libgcc/fp-bit.h

/* Header file for fp-bit.c.  */
/* Copyright (C) 2000-2021 Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.

GCC 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 General Public License
for more details.

Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.

You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
<http://www.gnu.org/licenses/>.  */

#ifndef GCC_FP_BIT_H
#define GCC_FP_BIT_H

/* Defining FINE_GRAINED_LIBRARIES allows one to select which routines
   from this file are compiled via additional -D options.

   This avoids the need to pull in the entire fp emulation library
   when only a small number of functions are needed.

   If FINE_GRAINED_LIBRARIES is not defined, then compile every
   suitable routine.  */
#ifndef FINE_GRAINED_LIBRARIES
#define L_pack_df
#define L_unpack_df
#define L_pack_sf
#define L_unpack_sf
#define L_addsub_sf
#define L_addsub_df
#define L_mul_sf
#define L_mul_df
#define L_div_sf
#define L_div_df
#define L_fpcmp_parts_sf
#define L_fpcmp_parts_df
#define L_compare_sf
#define L_compare_df
#define L_eq_sf
#define L_eq_df
#define L_ne_sf
#define L_ne_df
#define L_gt_sf
#define L_gt_df
#define L_ge_sf
#define L_ge_df
#define L_lt_sf
#define L_lt_df
#define L_le_sf
#define L_le_df
#define L_unord_sf
#define L_unord_df
#define L_usi_to_sf
#define L_usi_to_df
#define L_si_to_sf
#define L_si_to_df
#define L_sf_to_si
#define L_df_to_si
#define L_f_to_usi
#define L_df_to_usi
#define L_negate_sf
#define L_negate_df
#define L_make_sf
#define L_make_df
#define L_sf_to_df
#define L_df_to_sf
#ifdef FLOAT
#define L_thenan_sf
#else
#define L_thenan_df
#endif
#endif /* ! FINE_GRAINED_LIBRARIES */

#if __LDBL_MANT_DIG__ == 113 || __LDBL_MANT_DIG__ == 106
# if defined(TFLOAT) || defined(L_sf_to_tf) || defined(L_df_to_tf)
#  define TMODES
# endif
#endif

typedef float SFtype __attribute__ ((mode (SF)));
typedef float DFtype __attribute__ ((mode (DF)));
#ifdef TMODES
typedef float TFtype __attribute__ ((mode (TF)));
#endif

typedef int HItype __attribute__ ((mode (HI)));
typedef int SItype __attribute__ ((mode (SI)));
typedef int DItype __attribute__ ((mode (DI)));
#ifdef TMODES
typedef int TItype __attribute__ ((mode (TI)));
#endif

/* The type of the result of a floating point comparison.  This must
   match `__libgcc_cmp_return__' in GCC for the target.  */
#ifndef CMPtype
typedef int CMPtype __attribute__ ((mode (__libgcc_cmp_return__)));
#endif

typedef unsigned int UHItype __attribute__ ((mode (HI)));
typedef unsigned int USItype __attribute__ ((mode (SI)));
typedef unsigned int UDItype __attribute__ ((mode (DI)));
#ifdef TMODES
typedef unsigned int UTItype __attribute__ ((mode (TI)));
#endif

#define MAX_USI_INT  (~(USItype)0)
#define MAX_SI_INT   ((SItype) (MAX_USI_INT >> 1))
#define BITS_PER_SI  (4 * __CHAR_BIT__)
#ifdef TMODES
#define MAX_UDI_INT  (~(UDItype)0)
#define MAX_DI_INT   ((DItype) (MAX_UDI_INT >> 1))
#define BITS_PER_DI  (8 * __CHAR_BIT__)
#endif

#ifdef FLOAT_ONLY
#define NO_DI_MODE
#endif

#if __BYTE_ORDER__ != __FLOAT_WORD_ORDER__
#define FLOAT_WORD_ORDER_MISMATCH
#endif

#ifdef TFLOAT
# ifndef TMODES
#  error "TFLOAT requires long double to have 113 bits of mantissa"
# endif

