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1 /* Definitions of floating-point access for GNU compiler.
2 Copyright (C) 1989-2015 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 #ifndef GCC_REAL_H
21 #define GCC_REAL_H
23 /* An expanded form of the represented number. */
25 /* Enumerate the special cases of numbers that we encounter. */
26 enum real_value_class {
27 rvc_zero,
28 rvc_normal,
29 rvc_inf,
30 rvc_nan
33 #define SIGNIFICAND_BITS (128 + HOST_BITS_PER_LONG)
34 #define EXP_BITS (32 - 6)
35 #define MAX_EXP ((1 << (EXP_BITS - 1)) - 1)
36 #define SIGSZ (SIGNIFICAND_BITS / HOST_BITS_PER_LONG)
37 #define SIG_MSB ((unsigned long)1 << (HOST_BITS_PER_LONG - 1))
39 struct GTY(()) real_value {
40 /* Use the same underlying type for all bit-fields, so as to make
41 sure they're packed together, otherwise REAL_VALUE_TYPE_SIZE will
42 be miscomputed. */
43 unsigned int /* ENUM_BITFIELD (real_value_class) */ cl : 2;
44 unsigned int decimal : 1;
45 unsigned int sign : 1;
46 unsigned int signalling : 1;
47 unsigned int canonical : 1;
48 unsigned int uexp : EXP_BITS;
49 unsigned long sig[SIGSZ];
52 #define REAL_EXP(REAL) \
53 ((int)((REAL)->uexp ^ (unsigned int)(1 << (EXP_BITS - 1))) \
54 - (1 << (EXP_BITS - 1)))
55 #define SET_REAL_EXP(REAL, EXP) \
56 ((REAL)->uexp = ((unsigned int)(EXP) & (unsigned int)((1 << EXP_BITS) - 1)))
58 /* Various headers condition prototypes on #ifdef REAL_VALUE_TYPE, so it
59 needs to be a macro. We do need to continue to have a structure tag
60 so that other headers can forward declare it. */
61 #define REAL_VALUE_TYPE struct real_value
63 /* We store a REAL_VALUE_TYPE into an rtx, and we do this by putting it in
64 consecutive "w" slots. Moreover, we've got to compute the number of "w"
65 slots at preprocessor time, which means we can't use sizeof. Guess. */
67 #define REAL_VALUE_TYPE_SIZE (SIGNIFICAND_BITS + 32)
68 #define REAL_WIDTH \
69 (REAL_VALUE_TYPE_SIZE/HOST_BITS_PER_WIDE_INT \
70 + (REAL_VALUE_TYPE_SIZE%HOST_BITS_PER_WIDE_INT ? 1 : 0)) /* round up */
72 /* Verify the guess. */
73 extern char test_real_width
74 [sizeof (REAL_VALUE_TYPE) <= REAL_WIDTH * sizeof (HOST_WIDE_INT) ? 1 : -1];
76 /* Calculate the format for CONST_DOUBLE. We need as many slots as
77 are necessary to overlay a REAL_VALUE_TYPE on them. This could be
78 as many as four (32-bit HOST_WIDE_INT, 128-bit REAL_VALUE_TYPE).
80 A number of places assume that there are always at least two 'w'
81 slots in a CONST_DOUBLE, so we provide them even if one would suffice. */
83 #if REAL_WIDTH == 1
84 # define CONST_DOUBLE_FORMAT "ww"
85 #else
86 # if REAL_WIDTH == 2
87 # define CONST_DOUBLE_FORMAT "ww"
88 # else
89 # if REAL_WIDTH == 3
90 # define CONST_DOUBLE_FORMAT "www"
91 # else
92 # if REAL_WIDTH == 4
93 # define CONST_DOUBLE_FORMAT "wwww"
94 # else
95 # if REAL_WIDTH == 5
96 # define CONST_DOUBLE_FORMAT "wwwww"
97 # else
98 # if REAL_WIDTH == 6
99 # define CONST_DOUBLE_FORMAT "wwwwww"
100 # else
101 #error "REAL_WIDTH > 6 not supported"
102 # endif
103 # endif
104 # endif
105 # endif
106 # endif
107 #endif
110 /* Describes the properties of the specific target format in use. */
111 struct real_format
113 /* Move to and from the target bytes. */
114 void (*encode) (const struct real_format *, long *,
115 const REAL_VALUE_TYPE *);
116 void (*decode) (const struct real_format *, REAL_VALUE_TYPE *,
117 const long *);
119 /* The radix of the exponent and digits of the significand. */
120 int b;
122 /* Size of the significand in digits of radix B. */
123 int p;
125 /* Size of the significant of a NaN, in digits of radix B. */
126 int pnan;
128 /* The minimum negative integer, x, such that b**(x-1) is normalized. */
129 int emin;
131 /* The maximum integer, x, such that b**(x-1) is representable. */
132 int emax;
134 /* The bit position of the sign bit, for determining whether a value
135 is positive/negative, or -1 for a complex encoding. */
136 int signbit_ro;
138 /* The bit position of the sign bit, for changing the sign of a number,
139 or -1 for a complex encoding. */
140 int signbit_rw;
142 /* Default rounding mode for operations on this format. */
143 bool round_towards_zero;
144 bool has_sign_dependent_rounding;
146 /* Properties of the format. */
147 bool has_nans;
148 bool has_inf;
149 bool has_denorm;
150 bool has_signed_zero;
151 bool qnan_msb_set;
152 bool canonical_nan_lsbs_set;
153 const char *name;
157 /* The target format used for each floating point mode.
