Commit | Line | Data |
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6dc2ca62 MD |
1 | /* |
2 | * Common Trace Format | |
3 | * | |
4 | * Floating point read/write functions. | |
5 | * | |
ccd7e1c8 | 6 | * Copyright 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
6dc2ca62 | 7 | * |
ccd7e1c8 MD |
8 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
9 | * of this software and associated documentation files (the "Software"), to deal | |
10 | * in the Software without restriction, including without limitation the rights | |
11 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
12 | * copies of the Software, and to permit persons to whom the Software is | |
13 | * furnished to do so, subject to the following conditions: | |
de0ba614 | 14 | * |
ccd7e1c8 MD |
15 | * The above copyright notice and this permission notice shall be included in |
16 | * all copies or substantial portions of the Software. | |
6dc2ca62 | 17 | * |
de0ba614 | 18 | * Reference: ISO C99 standard 5.2.4 |
6dc2ca62 MD |
19 | */ |
20 | ||
d79865b9 | 21 | #include <babeltrace/ctf/types.h> |
6dc2ca62 | 22 | #include <glib.h> |
de0ba614 | 23 | #include <float.h> /* C99 floating point definitions */ |
a3dbc794 | 24 | #include <limits.h> /* C99 limits */ |
6dc2ca62 MD |
25 | #include <endian.h> |
26 | ||
de0ba614 MD |
27 | /* |
28 | * This library is limited to binary representation of floating point values. | |
29 | * Sign-extension of the exponents is assumed to keep the NaN, +inf, -inf | |
30 | * values, but this should be double-checked (TODO). | |
31 | */ | |
32 | ||
6dc2ca62 MD |
33 | /* |
34 | * Aliasing float/double and unsigned long is not strictly permitted by strict | |
f6625916 | 35 | * aliasing, but in practice declaration prunning is well supported, and this permits |
6dc2ca62 MD |
36 | * us to use per-word read/writes rather than per-byte. |
37 | */ | |
38 | ||
39 | #if defined(__GNUC__) || defined(__MINGW32__) || defined(_MSC_VER) | |
40 | #define HAS_TYPE_PRUNING | |
41 | #endif | |
42 | ||
de0ba614 MD |
43 | #if (FLT_RADIX != 2) |
44 | ||
45 | #error "Unsupported floating point radix" | |
46 | ||
6dc2ca62 | 47 | #endif |
6dc2ca62 MD |
48 | |
49 | union doubleIEEE754 { | |
50 | double v; | |
51 | #ifdef HAS_TYPE_PRUNING | |
52 | unsigned long bits[(sizeof(double) + sizeof(unsigned long) - 1) / sizeof(unsigned long)]; | |
53 | #else | |
54 | unsigned char bits[sizeof(double)]; | |
55 | #endif | |
56 | }; | |
57 | ||
de0ba614 MD |
58 | union ldoubleIEEE754 { |
59 | long double v; | |
60 | #ifdef HAS_TYPE_PRUNING | |
61 | unsigned long bits[(sizeof(long double) + sizeof(unsigned long) - 1) / sizeof(unsigned long)]; | |
62 | #else | |
63 | unsigned char bits[sizeof(long double)]; | |
64 | #endif | |
65 | }; | |
66 | ||
d11e9c49 MD |
67 | static struct declaration_float *static_ldouble_declaration; |
68 | ||
de0ba614 MD |
69 | struct pos_len { |
70 | size_t sign_start, exp_start, mantissa_start, len; | |
71 | }; | |
72 | ||
11d43b90 | 73 | void _ctf_float_copy(struct stream_pos *destp, |
d11e9c49 | 74 | struct definition_float *dest_definition, |
11d43b90 | 75 | struct stream_pos *srcp, |
d11e9c49 | 76 | const struct definition_float *src_definition) |
6dc2ca62 | 77 | { |
11d43b90 | 78 | /* Read */ |
d11e9c49 MD |
79 | if (src_definition->declaration->byte_order == LITTLE_ENDIAN) { |
80 | ctf_integer_read(srcp, &src_definition->mantissa->p); | |
81 | ctf_integer_read(srcp, &src_definition->exp->p); | |
82 | ctf_integer_read(srcp, &src_definition->sign->p); | |
de0ba614 | 83 | } else { |
d11e9c49 MD |
84 | ctf_integer_read(srcp, &src_definition->sign->p); |
85 | ctf_integer_read(srcp, &src_definition->exp->p); | |
86 | ctf_integer_read(srcp, &src_definition->mantissa->p); | |
