sysdeps/ieee754/dbl-64/s_totalorder.c

   1 /* Total order operation.
   2    Copyright (C) 2016-2024 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    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <math.h>
  20 #include <math_private.h>
  21 #include <nan-high-order-bit.h>
  22 #include <libm-alias-double.h>
  23 #include <stdint.h>
  24 #include <shlib-compat.h>
  25 #include <first-versions.h>
  26
  27 int
  28 __totalorder (const double *x, const double *y)
  29 {
  30   int64_t ix, iy;
  31   EXTRACT_WORDS64 (ix, *x);
  32   EXTRACT_WORDS64 (iy, *y);
  33 #if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
  34   /* For the preferred quiet NaN convention, this operation is a
  35      comparison of the representations of the arguments interpreted as
  36      sign-magnitude integers.  If both arguments are NaNs, invert the
  37      quiet/signaling bit so comparing that way works.  */
  38   if ((ix & 0x7fffffffffffffffULL) > 0x7ff0000000000000ULL
  39       && (iy & 0x7fffffffffffffffULL) > 0x7ff0000000000000ULL)
  40     {
  41       ix ^= 0x0008000000000000ULL;
  42       iy ^= 0x0008000000000000ULL;
  43     }
  44 #endif
  45   uint64_t ix_sign = ix >> 63;
  46   uint64_t iy_sign = iy >> 63;
  47   ix ^= ix_sign >> 1;
  48   iy ^= iy_sign >> 1;
  49   return ix <= iy;
  50 }
  51 #ifdef SHARED
  52 # define CONCATX(x, y) x ## y
  53 # define CONCAT(x, y) CONCATX (x, y)
  54 # define UNIQUE_ALIAS(name) CONCAT (name, __COUNTER__)
  55 # define do_symbol(orig_name, name, aliasname)          \
  56   strong_alias (orig_name, name)                        \
  57   versioned_symbol (libm, name, aliasname, GLIBC_2_31)
  58 # undef weak_alias
  59 # define weak_alias(name, aliasname)                    \
  60   do_symbol (name, UNIQUE_ALIAS (name), aliasname);
  61 #endif
  62 libm_alias_double (__totalorder, totalorder)
  63 #if SHLIB_COMPAT (libm, GLIBC_2_25, GLIBC_2_31)
  64 int
  65 attribute_compat_text_section
  66 __totalorder_compat (double x, double y)
  67 {
  68   return __totalorder (&x, &y);
  69 }
  70 #undef do_symbol
  71 #define do_symbol(orig_name, name, aliasname)                   \
  72   strong_alias (orig_name, name)                                \
  73   compat_symbol (libm, name, aliasname,                         \
  74                  CONCAT (FIRST_VERSION_libm_, aliasname))
  75 libm_alias_double (__totalorder_compat, totalorder)
  76 #endif