158 Float modes are followed by decimal float modes, with entries for
159 float modes indexed by (MODE - first float mode), and entries for
160 decimal float modes indexed by (MODE - first decimal float mode) +
161 the number of float modes. */
162 extern const struct real_format *
163 real_format_for_mode[MAX_MODE_FLOAT - MIN_MODE_FLOAT + 1
164 + MAX_MODE_DECIMAL_FLOAT - MIN_MODE_DECIMAL_FLOAT + 1];
166 #define REAL_MODE_FORMAT(MODE) \
167 (real_format_for_mode[DECIMAL_FLOAT_MODE_P (MODE) \
168 ? (((MODE) - MIN_MODE_DECIMAL_FLOAT) \
169 + (MAX_MODE_FLOAT - MIN_MODE_FLOAT + 1)) \
170 : ((MODE) - MIN_MODE_FLOAT)])
172 #define FLOAT_MODE_FORMAT(MODE) \
173 (REAL_MODE_FORMAT (SCALAR_FLOAT_MODE_P (MODE)? (MODE) \
174 : GET_MODE_INNER (MODE)))
176 /* The following macro determines whether the floating point format is
177 composite, i.e. may contain non-consecutive mantissa bits, in which
178 case compile-time FP overflow may not model run-time overflow. */
179 #define MODE_COMPOSITE_P(MODE) \
180 (FLOAT_MODE_P (MODE) \
181 && FLOAT_MODE_FORMAT (MODE)->pnan < FLOAT_MODE_FORMAT (MODE)->p)
183 /* Accessor macros for format properties. */
184 #define MODE_HAS_NANS(MODE) \
185 (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_nans)
186 #define MODE_HAS_INFINITIES(MODE) \
187 (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_inf)
188 #define MODE_HAS_SIGNED_ZEROS(MODE) \
189 (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_signed_zero)
190 #define MODE_HAS_SIGN_DEPENDENT_ROUNDING(MODE) \
191 (FLOAT_MODE_P (MODE) \
192 && FLOAT_MODE_FORMAT (MODE)->has_sign_dependent_rounding)
194 /* Declare functions in real.c. */
196 /* True if the given mode has a NaN representation and the treatment of
197 NaN operands is important. Certain optimizations, such as folding
198 x * 0 into 0, are not correct for NaN operands, and are normally
199 disabled for modes with NaNs. The user can ask for them to be
200 done anyway using the -funsafe-math-optimizations switch. */
201 extern bool HONOR_NANS (machine_mode);
202 extern bool HONOR_NANS (const_tree);
203 extern bool HONOR_NANS (const_rtx);
205 /* Like HONOR_NANs, but true if we honor signaling NaNs (or sNaNs). */
206 extern bool HONOR_SNANS (machine_mode);
207 extern bool HONOR_SNANS (const_tree);
208 extern bool HONOR_SNANS (const_rtx);
210 /* As for HONOR_NANS, but true if the mode can represent infinity and
211 the treatment of infinite values is important. */
212 extern bool HONOR_INFINITIES (machine_mode);
213 extern bool HONOR_INFINITIES (const_tree);
214 extern bool HONOR_INFINITIES (const_rtx);
216 /* Like HONOR_NANS, but true if the given mode distinguishes between
217 positive and negative zero, and the sign of zero is important. */
218 extern bool HONOR_SIGNED_ZEROS (machine_mode);
219 extern bool HONOR_SIGNED_ZEROS (const_tree);
220 extern bool HONOR_SIGNED_ZEROS (const_rtx);
222 /* Like HONOR_NANS, but true if given mode supports sign-dependent rounding,
223 and the rounding mode is important. */
224 extern bool HONOR_SIGN_DEPENDENT_ROUNDING (machine_mode);
225 extern bool HONOR_SIGN_DEPENDENT_ROUNDING (const_tree);
226 extern bool HONOR_SIGN_DEPENDENT_ROUNDING (const_rtx);
228 /* Binary or unary arithmetic on tree_code. */
229 extern bool real_arithmetic (REAL_VALUE_TYPE *, int, const REAL_VALUE_TYPE *,
230 const REAL_VALUE_TYPE *);
232 /* Compare reals by tree_code. */
233 extern bool real_compare (int, const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
