arch/mips/math-emu/dp_2008class.c

   1 /*
   2  * IEEE754 floating point arithmetic
   3  * double precision: CLASS.f
   4  * FPR[fd] = class(FPR[fs])
   5  *
   6  * MIPS floating point support
   7  * Copyright (C) 2015 Imagination Technologies, Ltd.
   8  * Author: Markos Chandras <markos.chandras@imgtec.com>
   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 as published by the
  12  *  Free Software Foundation; version 2 of the License.
  13  */
  14
  15 #include "ieee754dp.h"
  16
  17 int ieee754dp_2008class(union ieee754dp x)
  18 {
  19         COMPXDP;
  20
  21         EXPLODEXDP;
  22
  23         /*
  24          * 10 bit mask as follows:
  25          *
  26          * bit0 = SNAN
  27          * bit1 = QNAN
  28          * bit2 = -INF
  29          * bit3 = -NORM
  30          * bit4 = -DNORM
  31          * bit5 = -ZERO
  32          * bit6 = INF
  33          * bit7 = NORM
  34          * bit8 = DNORM
  35          * bit9 = ZERO
  36          */
  37
  38         switch(xc) {
  39         case IEEE754_CLASS_SNAN:
  40                 return 0x01;
  41         case IEEE754_CLASS_QNAN:
  42                 return 0x02;
  43         case IEEE754_CLASS_INF:
  44                 return 0x04 << (xs ? 0 : 4);
  45         case IEEE754_CLASS_NORM:
  46                 return 0x08 << (xs ? 0 : 4);
  47         case IEEE754_CLASS_DNORM:
  48                 return 0x10 << (xs ? 0 : 4);
  49         case IEEE754_CLASS_ZERO:
  50                 return 0x20 << (xs ? 0 : 4);
  51         default:
  52                 pr_err("Unknown class: %d\n", xc);
  53                 return 0;
  54         }
  55 }