gcc/real.h

   1 /* Definitions of floating-point access for GNU compiler.
   2    Copyright (C) 1989, 1991, 1994, 1996, 1997, 1998,
   3    1999, 2000, 2002 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.  */
  21
  22 #ifndef GCC_REAL_H
  23 #define GCC_REAL_H
  24
  25 /* Define codes for all the float formats that we know of.  */
  26 #define UNKNOWN_FLOAT_FORMAT 0
  27 #define IEEE_FLOAT_FORMAT 1
  28 #define VAX_FLOAT_FORMAT 2
  29 #define IBM_FLOAT_FORMAT 3
  30 #define C4X_FLOAT_FORMAT 4
  31
  32 /* Default to IEEE float if not specified.  Nearly all machines use it.  */
  33
  34 #ifndef TARGET_FLOAT_FORMAT
  35 #define TARGET_FLOAT_FORMAT     IEEE_FLOAT_FORMAT
  36 #endif
  37
  38 #ifndef HOST_FLOAT_FORMAT
  39 #define HOST_FLOAT_FORMAT       IEEE_FLOAT_FORMAT
  40 #endif
  41
  42 #ifndef INTEL_EXTENDED_IEEE_FORMAT
  43 #define INTEL_EXTENDED_IEEE_FORMAT 0
  44 #endif
  45
  46 /* If FLOAT_WORDS_BIG_ENDIAN and HOST_FLOAT_WORDS_BIG_ENDIAN are not defined
  47    in the header files, then this implies the word-endianness is the same as
  48    for integers.  */
  49
  50 /* This is defined 0 or 1, like WORDS_BIG_ENDIAN.  */
  51 #ifndef FLOAT_WORDS_BIG_ENDIAN
  52 #define FLOAT_WORDS_BIG_ENDIAN WORDS_BIG_ENDIAN
  53 #endif
  54
  55 /* This is defined 0 or 1, unlike HOST_WORDS_BIG_ENDIAN.  */
  56 #ifndef HOST_FLOAT_WORDS_BIG_ENDIAN
  57 #ifdef HOST_WORDS_BIG_ENDIAN
  58 #define HOST_FLOAT_WORDS_BIG_ENDIAN 1
  59 #else
  60 #define HOST_FLOAT_WORDS_BIG_ENDIAN 0
  61 #endif
  62 #endif
  63
  64 #ifndef LONG_DOUBLE_TYPE_SIZE
  65 #define LONG_DOUBLE_TYPE_SIZE 64
  66 #endif
  67 /* MAX_LONG_DOUBLE_TYPE_SIZE is a constant tested by #if.
  68    LONG_DOUBLE_TYPE_SIZE can vary at compiler run time.
  69    So long as macros like REAL_VALUE_TO_TARGET_LONG_DOUBLE cannot
  70    vary too, however, then XFmode and TFmode long double
  71    cannot both be supported at the same time.  */
  72 #ifndef MAX_LONG_DOUBLE_TYPE_SIZE
  73 #define MAX_LONG_DOUBLE_TYPE_SIZE LONG_DOUBLE_TYPE_SIZE
  74 #endif
  75
  76 /* **** Start of software floating point emulator interface macros **** */
  77
  78 /* REAL_VALUE_TYPE is an array of the minimum number of HOST_WIDE_INTs
  79    required to hold either a 96- or 160-bit extended precision floating
  80    point type.  This is true even if the maximum precision floating
  81    point type on the target is smaller.  */
  82 #if MAX_LONG_DOUBLE_TYPE_SIZE == 128 && !INTEL_EXTENDED_IEEE_FORMAT
  83 #define REAL_VALUE_TYPE_SIZE 160
  84 #else
  85 #define REAL_VALUE_TYPE_SIZE 96
  86 #endif
  87 #define REAL_WIDTH \
  88   (REAL_VALUE_TYPE_SIZE/HOST_BITS_PER_WIDE_INT \
  89    + (REAL_VALUE_TYPE_SIZE%HOST_BITS_PER_WIDE_INT ? 1 : 0)) /* round up */
  90 typedef struct {
  91   HOST_WIDE_INT r[REAL_WIDTH];
  92 } realvaluetype;
  93 /* Various headers condition prototypes on #ifdef REAL_VALUE_TYPE, so it needs
  94    to be a macro.  */
  95 #define REAL_VALUE_TYPE realvaluetype
  96
  97 /* Calculate the format for CONST_DOUBLE.  We need as many slots as
  98    are necessary to overlay a REAL_VALUE_TYPE on them.  This could be
  99    as many as five (32-bit HOST_WIDE_INT, 160-bit REAL_VALUE_TYPE).
