| 1 | /* $Id: kHlpMemMove.c 3608 2007-10-29 00:49:05Z bird $ */
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| 2 | /** @file
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| 3 | * kHlpString - kHlpMemMove.
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| 4 | */
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| 5 |
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| 6 | /*
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| 7 | * Copyright (c) 2006-2007 knut st. osmundsen <bird-kStuff-spam@anduin.net>
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| 8 | *
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| 9 | * This file is part of kStuff.
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| 10 | *
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| 11 | * kStuff is free software; you can redistribute it and/or
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| 12 | * modify it under the terms of the GNU Lesser General Public
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| 13 | * License as published by the Free Software Foundation; either
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| 14 | * version 2.1 of the License, or (at your option) any later version.
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| 15 | *
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| 16 | * In addition to the permissions in the GNU Lesser General Public
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| 17 | * License, you are granted unlimited permission to link the compiled
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| 18 | * version of this file into combinations with other programs, and to
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| 19 | * distribute those combinations without any restriction coming from
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| 20 | * the use of this file.
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| 21 | *
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| 22 | * kStuff is distributed in the hope that it will be useful,
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| 23 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 24 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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| 25 | * Lesser General Public License for more details.
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| 26 | *
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| 27 | * You should have received a copy of the GNU Lesser General Public
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| 28 | * License along with kStuff; if not, write to the Free Software
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| 29 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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| 30 | * 02110-1301, USA
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| 31 | */
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| 32 |
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| 33 | /*******************************************************************************
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| 34 | * Header Files *
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| 35 | *******************************************************************************/
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| 36 | #include <k/kHlpString.h>
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| 37 |
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| 38 |
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| 39 | KHLP_DECL(void *) kHlpMemMove(void *pv1, const void *pv2, KSIZE cb)
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| 40 | {
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| 41 | union
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| 42 | {
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| 43 | void *pv;
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| 44 | KU8 *pb;
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| 45 | KUPTR *pu;
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| 46 | } u1;
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| 47 | union
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| 48 | {
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| 49 | const void *pv;
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| 50 | volatile KU8 *pb;
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| 51 | volatile KUPTR *pu;
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| 52 | } u2;
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| 53 |
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| 54 | u1.pv = pv1;
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| 55 | u2.pv = pv2;
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| 56 |
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| 57 | if ((KUPTR)u1.pb <= (KUPTR)u2.pb)
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| 58 | {
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| 59 | /* forward copy */
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| 60 | if (cb >= 32)
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| 61 | {
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| 62 | while (cb > sizeof(KUPTR))
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| 63 | {
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| 64 | KUPTR u = *u2.pu++;
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| 65 | *u1.pu++ = u;
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| 66 | cb -= sizeof(KUPTR);
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| 67 | }
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| 68 | }
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| 69 |
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| 70 | while (cb-- > 0)
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| 71 | {
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| 72 | KU8 b = *u2.pb++;
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| 73 | *u1.pb++ = b;
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| 74 | }
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| 75 | }
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| 76 | else
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| 77 | {
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| 78 | /* backwards copy */
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| 79 | u1.pb += cb;
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| 80 | u2.pb += cb;
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| 81 |
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| 82 | if (cb >= 32)
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| 83 | {
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| 84 | while (cb > sizeof(KUPTR))
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| 85 | {
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| 86 | KUPTR u = *--u2.pu;
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| 87 | *--u1.pu = u;
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| 88 | cb -= sizeof(KUPTR);
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| 89 | }
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| 90 | }
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| 91 |
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| 92 | while (cb-- > 0)
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| 93 | {
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| 94 | KU8 b = *--u2.pb;
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| 95 | *--u1.pb = b;
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| 96 | }
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| 97 | }
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| 98 |
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| 99 | return pv1;
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| 100 | }
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| 101 |
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| 102 |
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