1 /* IEEE floating point support declarations, for GDB, the GNU Debugger. 2 Copyright (C) 1991-2016 Free Software Foundation, Inc. 3 4 This file is part of GDB. 5 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. 10 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. 15 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. */ 19 20 #if !defined (FLOATFORMAT_H) 21 #define FLOATFORMAT_H 1 22 23 #include "ansidecl.h" 24 25 #ifdef __cplusplus 26 extern "C" { 27 #endif 28 29 /* A floatformat consists of a sign bit, an exponent and a mantissa. Once the 30 bytes are concatenated according to the byteorder flag, then each of those 31 fields is contiguous. We number the bits with 0 being the most significant 32 (i.e. BITS_BIG_ENDIAN type numbering), and specify which bits each field 33 contains with the *_start and *_len fields. */ 34 35 /* What is the order of the bytes? */ 36 37 enum floatformat_byteorders { 38 /* Standard little endian byte order. 39 EX: 1.2345678e10 => 00 00 80 c5 e0 fe 06 42 */ 40 floatformat_little, 41 42 /* Standard big endian byte order. 43 EX: 1.2345678e10 => 42 06 fe e0 c5 80 00 00 */ 44 floatformat_big, 45 46 /* Little endian byte order but big endian word order. 47 EX: 1.2345678e10 => e0 fe 06 42 00 00 80 c5 */ 48 floatformat_littlebyte_bigword, 49 50 /* VAX byte order. Little endian byte order with 16-bit words. The 51 following example is an illustration of the byte order only; VAX 52 doesn't have a fully IEEE compliant floating-point format. 53 EX: 1.2345678e10 => 80 c5 00 00 06 42 e0 fe */ 54 floatformat_vax 55 }; 56 57 enum floatformat_intbit { floatformat_intbit_yes, floatformat_intbit_no }; 58 59 struct floatformat 60 { 61 enum floatformat_byteorders byteorder; 62 unsigned int totalsize; /* Total size of number in bits */ 63 64 /* Sign bit is always one bit long. 1 means negative, 0 means positive. */ 65 unsigned int sign_start; 66 67 unsigned int exp_start; 68 unsigned int exp_len; 69 /* Bias added to a "true" exponent to form the biased exponent. It 70 is intentionally signed as, otherwize, -exp_bias can turn into a 71 very large number (e.g., given the exp_bias of 0x3fff and a 64 72 bit long, the equation (long)(1 - exp_bias) evaluates to 73 4294950914) instead of -16382). */ 74 int exp_bias; 75 /* Exponent value which indicates NaN. This is the actual value stored in 76 the float, not adjusted by the exp_bias. This usually consists of all 77 one bits. */ 78 unsigned int exp_nan; 79 80 unsigned int man_start; 81 unsigned int man_len; 82 83 /* Is the integer bit explicit or implicit? */ 84 enum floatformat_intbit intbit; 85 86 /* Internal name for debugging. */ 87 const char *name; 88 89 /* Validator method. */ 90 int (*is_valid) (const struct floatformat *fmt, const void *from); 91 92 /* Is the format actually the sum of two smaller floating point 93 formats (IBM long double, as described in 94 gcc/config/rs6000/darwin-ldouble-format)? If so, this is the 95 smaller format in question, and the fields sign_start through 96 intbit describe the first half. If not, this is NULL. */ 97 const struct floatformat *split_half; 98 }; 99 100 /* floatformats for IEEE single and double, big and little endian. */ 101 102 extern const struct floatformat floatformat_ieee_half_big; 103 extern const struct floatformat floatformat_ieee_half_little; 104 extern const struct floatformat floatformat_ieee_single_big; 105 extern const struct floatformat floatformat_ieee_single_little; 106 extern const struct floatformat floatformat_ieee_double_big; 107 extern const struct floatformat floatformat_ieee_double_little; 108 109 /* floatformat for ARM IEEE double, little endian bytes and big endian words */ 110 111 extern const struct floatformat floatformat_ieee_double_littlebyte_bigword; 112 113 /* floatformats for VAX. */ 114 115 extern const struct floatformat floatformat_vax_f; 116 extern const struct floatformat floatformat_vax_d; 117 extern const struct floatformat floatformat_vax_g; 118 119 /* floatformats for various extendeds. */ 120 121 extern const struct floatformat floatformat_i387_ext; 122 extern const struct floatformat floatformat_m68881_ext; 123 extern const struct floatformat floatformat_i960_ext; 124 extern const struct floatformat floatformat_m88110_ext; 125 extern const struct floatformat floatformat_m88110_harris_ext; 126 extern const struct floatformat floatformat_arm_ext_big; 127 extern const struct floatformat floatformat_arm_ext_littlebyte_bigword; 128 /* IA-64 Floating Point register spilt into memory. */ 129 extern const struct floatformat floatformat_ia64_spill_big; 130 extern const struct floatformat floatformat_ia64_spill_little; 131 extern const struct floatformat floatformat_ia64_quad_big; 132 extern const struct floatformat floatformat_ia64_quad_little; 133 /* IBM long double (double+double). */ 134 extern const struct floatformat floatformat_ibm_long_double_big; 135 extern const struct floatformat floatformat_ibm_long_double_little; 136 137 /* Convert from FMT to a double. 138 FROM is the address of the extended float. 139 Store the double in *TO. */ 140 141 extern void 142 floatformat_to_double (const struct floatformat *, const void *, double *); 143 144 /* The converse: convert the double *FROM to FMT 145 and store where TO points. */ 146 147 extern void 148 floatformat_from_double (const struct floatformat *, const double *, void *); 149 150 /* Return non-zero iff the data at FROM is a valid number in format FMT. */ 151 152 extern int 153 floatformat_is_valid (const struct floatformat *fmt, const void *from); 154 155 #ifdef __cplusplus 156 } 157 #endif 158 159 #endif /* defined (FLOATFORMAT_H) */ 160
