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5191 | serge | 1 | /* IEEE floating point support declarations, for GDB, the GNU Debugger. |
2 | Copyright 1991, 1994, 1995, 1997, 2000, 2003, 2005, 2010 |
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3 | Free Software Foundation, Inc. |
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4 | |||
5 | This file is part of GDB. |
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6 | |||
7 | This program is free software; you can redistribute it and/or modify |
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8 | it under the terms of the GNU General Public License as published by |
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9 | the Free Software Foundation; either version 2 of the License, or |
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10 | (at your option) any later version. |
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11 | |||
12 | This program is distributed in the hope that it will be useful, |
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13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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15 | GNU General Public License for more details. |
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16 | |||
17 | You should have received a copy of the GNU General Public License |
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18 | along with this program; if not, write to the Free Software |
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19 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ |
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20 | |||
21 | #if !defined (FLOATFORMAT_H) |
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22 | #define FLOATFORMAT_H 1 |
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23 | |||
24 | #include "ansidecl.h" |
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25 | |||
26 | /* A floatformat consists of a sign bit, an exponent and a mantissa. Once the |
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27 | bytes are concatenated according to the byteorder flag, then each of those |
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28 | fields is contiguous. We number the bits with 0 being the most significant |
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29 | (i.e. BITS_BIG_ENDIAN type numbering), and specify which bits each field |
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30 | contains with the *_start and *_len fields. */ |
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31 | |||
32 | /* What is the order of the bytes? */ |
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33 | |||
34 | enum floatformat_byteorders { |
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35 | /* Standard little endian byte order. |
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36 | EX: 1.2345678e10 => 00 00 80 c5 e0 fe 06 42 */ |
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37 | floatformat_little, |
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38 | |||
39 | /* Standard big endian byte order. |
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40 | EX: 1.2345678e10 => 42 06 fe e0 c5 80 00 00 */ |
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41 | floatformat_big, |
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42 | |||
43 | /* Little endian byte order but big endian word order. |
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44 | EX: 1.2345678e10 => e0 fe 06 42 00 00 80 c5 */ |
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45 | floatformat_littlebyte_bigword, |
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46 | |||
47 | /* VAX byte order. Little endian byte order with 16-bit words. The |
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48 | following example is an illustration of the byte order only; VAX |
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49 | doesn't have a fully IEEE compliant floating-point format. |
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50 | EX: 1.2345678e10 => 80 c5 00 00 06 42 e0 fe */ |
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51 | floatformat_vax |
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52 | }; |
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53 | |||
54 | enum floatformat_intbit { floatformat_intbit_yes, floatformat_intbit_no }; |
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55 | |||
56 | struct floatformat |
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57 | { |
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58 | enum floatformat_byteorders byteorder; |
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59 | unsigned int totalsize; /* Total size of number in bits */ |
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60 | |||
61 | /* Sign bit is always one bit long. 1 means negative, 0 means positive. */ |
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62 | unsigned int sign_start; |
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63 | |||
64 | unsigned int exp_start; |
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65 | unsigned int exp_len; |
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66 | /* Bias added to a "true" exponent to form the biased exponent. It |
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67 | is intentionally signed as, otherwize, -exp_bias can turn into a |
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68 | very large number (e.g., given the exp_bias of 0x3fff and a 64 |
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69 | bit long, the equation (long)(1 - exp_bias) evaluates to |
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70 | 4294950914) instead of -16382). */ |
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71 | int exp_bias; |
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72 | /* Exponent value which indicates NaN. This is the actual value stored in |
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73 | the float, not adjusted by the exp_bias. This usually consists of all |
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74 | one bits. */ |
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75 | unsigned int exp_nan; |
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76 | |||
77 | unsigned int man_start; |
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78 | unsigned int man_len; |
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79 | |||
80 | /* Is the integer bit explicit or implicit? */ |
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81 | enum floatformat_intbit intbit; |
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82 | |||
83 | /* Internal name for debugging. */ |
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84 | const char *name; |
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85 | |||
86 | /* Validator method. */ |
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87 | int (*is_valid) (const struct floatformat *fmt, const void *from); |
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88 | |||
89 | /* Is the format actually the sum of two smaller floating point |
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90 | formats (IBM long double, as described in |
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91 | gcc/config/rs6000/darwin-ldouble-format)? If so, this is the |
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92 | smaller format in question, and the fields sign_start through |
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93 | intbit describe the first half. If not, this is NULL. */ |
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94 | const struct floatformat *split_half; |
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95 | }; |
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96 | |||
97 | /* floatformats for IEEE single and double, big and little endian. */ |
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98 | |||
99 | extern const struct floatformat floatformat_ieee_half_big; |
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100 | extern const struct floatformat floatformat_ieee_half_little; |
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101 | extern const struct floatformat floatformat_ieee_single_big; |
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102 | extern const struct floatformat floatformat_ieee_single_little; |
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103 | extern const struct floatformat floatformat_ieee_double_big; |
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104 | extern const struct floatformat floatformat_ieee_double_little; |
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105 | |||
106 | /* floatformat for ARM IEEE double, little endian bytes and big endian words */ |
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107 | |||
108 | extern const struct floatformat floatformat_ieee_double_littlebyte_bigword; |
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109 | |||
110 | /* floatformats for VAX. */ |
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111 | |||
112 | extern const struct floatformat floatformat_vax_f; |
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113 | extern const struct floatformat floatformat_vax_d; |
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114 | extern const struct floatformat floatformat_vax_g; |
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115 | |||
116 | /* floatformats for various extendeds. */ |
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117 | |||
118 | extern const struct floatformat floatformat_i387_ext; |
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119 | extern const struct floatformat floatformat_m68881_ext; |
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120 | extern const struct floatformat floatformat_i960_ext; |
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121 | extern const struct floatformat floatformat_m88110_ext; |
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122 | extern const struct floatformat floatformat_m88110_harris_ext; |
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123 | extern const struct floatformat floatformat_arm_ext_big; |
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124 | extern const struct floatformat floatformat_arm_ext_littlebyte_bigword; |
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125 | /* IA-64 Floating Point register spilt into memory. */ |
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126 | extern const struct floatformat floatformat_ia64_spill_big; |
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127 | extern const struct floatformat floatformat_ia64_spill_little; |
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128 | extern const struct floatformat floatformat_ia64_quad_big; |
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129 | extern const struct floatformat floatformat_ia64_quad_little; |
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130 | /* IBM long double (double+double). */ |
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131 | extern const struct floatformat floatformat_ibm_long_double_big; |
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132 | extern const struct floatformat floatformat_ibm_long_double_little; |
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133 | |||
134 | /* Convert from FMT to a double. |
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135 | FROM is the address of the extended float. |
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136 | Store the double in *TO. */ |
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137 | |||
138 | extern void |
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139 | floatformat_to_double (const struct floatformat *, const void *, double *); |
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140 | |||
141 | /* The converse: convert the double *FROM to FMT |
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142 | and store where TO points. */ |
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143 | |||
144 | extern void |
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145 | floatformat_from_double (const struct floatformat *, const double *, void *); |
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146 | |||
147 | /* Return non-zero iff the data at FROM is a valid number in format FMT. */ |
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148 | |||
149 | extern int |
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150 | floatformat_is_valid (const struct floatformat *fmt, const void *from); |
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151 | |||
152 | #endif /* defined (FLOATFORMAT_H) */ |