real.h revision 50397
1/* Definitions of floating-point access for GNU compiler.
2   Copyright (C) 1989, 1991, 1994, 1996, 1997 Free Software Foundation, Inc.
3
4This file is part of GNU CC.
5
6GNU CC is free software; you can redistribute it and/or modify
7it under the terms of the GNU General Public License as published by
8the Free Software Foundation; either version 2, or (at your option)
9any later version.
10
11GNU CC is distributed in the hope that it will be useful,
12but WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14GNU General Public License for more details.
15
16You should have received a copy of the GNU General Public License
17along with GNU CC; see the file COPYING.  If not, write to
18the Free Software Foundation, 59 Temple Place - Suite 330,
19Boston, MA 02111-1307, USA.  */
20
21#ifndef REAL_H_INCLUDED
22#define REAL_H_INCLUDED
23
24/* Define codes for all the float formats that we know of.  */
25#define UNKNOWN_FLOAT_FORMAT 0
26#define IEEE_FLOAT_FORMAT 1
27#define VAX_FLOAT_FORMAT 2
28#define IBM_FLOAT_FORMAT 3
29#define C4X_FLOAT_FORMAT 4
30
31/* Default to IEEE float if not specified.  Nearly all machines use it.  */
32
33#ifndef TARGET_FLOAT_FORMAT
34#define	TARGET_FLOAT_FORMAT	IEEE_FLOAT_FORMAT
35#endif
36
37#ifndef HOST_FLOAT_FORMAT
38#define	HOST_FLOAT_FORMAT	IEEE_FLOAT_FORMAT
39#endif
40
41#if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
42#define REAL_INFINITY
43#endif
44
45/* If FLOAT_WORDS_BIG_ENDIAN and HOST_FLOAT_WORDS_BIG_ENDIAN are not defined
46   in the header files, then this implies the word-endianness is the same as
47   for integers.  */
48
49/* This is defined 0 or 1, like WORDS_BIG_ENDIAN.  */
50#ifndef FLOAT_WORDS_BIG_ENDIAN
51#define FLOAT_WORDS_BIG_ENDIAN WORDS_BIG_ENDIAN
52#endif
53
54/* This is defined 0 or 1, unlike HOST_WORDS_BIG_ENDIAN.  */
55#ifndef HOST_FLOAT_WORDS_BIG_ENDIAN
56#ifdef HOST_WORDS_BIG_ENDIAN
57#define HOST_FLOAT_WORDS_BIG_ENDIAN 1
58#else
59#define HOST_FLOAT_WORDS_BIG_ENDIAN 0
60#endif
61#endif
62
63/* Defining REAL_ARITHMETIC invokes a floating point emulator
64   that can produce a target machine format differing by more
65   than just endian-ness from the host's format.  The emulator
66   is also used to support extended real XFmode.  */
67#ifndef LONG_DOUBLE_TYPE_SIZE
68#define LONG_DOUBLE_TYPE_SIZE 64
69#endif
70#if (LONG_DOUBLE_TYPE_SIZE == 96) || (LONG_DOUBLE_TYPE_SIZE == 128)
71#ifndef REAL_ARITHMETIC
72#define REAL_ARITHMETIC
73#endif
74#endif
75#ifdef REAL_ARITHMETIC
76/* **** Start of software floating point emulator interface macros **** */
77
78/* Support 80-bit extended real XFmode if LONG_DOUBLE_TYPE_SIZE
79   has been defined to be 96 in the tm.h machine file. */
80#if (LONG_DOUBLE_TYPE_SIZE == 96)
81#define REAL_IS_NOT_DOUBLE
82#define REAL_ARITHMETIC
83typedef struct {
84  HOST_WIDE_INT r[(11 + sizeof (HOST_WIDE_INT))/(sizeof (HOST_WIDE_INT))];
85} realvaluetype;
86#define REAL_VALUE_TYPE realvaluetype
87
88#else /* no XFmode support */
