Commit | Line | Data |
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6dc2ca62 MD |
1 | /* |
2 | * Common Trace Format | |
3 | * | |
4 | * Floating point read/write functions. | |
5 | * | |
64fa3fec MD |
6 | * Copyright 2010-2011 EfficiOS Inc. and Linux Foundation |
7 | * | |
8 | * Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
6dc2ca62 | 9 | * |
ccd7e1c8 MD |
10 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
11 | * of this software and associated documentation files (the "Software"), to deal | |
12 | * in the Software without restriction, including without limitation the rights | |
13 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
14 | * copies of the Software, and to permit persons to whom the Software is | |
15 | * furnished to do so, subject to the following conditions: | |
de0ba614 | 16 | * |
ccd7e1c8 MD |
17 | * The above copyright notice and this permission notice shall be included in |
18 | * all copies or substantial portions of the Software. | |
6dc2ca62 | 19 | * |
de0ba614 | 20 | * Reference: ISO C99 standard 5.2.4 |
6dc2ca62 MD |
21 | */ |
22 | ||
d79865b9 | 23 | #include <babeltrace/ctf/types.h> |
6dc2ca62 | 24 | #include <glib.h> |
de0ba614 | 25 | #include <float.h> /* C99 floating point definitions */ |
a3dbc794 | 26 | #include <limits.h> /* C99 limits */ |
6dc2ca62 MD |
27 | #include <endian.h> |
28 | ||
de0ba614 MD |
29 | /* |
30 | * This library is limited to binary representation of floating point values. | |
31 | * Sign-extension of the exponents is assumed to keep the NaN, +inf, -inf | |
32 | * values, but this should be double-checked (TODO). | |
33 | */ | |
34 | ||
6dc2ca62 MD |
35 | /* |
36 | * Aliasing float/double and unsigned long is not strictly permitted by strict | |
f6625916 | 37 | * aliasing, but in practice declaration prunning is well supported, and this permits |
6dc2ca62 MD |
38 | * us to use per-word read/writes rather than per-byte. |
39 | */ | |
40 | ||
41 | #if defined(__GNUC__) || defined(__MINGW32__) || defined(_MSC_VER) | |
42 | #define HAS_TYPE_PRUNING | |
43 | #endif | |
44 | ||
de0ba614 MD |
45 | #if (FLT_RADIX != 2) |
46 | ||
47 | #error "Unsupported floating point radix" | |
48 | ||
6dc2ca62 | 49 | #endif |
6dc2ca62 MD |
50 | |
51 | union doubleIEEE754 { | |
52 | double v; | |
53 | #ifdef HAS_TYPE_PRUNING | |
54 | unsigned long bits[(sizeof(double) + sizeof(unsigned long) - 1) / sizeof(unsigned long)]; | |
55 | #else | |
56 | unsigned char bits[sizeof(double)]; | |
57 | #endif | |
58 | }; | |
59 | ||
de0ba614 MD |
60 | union ldoubleIEEE754 { |
61 | long double v; | |
62 | #ifdef HAS_TYPE_PRUNING | |
63 | unsigned long bits[(sizeof(long double) + sizeof(unsigned long) - 1) / sizeof(unsigned long)]; | |
64 | #else | |
65 | unsigned char bits[sizeof(long double)]; | |
66 | #endif | |
67 | }; | |
68 | ||
d11e9c49 MD |
69 | static struct declaration_float *static_ldouble_declaration; |
70 | ||
de0ba614 MD |
71 | struct pos_len { |
72 | size_t sign_start, exp_start, mantissa_start, len; | |
73 | }; | |
74 | ||
c5e74408 MD |
75 | int _ctf_float_copy(struct stream_pos *destp, |
76 | struct definition_float *dest_definition, | |
77 | struct stream_pos *srcp, | |
78 | const struct definition_float *src_definition) | |
6dc2ca62 | 79 | { |
c5e74408 MD |
80 | int ret; |
81 | ||
11d43b90 | 82 | /* Read */ |
d11e9c49 | 83 | if (src_definition->declaration->byte_order == LITTLE_ENDIAN) { |
c5e74408 MD |
84 | ret = ctf_integer_read(srcp, &src_definition->mantissa->p); |
85 | if (ret) | |
86 | return ret; | |
87 | ret = ctf_integer_read(srcp, &src_definition->exp->p); | |
88 | if (ret) | |
89 | return ret; | |
90 | ret = ctf_integer_read(srcp, &src_definition->sign->p); | |
91 | if (ret) | |
92 | return ret; | |
de0ba614 | 93 | } else { |
c5e74408 MD |
94 | ret = ctf_integer_read(srcp, &src_definition->sign->p); |
95 | if (ret) | |
96 | return ret; | |
97 | ret = ctf_integer_read(srcp, &src_definition->exp->p); | |
98 | if (ret) | |
99 | return ret; | |
100 | ret = ctf_integer_read(srcp, &src_definition->mantissa->p); | |
101 | if (ret) | |
102 | return ret; | |
6dc2ca62 | 103 | } |
d11e9c49 MD |
104 | |
105 | dest_definition->mantissa->value._unsigned = | |