 100
 101    A number of places assume that there are always at least two 'w'
 102    slots in a CONST_DOUBLE, so we provide them even if one would suffice.  */
 103
 104 #if REAL_WIDTH == 1
 105 # define CONST_DOUBLE_FORMAT     "ww"
 106 #else
 107 # if REAL_WIDTH == 2
 108 #  define CONST_DOUBLE_FORMAT    "ww"
 109 # else
 110 #  if REAL_WIDTH == 3
 111 #   define CONST_DOUBLE_FORMAT   "www"
 112 #  else
 113 #   if REAL_WIDTH == 4
 114 #    define CONST_DOUBLE_FORMAT  "wwww"
 115 #   else
 116 #    if REAL_WIDTH == 5
 117 #     define CONST_DOUBLE_FORMAT "wwwww"
 118 #    else
 119       #error "REAL_WIDTH > 5 not supported"
 120 #    endif
 121 #   endif
 122 #  endif
 123 # endif
 124 #endif
 125
 126 extern unsigned int significand_size    PARAMS ((enum machine_mode));
 127
 128 #define REAL_ARITHMETIC(value, code, d1, d2) \
 129   earith (&(value), (code), &(d1), &(d2))
 130
 131 /* Declare functions in real.c.  */
 132 extern void earith              PARAMS ((REAL_VALUE_TYPE *, int,
 133                                        REAL_VALUE_TYPE *, REAL_VALUE_TYPE *));
 134 extern REAL_VALUE_TYPE etrunci  PARAMS ((REAL_VALUE_TYPE));
 135 extern REAL_VALUE_TYPE etruncui PARAMS ((REAL_VALUE_TYPE));
 136 extern REAL_VALUE_TYPE ereal_negate PARAMS ((REAL_VALUE_TYPE));
 137 extern HOST_WIDE_INT efixi      PARAMS ((REAL_VALUE_TYPE));
 138 extern unsigned HOST_WIDE_INT efixui PARAMS ((REAL_VALUE_TYPE));
 139 extern void ereal_from_int      PARAMS ((REAL_VALUE_TYPE *,
 140                                        HOST_WIDE_INT, HOST_WIDE_INT,
 141                                        enum machine_mode));
 142 extern void ereal_from_uint     PARAMS ((REAL_VALUE_TYPE *,
 143                                        unsigned HOST_WIDE_INT,
 144                                        unsigned HOST_WIDE_INT,
 145                                        enum machine_mode));
 146 extern void ereal_to_int        PARAMS ((HOST_WIDE_INT *, HOST_WIDE_INT *,
 147                                        REAL_VALUE_TYPE));
 148 extern REAL_VALUE_TYPE ereal_ldexp PARAMS ((REAL_VALUE_TYPE, int));
 149
 150 extern void etartdouble         PARAMS ((REAL_VALUE_TYPE, long *));
 151 extern void etarldouble         PARAMS ((REAL_VALUE_TYPE, long *));
 152 extern void etardouble          PARAMS ((REAL_VALUE_TYPE, long *));
 153 extern long etarsingle          PARAMS ((REAL_VALUE_TYPE));
 154 extern void ereal_to_decimal    PARAMS ((REAL_VALUE_TYPE, char *));
 155 extern int ereal_cmp            PARAMS ((REAL_VALUE_TYPE, REAL_VALUE_TYPE));
 156 extern int ereal_isneg          PARAMS ((REAL_VALUE_TYPE));
 157 extern REAL_VALUE_TYPE ereal_unto_float PARAMS ((long));
 158 extern REAL_VALUE_TYPE ereal_unto_double PARAMS ((long *));
 159 extern REAL_VALUE_TYPE ereal_from_float PARAMS ((HOST_WIDE_INT));
 160 extern REAL_VALUE_TYPE ereal_from_double PARAMS ((HOST_WIDE_INT *));
 161
 162 #define REAL_VALUES_EQUAL(x, y) (ereal_cmp ((x), (y)) == 0)
 163 /* true if x < y : */
 164 #define REAL_VALUES_LESS(x, y) (ereal_cmp ((x), (y)) == -1)
 165 #define REAL_VALUE_LDEXP(x, n) ereal_ldexp (x, n)
 166
 167 /* Compare two floating-point objects for bitwise identity.