#	define PREFIXFPDP tp
#	define PREFIXSFDF tf
#	define NGARDS 10L /* Is this right? */
#	define GARDROUND 0x1ff
#	define GARDMASK  0x3ff
#	define GARDMSB   0x200
#	define FRAC_NBITS 128

# if __LDBL_MANT_DIG__ == 113 /* IEEE quad */
#	define EXPBITS 15
#	define EXPBIAS 16383
#	define EXPMAX (0x7fff)
#	define QUIET_NAN ((TItype)0x8 << 108)
#	define FRACHIGH  ((TItype)0x8 << 124)
#	define FRACHIGH2 ((TItype)0xc << 124)
#	define FRACBITS 112
# endif

# if __LDBL_MANT_DIG__ == 106 /* IBM extended (double+double) */
#	define EXPBITS 11
#	define EXPBIAS 1023
#	define EXPMAX (0x7ff)
#	define QUIET_NAN ((TItype)0x8 << (48 + 64))
#	define FRACHIGH  ((TItype)0x8 << 124)
#	define FRACHIGH2 ((TItype)0xc << 124)
#	define FRACBITS 105
#	define HALFFRACBITS 52
#	define HALFSHIFT 64
# endif

#	define pack_d __pack_t
#	define unpack_d __unpack_t
#	define __fpcmp_parts __fpcmp_parts_t
	typedef UTItype fractype;
	typedef UDItype halffractype;
	typedef USItype qrtrfractype;
#define qrtrfractype qrtrfractype
	typedef TFtype FLO_type;
	typedef TItype intfrac;
#elif defined FLOAT
#	define NGARDS    7L
#	define GARDROUND 0x3f
#	define GARDMASK  0x7f
#	define GARDMSB   0x40
#	define EXPBITS 8
#	define EXPBIAS 127
#	define FRACBITS 23
#	define EXPMAX (0xff)
#	define QUIET_NAN 0x400000L
#	define FRAC_NBITS 32
#	define FRACHIGH  0x80000000L
#	define FRACHIGH2 0xc0000000L
#	define pack_d __pack_f
#	define unpack_d __unpack_f
#	define __fpcmp_parts __fpcmp_parts_f
	typedef USItype fractype;
	typedef UHItype halffractype;
	typedef SFtype FLO_type;
	typedef SItype intfrac;

#else
#	define PREFIXFPDP dp
#	define PREFIXSFDF df
#	define NGARDS 8L
#	define GARDROUND 0x7f
#	define GARDMASK  0xff
#	define GARDMSB   0x80
#	define EXPBITS 11
#	define EXPBIAS 1023
#	define FRACBITS 52
#	define EXPMAX (0x7ff)
#	define QUIET_NAN 0x8000000000000LL
#	define FRAC_NBITS 64
#	define FRACHIGH  0x8000000000000000LL
#	define FRACHIGH2 0xc000000000000000LL
#	define pack_d __pack_d
#	define unpack_d __unpack_d
#	define __fpcmp_parts __fpcmp_parts_d
	typedef UDItype fractype;
	typedef USItype halffractype;
	typedef DFtype FLO_type;
	typedef DItype intfrac;
#endif /* FLOAT */

