source: trunk/third/gcc/real.h @ 11288

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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
30/* Default to IEEE float if not specified.  Nearly all machines use it.  */
31
32#ifndef TARGET_FLOAT_FORMAT
33#define TARGET_FLOAT_FORMAT     IEEE_FLOAT_FORMAT
34#endif
35
36#ifndef HOST_FLOAT_FORMAT
37#define HOST_FLOAT_FORMAT       IEEE_FLOAT_FORMAT
38#endif
39
40#if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
41#define REAL_INFINITY
42#endif
43
44/* If FLOAT_WORDS_BIG_ENDIAN and HOST_FLOAT_WORDS_BIG_ENDIAN are not defined
45   in the header files, then this implies the word-endianness is the same as
46   for integers.  */
47
48/* This is defined 0 or 1, like WORDS_BIG_ENDIAN.  */
49#ifndef FLOAT_WORDS_BIG_ENDIAN
50#define FLOAT_WORDS_BIG_ENDIAN WORDS_BIG_ENDIAN
51#endif
52
53/* This is defined 0 or 1, unlike HOST_WORDS_BIG_ENDIAN.  */
54#ifndef HOST_FLOAT_WORDS_BIG_ENDIAN
55#ifdef HOST_WORDS_BIG_ENDIAN
56#define HOST_FLOAT_WORDS_BIG_ENDIAN 1
57#else
58#define HOST_FLOAT_WORDS_BIG_ENDIAN 0
59#endif
60#endif
61
62/* Defining REAL_ARITHMETIC invokes a floating point emulator
63   that can produce a target machine format differing by more
64   than just endian-ness from the host's format.  The emulator
65   is also used to support extended real XFmode.  */
66#ifndef LONG_DOUBLE_TYPE_SIZE
67#define LONG_DOUBLE_TYPE_SIZE 64
68#endif
69#if (LONG_DOUBLE_TYPE_SIZE == 96) || (LONG_DOUBLE_TYPE_SIZE == 128)
70#ifndef REAL_ARITHMETIC
71#define REAL_ARITHMETIC
72#endif
73#endif
74#ifdef REAL_ARITHMETIC
75/* **** Start of software floating point emulator interface macros **** */
76
77/* Support 80-bit extended real XFmode if LONG_DOUBLE_TYPE_SIZE
78   has been defined to be 96 in the tm.h machine file. */
79#if (LONG_DOUBLE_TYPE_SIZE == 96)
80#define REAL_IS_NOT_DOUBLE
81#define REAL_ARITHMETIC
82typedef struct {
83  HOST_WIDE_INT r[(11 + sizeof (HOST_WIDE_INT))/(sizeof (HOST_WIDE_INT))];
84} realvaluetype;
85#define REAL_VALUE_TYPE realvaluetype
86
87#else /* no XFmode support */
88
89#if (LONG_DOUBLE_TYPE_SIZE == 128)
90
91#define REAL_IS_NOT_DOUBLE
92#define REAL_ARITHMETIC
93typedef struct {
94  HOST_WIDE_INT r[(19 + sizeof (HOST_WIDE_INT))/(sizeof (HOST_WIDE_INT))];
95} realvaluetype;
96#define REAL_VALUE_TYPE realvaluetype
97
98#else /* not TFmode */
99
100#if HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT
101/* If no XFmode support, then a REAL_VALUE_TYPE is 64 bits wide
102   but it is not necessarily a host machine double. */
103#define REAL_IS_NOT_DOUBLE
104typedef struct {
105  HOST_WIDE_INT r[(7 + sizeof (HOST_WIDE_INT))/(sizeof (HOST_WIDE_INT))];
106} realvaluetype;
107#define REAL_VALUE_TYPE realvaluetype
108#else
109/* If host and target formats are compatible, then a REAL_VALUE_TYPE
110   is actually a host machine double. */
111#define REAL_VALUE_TYPE double
112#endif
113
114#endif /* no TFmode support */
115#endif /* no XFmode support */
116
117extern int significand_size     PROTO((enum machine_mode));
118
119/* If emulation has been enabled by defining REAL_ARITHMETIC or by
120   setting LONG_DOUBLE_TYPE_SIZE to 96 or 128, then define macros so that
121   they invoke emulator functions. This will succeed only if the machine
122   files have been updated to use these macros in place of any
123   references to host machine `double' or `float' types.  */
124#ifdef REAL_ARITHMETIC
125#undef REAL_ARITHMETIC
126#define REAL_ARITHMETIC(value, code, d1, d2) \
127  earith (&(value), (code), &(d1), &(d2))
128
129/* Declare functions in real.c. */
130extern void earith              PROTO((REAL_VALUE_TYPE *, int,
131                                       REAL_VALUE_TYPE *, REAL_VALUE_TYPE *));
