| 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 | |
| 5 | This file is part of GDB. |
| 6 | |
| 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. |
| 11 | |
| 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. |
| 16 | |
| 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. */ |
| 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 | |
| 34 | enum 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 | |
| 54 | enum floatformat_intbit { floatformat_intbit_yes, floatformat_intbit_no }; |
| 55 | |
| 56 | struct 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 | /* 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; |
| 95 | }; |
| 96 | |
| 97 | /* floatformats for IEEE single and double, big and little endian. */ |
| 98 | |
| 99 | extern const struct floatformat floatformat_ieee_single_big; |
| 100 | extern const struct floatformat floatformat_ieee_single_little; |
| 101 | extern const struct floatformat floatformat_ieee_double_big; |
| 102 | extern const struct floatformat floatformat_ieee_double_little; |
| 103 | |
| 104 | /* floatformat for ARM IEEE double, little endian bytes and big endian words */ |
| 105 | |
| 106 | extern const struct floatformat floatformat_ieee_double_littlebyte_bigword; |
| 107 | |
| 108 | /* floatformats for VAX. */ |
| 109 | |
| 110 | extern const struct floatformat floatformat_vax_f; |
| 111 | extern const struct floatformat floatformat_vax_d; |
| 112 | extern const struct floatformat floatformat_vax_g; |
| 113 | |
| 114 | /* floatformats for various extendeds. */ |
| 115 | |
| 116 | extern const struct floatformat floatformat_i387_ext; |
| 117 | extern const struct floatformat floatformat_m68881_ext; |
| 118 | extern const struct floatformat floatformat_i960_ext; |
| 119 | extern const struct floatformat floatformat_m88110_ext; |
| 120 | extern const struct floatformat floatformat_m88110_harris_ext; |
| 121 | extern const struct floatformat floatformat_arm_ext_big; |
| 122 | extern const struct floatformat floatformat_arm_ext_littlebyte_bigword; |
| 123 | /* IA-64 Floating Point register spilt into memory. */ |
| 124 | extern const struct floatformat floatformat_ia64_spill_big; |
| 125 | extern const struct floatformat floatformat_ia64_spill_little; |
| 126 | extern const struct floatformat floatformat_ia64_quad_big; |
| 127 | extern const struct floatformat floatformat_ia64_quad_little; |
| 128 | /* IBM long double (double+double). */ |
| 129 | extern const struct floatformat floatformat_ibm_long_double; |
| 130 | |
| 131 | /* Convert from FMT to a double. |
| 132 | FROM is the address of the extended float. |
| 133 | Store the double in *TO. */ |
| 134 | |
| 135 | extern void |
| 136 | floatformat_to_double (const struct floatformat *, const void *, double *); |
| 137 | |
| 138 | /* The converse: convert the double *FROM to FMT |
| 139 | and store where TO points. */ |
| 140 | |
| 141 | extern void |
| 142 | floatformat_from_double (const struct floatformat *, const double *, void *); |
| 143 | |
| 144 | /* Return non-zero iff the data at FROM is a valid number in format FMT. */ |
| 145 | |
| 146 | extern int |
| 147 | floatformat_is_valid (const struct floatformat *fmt, const void *from); |
| 148 | |
| 149 | #endif /* defined (FLOATFORMAT_H) */ |