Logo Search packages:      
Sourcecode: ksh version File versions  Download package

_sfputd.c

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1985-2009 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                  Common Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*            http://www.opensource.org/licenses/cpl1.0.txt             *
*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                  David Korn <dgk@research.att.com>                   *
*                   Phong Vo <kpv@research.att.com>                    *
*                                                                      *
***********************************************************************/
#include    "sfhdr.h"

/*    Write out a floating point value in a portable format
**
**    Written by Kiem-Phong Vo.
*/

#if __STD_C
int _sfputd(Sfio_t* f, Sfdouble_t v)
#else
int _sfputd(f,v)
Sfio_t*           f;
Sfdouble_t  v;
#endif
{
#define N_ARRAY         (16*sizeof(Sfdouble_t))
      reg ssize_t n, w;
      reg uchar   *s, *ends;
      int         exp;
      uchar       c[N_ARRAY];
      Sfdouble_t  x;
      SFMTXDECL(f);

      SFMTXENTER(f,-1);

      if(f->mode != SF_WRITE && _sfmode(f,SF_WRITE,0) < 0)
            SFMTXRETURN(f, -1);
      SFLOCK(f,0);

      /* get the sign of v */
      if(v < 0.)
      {     v = -v;
            n = 1;
      }
      else  n = 0;

      /* make the magnitude of v < 1 */
      if(v != 0.)
            v = frexpl(v,&exp);
      else  exp = 0;

      /* code the sign of v and exp */
      if((w = exp) < 0)
      {     n |= 02;
            w = -w;
      }

      /* write out the signs and the exp */
      SFOPEN(f,0);
      if(sfputc(f,n) < 0 || (w = sfputu(f,w)) < 0)
            SFMTXRETURN(f, -1);
      SFLOCK(f,0);
      w += 1;

      s = (ends = &c[0])+sizeof(c);
      while(s > ends)
      {     /* get 2^SF_PRECIS precision at a time */
            n = (int)(x = ldexpl(v,SF_PRECIS));
            *--s = n|SF_MORE;
            v = x-n;
            if(v <= 0.)
                  break;
      }

      /* last byte is not SF_MORE */
      ends = &c[0] + sizeof(c) -1;
      *ends &= ~SF_MORE;

      /* write out coded bytes */
      n = ends - s + 1;
      w = SFWRITE(f,(Void_t*)s,n) == n ? w+n : -1;

      SFOPEN(f,0);
      SFMTXRETURN(f,w);
}

Generated by  Doxygen 1.6.0   Back to index