1  /* Total order operation.
       2     Copyright (C) 2016-2023 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