libgcc/soft-fp/trunctfdf2.c

   1 /* Software floating-point emulation.
   2    Truncate IEEE quad into IEEE double
   3    Copyright (C) 1997-2018 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5    Contributed by Richard Henderson (rth@cygnus.com) and
   6                   Jakub Jelinek (jj@ultra.linux.cz).
   7
   8    The GNU C Library is free software; you can redistribute it and/or
   9    modify it under the terms of the GNU Lesser General Public
  10    License as published by the Free Software Foundation; either
  11    version 2.1 of the License, or (at your option) any later version.
  12
  13    In addition to the permissions in the GNU Lesser General Public
  14    License, the Free Software Foundation gives you unlimited
  15    permission to link the compiled version of this file into
  16    combinations with other programs, and to distribute those
  17    combinations without any restriction coming from the use of this
  18    file.  (The Lesser General Public License restrictions do apply in
  19    other respects; for example, they cover modification of the file,
  20    and distribution when not linked into a combine executable.)
  21
  22    The GNU C Library is distributed in the hope that it will be useful,
  23    but WITHOUT ANY WARRANTY; without even the implied warranty of
  24    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  25    Lesser General Public License for more details.
  26
  27    You should have received a copy of the GNU Lesser General Public
  28    License along with the GNU C Library; if not, see
  29    <http://www.gnu.org/licenses/>.  */
  30
  31 #include "soft-fp.h"
  32 #include "double.h"
  33 #include "quad.h"
  34
  35 DFtype
  36 __trunctfdf2 (TFtype a)
  37 {
  38   FP_DECL_EX;
  39   FP_DECL_Q (A);
  40   FP_DECL_D (R);
  41   DFtype r;
  42
  43   FP_INIT_ROUNDMODE;
  44   FP_UNPACK_SEMIRAW_Q (A, a);
  45 #if (2 * _FP_W_TYPE_SIZE) < _FP_FRACBITS_Q
  46   FP_TRUNC (D, Q, 2, 4, R, A);
  47 #else
  48   FP_TRUNC (D, Q, 1, 2, R, A);
  49 #endif
  50   FP_PACK_SEMIRAW_D (r, R);
  51   FP_HANDLE_EXCEPTIONS;
  52
  53   return r;
  54 }