arch/mips/math-emu/dp_logb.c

   1 /* IEEE754 floating point arithmetic
   2  * double precision: common utilities
   3  */
   4 /*
   5  * MIPS floating point support
   6  * Copyright (C) 1994-2000 Algorithmics Ltd.
   7  *
   8  * ########################################################################
   9  *
  10  *  This program is free software; you can distribute it and/or modify it
  11  *  under the terms of the GNU General Public License (Version 2) as
  12  *  published by the Free Software Foundation.
  13  *
  14  *  This program is distributed in the hope it will be useful, but WITHOUT
  15  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  17  *  for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License along
  20  *  with this program; if not, write to the Free Software Foundation, Inc.,
  21  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22  *
  23  * ########################################################################
  24  */
  25
  26
  27 #include "ieee754dp.h"
  28
  29 ieee754dp ieee754dp_logb(ieee754dp x)
  30 {
  31         COMPXDP;
  32
  33         CLEARCX;
  34
  35         EXPLODEXDP;
  36
  37         switch (xc) {
  38         case IEEE754_CLASS_SNAN:
  39                 return ieee754dp_nanxcpt(x, "logb", x);
  40         case IEEE754_CLASS_QNAN:
  41                 return x;
  42         case IEEE754_CLASS_INF:
  43                 return ieee754dp_inf(0);
  44         case IEEE754_CLASS_ZERO:
  45                 return ieee754dp_inf(1);
  46         case IEEE754_CLASS_DNORM:
  47                 DPDNORMX;
  48                 break;
  49         case IEEE754_CLASS_NORM:
  50                 break;
  51         }
  52         return ieee754dp_fint(xe);
  53 }