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

   1 /* Return classification value corresponding to argument.
   2    Copyright (C) 1997,1999,2002,2004,2006 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, write to the Free
  19    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  20    02111-1307 USA.  */
  21
  22 #include <math.h>
  23
  24 #include "math_private.h"
  25 #include <math_ldbl_opt.h>
  26
  27   /*
  28    *            hx                  lx
  29    * +NaN       7ffn nnnn nnnn nnnn xxxx xxxx xxxx xxxx
  30    * -NaN       fffn nnnn nnnn nnnn xxxx xxxx xxxx xxxx
  31    * +Inf       7ff0 0000 0000 0000 xxxx xxxx xxxx xxxx
  32    * -Inf       fff0 0000 0000 0000 xxxx xxxx xxxx xxxx
  33    * +0         0000 0000 0000 0000
  34    * -0         8000 0000 0000 0000
  35    * +normal    001n nnnn nnnn nnnn (smallest)
  36    * -normal    801n nnnn nnnn nnnn (smallest)
  37    * +normal    7fen nnnn nnnn nnnn (largest)
  38    * -normal    ffen nnnn nnnn nnnn (largest)
  39    * +denorm    000n nnnn nnnn nnnn
  40    * -denorm    800n nnnn nnnn nnnn
  41    */
  42
  43 int
  44 ___fpclassifyl (long double x)
  45 {
  46   u_int64_t hx, lx;
  47   int retval = FP_NORMAL;
  48
  49   GET_LDOUBLE_WORDS64 (hx, lx, x);
  50   if ((hx & 0x7ff0000000000000ULL) == 0x7ff0000000000000ULL) {
  51       /* +/-NaN or +/-Inf */
  52       if (hx & 0x000fffffffffffffULL) {
  53           /* +/-NaN */
  54           retval = FP_NAN;
  55       } else {
  56           retval = FP_INFINITE;
  57       }
  58   } else {
  59       /* +/-zero or +/- normal or +/- denormal */
  60       if (hx & 0x7fffffffffffffffULL) {
  61           /* +/- normal or +/- denormal */
  62           if ((hx & 0x7ff0000000000000ULL) >= 0x0360000000000000ULL) {
  63               /* +/- normal */
  64               retval = FP_NORMAL;
  65           } else {
  66               /* +/- denormal */
  67               retval = FP_SUBNORMAL;
  68           }
  69       } else {
  70           /* +/- zero */
  71           retval = FP_ZERO;
  72       }
  73   }
  74
  75   return retval;
  76 }
  77 long_double_symbol (libm, ___fpclassifyl, __fpclassifyl);
  78 #ifdef __LONG_DOUBLE_MATH_OPTIONAL
  79 libm_hidden_ver (___fpclassifyl, __fpclassifyl)
  80 #else
  81 libm_hidden_def (__fpclassifyl)
  82 #endif