89
90#if (LONG_DOUBLE_TYPE_SIZE == 128)
91
92#define REAL_IS_NOT_DOUBLE
93#define REAL_ARITHMETIC
94typedef struct {
95  HOST_WIDE_INT r[(19 + sizeof (HOST_WIDE_INT))/(sizeof (HOST_WIDE_INT))];
96} realvaluetype;
97#define REAL_VALUE_TYPE realvaluetype
98
99#else /* not TFmode */
100
101#if HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT
102/* If no XFmode support, then a REAL_VALUE_TYPE is 64 bits wide
103   but it is not necessarily a host machine double. */
104#define REAL_IS_NOT_DOUBLE
105typedef struct {
106  HOST_WIDE_INT r[(7 + sizeof (HOST_WIDE_INT))/(sizeof (HOST_WIDE_INT))];
107} realvaluetype;
108#define REAL_VALUE_TYPE realvaluetype
109#else
110/* If host and target formats are compatible, then a REAL_VALUE_TYPE
111   is actually a host machine double. */
112#define REAL_VALUE_TYPE double
113#endif
114
115#endif /* no TFmode support */
116#endif /* no XFmode support */
117
118extern int significand_size	PROTO((enum machine_mode));
119
120/* If emulation has been enabled by defining REAL_ARITHMETIC or by
121   setting LONG_DOUBLE_TYPE_SIZE to 96 or 128, then define macros so that
122   they invoke emulator functions. This will succeed only if the machine
123   files have been updated to use these macros in place of any
124   references to host machine `double' or `float' types.  */
125#ifdef REAL_ARITHMETIC
126#undef REAL_ARITHMETIC
127#define REAL_ARITHMETIC(value, code, d1, d2) \
128  earith (&(value), (code), &(d1), &(d2))
129
130/* Declare functions in real.c. */
131extern void earith		PROTO((REAL_VALUE_TYPE *, int,
132				       REAL_VALUE_TYPE *, REAL_VALUE_TYPE *));
133extern REAL_VALUE_TYPE etrunci	PROTO((REAL_VALUE_TYPE));
134extern REAL_VALUE_TYPE etruncui	PROTO((REAL_VALUE_TYPE));
135extern REAL_VALUE_TYPE ereal_atof PROTO((char *, enum machine_mode));
136extern REAL_VALUE_TYPE ereal_negate PROTO((REAL_VALUE_TYPE));
137extern HOST_WIDE_INT efixi	PROTO((REAL_VALUE_TYPE));
138extern unsigned HOST_WIDE_INT efixui PROTO((REAL_VALUE_TYPE));
139extern void ereal_from_int	PROTO((REAL_VALUE_TYPE *,
140				       HOST_WIDE_INT, HOST_WIDE_INT,
141				       enum machine_mode));
142extern void ereal_from_uint	PROTO((REAL_VALUE_TYPE *,
143				       unsigned HOST_WIDE_INT,
144				       unsigned HOST_WIDE_INT,
145				       enum machine_mode));
146extern void ereal_to_int	PROTO((HOST_WIDE_INT *, HOST_WIDE_INT *,
147				       REAL_VALUE_TYPE));
148extern REAL_VALUE_TYPE ereal_ldexp PROTO((REAL_VALUE_TYPE, int));
149
150extern void etartdouble		PROTO((REAL_VALUE_TYPE, long *));
151extern void etarldouble		PROTO((REAL_VALUE_TYPE, long *));
152extern void etardouble		PROTO((REAL_VALUE_TYPE, long *));
153extern long etarsingle		PROTO((REAL_VALUE_TYPE));
154extern void ereal_to_decimal	PROTO((REAL_VALUE_TYPE, char *));
155extern int ereal_cmp		PROTO((REAL_VALUE_TYPE, REAL_VALUE_TYPE));
156extern int ereal_isneg		PROTO((REAL_VALUE_TYPE));
157extern REAL_VALUE_TYPE ereal_unto_float PROTO((long));
158extern REAL_VALUE_TYPE ereal_unto_double PROTO((long *));
