1 /* IEEE floating point support declarations, for GDB, the GNU Debugger.
2 Copyright 1991, 1994, 1995, 1997, 2000, 2003, 2005, 2010
3 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
21 #if !defined (FLOATFORMAT_H)
22 #define FLOATFORMAT_H 1
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. */
32 /* What is the order of the bytes? */
34 enum floatformat_byteorders {
35 /* Standard little endian byte order.
36 EX: 1.2345678e10 => 00 00 80 c5 e0 fe 06 42 */
39 /* Standard big endian byte order.
40 EX: 1.2345678e10 => 42 06 fe e0 c5 80 00 00 */
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,
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 */
54 enum floatformat_intbit { floatformat_intbit_yes, floatformat_intbit_no };
58 enum floatformat_byteorders byteorder;
59 unsigned int totalsize; /* Total size of number in bits */
61 /* Sign bit is always one bit long. 1 means negative, 0 means positive. */
62 unsigned int sign_start;
64 unsigned int exp_start;
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). */
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
77 unsigned int man_start;
80 /* Is the integer bit explicit or implicit? */
81 enum floatformat_intbit intbit;
83 /* Internal name for debugging. */
86 /* Validator method. */
87 int (*is_valid) (const struct floatformat *fmt, const void *from);
89 /* Is the format actually the sum of two smaller floating point
90 formats (IBM long double, as described in
91 gcc/config/rs6000/darwin-ldouble-format)? If so, this is the
92 smaller format in question, and the fields sign_start through
93 intbit describe the first half. If not, this is NULL. */
94 const struct floatformat *split_half;
97 /* floatformats for IEEE single and double, big and little endian. */
99 extern const struct floatformat floatformat_ieee_half_big;
100 extern const struct floatformat floatformat_ieee_half_little;
101 extern const struct floatformat floatformat_ieee_single_big;
102 extern const struct floatformat floatformat_ieee_single_little;
103 extern const struct floatformat floatformat_ieee_double_big;
104 extern const struct floatformat floatformat_ieee_double_little;
106 /* floatformat for ARM IEEE double, little endian bytes and big endian words */
108 extern const struct floatformat floatformat_ieee_double_littlebyte_bigword;
110 /* floatformats for VAX. */
112 extern const struct floatformat floatformat_vax_f;
113 extern const struct floatformat floatformat_vax_d;
114 extern const struct floatformat floatformat_vax_g;
116 /* floatformats for various extendeds. */
118 extern const struct floatformat floatformat_i387_ext;
119 extern const struct floatformat floatformat_m68881_ext;
120 extern const struct floatformat floatformat_i960_ext;
121 extern const struct floatformat floatformat_m88110_ext;
122 extern const struct floatformat floatformat_m88110_harris_ext;
123 extern const struct floatformat floatformat_arm_ext_big;
124 extern const struct floatformat floatformat_arm_ext_littlebyte_bigword;
125 /* IA-64 Floating Point register spilt into memory. */
126 extern const struct floatformat floatformat_ia64_spill_big;
127 extern const struct floatformat floatformat_ia64_spill_little;
128 extern const struct floatformat floatformat_ia64_quad_big;
129 extern const struct floatformat floatformat_ia64_quad_little;
130 /* IBM long double (double+double). */
131 extern const struct floatformat floatformat_ibm_long_double;
133 /* Convert from FMT to a double.
134 FROM is the address of the extended float.
135 Store the double in *TO. */
138 floatformat_to_double (const struct floatformat *, const void *, double *);
140 /* The converse: convert the double *FROM to FMT
141 and store where TO points. */
144 floatformat_from_double (const struct floatformat *, const double *, void *);
146 /* Return non-zero iff the data at FROM is a valid number in format FMT. */
149 floatformat_is_valid (const struct floatformat *fmt, const void *from);
151 #endif /* defined (FLOATFORMAT_H) */
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