glibc/soft-fp/brain.h

/* Software floating-point emulation.
   Definitions for Brain Floating Point format (bfloat16).
   Copyright (C) 1997-2024 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   In addition to the permissions in the GNU Lesser General Public
   License, the Free Software Foundation gives you unlimited
   permission to link the compiled version of this file into
   combinations with other programs, and to distribute those
   combinations without any restriction coming from the use of this
   file.  (The Lesser General Public License restrictions do apply in
   other respects; for example, they cover modification of the file,
   and distribution when not linked into a combine executable.)

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#ifndef SOFT_FP_BRAIN_H
#define SOFT_FP_BRAIN_H	1

#if _FP_W_TYPE_SIZE < 32
# error "Here's a nickel kid.  Go buy yourself a real computer."
#endif

#define _FP_FRACTBITS_B		(_FP_W_TYPE_SIZE)

#define _FP_FRACTBITS_DW_B	(_FP_W_TYPE_SIZE)

#define _FP_FRACBITS_B		8
#define _FP_FRACXBITS_B		(_FP_FRACTBITS_B - _FP_FRACBITS_B)
#define _FP_WFRACBITS_B		(_FP_WORKBITS + _FP_FRACBITS_B)
#define _FP_WFRACXBITS_B	(_FP_FRACTBITS_B - _FP_WFRACBITS_B)
#define _FP_EXPBITS_B		8
#define _FP_EXPBIAS_B		127
#define _FP_EXPMAX_B		255

#define _FP_QNANBIT_B		((_FP_W_TYPE) 1 << (_FP_FRACBITS_B-2))
#define _FP_QNANBIT_SH_B	((_FP_W_TYPE) 1 << (_FP_FRACBITS_B-2+_FP_WORKBITS))
#define _FP_IMPLBIT_B		((_FP_W_TYPE) 1 << (_FP_FRACBITS_B-1))
#define _FP_IMPLBIT_SH_B	((_FP_W_TYPE) 1 << (_FP_FRACBITS_B-1+_FP_WORKBITS))
#define _FP_OVERFLOW_B		((_FP_W_TYPE) 1 << (_FP_WFRACBITS_B))

#define _FP_WFRACBITS_DW_B	(2 * _FP_WFRACBITS_B)
#define _FP_WFRACXBITS_DW_B	(_FP_FRACTBITS_DW_B - _FP_WFRACBITS_DW_B)
#define _FP_HIGHBIT_DW_B	\
  ((_FP_W_TYPE) 1 << (_FP_WFRACBITS_DW_B - 1) % _FP_W_TYPE_SIZE)

/* The implementation of _FP_MUL_MEAT_B and _FP_DIV_MEAT_B should be
   chosen by the target machine.  */

typedef float BFtype __attribute__ ((mode (BF)));

union _FP_UNION_B
{
  BFtype flt;
  struct _FP_STRUCT_LAYOUT
  {
#if __BYTE_ORDER == __BIG_ENDIAN
    unsigned sign : 1;
    unsigned exp  : _FP_EXPBITS_B;
    unsigned frac : _FP_FRACBITS_B - (_FP_IMPLBIT_B != 0);
#else
    unsigned frac : _FP_FRACBITS_B - (_FP_IMPLBIT_B != 0);
    unsigned exp  : _FP_EXPBITS_B;
    unsigned sign : 1;
#endif
  } bits;
};

#define FP_DECL_B(X)		_FP_DECL (1, X)
#define FP_UNPACK_RAW_B(X, val)	_FP_UNPACK_RAW_1 (B, X, (val))
#define FP_UNPACK_RAW_BP(X, val)	_FP_UNPACK_RAW_1_P (B, X, (val))
#define FP_PACK_RAW_B(val, X)	_FP_PACK_RAW_1 (B, (val), X)
#define FP_PACK_RAW_BP(val, X)			\
  do						\
    {						\
      if (!FP_INHIBIT_RESULTS)			\
	_FP_PACK_RAW_1_P (B, (val), X);		\
    }						\
  while (0)

#define FP_UNPACK_B(X, val)			\
  do						\
    {						\
      _FP_UNPACK_RAW_1 (B, X, (val));		\
      _FP_UNPACK_CANONICAL (B, 1, X);		\
    }						\
  while (0)

#define FP_UNPACK_BP(X, val)			\
  do						\
    {						\
      _FP_UNPACK_RAW_1_P (B, X, (val));		\
      _FP_UNPACK_CANONICAL (B, 1, X);		\
    }						\
  while (0)

#define FP_UNPACK_SEMIRAW_B(X, val)		\
  do						\
    {						\
      _FP_UNPACK_RAW_1 (B, X, (val));		\
      _FP_UNPACK_SEMIRAW (B, 1, X);		\
    }						\
  while (0)

#define FP_UNPACK_SEMIRAW_BP(X, val)		\
  do						\
    {						\
      _FP_UNPACK_RAW_1_P (B, X, (val));		\
      _FP_UNPACK_SEMIRAW (B, 1, X);		\
    }						\
  while (0)

#define FP_PACK_B(val, X)			\
  do						\
    {						\
      _FP_PACK_CANONICAL (B, 1, X);		\
      _FP_PACK_RAW_1 (B, (val), X);		\
    }						\
  while (0)

#define FP_PACK_BP(val, X)			\
  do						\
    {						\
      _FP_PACK_CANONICAL (B, 1, X);		\
      if (!FP_INHIBIT_RESULTS)			\
	_FP_PACK_RAW_1_P (B, (val), X);		\
    }						\
  while (0)

#define FP_PACK_SEMIRAW_B(val, X)		\
  do						\
    {						\
      _FP_PACK_SEMIRAW (B, 1, X);		\
      _FP_PACK_RAW_1 (B, (val), X);		\
    }						\
  while (0)

#define FP_PACK_SEMIRAW_BP(val, X)		\
  do						\
    {						\
      _FP_PACK_SEMIRAW (B, 1, X);		\
      if (!FP_INHIBIT_RESULTS)			\
	_FP_PACK_RAW_1_P (B, (val), X);		\
    }						\
  while (0)

#define FP_TO_INT_B(r, X, rsz, rsg)	_FP_TO_INT (B, 1, (r), X, (rsz), (rsg))
#define FP_TO_INT_ROUND_B(r, X, rsz, rsg)	\
  _FP_TO_INT_ROUND (B, 1, (r), X, (rsz), (rsg))
#define FP_FROM_INT_B(X, r, rs, rt)	_FP_FROM_INT (B, 1, X, (r), (rs), rt)

/* BFmode arithmetic is not implemented.  */

#define _FP_FRAC_HIGH_B(X)	_FP_FRAC_HIGH_1 (X)
#define _FP_FRAC_HIGH_RAW_B(X)	_FP_FRAC_HIGH_1 (X)
#define _FP_FRAC_HIGH_DW_B(X)	_FP_FRAC_HIGH_1 (X)

#define FP_CMP_EQ_B(r, X, Y, ex)       _FP_CMP_EQ (B, 1, (r), X, Y, (ex))

#endif /* !SOFT_FP_BRAIN_H */