235 /* Determine whether a floating-point value X is infinite. */
236 extern bool real_isinf (const REAL_VALUE_TYPE *);
238 /* Determine whether a floating-point value X is a NaN. */
239 extern bool real_isnan (const REAL_VALUE_TYPE *);
241 /* Determine whether a floating-point value X is finite. */
242 extern bool real_isfinite (const REAL_VALUE_TYPE *);
244 /* Determine whether a floating-point value X is negative. */
245 extern bool real_isneg (const REAL_VALUE_TYPE *);
247 /* Determine whether a floating-point value X is minus zero. */
248 extern bool real_isnegzero (const REAL_VALUE_TYPE *);
250 /* Compare two floating-point objects for bitwise identity. */
251 extern bool real_identical (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
253 /* Extend or truncate to a new mode. */
254 extern void real_convert (REAL_VALUE_TYPE *, machine_mode,
255 const REAL_VALUE_TYPE *);
257 /* Return true if truncating to NEW is exact. */
258 extern bool exact_real_truncate (machine_mode, const REAL_VALUE_TYPE *);
260 /* Render R as a decimal floating point constant. */
261 extern void real_to_decimal (char *, const REAL_VALUE_TYPE *, size_t,
262 size_t, int);
264 /* Render R as a decimal floating point constant, rounded so as to be
265 parsed back to the same value when interpreted in mode MODE. */
266 extern void real_to_decimal_for_mode (char *, const REAL_VALUE_TYPE *, size_t,
267 size_t, int, machine_mode);
269 /* Render R as a hexadecimal floating point constant. */
270 extern void real_to_hexadecimal (char *, const REAL_VALUE_TYPE *,
271 size_t, size_t, int);
273 /* Render R as an integer. */
274 extern HOST_WIDE_INT real_to_integer (const REAL_VALUE_TYPE *);
276 /* Initialize R from a decimal or hexadecimal string. Return -1 if
277 the value underflows, +1 if overflows, and 0 otherwise. */
278 extern int real_from_string (REAL_VALUE_TYPE *, const char *);
279 /* Wrapper to allow different internal representation for decimal floats. */
280 extern void real_from_string3 (REAL_VALUE_TYPE *, const char *, machine_mode);
282 extern long real_to_target_fmt (long *, const REAL_VALUE_TYPE *,
283 const struct real_format *);
284 extern long real_to_target (long *, const REAL_VALUE_TYPE *, machine_mode);
286 extern void real_from_target_fmt (REAL_VALUE_TYPE *, const long *,
287 const struct real_format *);
288 extern void real_from_target (REAL_VALUE_TYPE *, const long *,
289 machine_mode);
291 extern void real_inf (REAL_VALUE_TYPE *);
293 extern bool real_nan (REAL_VALUE_TYPE *, const char *, int, machine_mode);
295 extern void real_maxval (REAL_VALUE_TYPE *, int, machine_mode);
297 extern void real_2expN (REAL_VALUE_TYPE *, int, machine_mode);
299 extern unsigned int real_hash (const REAL_VALUE_TYPE *);
302 /* Target formats defined in real.c. */
303 extern const struct real_format ieee_single_format;
304 extern const struct real_format mips_single_format;
305 extern const struct real_format motorola_single_format;
306 extern const struct real_format spu_single_format;
307 extern const struct real_format ieee_double_format;
308 extern const struct real_format mips_double_format;
309 extern const struct real_format motorola_double_format;
310 extern const struct real_format ieee_extended_motorola_format;
311 extern const struct real_format ieee_extended_intel_96_format;
312 extern const struct real_format ieee_extended_intel_96_round_53_format;
313 extern const struct real_format ieee_extended_intel_128_format;
