1 /* IEEE floating point support declarations, for GDB, the GNU Debugger.
2 Copyright (C) 1991-2015 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
20 #if !defined (FLOATFORMAT_H)
21 #define FLOATFORMAT_H 1
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. */
31 /* What is the order of the bytes? */
33 enum floatformat_byteorders
{
34 /* Standard little endian byte order.
35 EX: 1.2345678e10 => 00 00 80 c5 e0 fe 06 42 */
38 /* Standard big endian byte order.
39 EX: 1.2345678e10 => 42 06 fe e0 c5 80 00 00 */
42 /* Little endian byte order but big endian word order.
43 EX: 1.2345678e10 => e0 fe 06 42 00 00 80 c5 */
44 floatformat_littlebyte_bigword
,
46 /* VAX byte order. Little endian byte order with 16-bit words. The
47 following example is an illustration of the byte order only; VAX
48 doesn't have a fully IEEE compliant floating-point format.
49 EX: 1.2345678e10 => 80 c5 00 00 06 42 e0 fe */
53 enum floatformat_intbit
{ floatformat_intbit_yes
, floatformat_intbit_no
};
57 enum floatformat_byteorders byteorder
;
58 unsigned int totalsize
; /* Total size of number in bits */
60 /* Sign bit is always one bit long. 1 means negative, 0 means positive. */
61 unsigned int sign_start
;
63 unsigned int exp_start
;
65 /* Bias added to a "true" exponent to form the biased exponent. It
66 is intentionally signed as, otherwize, -exp_bias can turn into a
67 very large number (e.g., given the exp_bias of 0x3fff and a 64
68 bit long, the equation (long)(1 - exp_bias) evaluates to
69 4294950914) instead of -16382). */
71 /* Exponent value which indicates NaN. This is the actual value stored in
72 the float, not adjusted by the exp_bias. This usually consists of all
76 unsigned int man_start
;
79 /* Is the integer bit explicit or implicit? */
80 enum floatformat_intbit intbit
;
82 /* Internal name for debugging. */
85 /* Validator method. */
86 int (*is_valid
) (const struct floatformat
*fmt
, const void *from
);
88 /* Is the format actually the sum of two smaller floating point
89 formats (IBM long double, as described in
90 gcc/config/rs6000/darwin-ldouble-format)? If so, this is the
91 smaller format in question, and the fields sign_start through
92 intbit describe the first half. If not, this is NULL. */
93 const struct floatformat
*split_half
;
96 /* floatformats for IEEE single and double, big and little endian. */
98 extern const struct floatformat floatformat_ieee_half_big
;
99 extern const struct floatformat floatformat_ieee_half_little
;
100 extern const struct floatformat floatformat_ieee_single_big
;
101 extern const struct floatformat floatformat_ieee_single_little
;
102 extern const struct floatformat floatformat_ieee_double_big
;
103 extern const struct floatformat floatformat_ieee_double_little
;
105 /* floatformat for ARM IEEE double, little endian bytes and big endian words */
107 extern const struct floatformat floatformat_ieee_double_littlebyte_bigword
;
109 /* floatformats for VAX. */
111 extern const struct floatformat floatformat_vax_f
;
112 extern const struct floatformat floatformat_vax_d
;
113 extern const struct floatformat floatformat_vax_g
;
115 /* floatformats for various extendeds. */
117 extern const struct floatformat floatformat_i387_ext
;
118 extern const struct floatformat floatformat_m68881_ext
;
119 extern const struct floatformat floatformat_i960_ext
;
120 extern const struct floatformat floatformat_m88110_ext
;
121 extern const struct floatformat floatformat_m88110_harris_ext
;
122 extern const struct floatformat floatformat_arm_ext_big
;
123 extern const struct floatformat floatformat_arm_ext_littlebyte_bigword
;
124 /* IA-64 Floating Point register spilt into memory. */
125 extern const struct floatformat floatformat_ia64_spill_big
;
126 extern const struct floatformat floatformat_ia64_spill_little
;
127 extern const struct floatformat floatformat_ia64_quad_big
;
128 extern const struct floatformat floatformat_ia64_quad_little
;
129 /* IBM long double (double+double). */
130 extern const struct floatformat floatformat_ibm_long_double_big
;
131 extern const struct floatformat floatformat_ibm_long_double_little
;
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) */