1/* Configuration for math routines.
2 Copyright (C) 2017-2018 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19#ifndef _MATH_CONFIG_H
20#define _MATH_CONFIG_H
21
22#include <math.h>
23#include <math_private.h>
24#include <nan-high-order-bit.h>
25#include <stdint.h>
26
27#ifndef WANT_ROUNDING
28/* Correct special case results in non-nearest rounding modes. */
29# define WANT_ROUNDING 1
30#endif
31#ifndef WANT_ERRNO
32/* Set errno according to ISO C with (math_errhandling & MATH_ERRNO) != 0. */
33# define WANT_ERRNO 1
34#endif
35#ifndef WANT_ERRNO_UFLOW
36/* Set errno to ERANGE if result underflows to 0 (in all rounding modes). */
37# define WANT_ERRNO_UFLOW (WANT_ROUNDING && WANT_ERRNO)
38#endif
39
40#ifndef TOINT_INTRINSICS
41# define TOINT_INTRINSICS 0
42#endif
43#ifndef TOINT_RINT
44# define TOINT_RINT 0
45#endif
46#ifndef TOINT_SHIFT
47# define TOINT_SHIFT 1
48#endif
49
50static inline uint32_t
51asuint (float f)
52{
53 union
54 {
55 float f;
56 uint32_t i;
57 } u = {f};
58 return u.i;
59}
60
61static inline float
62asfloat (uint32_t i)
63{
64 union
65 {
66 uint32_t i;
67 float f;
68 } u = {i};
69 return u.f;
70}
71
72static inline uint64_t
73asuint64 (double f)
74{
75 union
76 {
77 double f;
78 uint64_t i;
79 } u = {f};
80 return u.i;
81}
82
83static inline double
84asdouble (uint64_t i)
85{
86 union
87 {
88 uint64_t i;
89 double f;
90 } u = {i};
91 return u.f;
92}
93
94static inline int
95issignalingf_inline (float x)
96{
97 uint32_t ix = asuint (x);
98 if (HIGH_ORDER_BIT_IS_SET_FOR_SNAN)
99 return (ix & 0x7fc00000) == 0x7fc00000;
100 return 2 * (ix ^ 0x00400000) > 2u * 0x7fc00000;
101}
102
103#define NOINLINE __attribute__ ((noinline))
104
105attribute_hidden float __math_oflowf (uint32_t);
106attribute_hidden float __math_uflowf (uint32_t);
107attribute_hidden float __math_may_uflowf (uint32_t);
108attribute_hidden float __math_divzerof (uint32_t);
109attribute_hidden float __math_invalidf (float);
110
111/* Shared between expf, exp2f and powf. */
112#define EXP2F_TABLE_BITS 5
113#define EXP2F_POLY_ORDER 3
114extern const struct exp2f_data
115{
116 uint64_t tab[1 << EXP2F_TABLE_BITS];
117 double shift_scaled;
118 double poly[EXP2F_POLY_ORDER];
119 double shift;
120 double invln2_scaled;
121 double poly_scaled[EXP2F_POLY_ORDER];
122} __exp2f_data attribute_hidden;
123
124#define LOGF_TABLE_BITS 4
125#define LOGF_POLY_ORDER 4
126extern const struct logf_data
127{
128 struct
129 {
130 double invc, logc;
131 } tab[1 << LOGF_TABLE_BITS];
132 double ln2;
133 double poly[LOGF_POLY_ORDER - 1]; /* First order coefficient is 1. */
134} __logf_data attribute_hidden;
135
136#define LOG2F_TABLE_BITS 4
137#define LOG2F_POLY_ORDER 4
138extern const struct log2f_data
139{
140 struct
141 {
142 double invc, logc;
143 } tab[1 << LOG2F_TABLE_BITS];
144 double poly[LOG2F_POLY_ORDER];
145} __log2f_data attribute_hidden;
146
147#define POWF_LOG2_TABLE_BITS 4
148#define POWF_LOG2_POLY_ORDER 5
149#if TOINT_INTRINSICS
150# define POWF_SCALE_BITS EXP2F_TABLE_BITS
151#else
152# define POWF_SCALE_BITS 0
153#endif
154#define POWF_SCALE ((double) (1 << POWF_SCALE_BITS))
155extern const struct powf_log2_data
156{
157 struct
158 {
159 double invc, logc;
160 } tab[1 << POWF_LOG2_TABLE_BITS];
161 double poly[POWF_LOG2_POLY_ORDER];
162} __powf_log2_data attribute_hidden;
163
164#endif
165