132extern REAL_VALUE_TYPE etrunci  PROTO((REAL_VALUE_TYPE));
133extern REAL_VALUE_TYPE etruncui PROTO((REAL_VALUE_TYPE));
134extern REAL_VALUE_TYPE ereal_atof PROTO((char *, enum machine_mode));
135extern REAL_VALUE_TYPE ereal_negate PROTO((REAL_VALUE_TYPE));
136extern HOST_WIDE_INT efixi      PROTO((REAL_VALUE_TYPE));
137extern unsigned HOST_WIDE_INT efixui PROTO((REAL_VALUE_TYPE));
138extern void ereal_from_int      PROTO((REAL_VALUE_TYPE *,
139                                       HOST_WIDE_INT, HOST_WIDE_INT,
140                                       enum machine_mode));
141extern void ereal_from_uint     PROTO((REAL_VALUE_TYPE *,
142                                       unsigned HOST_WIDE_INT,
143                                       unsigned HOST_WIDE_INT,
144                                       enum machine_mode));
145extern void ereal_to_int        PROTO((HOST_WIDE_INT *, HOST_WIDE_INT *,
146                                       REAL_VALUE_TYPE));
147extern REAL_VALUE_TYPE ereal_ldexp PROTO((REAL_VALUE_TYPE, int));
148
149extern void etartdouble         PROTO((REAL_VALUE_TYPE, long *));
150extern void etarldouble         PROTO((REAL_VALUE_TYPE, long *));
151extern void etardouble          PROTO((REAL_VALUE_TYPE, long *));
152extern long etarsingle          PROTO((REAL_VALUE_TYPE));
153extern void ereal_to_decimal    PROTO((REAL_VALUE_TYPE, char *));
154extern int ereal_cmp            PROTO((REAL_VALUE_TYPE, REAL_VALUE_TYPE));
155extern int ereal_isneg          PROTO((REAL_VALUE_TYPE));
156extern REAL_VALUE_TYPE ereal_from_float PROTO((HOST_WIDE_INT));
157extern REAL_VALUE_TYPE ereal_from_double PROTO((HOST_WIDE_INT *));
158
159#define REAL_VALUES_EQUAL(x, y) (ereal_cmp ((x), (y)) == 0)
160/* true if x < y : */
161#define REAL_VALUES_LESS(x, y) (ereal_cmp ((x), (y)) == -1)
162#define REAL_VALUE_LDEXP(x, n) ereal_ldexp (x, n)
163
164/* These return REAL_VALUE_TYPE: */
165#define REAL_VALUE_RNDZINT(x) (etrunci (x))
166#define REAL_VALUE_UNSIGNED_RNDZINT(x) (etruncui (x))
167extern REAL_VALUE_TYPE real_value_truncate ();
168#define REAL_VALUE_TRUNCATE(mode, x)  real_value_truncate (mode, x)
169
170/* These return HOST_WIDE_INT: */
171/* Convert a floating-point value to integer, rounding toward zero.  */
172#define REAL_VALUE_FIX(x) (efixi (x))
173/* Convert a floating-point value to unsigned integer, rounding
174   toward zero. */
175#define REAL_VALUE_UNSIGNED_FIX(x) (efixui (x))
176
177#define REAL_VALUE_ATOF ereal_atof
178#define REAL_VALUE_NEGATE ereal_negate
179
180#define REAL_VALUE_MINUS_ZERO(x) \
181 ((ereal_cmp (x, dconst0) == 0) && (ereal_isneg (x) != 0 ))
182
183#define REAL_VALUE_TO_INT ereal_to_int
184
185/* Here the cast to HOST_WIDE_INT sign-extends arguments such as ~0.  */
186#define REAL_VALUE_FROM_INT(d, lo, hi, mode) \
187  ereal_from_int (&d, (HOST_WIDE_INT) (lo), (HOST_WIDE_INT) (hi), mode)
188
189#define REAL_VALUE_FROM_UNSIGNED_INT(d, lo, hi, mode) \
190  ereal_from_uint (&d, lo, hi, mode)
191
192/* IN is a REAL_VALUE_TYPE.  OUT is an array of longs. */
193#if LONG_DOUBLE_TYPE_SIZE == 96
194#define REAL_VALUE_TO_TARGET_LONG_DOUBLE(IN, OUT) (etarldouble ((IN), (OUT)))
195#else
196#define REAL_VALUE_TO_TARGET_LONG_DOUBLE(IN, OUT) (etartdouble ((IN), (OUT)))
197#endif
198#define REAL_VALUE_TO_TARGET_DOUBLE(IN, OUT) (etardouble ((IN), (OUT)))
199
200/* IN is a REAL_VALUE_TYPE.  OUT is a long. */
201#define REAL_VALUE_TO_TARGET_SINGLE(IN, OUT) ((OUT) = etarsingle ((IN)))
202
203/* d is an array of HOST_WIDE_INT that holds a double precision
204   value in the target computer's floating point format. */
205#define REAL_VALUE_FROM_TARGET_DOUBLE(d)  (ereal_from_double (d))
206
207/* f is a HOST_WIDE_INT containing a single precision target float value. */
