libgcc/soft-fp/floatbitinttf.c

   1 /* Software floating-point emulation.
   2    Convert a _BitInt to IEEE quad.
   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 "quad.h"
  29 #include "bitint.h"
  30
  31 #ifdef __BITINT_MAXWIDTH__
  32 #ifndef TI_BITS
  33 /* As mantissa is 112 bits + 1 implicit bit, we need 128-bit
  34    type, but on most 32-bit architectures TImode isn't supported.
  35    Use _BitInt(128) instead.  */
  36 typedef _BitInt(128) TItype;
  37 typedef unsigned _BitInt(128) UTItype;
  38 #define TI_BITS 128
  39 #endif
  40
  41 TFtype
  42 __floatbitinttf (const UBILtype *i, SItype iprec)
  43 {
  44   TItype iv;
  45   USItype shift = 0;
  46   FP_DECL_EX;
  47   FP_DECL_Q (A);
  48   TFtype a;
  49
  50   FP_FROM_BITINT (i, iprec, iv, shift, TI);
  51   FP_INIT_ROUNDMODE;
  52   FP_FROM_INT_Q (A, iv, TI_BITS, UTItype);
  53   if (shift)
  54     {
  55       A_e += shift;
  56       if (A_e >= _FP_EXPMAX_Q)
  57         {
  58           /* Exponent too big; overflow to infinity.  */
  59 #if _FP_W_TYPE_SIZE < 64
  60           _FP_OVERFLOW_SEMIRAW (Q, 4, A);
  61           _FP_PACK_SEMIRAW (Q, 4, A);
  62 #else
  63           _FP_OVERFLOW_SEMIRAW (Q, 2, A);
  64           _FP_PACK_SEMIRAW (Q, 2, A);
  65 #endif
  66         }
  67     }
  68   FP_PACK_RAW_Q (a, A);
  69   FP_HANDLE_EXCEPTIONS;
  70
  71   return a;
  72 }
  73 #endif