1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
|
/* Configuration for math routines.
Copyright (C) 2017-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef _MATH_CONFIG_H
#define _MATH_CONFIG_H
#include <math.h>
#include <math_private.h>
#include <nan-high-order-bit.h>
#include <stdint.h>
#ifndef WANT_ROUNDING
/* Correct special case results in non-nearest rounding modes. */
# define WANT_ROUNDING 1
#endif
#ifndef WANT_ERRNO
/* Set errno according to ISO C with (math_errhandling & MATH_ERRNO) != 0. */
# define WANT_ERRNO 1
#endif
#ifndef WANT_ERRNO_UFLOW
/* Set errno to ERANGE if result underflows to 0 (in all rounding modes). */
# define WANT_ERRNO_UFLOW (WANT_ROUNDING && WANT_ERRNO)
#endif
#ifndef TOINT_INTRINSICS
/* When set, the roundtoint and converttoint functions are provided with
the semantics documented below. */
# define TOINT_INTRINSICS 0
#endif
#if TOINT_INTRINSICS
/* Round x to nearest int in all rounding modes, ties have to be rounded
consistently with converttoint so the results match. If the result
would be outside of [-2^31, 2^31-1] then the semantics is unspecified. */
static inline double_t
roundtoint (double_t x);
/* Convert x to nearest int in all rounding modes, ties have to be rounded
consistently with roundtoint. If the result is not representible in an
int32_t then the semantics is unspecified. */
static inline int32_t
converttoint (double_t x);
#endif
static inline uint32_t
asuint (float f)
{
union
{
float f;
uint32_t i;
} u = {f};
return u.i;
}
static inline float
asfloat (uint32_t i)
{
union
{
uint32_t i;
float f;
} u = {i};
return u.f;
}
static inline uint64_t
asuint64 (double f)
{
union
{
double f;
uint64_t i;
} u = {f};
return u.i;
}
static inline double
asdouble (uint64_t i)
{
union
{
uint64_t i;
double f;
} u = {i};
return u.f;
}
static inline int
issignalingf_inline (float x)
{
uint32_t ix = asuint (x);
if (HIGH_ORDER_BIT_IS_SET_FOR_SNAN)
return (ix & 0x7fc00000) == 0x7fc00000;
return 2 * (ix ^ 0x00400000) > 2 * 0x7fc00000UL;
}
#define BIT_WIDTH 32
#define MANTISSA_WIDTH 23
#define EXPONENT_WIDTH 8
#define MANTISSA_MASK 0x007fffff
#define EXPONENT_MASK 0x7f800000
#define EXP_MANT_MASK 0x7fffffff
#define QUIET_NAN_MASK 0x00400000
#define SIGN_MASK 0x80000000
static inline bool
is_nan (uint32_t x)
{
return (x & EXP_MANT_MASK) > EXPONENT_MASK;
}
static inline uint32_t
get_mantissa (uint32_t x)
{
return x & MANTISSA_MASK;
}
/* Convert integer number X, unbiased exponent EP, and sign S to double:
result = X * 2^(EP+1 - exponent_bias)
NB: zero is not supported. */
static inline double
make_float (uint32_t x, int ep, uint32_t s)
{
int lz = __builtin_clz (x) - EXPONENT_WIDTH;
x <<= lz;
ep -= lz;
if (__glibc_unlikely (ep < 0 || x == 0))
{
x >>= -ep;
ep = 0;
}
return asfloat (s + x + (ep << MANTISSA_WIDTH));
}
#define NOINLINE __attribute__ ((noinline))
attribute_hidden float __math_oflowf (uint32_t);
attribute_hidden float __math_uflowf (uint32_t);
attribute_hidden float __math_may_uflowf (uint32_t);
attribute_hidden float __math_divzerof (uint32_t);
attribute_hidden float __math_invalidf (float);
/* Shared between expf, exp2f, exp10f, and powf. */
#define EXP2F_TABLE_BITS 5
#define EXP2F_POLY_ORDER 3
extern const struct exp2f_data
{
uint64_t tab[1 << EXP2F_TABLE_BITS];
double shift_scaled;
double poly[EXP2F_POLY_ORDER];
double shift;
double invln2_scaled;
double poly_scaled[EXP2F_POLY_ORDER];
} __exp2f_data attribute_hidden;
#define LOGF_TABLE_BITS 4
#define LOGF_POLY_ORDER 4
extern const struct logf_data
{
struct
{
double invc, logc;
} tab[1 << LOGF_TABLE_BITS];
double ln2;
double poly[LOGF_POLY_ORDER - 1]; /* First order coefficient is 1. */
} __logf_data attribute_hidden;
#define LOG2F_TABLE_BITS 4
#define LOG2F_POLY_ORDER 4
extern const struct log2f_data
{
struct
{
double invc, logc;
} tab[1 << LOG2F_TABLE_BITS];
double poly[LOG2F_POLY_ORDER];
} __log2f_data attribute_hidden;
#define POWF_LOG2_TABLE_BITS 4
#define POWF_LOG2_POLY_ORDER 5
#if TOINT_INTRINSICS
# define POWF_SCALE_BITS EXP2F_TABLE_BITS
#else
# define POWF_SCALE_BITS 0
#endif
#define POWF_SCALE ((double) (1 << POWF_SCALE_BITS))
extern const struct powf_log2_data
{
struct
{
double invc, logc;
} tab[1 << POWF_LOG2_TABLE_BITS];
double poly[POWF_LOG2_POLY_ORDER];
} __powf_log2_data attribute_hidden;
#endif
|