setstride.c

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/*

  Copyright (C) 2000, 2001, Silicon Graphics, Inc.  All Rights Reserved.

  This program is free software; you can redistribute it and/or modify it
  under the terms of version 2.1 of the GNU Lesser General Public License 
  as published by the Free Software Foundation.

  This program is distributed in the hope that it would be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  

  Further, this software is distributed without any warranty that it is
  free of the rightful claim of any third person regarding infringement 
  or the like.  Any license provided herein, whether implied or 
  otherwise, applies only to this software file.  Patent licenses, if
  any, provided herein do not apply to combinations of this program with 
  other software, or any other product whatsoever.  

  You should have received a copy of the GNU Lesser General Public 
  License along with this program; if not, write the Free Software 
  Foundation, Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, 
  USA.

  Contact information:  Silicon Graphics, Inc., 1600 Amphitheatre Pky,
  Mountain View, CA 94043, or:

  http://www.sgi.com

  For further information regarding this notice, see:

  http://oss.sgi.com/projects/GenInfo/NoticeExplan

*/



#pragma ident "@(#) libf/fio/setstride.c        92.2    06/21/99 10:37:55"

#include <fortran.h>
#include <memory.h>
#include <cray/nassert.h>
#include <cray/portdefs.h>
#if     defined(__mips) || defined(_LITTLE_ENDIAN)
struct eightby          { int w[2]; };
struct sixteenby        { int w[4]; };
struct thirtytwoby      { int w[8]; };
#else
struct biword   { long w[2]; };

struct quadword { long w[4]; };
#endif
#define BYTE    unsigned char   

#if     defined(__mips) || defined(_LITTLE_ENDIAN)
#define EIGHTBWORD      struct eightby
#define DOUBLEWORD      struct sixteenby
#define QUADWORD        struct thirtytwoby
#else
#define WORD            int64
#ifdef  _CRAYMPP        /* Temporary until `long double' is implemented */
#define DOUBLEWORD      struct biword
#elif   !defined(_WORD32)
#define DOUBLEWORD      long double
#else
#define DOUBLEWORD      long long
#endif

#define QUADWORD        struct quadword
#endif

#define XFER_CASE(TYPE)                         \
{                                               \
        register TYPE   datum;                  \
        TYPE            *data;                  \
        datum   = *(TYPE *)src;                 \
        data    = (TYPE *)dest;                 \
        for (i = 0; i < count; i++)             \
                data[i*inc]     = datum;        \
}                                               \

/*
 *      _set_stride     Copies an item consisting of a contiguous chunk of
 *                      bytes into a strided vector of items.  This is a
 *                      generalized version of memcpy() and memwcpy(), with
 *                      support for striding and item sizes of greater than
 *                      one byte or one word.
 */
void
_set_stride(
        void    *dest,          /* Destination address          */
        void    *src,           /* Source address               */
        long    count,          /* Number of items to transfer  */
        int     elsize,         /* Size of each item, in bytes  */
        long    stride)         /* Stride between items (bytes) */
{
        register int    i;
        register long   inc;    /* Stride between items (in elsize units) */

        /* Assertions */

        assert (dest != NULL);
        assert (src != NULL);
        assert (count > 0);
        assert (elsize > 0);

        inc     = stride / elsize;

        switch (elsize) {

                case 1:
                        XFER_CASE(BYTE)         /* does not vectorize */
                        break;

#ifdef  _F_INT2
                case 2:
                        XFER_CASE(short)        /* Temporary until _f_int2 */
                        break;
#endif

#ifdef  _F_INT4
                case 4:
                        XFER_CASE(_f_int4)
                        break;
#endif

                case 8:
#if     defined(__mips) || defined(_LITTLE_ENDIAN)
                        XFER_CASE(EIGHTBWORD)   
#else
                        XFER_CASE(_f_int8)      /* vectorizes! */
#endif
                        break;

                case 16:
                        XFER_CASE(DOUBLEWORD)   /* vectorizes! */
                        break;

                case 32:
                        XFER_CASE(QUADWORD)     /* should vectorize with CC 4.0 (?) */
                        break;

                default:
                        for (i = 0; i < count; i++)
                                (void) memcpy((char *)dest + i*inc, src, elsize);
        } /* switch */

        return;
}