314 extern const struct real_format ibm_extended_format;
315 extern const struct real_format mips_extended_format;
316 extern const struct real_format ieee_quad_format;
317 extern const struct real_format mips_quad_format;
318 extern const struct real_format vax_f_format;
319 extern const struct real_format vax_d_format;
320 extern const struct real_format vax_g_format;
321 extern const struct real_format real_internal_format;
322 extern const struct real_format decimal_single_format;
323 extern const struct real_format decimal_double_format;
324 extern const struct real_format decimal_quad_format;
325 extern const struct real_format ieee_half_format;
326 extern const struct real_format arm_half_format;
329 /* ====================================================================== */
330 /* Crap. */
332 #define REAL_ARITHMETIC(value, code, d1, d2) \
333 real_arithmetic (&(value), code, &(d1), &(d2))
335 #define REAL_VALUES_IDENTICAL(x, y) real_identical (&(x), &(y))
336 #define REAL_VALUES_EQUAL(x, y) real_compare (EQ_EXPR, &(x), &(y))
337 #define REAL_VALUES_LESS(x, y) real_compare (LT_EXPR, &(x), &(y))
339 /* Determine whether a floating-point value X is infinite. */
340 #define REAL_VALUE_ISINF(x) real_isinf (&(x))
342 /* Determine whether a floating-point value X is a NaN. */
343 #define REAL_VALUE_ISNAN(x) real_isnan (&(x))
345 /* Determine whether a floating-point value X is negative. */
346 #define REAL_VALUE_NEGATIVE(x) real_isneg (&(x))
348 /* Determine whether a floating-point value X is minus zero. */
349 #define REAL_VALUE_MINUS_ZERO(x) real_isnegzero (&(x))
351 /* IN is a REAL_VALUE_TYPE. OUT is an array of longs. */
352 #define REAL_VALUE_TO_TARGET_LONG_DOUBLE(IN, OUT) \
353 real_to_target (OUT, &(IN), \
354 mode_for_size (LONG_DOUBLE_TYPE_SIZE, MODE_FLOAT, 0))
356 #define REAL_VALUE_TO_TARGET_DOUBLE(IN, OUT) \
357 real_to_target (OUT, &(IN), mode_for_size (64, MODE_FLOAT, 0))
359 /* IN is a REAL_VALUE_TYPE. OUT is a long. */
360 #define REAL_VALUE_TO_TARGET_SINGLE(IN, OUT) \
361 ((OUT) = real_to_target (NULL, &(IN), mode_for_size (32, MODE_FLOAT, 0)))
363 /* Real values to IEEE 754 decimal floats. */
365 /* IN is a REAL_VALUE_TYPE. OUT is an array of longs. */
366 #define REAL_VALUE_TO_TARGET_DECIMAL128(IN, OUT) \
367 real_to_target (OUT, &(IN), mode_for_size (128, MODE_DECIMAL_FLOAT, 0))
369 #define REAL_VALUE_TO_TARGET_DECIMAL64(IN, OUT) \
370 real_to_target (OUT, &(IN), mode_for_size (64, MODE_DECIMAL_FLOAT, 0))
372 /* IN is a REAL_VALUE_TYPE. OUT is a long. */
373 #define REAL_VALUE_TO_TARGET_DECIMAL32(IN, OUT) \
374 ((OUT) = real_to_target (NULL, &(IN), mode_for_size (32, MODE_DECIMAL_FLOAT, 0)))
376 extern REAL_VALUE_TYPE real_value_truncate (machine_mode,
377 REAL_VALUE_TYPE);
379 extern REAL_VALUE_TYPE real_value_negate (const REAL_VALUE_TYPE *);
380 extern REAL_VALUE_TYPE real_value_abs (const REAL_VALUE_TYPE *);
382 extern int significand_size (machine_mode);
384 extern REAL_VALUE_TYPE real_from_string2 (const char *, machine_mode);
386 #define REAL_VALUE_ATOF(s, m) \
387 real_from_string2 (s, m)
389 #define CONST_DOUBLE_ATOF(s, m) \
390 CONST_DOUBLE_FROM_REAL_VALUE (real_from_string2 (s, m), m)
392 #define REAL_VALUE_FIX(r) \
393 real_to_integer (&(r))
395 /* ??? Not quite right. */
396 #define REAL_VALUE_UNSIGNED_FIX(r) \
397 real_to_integer (&(r))
399 /* ??? These were added for Paranoia support. */
401 /* Return floor log2(R). */
402 extern int real_exponent (const REAL_VALUE_TYPE *);