#ifdef TFLOAT
#	define add 		__addtf3
#	define sub 		__subtf3
#	define multiply 	__multf3
#	define divide 		__divtf3
#	define compare 		__cmptf2
#	define _eq_f2 		__eqtf2
#	define _ne_f2 		__netf2
#	define _gt_f2 		__gttf2
#	define _ge_f2 		__getf2
#	define _lt_f2 		__lttf2
#	define _le_f2 		__letf2
#	define _unord_f2	__unordtf2
#	define usi_to_float 	__floatunsitf
#	define si_to_float 	__floatsitf
#	define float_to_si 	__fixtfsi
#	define float_to_usi 	__fixunstfsi
#	define negate 		__negtf2
#	define tf_to_sf		__trunctfsf2
#	define tf_to_df		__trunctfdf2
#elif defined FLOAT
#	define add 		__addsf3
#	define sub 		__subsf3
#	define multiply 	__mulsf3
#	define divide 		__divsf3
#	define compare 		__cmpsf2
#	define _eq_f2 		__eqsf2
#	define _ne_f2 		__nesf2
#	define _gt_f2 		__gtsf2
#	define _ge_f2 		__gesf2
#	define _lt_f2 		__ltsf2
#	define _le_f2 		__lesf2
#	define _unord_f2	__unordsf2
#	define usi_to_float 	__floatunsisf
#	define si_to_float 	__floatsisf
#	define float_to_si 	__fixsfsi
#	define float_to_usi 	__fixunssfsi
#	define negate 		__negsf2
#	define sf_to_df		__extendsfdf2
#	define sf_to_tf		__extendsftf2
#else
#	define add 		__adddf3
#	define sub 		__subdf3
#	define multiply 	__muldf3
#	define divide 		__divdf3
#	define compare 		__cmpdf2
#	define _eq_f2 		__eqdf2
#	define _ne_f2 		__nedf2
#	define _gt_f2 		__gtdf2
#	define _ge_f2 		__gedf2
#	define _lt_f2 		__ltdf2
#	define _le_f2 		__ledf2
#	define _unord_f2	__unorddf2
#	define usi_to_float 	__floatunsidf
#	define si_to_float 	__floatsidf
#	define float_to_si 	__fixdfsi
#	define float_to_usi 	__fixunsdfsi
#	define negate 		__negdf2
#	define df_to_sf		__truncdfsf2
#	define df_to_tf		__extenddftf2
#endif /* FLOAT */

#ifndef INLINE
#define INLINE __inline__
#endif

/* Preserve the sticky-bit when shifting fractions to the right.  */
#define LSHIFT(a, s) { a = (a >> s) | !!(a & (((fractype) 1 << s) - 1)); }

/* numeric parameters */
/* F_D_BITOFF is the number of bits offset between the MSB of the mantissa
   of a float and of a double. Assumes there are only two float types.
   (double::FRAC_BITS+double::NGARDS-(float::FRAC_BITS+float::NGARDS))
 */
#define F_D_BITOFF (52+8-(23+7))

#ifdef TMODES
# define F_T_BITOFF (__LDBL_MANT_DIG__-1+10-(23+7))
# define D_T_BITOFF (__LDBL_MANT_DIG__-1+10-(52+8))
#endif


#define NORMAL_EXPMIN (-(EXPBIAS)+1)
#define IMPLICIT_1 ((fractype)1<<(FRACBITS+NGARDS))
#define IMPLICIT_2 ((fractype)1<<(FRACBITS+1+NGARDS))

/* common types */

typedef enum
{
  CLASS_SNAN,
  CLASS_QNAN,
  CLASS_ZERO,
  CLASS_NUMBER,
  CLASS_INFINITY
} fp_class_type;

typedef struct
{
#ifdef SMALL_MACHINE
  char class;
  unsigned char sign;
  short normal_exp;
#else
  fp_class_type class;
  unsigned int sign;
  int normal_exp;
#endif

  union
    {
      fractype ll;
      halffractype l[2];
    } fraction;
} fp_number_type;

typedef union
{
  FLO_type value;
  fractype value_raw;

#ifndef FLOAT
# ifdef qrtrfractype
  qrtrfractype qwords[4];
# else
  halffractype words[2];
# endif
#endif

#ifdef _DEBUG_BITFLOAT
  struct
    {
      unsigned int sign:1 __attribute__ ((packed));
      unsigned int exp:EXPBITS __attribute__ ((packed));
      fractype fraction:FRACBITS __attribute__ ((packed));
    }
  bits_big_endian;

  struct
    {
      fractype fraction:FRACBITS __attribute__ ((packed));
      unsigned int exp:EXPBITS __attribute__ ((packed));
      unsigned int sign:1 __attribute__ ((packed));
    }
  bits_little_endian;
#endif
}
FLO_union_type;

/* Prototypes.  */

#if defined(L_pack_df) || defined(L_pack_sf) || defined(L_pack_tf)
extern FLO_type pack_d (const fp_number_type *);
#endif

extern void unpack_d (FLO_union_type *, fp_number_type *);

#if defined(L_addsub_sf) || defined(L_addsub_df) || defined(L_addsub_tf)
extern FLO_type add (FLO_type, FLO_type);
extern FLO_type sub (FLO_type, FLO_type);
#endif

