sysdeps/ieee754/ldbl-96/s_totalorderl.c

   1 /* Total order operation.  ldbl-96 version.
   2    Copyright (C) 2016 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <float.h>
  20 #include <math.h>
  21 #include <math_private.h>
  22 #include <nan-high-order-bit.h>
  23 #include <stdint.h>
  24
  25 int
  26 totalorderl (long double x, long double y)
  27 {
  28   int16_t expx, expy;
  29   uint32_t hx, hy;
  30   uint32_t lx, ly;
  31   GET_LDOUBLE_WORDS (expx, hx, lx, x);
  32   GET_LDOUBLE_WORDS (expy, hy, ly, y);
  33   if (LDBL_MIN_EXP == -16382)
  34     {
  35       /* M68K variant: for the greatest exponent, the high mantissa
  36          bit is not significant and both values of it are valid, so
  37          set it before comparing.  For the Intel variant, only one
  38          value of the high mantissa bit is valid for each exponent, so
  39          this is not necessary.  */
  40       if ((expx & 0x7fff) == 0x7fff)
  41         hx |= 0x80000000;
  42       if ((expy & 0x7fff) == 0x7fff)
  43         hy |= 0x80000000;
  44     }
  45 #if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
  46 # error not implemented
  47 #endif
  48   uint32_t x_sign = expx >> 15;
  49   uint32_t y_sign = expy >> 15;
  50   expx ^= x_sign >> 17;
  51   hx ^= x_sign;
  52   lx ^= x_sign;
  53   expy ^= y_sign >> 17;
  54   hy ^= y_sign;
  55   ly ^= y_sign;
  56   return expx < expy || (expx == expy && (hx < hy || (hx == hy && lx <= ly)));
  57 }