404 /* R = A * 2**EXP. */
405 extern void real_ldexp (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *, int);
407 /* **** End of software floating point emulator interface macros **** */
409 /* Constant real values 0, 1, 2, -1 and 0.5. */
411 extern REAL_VALUE_TYPE dconst0;
412 extern REAL_VALUE_TYPE dconst1;
413 extern REAL_VALUE_TYPE dconst2;
414 extern REAL_VALUE_TYPE dconstm1;
415 extern REAL_VALUE_TYPE dconsthalf;
417 #define dconst_e() (*dconst_e_ptr ())
418 #define dconst_third() (*dconst_third_ptr ())
419 #define dconst_sqrt2() (*dconst_sqrt2_ptr ())
421 /* Function to return the real value special constant 'e'. */
422 extern const REAL_VALUE_TYPE * dconst_e_ptr (void);
424 /* Returns the special REAL_VALUE_TYPE corresponding to 1/3. */
425 extern const REAL_VALUE_TYPE * dconst_third_ptr (void);
427 /* Returns the special REAL_VALUE_TYPE corresponding to sqrt(2). */
428 extern const REAL_VALUE_TYPE * dconst_sqrt2_ptr (void);
430 /* Function to return a real value (not a tree node)
431 from a given integer constant. */
432 REAL_VALUE_TYPE real_value_from_int_cst (const_tree, const_tree);
434 /* Given a CONST_DOUBLE in FROM, store into TO the value it represents. */
435 #define REAL_VALUE_FROM_CONST_DOUBLE(to, from) \
436 ((to) = *CONST_DOUBLE_REAL_VALUE (from))
438 /* Return a CONST_DOUBLE with value R and mode M. */
439 #define CONST_DOUBLE_FROM_REAL_VALUE(r, m) \
440 const_double_from_real_value (r, m)
441 extern rtx const_double_from_real_value (REAL_VALUE_TYPE, machine_mode);
443 /* Replace R by 1/R in the given machine mode, if the result is exact. */
444 extern bool exact_real_inverse (machine_mode, REAL_VALUE_TYPE *);
446 /* Return true if arithmetic on values in IMODE that were promoted
447 from values in TMODE is equivalent to direct arithmetic on values
448 in TMODE. */
449 bool real_can_shorten_arithmetic (machine_mode, machine_mode);
451 /* In tree.c: wrap up a REAL_VALUE_TYPE in a tree node. */
452 extern tree build_real (tree, REAL_VALUE_TYPE);
454 /* Calculate R as X raised to the integer exponent N in mode MODE. */
455 extern bool real_powi (REAL_VALUE_TYPE *, machine_mode,
456 const REAL_VALUE_TYPE *, HOST_WIDE_INT);
458 /* Standard round to integer value functions. */
459 extern void real_trunc (REAL_VALUE_TYPE *, machine_mode,
460 const REAL_VALUE_TYPE *);
461 extern void real_floor (REAL_VALUE_TYPE *, machine_mode,
462 const REAL_VALUE_TYPE *);
463 extern void real_ceil (REAL_VALUE_TYPE *, machine_mode,
464 const REAL_VALUE_TYPE *);
465 extern void real_round (REAL_VALUE_TYPE *, machine_mode,
466 const REAL_VALUE_TYPE *);
468 /* Set the sign of R to the sign of X. */
469 extern void real_copysign (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
471 /* Check whether the real constant value given is an integer. */
472 extern bool real_isinteger (const REAL_VALUE_TYPE *c, machine_mode mode);
474 /* Write into BUF the maximum representable finite floating-point
475 number, (1 - b**-p) * b**emax for a given FP format FMT as a hex
476 float string. BUF must be large enough to contain the result. */
477 extern void get_max_float (const struct real_format *, char *, size_t);
479 #ifndef GENERATOR_FILE
480 /* real related routines. */
481 extern wide_int real_to_integer (const REAL_VALUE_TYPE *, bool *, int);
482 extern void real_from_integer (REAL_VALUE_TYPE *, machine_mode,
483 const wide_int_ref &, signop);
484 #endif
486 #endif /* ! GCC_REAL_H */