soft-fp/brain.h

   1 /* Software floating-point emulation.
   2    Definitions for Brain Floating Point format (bfloat16).
   3    Copyright (C) 1997-2024 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    In addition to the permissions in the GNU Lesser General Public
  12    License, the Free Software Foundation gives you unlimited
  13    permission to link the compiled version of this file into
  14    combinations with other programs, and to distribute those
  15    combinations without any restriction coming from the use of this
  16    file.  (The Lesser General Public License restrictions do apply in
  17    other respects; for example, they cover modification of the file,
  18    and distribution when not linked into a combine executable.)
  19
  20    The GNU C Library is distributed in the hope that it will be useful,
  21    but WITHOUT ANY WARRANTY; without even the implied warranty of
  22    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  23    Lesser General Public License for more details.
  24
  25    You should have received a copy of the GNU Lesser General Public
  26    License along with the GNU C Library; if not, see
  27    <https://www.gnu.org/licenses/>.  */
  28
  29 #ifndef SOFT_FP_BRAIN_H
  30 #define SOFT_FP_BRAIN_H 1
  31
  32 #if _FP_W_TYPE_SIZE < 32
  33 # error "Here's a nickel kid.  Go buy yourself a real computer."
  34 #endif
  35
  36 #define _FP_FRACTBITS_B         (_FP_W_TYPE_SIZE)
  37
  38 #define _FP_FRACTBITS_DW_B      (_FP_W_TYPE_SIZE)
  39
  40 #define _FP_FRACBITS_B          8
  41 #define _FP_FRACXBITS_B         (_FP_FRACTBITS_B - _FP_FRACBITS_B)
  42 #define _FP_WFRACBITS_B         (_FP_WORKBITS + _FP_FRACBITS_B)
  43 #define _FP_WFRACXBITS_B        (_FP_FRACTBITS_B - _FP_WFRACBITS_B)
  44 #define _FP_EXPBITS_B           8
  45 #define _FP_EXPBIAS_B           127
  46 #define _FP_EXPMAX_B            255
  47
  48 #define _FP_QNANBIT_B           ((_FP_W_TYPE) 1 << (_FP_FRACBITS_B-2))
  49 #define _FP_QNANBIT_SH_B        ((_FP_W_TYPE) 1 << (_FP_FRACBITS_B-2+_FP_WORKBITS))
  50 #define _FP_IMPLBIT_B           ((_FP_W_TYPE) 1 << (_FP_FRACBITS_B-1))
  51 #define _FP_IMPLBIT_SH_B        ((_FP_W_TYPE) 1 << (_FP_FRACBITS_B-1+_FP_WORKBITS))
  52 #define _FP_OVERFLOW_B          ((_FP_W_TYPE) 1 << (_FP_WFRACBITS_B))
  53
  54 #define _FP_WFRACBITS_DW_B      (2 * _FP_WFRACBITS_B)
  55 #define _FP_WFRACXBITS_DW_B     (_FP_FRACTBITS_DW_B - _FP_WFRACBITS_DW_B)
  56 #define _FP_HIGHBIT_DW_B        \
  57   ((_FP_W_TYPE) 1 << (_FP_WFRACBITS_DW_B - 1) % _FP_W_TYPE_SIZE)
  58
  59 /* The implementation of _FP_MUL_MEAT_B and _FP_DIV_MEAT_B should be
  60    chosen by the target machine.  */
  61
  62 typedef float BFtype __attribute__ ((mode (BF)));
  63
  64 union _FP_UNION_B
  65 {
  66   BFtype flt;
  67   struct _FP_STRUCT_LAYOUT
  68   {
  69 #if __BYTE_ORDER == __BIG_ENDIAN
  70     unsigned sign : 1;
  71     unsigned exp  : _FP_EXPBITS_B;
  72     unsigned frac : _FP_FRACBITS_B - (_FP_IMPLBIT_B != 0);
  73 #else
  74     unsigned frac : _FP_FRACBITS_B - (_FP_IMPLBIT_B != 0);
  75     unsigned exp  : _FP_EXPBITS_B;
  76     unsigned sign : 1;
  77 #endif
  78   } bits;
  79 };
  80
  81 #define FP_DECL_B(X)            _FP_DECL (1, X)
  82 #define FP_UNPACK_RAW_B(X, val) _FP_UNPACK_RAW_1 (B, X, (val))
  83 #define FP_UNPACK_RAW_BP(X, val)        _FP_UNPACK_RAW_1_P (B, X, (val))
  84 #define FP_PACK_RAW_B(val, X)   _FP_PACK_RAW_1 (B, (val), X)
  85 #define FP_PACK_RAW_BP(val, X)                  \
  86   do                                            \
  87     {                                           \
  88       if (!FP_INHIBIT_RESULTS)                  \
