floatformat.h revision 77298
1/* IEEE floating point support declarations, for GDB, the GNU Debugger. 2 Copyright (C) 1991, 2000 Free Software Foundation, Inc. 3 4This file is part of GDB. 5 6This program is free software; you can redistribute it and/or modify 7it under the terms of the GNU General Public License as published by 8the Free Software Foundation; either version 2 of the License, or 9(at your option) any later version. 10 11This program is distributed in the hope that it will be useful, 12but WITHOUT ANY WARRANTY; without even the implied warranty of 13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14GNU General Public License for more details. 15 16You should have received a copy of the GNU General Public License 17along with this program; if not, write to the Free Software 18Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ 19 20#if !defined (FLOATFORMAT_H) 21#define FLOATFORMAT_H 1 22 23#include "ansidecl.h" 24 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. */ 30 31/* What is the order of the bytes. */ 32 33enum floatformat_byteorders { 34 35 /* Standard little endian byte order. 36 EX: 1.2345678e10 => 00 00 80 c5 e0 fe 06 42 */ 37 38 floatformat_little, 39 40 /* Standard big endian byte order. 41 EX: 1.2345678e10 => 42 06 fe e0 c5 80 00 00 */ 42 43 floatformat_big, 44 45 /* Little endian byte order but big endian word order. 46 EX: 1.2345678e10 => e0 fe 06 42 00 00 80 c5 */ 47 48 floatformat_littlebyte_bigword 49 50}; 51 52enum floatformat_intbit { floatformat_intbit_yes, floatformat_intbit_no }; 53 54struct floatformat 55{ 56 enum floatformat_byteorders byteorder; 57 unsigned int totalsize; /* Total size of number in bits */ 58 59 /* Sign bit is always one bit long. 1 means negative, 0 means positive. */ 60 unsigned int sign_start; 61 62 unsigned int exp_start; 63 unsigned int exp_len; 64 /* Amount added to "true" exponent. 0x3fff for many IEEE extendeds. */ 65 unsigned int exp_bias; 66 /* Exponent value which indicates NaN. This is the actual value stored in 67 the float, not adjusted by the exp_bias. This usually consists of all 68 one bits. */ 69 unsigned int exp_nan; 70 71 unsigned int man_start; 72 unsigned int man_len; 73 74 /* Is the integer bit explicit or implicit? */ 75 enum floatformat_intbit intbit; 76 77 /* Internal name for debugging. */ 78 const char *name; 79}; 80 81/* floatformats for IEEE single and double, big and little endian. */ 82 83extern const struct floatformat floatformat_ieee_single_big; 84extern const struct floatformat floatformat_ieee_single_little; 85extern const struct floatformat floatformat_ieee_double_big; 86extern const struct floatformat floatformat_ieee_double_little; 87 88/* floatformat for ARM IEEE double, little endian bytes and big endian words */ 89 90extern const struct floatformat floatformat_ieee_double_littlebyte_bigword; 91 92/* floatformats for various extendeds. */ 93 94extern const struct floatformat floatformat_i387_ext; 95extern const struct floatformat floatformat_m68881_ext; 96extern const struct floatformat floatformat_i960_ext; 97extern const struct floatformat floatformat_m88110_ext; 98extern const struct floatformat floatformat_arm_ext; 99 100/* Convert from FMT to a double. 101 FROM is the address of the extended float. 102 Store the double in *TO. */ 103 104extern void 105floatformat_to_double PARAMS ((const struct floatformat *, char *, double *)); 106 107/* The converse: convert the double *FROM to FMT 108 and store where TO points. */ 109 110extern void 111floatformat_from_double PARAMS ((const struct floatformat *, 112 double *, char *)); 113 114#endif /* defined (FLOATFORMAT_H) */ 115