159extern REAL_VALUE_TYPE ereal_from_float PROTO((HOST_WIDE_INT));
160extern REAL_VALUE_TYPE ereal_from_double PROTO((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/* These return REAL_VALUE_TYPE: */
168#define REAL_VALUE_RNDZINT(x) (etrunci (x))
169#define REAL_VALUE_UNSIGNED_RNDZINT(x) (etruncui (x))
170extern REAL_VALUE_TYPE real_value_truncate	PROTO ((enum machine_mode,
171							REAL_VALUE_TYPE));
172#define REAL_VALUE_TRUNCATE(mode, x)  real_value_truncate (mode, x)
173
174/* These return HOST_WIDE_INT: */
175/* Convert a floating-point value to integer, rounding toward zero.  */
176#define REAL_VALUE_FIX(x) (efixi (x))
177/* Convert a floating-point value to unsigned integer, rounding
178   toward zero. */
179#define REAL_VALUE_UNSIGNED_FIX(x) (efixui (x))
180
181#define REAL_VALUE_ATOF ereal_atof
182#define REAL_VALUE_NEGATE ereal_negate
183
184#define REAL_VALUE_MINUS_ZERO(x) \
185 ((ereal_cmp (x, dconst0) == 0) && (ereal_isneg (x) != 0 ))
186
187#define REAL_VALUE_TO_INT ereal_to_int
188
189/* Here the cast to HOST_WIDE_INT sign-extends arguments such as ~0.  */
190#define REAL_VALUE_FROM_INT(d, lo, hi, mode) \
191  ereal_from_int (&d, (HOST_WIDE_INT) (lo), (HOST_WIDE_INT) (hi), mode)
192
193#define REAL_VALUE_FROM_UNSIGNED_INT(d, lo, hi, mode) \
194  ereal_from_uint (&d, lo, hi, mode)
195
196/* IN is a REAL_VALUE_TYPE.  OUT is an array of longs. */
197#if LONG_DOUBLE_TYPE_SIZE == 96
198#define REAL_VALUE_TO_TARGET_LONG_DOUBLE(IN, OUT) (etarldouble ((IN), (OUT)))
199#else
200#define REAL_VALUE_TO_TARGET_LONG_DOUBLE(IN, OUT) (etartdouble ((IN), (OUT)))
201#endif
202#define REAL_VALUE_TO_TARGET_DOUBLE(IN, OUT) (etardouble ((IN), (OUT)))
203
204/* IN is a REAL_VALUE_TYPE.  OUT is a long. */
205#define REAL_VALUE_TO_TARGET_SINGLE(IN, OUT) ((OUT) = etarsingle ((IN)))
206
207/* Inverse of REAL_VALUE_TO_TARGET_DOUBLE. */
208#define REAL_VALUE_UNTO_TARGET_DOUBLE(d)  (ereal_unto_double (d))
209
210/* Inverse of REAL_VALUE_TO_TARGET_SINGLE. */
211#define REAL_VALUE_UNTO_TARGET_SINGLE(f)  (ereal_unto_float (f))
212
213/* d is an array of HOST_WIDE_INT that holds a double precision
214   value in the target computer's floating point format. */
215#define REAL_VALUE_FROM_TARGET_DOUBLE(d)  (ereal_from_double (d))
216
217/* f is a HOST_WIDE_INT containing a single precision target float value. */
218#define REAL_VALUE_FROM_TARGET_SINGLE(f)  (ereal_from_float (f))
219
220/* Conversions to decimal ASCII string.  */
221#define REAL_VALUE_TO_DECIMAL(r, fmt, s) (ereal_to_decimal (r, s))
222
223#endif /* REAL_ARITHMETIC defined */
224
225/* **** End of software floating point emulator interface macros **** */
226#else /* No XFmode or TFmode and REAL_ARITHMETIC not defined */
227
228/* old interface */
229#ifdef REAL_ARITHMETIC
230/* Defining REAL_IS_NOT_DOUBLE breaks certain initializations
231   when REAL_ARITHMETIC etc. are not defined.  */
232
233/* Now see if the host and target machines use the same format.
