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. 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 #ifdef __cplusplus 27 extern "C" { 28 #endif 29 30 /* A floatformat consists of a sign bit, an exponent and a mantissa. Once the 31 bytes are concatenated according to the byteorder flag, then each of those 32 fields is contiguous. We number the bits with 0 being the most significant 33 (i.e. BITS_BIG_ENDIAN type numbering), and specify which bits each field 34 contains with the *_start and *_len fields. */ 35 36 /* What is the order of the bytes? */ 37 38 enum floatformat_byteorders { 39 /* Standard little endian byte order. 40 EX: 1.2345678e10 => 00 00 80 c5 e0 fe 06 42 */ 41 floatformat_little, 42 43 /* Standard big endian byte order. 44 EX: 1.2345678e10 => 42 06 fe e0 c5 80 00 00 */ 45 floatformat_big, 46 47 /* Little endian byte order but big endian word order. 48 EX: 1.2345678e10 => e0 fe 06 42 00 00 80 c5 */ 49 floatformat_littlebyte_bigword, 50 51 /* VAX byte order. Little endian byte order with 16-bit words. The 52 following example is an illustration of the byte order only; VAX 53 doesn't have a fully IEEE compliant floating-point format. 54 EX: 1.2345678e10 => 80 c5 00 00 06 42 e0 fe */ 55 floatformat_vax 56 }; 57 58 enum floatformat_intbit { floatformat_intbit_yes, floatformat_intbit_no }; 59 60 struct floatformat 61 { 62 enum floatformat_byteorders byteorder; 63 unsigned int totalsize; /* Total size of number in bits */ 64 65 /* Sign bit is always one bit long. 1 means negative, 0 means positive. */ 66 unsigned int sign_start; 67 68 unsigned int exp_start; 69 unsigned int exp_len; 70 /* Bias added to a "true" exponent to form the biased exponent. It 71 is intentionally signed as, otherwize, -exp_bias can turn into a 72 very large number (e.g., given the exp_bias of 0x3fff and a 64 73 bit long, the equation (long)(1 - exp_bias) evaluates to 74 4294950914) instead of -16382). */ 75 int exp_bias; 76 /* Exponent value which indicates NaN. This is the actual value stored in 77 the float, not adjusted by the exp_bias. This usually consists of all 78 one bits. */ 79 unsigned int exp_nan; 80 81 unsigned int man_start; 82 unsigned int man_len; 83 84 /* Is the integer bit explicit or implicit? */ 85 enum floatformat_intbit intbit; 86 87 /* Internal name for debugging. */ 88 const char *name; 89 90 /* Validator method. */ 91 int (*is_valid) (const struct floatformat *fmt, const void *from); 92 93 /* Is the format actually the sum of two smaller floating point 94 formats (IBM long double, as described in 95 gcc/config/rs6000/darwin-ldouble-format)? If so, this is the 96 smaller format in question, and the fields sign_start through 97 intbit describe the first half. If not, this is NULL. */ 98 const struct floatformat *split_half; 99 }; 100 101 /* floatformats for IEEE single and double, big and little endian. */ 102 103 extern const struct floatformat floatformat_ieee_half_big; 104 extern const struct floatformat floatformat_ieee_half_little; 105 extern const struct floatformat floatformat_ieee_single_big; 106 extern const struct floatformat floatformat_ieee_single_little; 107 extern const struct floatformat floatformat_ieee_double_big; 108 extern const struct floatformat floatformat_ieee_double_little; 109 110 /* floatformat for ARM IEEE double, little endian bytes and big endian words */ 111 112 extern const struct floatformat floatformat_ieee_double_littlebyte_bigword; 113 114 /* floatformats for VAX. */ 115 116 extern const struct floatformat floatformat_vax_f; 117 extern const struct floatformat floatformat_vax_d; 118 extern const struct floatformat floatformat_vax_g; 119 120 /* floatformats for various extendeds. */ 121 122 extern const struct floatformat floatformat_i387_ext; 123 extern const struct floatformat floatformat_m68881_ext; 124 extern const struct floatformat floatformat_i960_ext; 125 extern const struct floatformat floatformat_m88110_ext; 126 extern const struct floatformat floatformat_m88110_harris_ext; 127 extern const struct floatformat floatformat_arm_ext_big; 128 extern const struct floatformat floatformat_arm_ext_littlebyte_bigword; 129 /* IA-64 Floating Point register spilt into memory. */ 130 extern const struct floatformat floatformat_ia64_spill_big; 131 extern const struct floatformat floatformat_ia64_spill_little; 132 extern const struct floatformat floatformat_ia64_quad_big; 133 extern const struct floatformat floatformat_ia64_quad_little; 134 /* IBM long double (double+double). */ 135 extern const struct floatformat floatformat_ibm_long_double_big; 136 extern const struct floatformat floatformat_ibm_long_double_little; 137 138 /* Convert from FMT to a double. 139 FROM is the address of the extended float. 140 Store the double in *TO. */ 141 142 extern void 143 floatformat_to_double (const struct floatformat *, const void *, double *); 144 145 /* The converse: convert the double *FROM to FMT 146 and store where TO points. */ 147 148 extern void 149 floatformat_from_double (const struct floatformat *, const double *, void *); 150 151 /* Return non-zero iff the data at FROM is a valid number in format FMT. */ 152 153 extern int 154 floatformat_is_valid (const struct floatformat *fmt, const void *from); 155 156 #ifdef __cplusplus 157 } 158 #endif 159 160 #endif /* defined (FLOATFORMAT_H) */ 161