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Diffstat (limited to '')
-rw-r--r-- | src/VBox/Runtime/common/string/memset.cpp | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/string/memset.cpp b/src/VBox/Runtime/common/string/memset.cpp new file mode 100644 index 00000000..4cc7e16e --- /dev/null +++ b/src/VBox/Runtime/common/string/memset.cpp @@ -0,0 +1,74 @@ +/* $Id: memset.cpp $ */ +/** @file + * IPRT - CRT Strings, memset(). + */ + +/* + * Copyright (C) 2006-2019 Oracle Corporation + * + * This file is part of VirtualBox Open Source Edition (OSE), as + * available from http://www.virtualbox.org. This file is free software; + * you can redistribute it and/or modify it under the terms of the GNU + * General Public License (GPL) as published by the Free Software + * Foundation, in version 2 as it comes in the "COPYING" file of the + * VirtualBox OSE distribution. VirtualBox OSE is distributed in the + * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. + * + * The contents of this file may alternatively be used under the terms + * of the Common Development and Distribution License Version 1.0 + * (CDDL) only, as it comes in the "COPYING.CDDL" file of the + * VirtualBox OSE distribution, in which case the provisions of the + * CDDL are applicable instead of those of the GPL. + * + * You may elect to license modified versions of this file under the + * terms and conditions of either the GPL or the CDDL or both. + */ + + +/********************************************************************************************************************************* +* Header Files * +*********************************************************************************************************************************/ +#include <iprt/string.h> + + +/** + * Fill a memory block with specific byte. + * + * @returns pvDst. + * @param pvDst Pointer to the block. + * @param ch The filler char. + * @param cb The size of the block. + */ +#ifdef _MSC_VER +# if _MSC_VER >= 1400 +void * __cdecl memset(__out_bcount_full_opt(_Size) void *pvDst, __in int ch, __in size_t cb) +# else +void *memset(void *pvDst, int ch, size_t cb) +# endif +#else +void *memset(void *pvDst, int ch, size_t cb) +#endif +{ + register union + { + uint8_t *pu8; + uint32_t *pu32; + void *pvDst; + } u; + u.pvDst = pvDst; + + /* 32-bit word moves. */ + register uint32_t u32 = ch | (ch << 8); + u32 |= u32 << 16; + register size_t c = cb >> 2; + while (c-- > 0) + *u.pu32++ = u32; + + /* Remaining byte moves. */ + c = cb & 3; + while (c-- > 0) + *u.pu8++ = (uint8_t)u32; + + return pvDst; +} + |