1/* IEEE floating point support declarations, for GDB, the GNU Debugger.
2   Copyright 1991, 1994, 1995, 1997, 2000, 2003, 2005
3   Free Software Foundation, Inc.
4
5This file is part of GDB.
6
7This program is free software; you can redistribute it and/or modify
8it under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 2 of the License, or
10(at your option) any later version.
11
12This program is distributed in the hope that it will be useful,
13but WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15GNU General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along with this program; if not, write to the Free Software
19Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
20
21#if !defined (FLOATFORMAT_H)
22#define FLOATFORMAT_H 1
23
24#include "ansidecl.h"
25
26/* A floatformat consists of a sign bit, an exponent and a mantissa.  Once the
27   bytes are concatenated according to the byteorder flag, then each of those
28   fields is contiguous.  We number the bits with 0 being the most significant
29   (i.e. BITS_BIG_ENDIAN type numbering), and specify which bits each field
30   contains with the *_start and *_len fields.  */
31
32/* What is the order of the bytes?  */
33
34enum floatformat_byteorders {
35  /* Standard little endian byte order.
36     EX: 1.2345678e10 => 00 00 80 c5 e0 fe 06 42 */
37  floatformat_little,
38
39  /* Standard big endian byte order.
40     EX: 1.2345678e10 => 42 06 fe e0 c5 80 00 00 */
41  floatformat_big,
42
43  /* Little endian byte order but big endian word order.
44     EX: 1.2345678e10 => e0 fe 06 42 00 00 80 c5 */
45  floatformat_littlebyte_bigword,
46
47  /* VAX byte order.  Little endian byte order with 16-bit words.  The
48     following example is an illustration of the byte order only; VAX
49     doesn't have a fully IEEE compliant floating-point format.
50     EX: 1.2345678e10 => 80 c5 00 00 06 42 e0 fe */
51  floatformat_vax
52};
53
54enum floatformat_intbit { floatformat_intbit_yes, floatformat_intbit_no };
55
56struct floatformat
57{
58  enum floatformat_byteorders byteorder;
59  unsigned int totalsize;	/* Total size of number in bits */
60
61  /* Sign bit is always one bit long.  1 means negative, 0 means positive.  */
62  unsigned int sign_start;
63
64  unsigned int exp_start;
65  unsigned int exp_len;
66  /* Bias added to a "true" exponent to form the biased exponent.  It
67     is intentionally signed as, otherwize, -exp_bias can turn into a
68     very large number (e.g., given the exp_bias of 0x3fff and a 64
69     bit long, the equation (long)(1 - exp_bias) evaluates to
70     4294950914) instead of -16382).  */
71  int exp_bias;
72  /* Exponent value which indicates NaN.  This is the actual value stored in
73     the float, not adjusted by the exp_bias.  This usually consists of all
74     one bits.  */
75  unsigned int exp_nan;
76
77  unsigned int man_start;
78  unsigned int man_len;
79
80  /* Is the integer bit explicit or implicit?  */
81  enum floatformat_intbit intbit;
82
83  /* Internal name for debugging. */
84  const char *name;
85
86  /* Validator method.  */
87  int (*is_valid) (const struct floatformat *fmt, const void *from);
88};
89
90/* floatformats for IEEE single and double, big and little endian.  */
91
92extern const struct floatformat floatformat_ieee_single_big;
93extern const struct floatformat floatformat_ieee_single_little;
94extern const struct floatformat floatformat_ieee_double_big;
95extern const struct floatformat floatformat_ieee_double_little;
96
97/* floatformat for ARM IEEE double, little endian bytes and big endian words */
98
99extern const struct floatformat floatformat_ieee_double_littlebyte_bigword;
100
101/* floatformats for VAX.  */
102
103extern const struct floatformat floatformat_vax_f;
104extern const struct floatformat floatformat_vax_d;
105extern const struct floatformat floatformat_vax_g;
106
107/* floatformats for various extendeds.  */
108
109extern const struct floatformat floatformat_i387_ext;
110extern const struct floatformat floatformat_m68881_ext;
111extern const struct floatformat floatformat_i960_ext;
112extern const struct floatformat floatformat_m88110_ext;
113extern const struct floatformat floatformat_m88110_harris_ext;
114extern const struct floatformat floatformat_arm_ext_big;
115extern const struct floatformat floatformat_arm_ext_littlebyte_bigword;
116/* IA-64 Floating Point register spilt into memory.  */
117extern const struct floatformat floatformat_ia64_spill_big;
118extern const struct floatformat floatformat_ia64_spill_little;
119extern const struct floatformat floatformat_ia64_quad_big;
120extern const struct floatformat floatformat_ia64_quad_little;
121
122/* Convert from FMT to a double.
123   FROM is the address of the extended float.
124   Store the double in *TO.  */
125
126extern void
127floatformat_to_double (const struct floatformat *, const void *, double *);
128
129/* The converse: convert the double *FROM to FMT
130   and store where TO points.  */
131
132extern void
133floatformat_from_double (const struct floatformat *, const double *, void *);
134
135/* Return non-zero iff the data at FROM is a valid number in format FMT.  */
136
137extern int
138floatformat_is_valid (const struct floatformat *fmt, const void *from);
139
140#endif	/* defined (FLOATFORMAT_H) */
141