 168    This is not the same as comparing for equality on IEEE hosts:
 169    -0.0 equals 0.0 but they are not identical, and conversely
 170    two NaNs might be identical but they cannot be equal.  */
 171 #define REAL_VALUES_IDENTICAL(x, y) \
 172   (!memcmp ((char *) &(x), (char *) &(y), sizeof (REAL_VALUE_TYPE)))
 173
 174 /* These return REAL_VALUE_TYPE: */
 175 #define REAL_VALUE_RNDZINT(x) (etrunci (x))
 176 #define REAL_VALUE_UNSIGNED_RNDZINT(x) (etruncui (x))
 177
 178 /* Truncate the floating-point value X to mode MODE.  */
 179 #define REAL_VALUE_TRUNCATE(mode, x)  real_value_truncate (mode, x)
 180 extern REAL_VALUE_TYPE real_value_truncate PARAMS ((enum machine_mode,
 181                                                  REAL_VALUE_TYPE));
 182
 183 /* These return HOST_WIDE_INT: */
 184 /* Convert a floating-point value to integer, rounding toward zero.  */
 185 #define REAL_VALUE_FIX(x) (efixi (x))
 186 /* Convert a floating-point value to unsigned integer, rounding
 187    toward zero.  */
 188 #define REAL_VALUE_UNSIGNED_FIX(x) (efixui (x))
 189
 190 /* Convert ASCII string S to floating point in mode M.
 191    Decimal input uses ATOF.  Hexadecimal uses HTOF.  */
 192 #define REAL_VALUE_ATOF(s,m) ereal_atof(s,m)
 193 #define REAL_VALUE_HTOF(s,m) ereal_atof(s,m)
 194
 195 #define REAL_VALUE_NEGATE ereal_negate
 196
 197 /* Compute the absolute value of a floating-point value X.  */
 198 #define REAL_VALUE_ABS(x) \
 199    (REAL_VALUE_NEGATIVE (x) ? REAL_VALUE_NEGATE (x) : (x))
 200
 201 /* Determine whether a floating-point value X is infinite.  */
 202 #define REAL_VALUE_ISINF(x) (target_isinf (x))
 203
 204 /* Determine whether a floating-point value X is a NaN.  */
 205 #define REAL_VALUE_ISNAN(x) (target_isnan (x))
 206
 207 /* Determine whether a floating-point value X is negative.  */
 208 #define REAL_VALUE_NEGATIVE(x) (target_negative (x))
 209
 210 /* Determine whether a floating-point value X is minus zero.  */
 211 #define REAL_VALUE_MINUS_ZERO(x) \
 212  ((ereal_cmp (x, dconst0) == 0) && (ereal_isneg (x) != 0 ))
 213
 214 #define REAL_VALUE_TO_INT ereal_to_int
 215
 216 /* Here the cast to HOST_WIDE_INT sign-extends arguments such as ~0.  */
 217 #define REAL_VALUE_FROM_INT(d, lo, hi, mode) \
 218   ereal_from_int (&d, (HOST_WIDE_INT) (lo), (HOST_WIDE_INT) (hi), mode)
 219
 220 #define REAL_VALUE_FROM_UNSIGNED_INT(d, lo, hi, mode) \
 221   ereal_from_uint (&d, lo, hi, mode)
 222
 223 /* IN is a REAL_VALUE_TYPE.  OUT is an array of longs.  */
 224 #define REAL_VALUE_TO_TARGET_LONG_DOUBLE(IN, OUT)               \
 225    (LONG_DOUBLE_TYPE_SIZE == 64 ? etardouble ((IN), (OUT))      \
 226     : LONG_DOUBLE_TYPE_SIZE == 96 ? etarldouble ((IN), (OUT))   \
 227     : LONG_DOUBLE_TYPE_SIZE == 128 ? etartdouble ((IN), (OUT))  \