106 | src_definition->mantissa->value._unsigned; | |
107 | dest_definition->exp->value._signed = | |
108 | src_definition->exp->value._signed; | |
109 | dest_definition->sign->value._unsigned = | |
110 | src_definition->sign->value._unsigned; | |
111 | ||
11d43b90 | 112 | /* Write */ |
d11e9c49 | 113 | if (dest_definition->declaration->byte_order == LITTLE_ENDIAN) { |
c5e74408 MD |
114 | ret = ctf_integer_write(destp, &dest_definition->mantissa->p); |
115 | if (ret) | |
116 | return ret; | |
117 | ret = ctf_integer_write(destp, &dest_definition->exp->p); | |
118 | if (ret) | |
119 | return ret; | |
120 | ret = ctf_integer_write(destp, &dest_definition->sign->p); | |
121 | if (ret) | |
122 | return ret; | |
de0ba614 | 123 | } else { |
c5e74408 MD |
124 | ret = ctf_integer_write(destp, &dest_definition->sign->p); |
125 | if (ret) | |
126 | return ret; | |
127 | ret = ctf_integer_write(destp, &dest_definition->exp->p); | |
128 | if (ret) | |
129 | return ret; | |
130 | ret = ctf_integer_write(destp, &dest_definition->mantissa->p); | |
131 | if (ret) | |
132 | return ret; | |
6dc2ca62 | 133 | } |
c5e74408 | 134 | return 0; |
11d43b90 | 135 | } |
de0ba614 | 136 | |
c5e74408 | 137 | int ctf_float_read(struct stream_pos *ppos, struct definition *definition) |
6dc2ca62 | 138 | { |
d11e9c49 MD |
139 | struct definition_float *float_definition = |
140 | container_of(definition, struct definition_float, p); | |
141 | const struct declaration_float *float_declaration = | |
142 | float_definition->declaration; | |
143 | struct ctf_stream_pos *pos = ctf_pos(ppos); | |
144 | union ldoubleIEEE754 u; | |
145 | struct definition *tmpdef = | |
146 | static_ldouble_declaration->p.definition_new(&static_ldouble_declaration->p, | |
98df1c9f | 147 | NULL, 0, 0, NULL); |
d11e9c49 MD |
148 | struct definition_float *tmpfloat = |
149 | container_of(tmpdef, struct definition_float, p); | |
46322b33 | 150 | struct ctf_stream_pos destp; |
c5e74408 | 151 | int ret; |
11d43b90 | 152 | |
989c73bc | 153 | ctf_init_pos(&destp, -1, O_RDWR); |
0f980a35 | 154 | destp.base = (char *) u.bits; |
d11e9c49 MD |
155 | |
156 | ctf_align_pos(pos, float_declaration->p.alignment); | |
c5e74408 | 157 | ret = _ctf_float_copy(&destp.parent, tmpfloat, ppos, float_definition); |
d11e9c49 MD |
158 | float_definition->value = u.v; |
159 | definition_unref(tmpdef); | |
c5e74408 | 160 | return ret; |
de0ba614 MD |
161 | } |
162 | ||
c5e74408 | 163 | int ctf_float_write(struct stream_pos *ppos, struct definition *definition) |
de0ba614 | 164 | { |
d11e9c49 MD |
165 | struct definition_float *float_definition = |
166 | container_of(definition, struct definition_float, p); | |
167 | const struct declaration_float *float_declaration = | |
168 | float_definition->declaration; | |
169 | struct ctf_stream_pos *pos = ctf_pos(ppos); | |
170 | union ldoubleIEEE754 u; | |
171 | struct definition *tmpdef = | |
172 | static_ldouble_declaration->p.definition_new(&static_ldouble_declaration->p, | |
98df1c9f | 173 | NULL, 0, 0, NULL); |
d11e9c49 MD |
174 | struct definition_float *tmpfloat = |
175 | container_of(tmpdef, struct definition_float, p); | |
46322b33 | 176 | struct ctf_stream_pos srcp; |
c5e74408 | 177 | int ret; |
11d43b90 | 178 | |
8563e754 | 179 | ctf_init_pos(&srcp, -1, O_RDONLY); |
0f980a35 | 180 | srcp.base = (char *) u.bits; |
d11e9c49 MD |
181 | |
182 | u.v = float_definition->value; | |
183 | ctf_align_pos(pos, float_declaration->p.alignment); | |
c5e74408 | 184 | ret = _ctf_float_copy(ppos, float_definition, &srcp.parent, tmpfloat); |
d11e9c49 | 185 | definition_unref(tmpdef); |
c5e74408 | 186 | return ret; |
de0ba614 | 187 | } |
6dc2ca62 | 188 | |
d11e9c49 | 189 | void __attribute__((constructor)) ctf_float_init(void) |
de0ba614 | 190 | { |
d11e9c49 | 191 | static_ldouble_declaration = |
add40b62 | 192 | float_declaration_new(LDBL_MANT_DIG, |
11d43b90 MD |
193 | sizeof(long double) * CHAR_BIT - LDBL_MANT_DIG, |
194 | BYTE_ORDER, | |
195 | __alignof__(long double)); | |
de0ba614 MD |
196 | } |
197 | ||
d11e9c49 | 198 | void __attribute__((destructor)) ctf_float_fini(void) |
de0ba614 | 199 | { |
d11e9c49 | 200 | declaration_unref(&static_ldouble_declaration->p); |
6dc2ca62 | 201 | } |