  89         _FP_PACK_RAW_1_P (B, (val), X);         \
  90     }                                           \
  91   while (0)
  92
  93 #define FP_UNPACK_B(X, val)                     \
  94   do                                            \
  95     {                                           \
  96       _FP_UNPACK_RAW_1 (B, X, (val));           \
  97       _FP_UNPACK_CANONICAL (B, 1, X);           \
  98     }                                           \
  99   while (0)
 100
 101 #define FP_UNPACK_BP(X, val)                    \
 102   do                                            \
 103     {                                           \
 104       _FP_UNPACK_RAW_1_P (B, X, (val));         \
 105       _FP_UNPACK_CANONICAL (B, 1, X);           \
 106     }                                           \
 107   while (0)
 108
 109 #define FP_UNPACK_SEMIRAW_B(X, val)             \
 110   do                                            \
 111     {                                           \
 112       _FP_UNPACK_RAW_1 (B, X, (val));           \
 113       _FP_UNPACK_SEMIRAW (B, 1, X);             \
 114     }                                           \
 115   while (0)
 116
 117 #define FP_UNPACK_SEMIRAW_BP(X, val)            \
 118   do                                            \
 119     {                                           \
 120       _FP_UNPACK_RAW_1_P (B, X, (val));         \
 121       _FP_UNPACK_SEMIRAW (B, 1, X);             \
 122     }                                           \
 123   while (0)
 124
 125 #define FP_PACK_B(val, X)                       \
 126   do                                            \
 127     {                                           \
 128       _FP_PACK_CANONICAL (B, 1, X);             \
 129       _FP_PACK_RAW_1 (B, (val), X);             \
 130     }                                           \
 131   while (0)
 132
 133 #define FP_PACK_BP(val, X)                      \
 134   do                                            \
 135     {                                           \
 136       _FP_PACK_CANONICAL (B, 1, X);             \
 137       if (!FP_INHIBIT_RESULTS)                  \
 138         _FP_PACK_RAW_1_P (B, (val), X);         \
 139     }                                           \
 140   while (0)
 141
 142 #define FP_PACK_SEMIRAW_B(val, X)               \
 143   do                                            \
 144     {                                           \
 145       _FP_PACK_SEMIRAW (B, 1, X);               \
 146       _FP_PACK_RAW_1 (B, (val), X);             \
 147     }                                           \
 148   while (0)
 149
 150 #define FP_PACK_SEMIRAW_BP(val, X)              \
 151   do                                            \
 152     {                                           \
 153       _FP_PACK_SEMIRAW (B, 1, X);               \
 154       if (!FP_INHIBIT_RESULTS)                  \
 155         _FP_PACK_RAW_1_P (B, (val), X);         \
 156     }                                           \
 157   while (0)
 158
 159 #define FP_TO_INT_B(r, X, rsz, rsg)     _FP_TO_INT (B, 1, (r), X, (rsz), (rsg))
 160 #define FP_TO_INT_ROUND_B(r, X, rsz, rsg)       \
 161   _FP_TO_INT_ROUND (B, 1, (r), X, (rsz), (rsg))
 162 #define FP_FROM_INT_B(X, r, rs, rt)     _FP_FROM_INT (B, 1, X, (r), (rs), rt)
 163
 164 /* BFmode arithmetic is not implemented.  */
 165
 166 #define _FP_FRAC_HIGH_B(X)      _FP_FRAC_HIGH_1 (X)
 167 #define _FP_FRAC_HIGH_RAW_B(X)  _FP_FRAC_HIGH_1 (X)
 168 #define _FP_FRAC_HIGH_DW_B(X)   _FP_FRAC_HIGH_1 (X)
 169
 170 #define FP_CMP_EQ_B(r, X, Y, ex)       _FP_CMP_EQ (B, 1, (r), X, Y, (ex))
 171
 172 #endif /* !SOFT_FP_BRAIN_H */