 228     : abort ())
 229 #define REAL_VALUE_TO_TARGET_DOUBLE(IN, OUT) (etardouble ((IN), (OUT)))
 230
 231 /* IN is a REAL_VALUE_TYPE.  OUT is a long.  */
 232 #define REAL_VALUE_TO_TARGET_SINGLE(IN, OUT) ((OUT) = etarsingle ((IN)))
 233
 234 /* Inverse of REAL_VALUE_TO_TARGET_DOUBLE.  */
 235 #define REAL_VALUE_UNTO_TARGET_DOUBLE(d)  (ereal_unto_double (d))
 236
 237 /* Inverse of REAL_VALUE_TO_TARGET_SINGLE.  */
 238 #define REAL_VALUE_UNTO_TARGET_SINGLE(f)  (ereal_unto_float (f))
 239
 240 /* d is an array of HOST_WIDE_INT that holds a double precision
 241    value in the target computer's floating point format.  */
 242 #define REAL_VALUE_FROM_TARGET_DOUBLE(d)  (ereal_from_double (d))
 243
 244 /* f is a HOST_WIDE_INT containing a single precision target float value.  */
 245 #define REAL_VALUE_FROM_TARGET_SINGLE(f)  (ereal_from_float (f))
 246
 247 /* Conversions to decimal ASCII string.  */
 248 #define REAL_VALUE_TO_DECIMAL(r, fmt, s) (ereal_to_decimal (r, s))
 249
 250 /* **** End of software floating point emulator interface macros **** */
 251 \f
 252 /* Constant real values 0, 1, 2, and -1.  */
 253
 254 extern REAL_VALUE_TYPE dconst0;
 255 extern REAL_VALUE_TYPE dconst1;
 256 extern REAL_VALUE_TYPE dconst2;
 257 extern REAL_VALUE_TYPE dconstm1;
 258
 259 /* Given a CONST_DOUBLE in FROM, store into TO the value it represents.  */
 260 /* Function to return a real value (not a tree node)
 261    from a given integer constant.  */
 262 union tree_node;
 263 REAL_VALUE_TYPE real_value_from_int_cst PARAMS ((union tree_node *,
 264                                                 union tree_node *));
 265
 266 #define REAL_VALUE_FROM_CONST_DOUBLE(to, from)          \
 267   memcpy (&(to), &CONST_DOUBLE_LOW ((from)), sizeof (REAL_VALUE_TYPE))
 268
 269 /* Return a CONST_DOUBLE with value R and mode M.  */
 270
 271 #define CONST_DOUBLE_FROM_REAL_VALUE(r, m) \
 272   const_double_from_real_value (r, m)
 273 extern rtx const_double_from_real_value PARAMS ((REAL_VALUE_TYPE,
 274                                                  enum machine_mode));
 275
 276 /* Shorthand; can be handy in machine descriptions.  */
 277 #define CONST_DOUBLE_ATOF(s, m) \
 278   CONST_DOUBLE_FROM_REAL_VALUE (REAL_VALUE_ATOF (s, m), m)
 279
 280 /* Replace R by 1/R in the given machine mode, if the result is exact.  */
 281 extern int exact_real_inverse   PARAMS ((enum machine_mode, REAL_VALUE_TYPE *));
 282 extern int target_isnan         PARAMS ((REAL_VALUE_TYPE));
 283 extern int target_isinf         PARAMS ((REAL_VALUE_TYPE));
 284 extern int target_negative      PARAMS ((REAL_VALUE_TYPE));
 285 extern void debug_real          PARAMS ((REAL_VALUE_TYPE));
 286 extern REAL_VALUE_TYPE ereal_atof PARAMS ((const char *, enum machine_mode));
 287
 288 #endif /* ! GCC_REAL_H */