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

   1 /* Return classification value corresponding to argument.
   2    Copyright (C) 1997,1999,2002,2004,2006,2007 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
  50   GET_LDOUBLE_WORDS64 (hx, lx, x);
  51   if ((hx & 0x7ff0000000000000ULL) == 0x7ff0000000000000ULL) {
  52       /* +/-NaN or +/-Inf */
  53       if (hx & 0x000fffffffffffffULL) {
  54           /* +/-NaN */
  55           retval = FP_NAN;
  56       } else {
  57           retval = FP_INFINITE;
  58       }
  59   } else {
  60       /* +/-zero or +/- normal or +/- denormal */
  61       if (hx & 0x7fffffffffffffffULL) {
  62           /* +/- normal or +/- denormal */
  63           if ((hx & 0x7ff0000000000000ULL) > 0x0360000000000000ULL) {
  64               /* +/- normal */
  65               retval = FP_NORMAL;
  66           } else {
  67               if ((hx & 0x7ff0000000000000ULL) == 0x0360000000000000ULL) {
  68                   if ((lx & 0x7fffffffffffffff) /* lower is non-zero */
  69                   && ((lx^hx) & 0x8000000000000000ULL)) { /* and sign differs */
  70                       /* +/- denormal */
  71                       retval = FP_SUBNORMAL;
  72                   } else {
  73                       /* +/- normal */
  74                       retval = FP_NORMAL;
  75                   }
  76               } else {
  77                   /* +/- denormal */
  78                   retval = FP_SUBNORMAL;
  79               }
  80           }
  81       } else {
  82           /* +/- zero */
  83           retval = FP_ZERO;
  84       }
  85   }
  86
  87   return retval;
  88 }
  89 long_double_symbol (libm, ___fpclassifyl, __fpclassifyl);
  90 #ifdef __LONG_DOUBLE_MATH_OPTIONAL
  91 libm_hidden_ver (___fpclassifyl, __fpclassifyl)
  92 #else
  93 libm_hidden_def (__fpclassifyl)
  94 #endif