6dc2ca62 | 87 | } |
d11e9c49 MD |
88 | |
89 | dest_definition->mantissa->value._unsigned = | |
90 | src_definition->mantissa->value._unsigned; | |
91 | dest_definition->exp->value._signed = | |
92 | src_definition->exp->value._signed; | |
93 | dest_definition->sign->value._unsigned = | |
94 | src_definition->sign->value._unsigned; | |
95 | ||
11d43b90 | 96 | /* Write */ |
d11e9c49 MD |
97 | if (dest_definition->declaration->byte_order == LITTLE_ENDIAN) { |
98 | ctf_integer_write(destp, &dest_definition->mantissa->p); | |
99 | ctf_integer_write(destp, &dest_definition->exp->p); | |
100 | ctf_integer_write(destp, &dest_definition->sign->p); | |
de0ba614 | 101 | } else { |
d11e9c49 MD |
102 | ctf_integer_write(destp, &dest_definition->sign->p); |
103 | ctf_integer_write(destp, &dest_definition->exp->p); | |
104 | ctf_integer_write(destp, &dest_definition->mantissa->p); | |
6dc2ca62 | 105 | } |
11d43b90 | 106 | } |
de0ba614 | 107 | |
d11e9c49 | 108 | void ctf_float_read(struct stream_pos *ppos, struct definition *definition) |
6dc2ca62 | 109 | { |
d11e9c49 MD |
110 | struct definition_float *float_definition = |
111 | container_of(definition, struct definition_float, p); | |
112 | const struct declaration_float *float_declaration = | |
113 | float_definition->declaration; | |
114 | struct ctf_stream_pos *pos = ctf_pos(ppos); | |
115 | union ldoubleIEEE754 u; | |
116 | struct definition *tmpdef = | |
117 | static_ldouble_declaration->p.definition_new(&static_ldouble_declaration->p, | |
118 | NULL, 0, 0); | |
119 | struct definition_float *tmpfloat = | |
120 | container_of(tmpdef, struct definition_float, p); | |
46322b33 | 121 | struct ctf_stream_pos destp; |
11d43b90 | 122 | |
46322b33 | 123 | ctf_init_pos(&destp, -1); |
0f980a35 | 124 | destp.base = (char *) u.bits; |
d11e9c49 MD |
125 | |
126 | ctf_align_pos(pos, float_declaration->p.alignment); | |
127 | _ctf_float_copy(&destp.parent, tmpfloat, ppos, float_definition); | |
128 | float_definition->value = u.v; | |
129 | definition_unref(tmpdef); | |
de0ba614 MD |
130 | } |
131 | ||
d11e9c49 | 132 | void ctf_float_write(struct stream_pos *ppos, struct definition *definition) |
de0ba614 | 133 | { |
d11e9c49 MD |
134 | struct definition_float *float_definition = |
135 | container_of(definition, struct definition_float, p); | |
136 | const struct declaration_float *float_declaration = | |
137 | float_definition->declaration; | |
138 | struct ctf_stream_pos *pos = ctf_pos(ppos); | |
139 | union ldoubleIEEE754 u; | |
140 | struct definition *tmpdef = | |
141 | static_ldouble_declaration->p.definition_new(&static_ldouble_declaration->p, | |
142 | NULL, 0, 0); | |
143 | struct definition_float *tmpfloat = | |
144 | container_of(tmpdef, struct definition_float, p); | |
46322b33 | 145 | struct ctf_stream_pos srcp; |
11d43b90 | 146 | |
46322b33 | 147 | ctf_init_pos(&srcp, -1); |
0f980a35 | 148 | srcp.base = (char *) u.bits; |
d11e9c49 MD |
149 | |
150 | u.v = float_definition->value; | |
151 | ctf_align_pos(pos, float_declaration->p.alignment); | |
152 | _ctf_float_copy(ppos, float_definition, &srcp.parent, tmpfloat); | |
153 | definition_unref(tmpdef); | |
de0ba614 | 154 | } |
6dc2ca62 | 155 | |
d11e9c49 | 156 | void __attribute__((constructor)) ctf_float_init(void) |
de0ba614 | 157 | { |
d11e9c49 | 158 | static_ldouble_declaration = |
add40b62 | 159 | float_declaration_new(LDBL_MANT_DIG, |
11d43b90 MD |
160 | sizeof(long double) * CHAR_BIT - LDBL_MANT_DIG, |
161 | BYTE_ORDER, | |
162 | __alignof__(long double)); | |
de0ba614 MD |
163 | } |
164 | ||
d11e9c49 | 165 | void __attribute__((destructor)) ctf_float_fini(void) |
de0ba614 | 166 | { |
d11e9c49 | 167 | declaration_unref(&static_ldouble_declaration->p); |
6dc2ca62 | 168 | } |