linux/arch/mips/math-emu/dp_fsp.c
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   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
  29ieee754dp ieee754dp_fsp(ieee754sp x)
  30{
  31        COMPXSP;
  32
  33        EXPLODEXSP;
  34
  35        CLEARCX;
  36
  37        FLUSHXSP;
  38
  39        switch (xc) {
  40        case IEEE754_CLASS_SNAN:
  41                SETCX(IEEE754_INVALID_OPERATION);
  42                return ieee754dp_nanxcpt(ieee754dp_indef(), "fsp");
  43        case IEEE754_CLASS_QNAN:
  44                return ieee754dp_nanxcpt(builddp(xs,
  45                                                 DP_EMAX + 1 + DP_EBIAS,
  46                                                 ((u64) xm
  47                                                  << (DP_MBITS -
  48                                                      SP_MBITS))), "fsp",
  49                                         x);
  50        case IEEE754_CLASS_INF:
  51                return ieee754dp_inf(xs);
  52        case IEEE754_CLASS_ZERO:
  53                return ieee754dp_zero(xs);
  54        case IEEE754_CLASS_DNORM:
  55                /* normalize */
  56                while ((xm >> SP_MBITS) == 0) {
  57                        xm <<= 1;
  58                        xe--;
  59                }
  60                break;
  61        case IEEE754_CLASS_NORM:
  62                break;
  63        }
  64
  65        /* CAN'T possibly overflow,underflow, or need rounding
  66         */
  67
  68        /* drop the hidden bit */
  69        xm &= ~SP_HIDDEN_BIT;
  70
  71        return builddp(xs, xe + DP_EBIAS,
  72                       (u64) xm << (DP_MBITS - SP_MBITS));
  73}
  74