1/* Configuration for math routines.
2 Copyright (C) 2017-2020 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 <https://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/* When set, the roundtoint and converttoint functions are provided with
42 the semantics documented below. */
43# define TOINT_INTRINSICS 0
44#endif
45
46#if TOINT_INTRINSICS
47/* Round x to nearest int in all rounding modes, ties have to be rounded
48 consistently with converttoint so the results match. If the result
49 would be outside of [-2^31, 2^31-1] then the semantics is unspecified. */
50static inline double_t
51roundtoint (double_t x);
52
53/* Convert x to nearest int in all rounding modes, ties have to be rounded
54 consistently with roundtoint. If the result is not representible in an
55 int32_t then the semantics is unspecified. */
56static inline int32_t
57converttoint (double_t x);
58#endif
59
60static inline uint32_t
61asuint (float f)
62{
63 union
64 {
65 float f;
66 uint32_t i;
67 } u = {f};
68 return u.i;
69}
70
71static inline float
72asfloat (uint32_t i)
73{
74 union
75 {
76 uint32_t i;
77 float f;
78 } u = {i};
79 return u.f;
80}
81
82static inline uint64_t
83asuint64 (double f)
84{
85 union
86 {
87 double f;
88 uint64_t i;
89 } u = {f};
90 return u.i;
91}
92
93static inline double
94asdouble (uint64_t i)
95{
96 union
97 {
98 uint64_t i;
99 double f;
100 } u = {i};
101 return u.f;
102}
103
104#define NOINLINE __attribute__ ((noinline))
105
106attribute_hidden float __math_oflowf (uint32_t);
107attribute_hidden float __math_uflowf (uint32_t);
108attribute_hidden float __math_may_uflowf (uint32_t);
109attribute_hidden float __math_divzerof (uint32_t);
110attribute_hidden float __math_invalidf (float);
111
112/* Shared between expf, exp2f, exp10f, and powf. */
113#define EXP2F_TABLE_BITS 5
114#define EXP2F_POLY_ORDER 3
115extern const struct exp2f_data
116{
117 uint64_t tab[1 << EXP2F_TABLE_BITS];
118 double shift_scaled;
119 double poly[EXP2F_POLY_ORDER];
120 double shift;
121 double invln2_scaled;
122 double poly_scaled[EXP2F_POLY_ORDER];
123} __exp2f_data attribute_hidden;
124
125#define LOGF_TABLE_BITS 4
126#define LOGF_POLY_ORDER 4
127extern const struct logf_data
128{
129 struct
130 {
131 double invc, logc;
132 } tab[1 << LOGF_TABLE_BITS];
133 double ln2;
134 double poly[LOGF_POLY_ORDER - 1]; /* First order coefficient is 1. */
135} __logf_data attribute_hidden;
136
137#define LOG2F_TABLE_BITS 4
138#define LOG2F_POLY_ORDER 4
139extern const struct log2f_data
140{
141 struct
142 {
143 double invc, logc;
144 } tab[1 << LOG2F_TABLE_BITS];
145 double poly[LOG2F_POLY_ORDER];
146} __log2f_data attribute_hidden;
147
148#define POWF_LOG2_TABLE_BITS 4
149#define POWF_LOG2_POLY_ORDER 5
150#if TOINT_INTRINSICS
151# define POWF_SCALE_BITS EXP2F_TABLE_BITS
152#else
153# define POWF_SCALE_BITS 0
154#endif
155#define POWF_SCALE ((double) (1 << POWF_SCALE_BITS))
156extern const struct powf_log2_data
157{
158 struct
159 {
160 double invc, logc;
161 } tab[1 << POWF_LOG2_TABLE_BITS];
162 double poly[POWF_LOG2_POLY_ORDER];
163} __powf_log2_data attribute_hidden;
164
165#endif
166