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 /* 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_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; 105 106 /* floatformat for ARM IEEE double, little endian bytes and big endian words */ 107 108 extern const struct floatformat floatformat_ieee_double_littlebyte_bigword; 109 110 /* floatformats for VAX. */ 111 112 extern const struct floatformat floatformat_vax_f; 113 extern const struct floatformat floatformat_vax_d; 114 extern const struct floatformat floatformat_vax_g; 115 116 /* floatformats for various extendeds. */ 117 118 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_big; 132 extern const struct floatformat floatformat_ibm_long_double_little; 133 134 /* Convert from FMT to a double. 135 FROM is the address of the extended float. 136 Store the double in *TO. */ 137 138 extern void 139 floatformat_to_double (const struct floatformat *, const void *, double *); 140 141 /* The converse: convert the double *FROM to FMT 142 and store where TO points. */ 143 144 extern void 145 floatformat_from_double (const struct floatformat *, const double *, void *); 146 147 /* Return non-zero iff the data at FROM is a valid number in format FMT. */ 148 149 extern int 150 floatformat_is_valid (const struct floatformat *fmt, const void *from); 151 152 #endif /* defined (FLOATFORMAT_H) */ 153