234   If not, define REAL_IS_NOT_DOUBLE (even if we end up representing
235   reals as doubles because we have no better way in this cross compiler.)
236   This turns off various optimizations that can happen when we know the
237   compiler's float format matches the target's float format.
238   */
239#if HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT
240#define	REAL_IS_NOT_DOUBLE
241#ifndef REAL_VALUE_TYPE
242typedef struct {
243    HOST_WIDE_INT r[sizeof (double)/sizeof (HOST_WIDE_INT)];
244  } realvaluetype;
245#define REAL_VALUE_TYPE realvaluetype
246#endif /* no REAL_VALUE_TYPE */
247#endif /* formats differ */
248#endif /* 0 */
249
250#endif /* emulator not used */
251
252/* If we are not cross-compiling, use a `double' to represent the
253   floating-point value.  Otherwise, use some other type
254   (probably a struct containing an array of longs).  */
255#ifndef REAL_VALUE_TYPE
256#define REAL_VALUE_TYPE double
257#else
258#define REAL_IS_NOT_DOUBLE
259#endif
260
261#if HOST_FLOAT_FORMAT == TARGET_FLOAT_FORMAT
262
263/* Convert a type `double' value in host format first to a type `float'
264   value in host format and then to a single type `long' value which
265   is the bitwise equivalent of the `float' value.  */
266#ifndef REAL_VALUE_TO_TARGET_SINGLE
267#define REAL_VALUE_TO_TARGET_SINGLE(IN, OUT)		\
268do {							\
269  union {						\
270    float f;						\
271    HOST_WIDE_INT l;					\
272  } u;							\
273  if (sizeof(HOST_WIDE_INT) < sizeof(float))		\
274    abort();						\
275  u.l = 0;						\
276  u.f = (IN);						\
277  (OUT) = u.l;						\
278} while (0)
279#endif
280
281/* Convert a type `double' value in host format to a pair of type `long'
282   values which is its bitwise equivalent, but put the two words into
283   proper word order for the target.  */
284#ifndef REAL_VALUE_TO_TARGET_DOUBLE
285#define REAL_VALUE_TO_TARGET_DOUBLE(IN, OUT)				\
286do {									\
287  union {								\
288    REAL_VALUE_TYPE f;							\
289    HOST_WIDE_INT l[2];							\
290  } u;									\
291  if (sizeof(HOST_WIDE_INT) * 2 < sizeof(REAL_VALUE_TYPE))		\
292    abort();								\
293  u.l[0] = u.l[1] = 0;							\
294  u.f = (IN);								\
295  if (HOST_FLOAT_WORDS_BIG_ENDIAN == FLOAT_WORDS_BIG_ENDIAN)		\
296    (OUT)[0] = u.l[0], (OUT)[1] = u.l[1];				\
297  else									\
298    (OUT)[1] = u.l[0], (OUT)[0] = u.l[1];				\
299} while (0)
300#endif
301#endif /* HOST_FLOAT_FORMAT == TARGET_FLOAT_FORMAT */
302
303/* In this configuration, double and long double are the same. */
304#ifndef REAL_VALUE_TO_TARGET_LONG_DOUBLE
305#define REAL_VALUE_TO_TARGET_LONG_DOUBLE(a, b) REAL_VALUE_TO_TARGET_DOUBLE (a, b)
306#endif
307
308/* Compare two floating-point objects for bitwise identity.
