1  /* Subtract long double (ldbl-128) values, narrowing the result to
       2     double, using soft-fp.
       3     Copyright (C) 2018-2023 Free Software Foundation, Inc.
       4     This file is part of the GNU C Library.
       5  
       6     The GNU C Library is free software; you can redistribute it and/or
       7     modify it under the terms of the GNU Lesser General Public
       8     License as published by the Free Software Foundation; either
       9     version 2.1 of the License, or (at your option) any later version.
      10  
      11     The GNU C Library is distributed in the hope that it will be useful,
      12     but WITHOUT ANY WARRANTY; without even the implied warranty of
      13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      14     Lesser General Public License for more details.
      15  
      16     You should have received a copy of the GNU Lesser General Public
      17     License along with the GNU C Library; if not, see
      18     <https://www.gnu.org/licenses/>.  */
      19  
      20  #define f32xsubf64x __hide_f32xsubf64x
      21  #define f32xsubf128 __hide_f32xsubf128
      22  #define f64subf64x __hide_f64subf64x
      23  #define f64subf128 __hide_f64subf128
      24  #include <math.h>
      25  #undef f32xsubf64x
      26  #undef f32xsubf128
      27  #undef f64subf64x
      28  #undef f64subf128
      29  
      30  #include <math-narrow.h>
      31  #include <soft-fp.h>
      32  #include <double.h>
      33  #include <quad.h>
      34  
      35  double
      36  __dsubl (_Float128 x, _Float128 y)
      37  {
      38    FP_DECL_EX;
      39    FP_DECL_Q (X);
      40    FP_DECL_Q (Y);
      41    FP_DECL_Q (R);
      42    FP_DECL_D (RN);
      43    double ret;
      44  
      45    FP_INIT_ROUNDMODE;
      46    FP_UNPACK_SEMIRAW_Q (X, x);
      47    FP_UNPACK_SEMIRAW_Q (Y, y);
      48    FP_SUB_Q (R, X, Y);
      49  #if _FP_W_TYPE_SIZE < 64
      50    FP_TRUNC (D, Q, 2, 4, RN, R);
      51  #else
      52    FP_TRUNC (D, Q, 1, 2, RN, R);
      53  #endif
      54    FP_PACK_SEMIRAW_D (ret, RN);
      55    FP_HANDLE_EXCEPTIONS;
      56    CHECK_NARROW_SUB (ret, x, y);
      57    return ret;
      58  }
      59  libm_alias_double_ldouble (sub)