sysdeps/ieee754/ldbl-128ibm/s_fpclassifyl.c

   1 /* Return classification value corresponding to argument.
   2    Copyright (C) 1997-2014 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and
   5                   Jakub Jelinek <jj@ultra.linux.cz>, 1999.
   6
   7    The GNU C Library is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU Lesser General Public
   9    License as published by the Free Software Foundation; either
  10    version 2.1 of the License, or (at your option) any later version.
  11
  12    The GNU C Library is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    Lesser General Public License for more details.
  16
  17    You should have received a copy of the GNU Lesser General Public
  18    License along with the GNU C Library; if not, see
  19    <http://www.gnu.org/licenses/>.  */
  20
  21 #include <math.h>
  22
  23 #include <math_private.h>
  24 #include <math_ldbl_opt.h>
  25
  26   /*
  27    *            hx                  lx
  28    * +NaN       7ffn nnnn nnnn nnnn xxxx xxxx xxxx xxxx
  29    * -NaN       fffn nnnn nnnn nnnn xxxx xxxx xxxx xxxx
  30    * +Inf       7ff0 0000 0000 0000 xxxx xxxx xxxx xxxx
  31    * -Inf       fff0 0000 0000 0000 xxxx xxxx xxxx xxxx
  32    * +0         0000 0000 0000 0000 xxxx xxxx xxxx xxxx
  33    * -0         8000 0000 0000 0000 xxxx xxxx xxxx xxxx
  34    * +normal    0360 0000 0000 0000 0000 0000 0000 0000 (smallest)
  35    * -normal    8360 0000 0000 0000 0000 0000 0000 0000 (smallest)
  36    * +normal    7fef ffff ffff ffff 7c8f ffff ffff fffe (largest)
  37    * +normal    ffef ffff ffff ffff fc8f ffff ffff fffe (largest)
  38    * +denorm    0360 0000 0000 0000 8000 0000 0000 0001 (largest)
  39    * -denorm    8360 0000 0000 0000 0000 0000 0000 0001 (largest)
  40    * +denorm    000n nnnn nnnn nnnn xxxx xxxx xxxx xxxx
  41    * -denorm    800n nnnn nnnn nnnn xxxx xxxx xxxx xxxx
  42    */
  43
  44 int
  45 ___fpclassifyl (long double x)
  46 {
  47   u_int64_t hx, lx;
  48   int retval = FP_NORMAL;
  49   double xhi, xlo;
  50
  51   ldbl_unpack (x, &xhi, &xlo);
  52   EXTRACT_WORDS64 (hx, xhi);
  53   if ((hx & 0x7ff0000000000000ULL) == 0x7ff0000000000000ULL) {
  54       /* +/-NaN or +/-Inf */
  55       if (hx & 0x000fffffffffffffULL) {
  56           /* +/-NaN */
  57           retval = FP_NAN;
  58       } else {
  59           retval = FP_INFINITE;
  60       }
  61   } else {
  62       /* +/-zero or +/- normal or +/- denormal */
  63       if (hx & 0x7fffffffffffffffULL) {
  64           /* +/- normal or +/- denormal */
  65           if ((hx & 0x7ff0000000000000ULL) > 0x0360000000000000ULL) {
  66               /* +/- normal */
  67               retval = FP_NORMAL;
  68           } else {
  69               if ((hx & 0x7ff0000000000000ULL) == 0x0360000000000000ULL) {
  70                   EXTRACT_WORDS64 (lx, xlo);
  71                   if ((lx & 0x7fffffffffffffff) /* lower is non-zero */
  72                   && ((lx^hx) & 0x8000000000000000ULL)) { /* and sign differs */
  73                       /* +/- denormal */
  74                       retval = FP_SUBNORMAL;
  75                   } else {
  76                       /* +/- normal */
  77                       retval = FP_NORMAL;
  78                   }
  79               } else {
  80                   /* +/- denormal */
  81                   retval = FP_SUBNORMAL;
  82               }
  83           }
  84       } else {
  85           /* +/- zero */
  86           retval = FP_ZERO;
  87       }
  88   }
  89
  90   return retval;
  91 }
  92 long_double_symbol (libm, ___fpclassifyl, __fpclassifyl);
  93 #ifdef __LONG_DOUBLE_MATH_OPTIONAL
  94 libm_hidden_ver (___fpclassifyl, __fpclassifyl)
  95 #else
  96 libm_hidden_def (__fpclassifyl)
  97 #endif