309   This is not the same as comparing for equality on IEEE hosts:
310   -0.0 equals 0.0 but they are not identical, and conversely
311   two NaNs might be identical but they cannot be equal.  */
312#define REAL_VALUES_IDENTICAL(x, y) \
313  (!bcmp ((char *) &(x), (char *) &(y), sizeof (REAL_VALUE_TYPE)))
314
315/* Compare two floating-point values for equality.  */
316#ifndef REAL_VALUES_EQUAL
317#define REAL_VALUES_EQUAL(x, y) ((x) == (y))
318#endif
319
320/* Compare two floating-point values for less than.  */
321#ifndef REAL_VALUES_LESS
322#define REAL_VALUES_LESS(x, y) ((x) < (y))
323#endif
324
325/* Truncate toward zero to an integer floating-point value.  */
326#ifndef REAL_VALUE_RNDZINT
327#define REAL_VALUE_RNDZINT(x) ((double) ((int) (x)))
328#endif
329
330/* Truncate toward zero to an unsigned integer floating-point value.  */
331#ifndef REAL_VALUE_UNSIGNED_RNDZINT
332#define REAL_VALUE_UNSIGNED_RNDZINT(x) ((double) ((unsigned int) (x)))
333#endif
334
335/* Convert a floating-point value to integer, rounding toward zero.  */
336#ifndef REAL_VALUE_FIX
337#define REAL_VALUE_FIX(x) ((int) (x))
338#endif
339
340/* Convert a floating-point value to unsigned integer, rounding
341   toward zero. */
342#ifndef REAL_VALUE_UNSIGNED_FIX
343#define REAL_VALUE_UNSIGNED_FIX(x) ((unsigned int) (x))
344#endif
345
346/* Scale X by Y powers of 2.  */
347#ifndef REAL_VALUE_LDEXP
348#define REAL_VALUE_LDEXP(x, y) ldexp (x, y)
349extern double ldexp ();
350#endif
351
352/* Convert the string X to a floating-point value.  */
353#ifndef REAL_VALUE_ATOF
354#if 1
355/* Use real.c to convert decimal numbers to binary, ... */
356REAL_VALUE_TYPE ereal_atof ();
357#define REAL_VALUE_ATOF(x, s) ereal_atof (x, s)
358#else
359/* ... or, if you like the host computer's atof, go ahead and use it: */
360#define REAL_VALUE_ATOF(x, s) atof (x)
361#if defined (MIPSEL) || defined (MIPSEB)
362/* MIPS compiler can't handle parens around the function name.
363   This problem *does not* appear to be connected with any
364   macro definition for atof.  It does not seem there is one.  */
365extern double atof ();
366#else
367extern double (atof) ();
368#endif
369#endif
370#endif
371
372/* Negate the floating-point value X.  */
373#ifndef REAL_VALUE_NEGATE
374#define REAL_VALUE_NEGATE(x) (- (x))
375#endif
376
377/* Truncate the floating-point value X to mode MODE.  This is correct only
378   for the most common case where the host and target have objects of the same
379   size and where `float' is SFmode.  */
380
381/* Don't use REAL_VALUE_TRUNCATE directly--always call real_value_truncate.  */
382extern REAL_VALUE_TYPE real_value_truncate PROTO((enum machine_mode, REAL_VALUE_TYPE));
383
384#ifndef REAL_VALUE_TRUNCATE
385#define REAL_VALUE_TRUNCATE(mode, x) \
386 (GET_MODE_BITSIZE (mode) == sizeof (float) * HOST_BITS_PER_CHAR	\
387  ? (float) (x) : (x))
388#endif
389
390/* Determine whether a floating-point value X is infinite. */
391#ifndef REAL_VALUE_ISINF
392#define REAL_VALUE_ISINF(x) (target_isinf (x))
393#endif
394
395/* Determine whether a floating-point value X is a NaN. */
396#ifndef REAL_VALUE_ISNAN
397#define REAL_VALUE_ISNAN(x) (target_isnan (x))
398#endif