208#define REAL_VALUE_FROM_TARGET_SINGLE(f)  (ereal_from_float (f))
209
210/* Conversions to decimal ASCII string.  */
211#define REAL_VALUE_TO_DECIMAL(r, fmt, s) (ereal_to_decimal (r, s))
212
213#endif /* REAL_ARITHMETIC defined */
214
215/* **** End of software floating point emulator interface macros **** */
216#else /* No XFmode or TFmode and REAL_ARITHMETIC not defined */
217
218/* old interface */
219#ifdef REAL_ARITHMETIC
220/* Defining REAL_IS_NOT_DOUBLE breaks certain initializations
221   when REAL_ARITHMETIC etc. are not defined.  */
222
223/* Now see if the host and target machines use the same format.
224   If not, define REAL_IS_NOT_DOUBLE (even if we end up representing
225   reals as doubles because we have no better way in this cross compiler.)
226   This turns off various optimizations that can happen when we know the
227   compiler's float format matches the target's float format.
228   */
229#if HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT
230#define REAL_IS_NOT_DOUBLE
231#ifndef REAL_VALUE_TYPE
232typedef struct {
233    HOST_WIDE_INT r[sizeof (double)/sizeof (HOST_WIDE_INT)];
234  } realvaluetype;
235#define REAL_VALUE_TYPE realvaluetype
236#endif /* no REAL_VALUE_TYPE */
237#endif /* formats differ */
238#endif /* 0 */
239
240#endif /* emulator not used */
241
242/* If we are not cross-compiling, use a `double' to represent the
243   floating-point value.  Otherwise, use some other type
244   (probably a struct containing an array of longs).  */
245#ifndef REAL_VALUE_TYPE
246#define REAL_VALUE_TYPE double
247#else
248#define REAL_IS_NOT_DOUBLE
249#endif
250
251#if HOST_FLOAT_FORMAT == TARGET_FLOAT_FORMAT
252
253/* Convert a type `double' value in host format first to a type `float'
254   value in host format and then to a single type `long' value which
255   is the bitwise equivalent of the `float' value.  */
256#ifndef REAL_VALUE_TO_TARGET_SINGLE
257#define REAL_VALUE_TO_TARGET_SINGLE(IN, OUT)                            \
258do { float f = (float) (IN);                                            \
259     (OUT) = *(long *) &f;                                              \
260   } while (0)
261#endif
262
263/* Convert a type `double' value in host format to a pair of type `long'
264   values which is its bitwise equivalent, but put the two words into
265   proper word order for the target.  */
266#ifndef REAL_VALUE_TO_TARGET_DOUBLE
267#define REAL_VALUE_TO_TARGET_DOUBLE(IN, OUT)                            \
268do { REAL_VALUE_TYPE in = (IN);  /* Make sure it's not in a register.  */\
269     if (HOST_FLOAT_WORDS_BIG_ENDIAN == FLOAT_WORDS_BIG_ENDIAN)         \
270       {                                                                \
271         (OUT)[0] = ((long *) &in)[0];                                  \
272         (OUT)[1] = ((long *) &in)[1];                                  \
273       }                                                                \
274     else                                                               \
275       {                                                                \
276         (OUT)[1] = ((long *) &in)[0];                                  \
277         (OUT)[0] = ((long *) &in)[1];                                  \
278       }                                                                \
279   } while (0)
280#endif
281#endif /* HOST_FLOAT_FORMAT == TARGET_FLOAT_FORMAT */
282
283/* In this configuration, double and long double are the same. */
284#ifndef REAL_VALUE_TO_TARGET_LONG_DOUBLE
285#define REAL_VALUE_TO_TARGET_LONG_DOUBLE(a, b) REAL_VALUE_TO_TARGET_DOUBLE (a, b)
286#endif
287
288/* Compare two floating-point objects for bitwise identity.
