memset.cpp revision 657bb8e28db7945bfea1ea60a67f9543609f3fd0
/* $Id$ */
/** @file
* innotek Portable Runtime - CRT Strings, memset().
*/
/*
* Copyright (C) 2006-2007 innotek GmbH
*
* 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 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.
*/
/*******************************************************************************
* 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;
}