1  /* Subtract double values, narrowing the result to float, using soft-fp.
       2     Copyright (C) 2018-2023 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  #define f32subf64 __hide_f32subf64
      20  #define f32subf32x __hide_f32subf32x
      21  #define fsubl __hide_fsubl
      22  #include <math.h>
      23  #undef f32subf64
      24  #undef f32subf32x
      25  #undef fsubl
      26  
      27  #include <math-narrow.h>
      28  #include <soft-fp.h>
      29  #include <single.h>
      30  #include <double.h>
      31  
      32  float
      33  __fsub (double x, double y)
      34  {
      35    FP_DECL_EX;
      36    FP_DECL_D (X);
      37    FP_DECL_D (Y);
      38    FP_DECL_D (R);
      39    FP_DECL_S (RN);
      40    float ret;
      41  
      42    FP_INIT_ROUNDMODE;
      43    FP_UNPACK_SEMIRAW_D (X, x);
      44    FP_UNPACK_SEMIRAW_D (Y, y);
      45    FP_SUB_D (R, X, Y);
      46  #if _FP_W_TYPE_SIZE < _FP_FRACBITS_D
      47    FP_TRUNC (S, D, 1, 2, RN, R);
      48  #else
      49    FP_TRUNC (S, D, 1, 1, RN, R);
      50  #endif
      51    FP_PACK_SEMIRAW_S (ret, RN);
      52    FP_HANDLE_EXCEPTIONS;
      53    CHECK_NARROW_SUB (ret, x, y);
      54    return ret;
      55  }
      56  libm_alias_float_double (sub)