289   This is not the same as comparing for equality on IEEE hosts:
290   -0.0 equals 0.0 but they are not identical, and conversely
291   two NaNs might be identical but they cannot be equal.  */
292#define REAL_VALUES_IDENTICAL(x, y) \
293  (!bcmp ((char *) &(x), (char *) &(y), sizeof (REAL_VALUE_TYPE)))
294
295/* Compare two floating-point values for equality.  */
296#ifndef REAL_VALUES_EQUAL
297#define REAL_VALUES_EQUAL(x, y) ((x) == (y))
298#endif
299
300/* Compare two floating-point values for less than.  */
301#ifndef REAL_VALUES_LESS
302#define REAL_VALUES_LESS(x, y) ((x) < (y))
303#endif
304
305/* Truncate toward zero to an integer floating-point value.  */
306#ifndef REAL_VALUE_RNDZINT
307#define REAL_VALUE_RNDZINT(x) ((double) ((int) (x)))
308#endif
309
310/* Truncate toward zero to an unsigned integer floating-point value.  */
311#ifndef REAL_VALUE_UNSIGNED_RNDZINT
312#define REAL_VALUE_UNSIGNED_RNDZINT(x) ((double) ((unsigned int) (x)))
313#endif
314
315/* Convert a floating-point value to integer, rounding toward zero.  */
316#ifndef REAL_VALUE_FIX
317#define REAL_VALUE_FIX(x) ((int) (x))
318#endif
319
320/* Convert a floating-point value to unsigned integer, rounding
321   toward zero. */
322#ifndef REAL_VALUE_UNSIGNED_FIX
323#define REAL_VALUE_UNSIGNED_FIX(x) ((unsigned int) (x))
324#endif
325
326/* Scale X by Y powers of 2.  */
327#ifndef REAL_VALUE_LDEXP
328#define REAL_VALUE_LDEXP(x, y) ldexp (x, y)
329extern double ldexp ();
330#endif
331
332/* Convert the string X to a floating-point value.  */
333#ifndef REAL_VALUE_ATOF
334#if 1
335/* Use real.c to convert decimal numbers to binary, ... */
336REAL_VALUE_TYPE ereal_atof ();
337#define REAL_VALUE_ATOF(x, s) ereal_atof (x, s)
338#else
339/* ... or, if you like the host computer's atof, go ahead and use it: */
340#define REAL_VALUE_ATOF(x, s) atof (x)
341#if defined (MIPSEL) || defined (MIPSEB)
342/* MIPS compiler can't handle parens around the function name.
