| 1 | /* $Id: bs3-cmn-MemMove.c 93115 2022-01-01 11:31:46Z vboxsync $ */
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| 2 | /** @file
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| 3 | * BS3Kit - Bs3MemMove
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| 4 | */
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| 5 |
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| 6 | /*
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| 7 | * Copyright (C) 2007-2022 Oracle Corporation
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| 8 | *
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| 9 | * This file is part of VirtualBox Open Source Edition (OSE), as
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| 10 | * available from http://www.virtualbox.org. This file is free software;
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| 11 | * you can redistribute it and/or modify it under the terms of the GNU
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| 12 | * General Public License (GPL) as published by the Free Software
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| 13 | * Foundation, in version 2 as it comes in the "COPYING" file of the
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| 14 | * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
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| 15 | * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
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| 16 | *
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| 17 | * The contents of this file may alternatively be used under the terms
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| 18 | * of the Common Development and Distribution License Version 1.0
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| 19 | * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
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| 20 | * VirtualBox OSE distribution, in which case the provisions of the
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| 21 | * CDDL are applicable instead of those of the GPL.
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| 22 | *
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| 23 | * You may elect to license modified versions of this file under the
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| 24 | * terms and conditions of either the GPL or the CDDL or both.
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| 25 | */
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| 26 |
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| 27 | #include "bs3kit-template-header.h"
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| 28 |
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| 29 | #undef Bs3MemMove
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| 30 | BS3_CMN_DEF(void BS3_FAR *, Bs3MemMove,(void BS3_FAR *pvDst, const void BS3_FAR *pvSrc, size_t cbToCopy))
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| 31 | {
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| 32 | size_t cLargeRounds;
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| 33 | BS3CVPTRUNION uSrc;
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| 34 | BS3PTRUNION uDst;
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| 35 | uSrc.pv = pvSrc;
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| 36 | uDst.pv = pvDst;
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| 37 |
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| 38 | /* We don't care about segment wrapping here. */
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| 39 | if ((uintptr_t)pvDst > (uintptr_t)pvSrc + cbToCopy)
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| 40 | {
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| 41 | /* Reverse copy. */
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| 42 | uSrc.pb += cbToCopy;
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| 43 | uDst.pb += cbToCopy;
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| 44 |
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| 45 | cLargeRounds = cbToCopy / sizeof(*uSrc.pcb);
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| 46 | while (cLargeRounds-- > 0)
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| 47 | {
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| 48 | size_t uTmp = *--uSrc.pcb;
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| 49 | *--uDst.pcb = uTmp;
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| 50 | }
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| 51 |
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| 52 | cbToCopy %= sizeof(*uSrc.pcb);
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| 53 | while (cbToCopy-- > 0)
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| 54 | {
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| 55 | uint8_t b = *--uSrc.pb;
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| 56 | *--uDst.pb = b;
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| 57 | }
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| 58 | }
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| 59 | else
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| 60 | {
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| 61 | /* Forward copy. */
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| 62 | cLargeRounds = cbToCopy / sizeof(*uSrc.pcb);
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| 63 | while (cLargeRounds-- > 0)
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| 64 | {
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| 65 | size_t uTmp = *uSrc.pcb++;
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| 66 | *uDst.pcb++ = uTmp;
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| 67 | }
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| 68 |
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| 69 | cbToCopy %= sizeof(*uSrc.pcb);
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| 70 | while (cbToCopy-- > 0)
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| 71 | {
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| 72 | uint8_t b = *uSrc.pb++;
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| 73 | *uDst.pb++ = b;
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| 74 | }
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| 75 | }
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| 76 | return pvDst;
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| 77 | }
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| 78 |
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