1/* IEEE floating point support declarations, for GDB, the GNU Debugger.
2   Copyright 1991, 1994, 1995, 1997, 2000, 2003 Free Software Foundation, Inc.
3
4This file is part of GDB.
5
6This program 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 of the License, or
9(at your option) any later version.
10
11This program 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 this program; if not, write to the Free Software
18Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
19
20#if !defined (FLOATFORMAT_H)
21#define FLOATFORMAT_H 1
22
23#include "ansidecl.h"
24
25/* A floatformat consists of a sign bit, an exponent and a mantissa.  Once the
26   bytes are concatenated according to the byteorder flag, then each of those
27   fields is contiguous.  We number the bits with 0 being the most significant
28   (i.e. BITS_BIG_ENDIAN type numbering), and specify which bits each field
29   contains with the *_start and *_len fields.  */
30
31/* What is the order of the bytes. */
32
33enum floatformat_byteorders {
34
35  /* Standard little endian byte order.
36     EX: 1.2345678e10 => 00 00 80 c5 e0 fe 06 42 */
37
38  floatformat_little,
39
40  /* Standard big endian byte order.
41     EX: 1.2345678e10 => 42 06 fe e0 c5 80 00 00 */
42
43  floatformat_big,
44
45  /* Little endian byte order but big endian word order.
46     EX: 1.2345678e10 => e0 fe 06 42 00 00 80 c5 */
47
48  floatformat_littlebyte_bigword
49
50};
51
52enum floatformat_intbit { floatformat_intbit_yes, floatformat_intbit_no };
53
54struct floatformat
55{
56  enum floatformat_byteorders byteorder;
57  unsigned int totalsize;	/* Total size of number in bits */
58
59  /* Sign bit is always one bit long.  1 means negative, 0 means positive.  */
60  unsigned int sign_start;
61
62  unsigned int exp_start;
63  unsigned int exp_len;
64  /* Bias added to a "true" exponent to form the biased exponent.  It
65     is intentionally signed as, otherwize, -exp_bias can turn into a
66     very large number (e.g., given the exp_bias of 0x3fff and a 64
67     bit long, the equation (long)(1 - exp_bias) evaluates to
68     4294950914) instead of -16382).  */
69  int exp_bias;
70  /* Exponent value which indicates NaN.  This is the actual value stored in
71     the float, not adjusted by the exp_bias.  This usually consists of all
72     one bits.  */
73  unsigned int exp_nan;
74
75  unsigned int man_start;
76  unsigned int man_len;
77
78  /* Is the integer bit explicit or implicit?  */
79  enum floatformat_intbit intbit;
80
81  /* Internal name for debugging. */
82  const char *name;
83
84  /* Validator method.  */
85  int (*is_valid) PARAMS ((const struct floatformat *fmt, const char *from));
86};
87
88/* floatformats for IEEE single and double, big and little endian.  */
89
90extern const struct floatformat floatformat_ieee_single_big;
91extern const struct floatformat floatformat_ieee_single_little;
92extern const struct floatformat floatformat_ieee_double_big;
93extern const struct floatformat floatformat_ieee_double_little;
94
95/* floatformat for ARM IEEE double, little endian bytes and big endian words */
96
97extern const struct floatformat floatformat_ieee_double_littlebyte_bigword;
98
99/* floatformats for various extendeds.  */
100
101extern const struct floatformat floatformat_i387_ext;
102extern const struct floatformat floatformat_m68881_ext;
103extern const struct floatformat floatformat_i960_ext;
104extern const struct floatformat floatformat_m88110_ext;
105extern const struct floatformat floatformat_m88110_harris_ext;
106extern const struct floatformat floatformat_arm_ext_big;
107extern const struct floatformat floatformat_arm_ext_littlebyte_bigword;
108/* IA-64 Floating Point register spilt into memory.  */
109extern const struct floatformat floatformat_ia64_spill_big;
110extern const struct floatformat floatformat_ia64_spill_little;
111extern const struct floatformat floatformat_ia64_quad_big;
112extern const struct floatformat floatformat_ia64_quad_little;
113
114/* Convert from FMT to a double.
115   FROM is the address of the extended float.
116   Store the double in *TO.  */
117
118extern void
119floatformat_to_double PARAMS ((const struct floatformat *, const char *, double *));
120
121/* The converse: convert the double *FROM to FMT
122   and store where TO points.  */
123
124extern void
125floatformat_from_double PARAMS ((const struct floatformat *,
126				 const double *, char *));
127
128/* Return non-zero iff the data at FROM is a valid number in format FMT.  */
129
130extern int
131floatformat_is_valid PARAMS ((const struct floatformat *fmt, const char *from));
132
133#endif	/* defined (FLOATFORMAT_H) */
134