#if defined(L_mul_sf) || defined(L_mul_df) || defined(L_mul_tf)
extern FLO_type multiply (FLO_type, FLO_type);
#endif

#if defined(L_div_sf) || defined(L_div_df) || defined(L_div_tf)
extern FLO_type divide (FLO_type, FLO_type);
#endif

extern int __fpcmp_parts (fp_number_type *, fp_number_type *);

#if defined(L_compare_sf) || defined(L_compare_df) || defined(L_compare_tf)
extern CMPtype compare (FLO_type, FLO_type);
#endif

#if defined(L_eq_sf) || defined(L_eq_df) || defined(L_eq_tf)
extern CMPtype _eq_f2 (FLO_type, FLO_type);
#endif

#if defined(L_ne_sf) || defined(L_ne_df) || defined(L_ne_tf)
extern CMPtype _ne_f2 (FLO_type, FLO_type);
#endif

#if defined(L_gt_sf) || defined(L_gt_df) || defined(L_gt_tf)
extern CMPtype _gt_f2 (FLO_type, FLO_type);
#endif

#if defined(L_ge_sf) || defined(L_ge_df) || defined(L_ge_tf)
extern CMPtype _ge_f2 (FLO_type, FLO_type);
#endif

#if defined(L_lt_sf) || defined(L_lt_df) || defined(L_lt_tf)
extern CMPtype _lt_f2 (FLO_type, FLO_type);
#endif

#if defined(L_le_sf) || defined(L_le_df) || defined(L_le_tf)
extern CMPtype _le_f2 (FLO_type, FLO_type);
#endif

#if defined(L_unord_sf) || defined(L_unord_df) || defined(L_unord_tf)
extern CMPtype _unord_f2 (FLO_type, FLO_type);
#endif

#if defined(L_si_to_sf) || defined(L_si_to_df) || defined(L_si_to_tf)
extern FLO_type si_to_float (SItype);
#endif

#if defined(L_sf_to_si) || defined(L_df_to_si) || defined(L_tf_to_si)
extern SItype float_to_si (FLO_type);
#endif

#if defined(L_tf_to_usi)
extern USItype float_to_usi (FLO_type);
#endif

#if defined(L_usi_to_sf) || defined(L_usi_to_df) || defined(L_usi_to_tf)
extern FLO_type usi_to_float (USItype);
#endif

#if defined(L_negate_sf) || defined(L_negate_df) || defined(L_negate_tf)
extern FLO_type negate (FLO_type);
#endif

#ifdef FLOAT
#if defined(L_make_sf)
extern SFtype __make_fp (fp_class_type, unsigned int, int, USItype);
#endif
#ifndef FLOAT_ONLY
extern DFtype __make_dp (fp_class_type, unsigned int, int, UDItype);
#if defined(L_sf_to_df)
extern DFtype sf_to_df (SFtype);
#endif
#if defined(L_sf_to_tf) && defined(TMODES)
extern TFtype sf_to_tf (SFtype);
#endif
#endif /* ! FLOAT_ONLY */
#endif /* FLOAT */

#ifndef FLOAT
extern SFtype __make_fp (fp_class_type, unsigned int, int, USItype);
#if defined(L_make_df)
extern DFtype __make_dp (fp_class_type, unsigned int, int, UDItype);
#endif
#if defined(L_df_to_sf)
extern SFtype df_to_sf (DFtype);
#endif
#if defined(L_df_to_tf) && defined(TMODES)
extern TFtype df_to_tf (DFtype);
#endif
#endif /* ! FLOAT */

#ifdef TMODES
extern DFtype __make_dp (fp_class_type, unsigned int, int, UDItype);
extern TFtype __make_tp (fp_class_type, unsigned int, int, UTItype);
#ifdef TFLOAT
#if defined(L_tf_to_sf)
extern SFtype tf_to_sf (TFtype);
#endif
#if defined(L_tf_to_df)
extern DFtype tf_to_df (TFtype);
#endif
#if defined(L_di_to_tf)
extern TFtype di_to_df (DItype);
#endif
#endif /* TFLOAT */
#endif /* TMODES */

#endif /* ! GCC_FP_BIT_H */