1 | /* $Id: memset.cpp 76553 2019-01-01 01:45:53Z vboxsync $ */
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2 | /** @file
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3 | * IPRT - CRT Strings, memset().
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4 | */
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5 |
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6 | /*
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7 | * Copyright (C) 2006-2019 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 |
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28 | /*********************************************************************************************************************************
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29 | * Header Files *
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30 | *********************************************************************************************************************************/
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31 | #include <iprt/string.h>
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32 |
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33 |
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34 | /**
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35 | * Fill a memory block with specific byte.
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36 | *
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37 | * @returns pvDst.
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38 | * @param pvDst Pointer to the block.
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39 | * @param ch The filler char.
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40 | * @param cb The size of the block.
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41 | */
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42 | #ifdef _MSC_VER
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43 | # if _MSC_VER >= 1400
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44 | void * __cdecl memset(__out_bcount_full_opt(_Size) void *pvDst, __in int ch, __in size_t cb)
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45 | # else
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46 | void *memset(void *pvDst, int ch, size_t cb)
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47 | # endif
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48 | #else
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49 | void *memset(void *pvDst, int ch, size_t cb)
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50 | #endif
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51 | {
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52 | register union
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53 | {
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54 | uint8_t *pu8;
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55 | uint32_t *pu32;
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56 | void *pvDst;
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57 | } u;
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58 | u.pvDst = pvDst;
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59 |
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60 | /* 32-bit word moves. */
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61 | register uint32_t u32 = ch | (ch << 8);
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62 | u32 |= u32 << 16;
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63 | register size_t c = cb >> 2;
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64 | while (c-- > 0)
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65 | *u.pu32++ = u32;
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66 |
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67 | /* Remaining byte moves. */
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68 | c = cb & 3;
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69 | while (c-- > 0)
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70 | *u.pu8++ = (uint8_t)u32;
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71 |
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72 | return pvDst;
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73 | }
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74 |
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