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      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
     72