libgcc/soft-fp/fixdfbitint.c

   1 /* Software floating-point emulation.
   2    Convert IEEE double to signed or unsigned _BitInt.
   3
   4    Copyright (C) 2023 Free Software Foundation, Inc.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 Under Section 7 of GPL version 3, you are granted additional
  19 permissions described in the GCC Runtime Library Exception, version
  20 3.1, as published by the Free Software Foundation.
  21
  22 You should have received a copy of the GNU General Public License and
  23 a copy of the GCC Runtime Library Exception along with this program;
  24 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  25 <http://www.gnu.org/licenses/>.  */
  26
  27 #include "soft-fp.h"
  28 #include "double.h"
  29 #include "bitint.h"
  30
  31 #ifdef __BITINT_MAXWIDTH__
  32 void
  33 __fixdfbitint (UBILtype *r, SItype rprec, DFtype a)
  34 {
  35   FP_DECL_EX;
  36   FP_DECL_D (A);
  37   USItype arprec = rprec < 0 ? -rprec : rprec;
  38   USItype rn = ((USItype) arprec + BIL_TYPE_SIZE - 1) / BIL_TYPE_SIZE;
  39   UDItype rv;
  40   USItype rsize = arprec > DI_BITS ? DI_BITS : arprec;
  41   USItype rsigned = rprec < 0;
  42   USItype ovf = 0;
  43   USItype shift = 0;
  44
  45   FP_INIT_EXCEPTIONS;
  46   FP_UNPACK_RAW_D (A, a);
  47   if (arprec > DI_BITS)
  48     {
  49       if (A_e < _FP_EXPBIAS_D || (A_s && !rsigned))
  50         ovf = 1;
  51       else if (A_e >= (_FP_EXPMAX_D < _FP_EXPBIAS_D + arprec
  52                        ? _FP_EXPMAX_D
  53                        : _FP_EXPBIAS_D + arprec - rsigned))
  54         {
  55           ovf = 1;
  56           if (A_s
  57               && A_e == _FP_EXPBIAS_D + arprec - 1
  58               && A_e < _FP_EXPMAX_D)
  59             A_e -= arprec - DI_BITS;
  60         }
  61       else if (A_e >= _FP_EXPBIAS_D + DI_BITS - rsigned)
  62         {
  63           shift = A_e - (_FP_EXPBIAS_D + DI_BITS - rsigned - 1);
  64           A_e -= shift;
  65         }
  66     }
  67   FP_TO_INT_D (rv, A, rsize, rsigned);
  68   FP_HANDLE_EXCEPTIONS;
  69   FP_TO_BITINT (r, rn, arprec, shift, rv, rsize, rsigned, ovf, DI);
  70 }
  71 #endif