back one. */ | 
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| 50 | if ((dp < sp && dp+len < sp) || (sp < dp && sp+len < dp)) | 
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| 51 | return memcpy(dest, src, len); | 
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| 52 | # endif | 
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| 53 |  | 
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| 54 | /* I tried real hard to avoid getting to this point. | 
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| 55 | You *really* ought to upgrade your system's libraries; | 
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| 56 | the performance of this implementation sucks. */ | 
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| 57 | if (dp < sp) | 
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| 58 | { | 
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| 59 | while (len-- > 0) | 
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| 60 | *dp++ = *sp++; | 
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| 61 | } | 
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| 62 | else | 
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| 63 | { | 
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| 64 | if (dp == sp) | 
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| 65 | return dest; | 
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| 66 | dp += len; | 
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| 67 | sp += len; | 
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| 68 | while (len-- > 0) | 
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| 69 | *--dp = *--sp; | 
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| 70 | } | 
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| 71 | #endif /*!HAVE_BCOPY*/ | 
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| 72 |  | 
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| 73 | return dest; | 
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| 74 | } | 
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| 75 |  | 
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| 76 | #endif  /*!HAVE_MEMMOVE*/ | 
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