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/*===========================================================================

//

//      memset.c

//

//      ANSI standard memset() routine

//

//==========================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

// -------------------------------------------

// This file is part of eCos, the Embedded Configurable Operating System.

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.

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// eCos 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

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// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

// for more details.

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// You should have received a copy of the GNU General Public License along

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// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

//

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// or inline functions from this file, or you compile this file and link it

// with other works to produce a work based on this file, this file does not

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//####ECOSGPLCOPYRIGHTEND####

//==========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):   jlarmour

// Contributors:  jlarmour

// Date:        1998-06-04

// Purpose:     This file implements the ANSI memset() function

// Description: This file implements the memset() function defined in ANSI para

//              7.11.6.1. This is implemented in the kernel rather than the

//              C library due to it being required by gcc whether or not the

//              C library has been configured in.

//

//####DESCRIPTIONEND####

//

//==========================================================================*/

/* INCLUDES */

#include <pkgconf/infra.h>      /* Configuration of infra package */

#include <cyg/infra/cyg_type.h> /* Common type definitions */

#include <cyg/infra/cyg_trac.h> /* Tracing support */

#include <cyg/infra/cyg_ass.h>  /* Assertion support */

#include <stddef.h>             /* Compiler defns such as size_t, NULL etc. */

/* MACROS */

/* Nonzero if X is not aligned on a word boundary. */

#define CYG_STR_UNALIGNED(X) ((CYG_WORD)(X) & (sizeof (CYG_WORD) - 1))

/* How many bytes are copied each iteration of the word copy loop in the

 * optimised string implementation

 */

#define CYG_STR_OPT_LITTLEBLOCKSIZE (sizeof (CYG_WORD))

/* EXPORTED SYMBOLS */

externC void *

memset( void *s, int c, size_t n ) __attribute__ ((weak, alias("_memset")));

/* FUNCTIONS */

void *

_memset( void *s, int c, size_t n )

{

#if defined(CYGIMP_INFRA_PREFER_SMALL_TO_FAST_MEMSET) || defined(__OPTIMIZE_SIZE__)

    char *char_ptr = (char *)s;

#ifdef CYG_TRACING_FIXED

    CYG_REPORT_FUNCNAMETYPE( "_memset", "returning %08x" );

    CYG_REPORT_FUNCARG3( "s=%08x, c=%d, n=%d", s, c, n );

    if (n != 0)

    {

        CYG_CHECK_DATA_PTR( char_ptr, "s is not a valid pointer!" );

        CYG_CHECK_DATA_PTR( (&char_ptr[n-1]), "s+n-1 is not a valid address!" );

    }

#endif

    while (n-- != 0)

    {

        *char_ptr++ = (char) c;

    }

#ifdef CYG_TRACING_FIXED

    CYG_REPORT_RETVAL( s );

#endif

    return s;

#else

    char *char_ptr = (char *)s;

    cyg_ucount8 count;

    CYG_WORD buffer;

    CYG_WORD *aligned_addr;

    char *unaligned_addr;

#ifdef CYG_TRACING_FIXED

    CYG_REPORT_FUNCNAMETYPE( "_memset", "returning %08x" );

    CYG_REPORT_FUNCARG3( "s=%08x, c=%d, n=%d", s, c, n );

    if (n != 0)

    {

        CYG_CHECK_DATA_PTR( s, "s is not a valid pointer!" );

        CYG_CHECK_DATA_PTR( (char *)s+n-1, "s+n-1 is not a valid address!" );

    }

#endif

    if (n < sizeof(CYG_WORD) || CYG_STR_UNALIGNED (s))

    {

        while (n-- != 0)

        {

            *char_ptr++ = (char) c;

        }

#ifdef CYG_TRACING_FIXED

        CYG_REPORT_RETVAL( s );

#endif

        return s;

    }

    /* If we get this far, we know that n is large and s is word-aligned. */

    aligned_addr = (CYG_WORD *)s;

    /* Store C into each char sized location in BUFFER so that

     * we can set large blocks quickly.

     */

    c &= 0xff;

    if (CYG_STR_OPT_LITTLEBLOCKSIZE == 4)

    {

        buffer = (c << 8) | c;

        buffer |= (buffer << 16);

    }

    else

    {

        buffer = 0;

        for (count = 0; count < CYG_STR_OPT_LITTLEBLOCKSIZE; count++)

            buffer = (buffer << 8) | c;

    }

    while (n >= CYG_STR_OPT_LITTLEBLOCKSIZE*4)

    {

        *aligned_addr++ = buffer;

        *aligned_addr++ = buffer;

        *aligned_addr++ = buffer;

        *aligned_addr++ = buffer;

        n -= 4*CYG_STR_OPT_LITTLEBLOCKSIZE;

    }

    while (n >= CYG_STR_OPT_LITTLEBLOCKSIZE)

    {

        *aligned_addr++ = buffer;

        n -= CYG_STR_OPT_LITTLEBLOCKSIZE;

    }

    /* Pick up the remainder with a bytewise loop. */

    unaligned_addr = (char*)aligned_addr;

    while (n)

    {

        *unaligned_addr++ = (char)c;

        n--;

    }

#ifdef CYG_TRACING_FIXED

    CYG_REPORT_RETVAL( s );

#endif

    return s;

#endif /* not defined(CYGIMP_PREFER_SMALL_TO_FAST_MEMSET) ||

        * defined(__OPTIMIZE_SIZE__) */

} /* _memset() */

/* EOF memset.c */