343   This problem *does not* appear to be connected with any
344   macro definition for atof.  It does not seem there is one.  */
345extern double atof ();
346#else
347extern double (atof) ();
348#endif
349#endif
350#endif
351
352/* Negate the floating-point value X.  */
353#ifndef REAL_VALUE_NEGATE
354#define REAL_VALUE_NEGATE(x) (- (x))
355#endif
356
357/* Truncate the floating-point value X to mode MODE.  This is correct only
358   for the most common case where the host and target have objects of the same
359   size and where `float' is SFmode.  */
360
361/* Don't use REAL_VALUE_TRUNCATE directly--always call real_value_truncate.  */
362extern REAL_VALUE_TYPE real_value_truncate PROTO((enum machine_mode, REAL_VALUE_TYPE));
363
364#ifndef REAL_VALUE_TRUNCATE
365#define REAL_VALUE_TRUNCATE(mode, x) \
366 (GET_MODE_BITSIZE (mode) == sizeof (float) * HOST_BITS_PER_CHAR        \
367  ? (float) (x) : (x))
368#endif
369
370/* Determine whether a floating-point value X is infinite. */
371#ifndef REAL_VALUE_ISINF
372#define REAL_VALUE_ISINF(x) (target_isinf (x))
373#endif
374
375/* Determine whether a floating-point value X is a NaN. */
376#ifndef REAL_VALUE_ISNAN
377#define REAL_VALUE_ISNAN(x) (target_isnan (x))
378#endif
379
380/* Determine whether a floating-point value X is negative. */
381#ifndef REAL_VALUE_NEGATIVE
382#define REAL_VALUE_NEGATIVE(x) (target_negative (x))
383#endif
384
385extern int target_isnan                 PROTO ((REAL_VALUE_TYPE));
386extern int target_isinf                 PROTO ((REAL_VALUE_TYPE));
387extern int target_negative              PROTO ((REAL_VALUE_TYPE));
388
389/* Determine whether a floating-point value X is minus 0. */
390#ifndef REAL_VALUE_MINUS_ZERO
391#define REAL_VALUE_MINUS_ZERO(x) ((x) == 0 && REAL_VALUE_NEGATIVE (x))
392#endif
393
394/* Constant real values 0, 1, 2, and -1.  */
395
396extern REAL_VALUE_TYPE dconst0;
397extern REAL_VALUE_TYPE dconst1;
398extern REAL_VALUE_TYPE dconst2;
399extern REAL_VALUE_TYPE dconstm1;
400
401/* Union type used for extracting real values from CONST_DOUBLEs
402   or putting them in.  */
403
404union real_extract
405{
406  REAL_VALUE_TYPE d;
407  HOST_WIDE_INT i[sizeof (REAL_VALUE_TYPE) / sizeof (HOST_WIDE_INT)];
408};
409
410/* For a CONST_DOUBLE:
411   The usual two ints that hold the value.
412   For a DImode, that is all there are;
413    and CONST_DOUBLE_LOW is the low-order word and ..._HIGH the high-order.
414   For a float, the number of ints varies,
415    and CONST_DOUBLE_LOW is the one that should come first *in memory*.
416    So use &CONST_DOUBLE_LOW(r) as the address of an array of ints.  */
417#define CONST_DOUBLE_LOW(r) XWINT (r, 2)
418#define CONST_DOUBLE_HIGH(r) XWINT (r, 3)
419
420/* Link for chain of all CONST_DOUBLEs in use in current function.  */
421#define CONST_DOUBLE_CHAIN(r) XEXP (r, 1)
422/* The MEM which represents this CONST_DOUBLE's value in memory,
423   or const0_rtx if no MEM has been made for it yet,
424   or cc0_rtx if it is not on the chain.  */
425#define CONST_DOUBLE_MEM(r) XEXP (r, 0)
426
427/* Function to return a real value (not a tree node)
428   from a given integer constant.  */
429REAL_VALUE_TYPE real_value_from_int_cst ();
430
431/* Given a CONST_DOUBLE in FROM, store into TO the value it represents.  */
432
433#define REAL_VALUE_FROM_CONST_DOUBLE(to, from)          \
434do { union real_extract u;                              \
435     bcopy ((char *) &CONST_DOUBLE_LOW ((from)), (char *) &u, sizeof u); \
436     to = u.d; } while (0)
437
438/* Return a CONST_DOUBLE with value R and mode M.  */
439
440#define CONST_DOUBLE_FROM_REAL_VALUE(r, m) immed_real_const_1 (r,  m)
441extern struct rtx_def *immed_real_const_1       PROTO((REAL_VALUE_TYPE,
442                                                       enum machine_mode));
443
444
445/* Convert a floating point value `r', that can be interpreted
446   as a host machine float or double, to a decimal ASCII string `s'
447   using printf format string `fmt'.  */
448#ifndef REAL_VALUE_TO_DECIMAL
449#define REAL_VALUE_TO_DECIMAL(r, fmt, s) (sprintf (s, fmt, r))
450#endif
451
452/* Replace R by 1/R in the given machine mode, if the result is exact.  */
453extern int exact_real_inverse PROTO((enum machine_mode, REAL_VALUE_TYPE *));
454
455extern void debug_real                  PROTO ((REAL_VALUE_TYPE));
456
457/* In varasm.c */
458extern void assemble_real               PROTO ((REAL_VALUE_TYPE,
459                                                enum machine_mode));
460#endif /* Not REAL_H_INCLUDED */
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