399
400/* Determine whether a floating-point value X is negative. */
401#ifndef REAL_VALUE_NEGATIVE
402#define REAL_VALUE_NEGATIVE(x) (target_negative (x))
403#endif
404
405extern int target_isnan			PROTO ((REAL_VALUE_TYPE));
406extern int target_isinf			PROTO ((REAL_VALUE_TYPE));
407extern int target_negative		PROTO ((REAL_VALUE_TYPE));
408
409/* Determine whether a floating-point value X is minus 0. */
410#ifndef REAL_VALUE_MINUS_ZERO
411#define REAL_VALUE_MINUS_ZERO(x) ((x) == 0 && REAL_VALUE_NEGATIVE (x))
412#endif
413
414/* Constant real values 0, 1, 2, and -1.  */
415
416extern REAL_VALUE_TYPE dconst0;
417extern REAL_VALUE_TYPE dconst1;
418extern REAL_VALUE_TYPE dconst2;
419extern REAL_VALUE_TYPE dconstm1;
420
421/* Union type used for extracting real values from CONST_DOUBLEs
422   or putting them in.  */
423
424union real_extract
425{
426  REAL_VALUE_TYPE d;
427  HOST_WIDE_INT i[sizeof (REAL_VALUE_TYPE) / sizeof (HOST_WIDE_INT)];
428};
429
430/* For a CONST_DOUBLE:
431   The usual two ints that hold the value.
432   For a DImode, that is all there are;
433    and CONST_DOUBLE_LOW is the low-order word and ..._HIGH the high-order.
434   For a float, the number of ints varies,
435    and CONST_DOUBLE_LOW is the one that should come first *in memory*.
436    So use &CONST_DOUBLE_LOW(r) as the address of an array of ints.  */
437#define CONST_DOUBLE_LOW(r) XWINT (r, 2)
438#define CONST_DOUBLE_HIGH(r) XWINT (r, 3)
439
440/* Link for chain of all CONST_DOUBLEs in use in current function.  */
441#define CONST_DOUBLE_CHAIN(r) XEXP (r, 1)
442/* The MEM which represents this CONST_DOUBLE's value in memory,
443   or const0_rtx if no MEM has been made for it yet,
444   or cc0_rtx if it is not on the chain.  */
445#define CONST_DOUBLE_MEM(r) XEXP (r, 0)
446
447/* Given a CONST_DOUBLE in FROM, store into TO the value it represents.  */
448/* Function to return a real value (not a tree node)
449   from a given integer constant.  */
450union tree_node;
451REAL_VALUE_TYPE real_value_from_int_cst	PROTO ((union tree_node *,
452						union tree_node *));
453
454#define REAL_VALUE_FROM_CONST_DOUBLE(to, from)		\
455do { union real_extract u;				\
456     bcopy ((char *) &CONST_DOUBLE_LOW ((from)), (char *) &u, sizeof u); \
457     to = u.d; } while (0)
458
459/* Return a CONST_DOUBLE with value R and mode M.  */
460
461#define CONST_DOUBLE_FROM_REAL_VALUE(r, m) immed_real_const_1 (r,  m)
462extern struct rtx_def *immed_real_const_1	PROTO((REAL_VALUE_TYPE,
463						       enum machine_mode));
464
465
466/* Convert a floating point value `r', that can be interpreted
467   as a host machine float or double, to a decimal ASCII string `s'
468   using printf format string `fmt'.  */
469#ifndef REAL_VALUE_TO_DECIMAL
470#define REAL_VALUE_TO_DECIMAL(r, fmt, s) (sprintf (s, fmt, r))
471#endif
472
473/* Replace R by 1/R in the given machine mode, if the result is exact.  */
474extern int exact_real_inverse PROTO((enum machine_mode, REAL_VALUE_TYPE *));
475
476extern void debug_real			PROTO ((REAL_VALUE_TYPE));
477
478/* In varasm.c */
479extern void assemble_real		PROTO ((REAL_VALUE_TYPE,
480						enum machine_mode));
481#endif /* Not REAL_H_INCLUDED */
482