1 /* Compute sine and cosine of argument.
2 Copyright (C) 2018-2021 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 #include <errno.h>
20 #include <stdint.h>
21 #include <math.h>
22 #include <math-barriers.h>
23 #include <libm-alias-float.h>
24 #include "math_config.h"
25 #include "s_sincosf.h"
26
27 #ifndef SINCOSF
28 # define SINCOSF_FUNC __sincosf
29 #else
30 # define SINCOSF_FUNC SINCOSF
31 #endif
32
33 /* Fast sincosf implementation. Worst-case ULP is 0.5607, maximum relative
34 error is 0.5303 * 2^-23. A single-step range reduction is used for
35 small values. Large inputs have their range reduced using fast integer
36 arithmetic. */
37 void
SINCOSF_FUNC(float y,float * sinp,float * cosp)38 SINCOSF_FUNC (float y, float *sinp, float *cosp)
39 {
40 double x = y;
41 double s;
42 int n;
43 const sincos_t *p = &__sincosf_table[0];
44
45 if (abstop12 (y) < abstop12 (pio4))
46 {
47 double x2 = x * x;
48
49 if (__glibc_unlikely (abstop12 (y) < abstop12 (0x1p-12f)))
50 {
51 /* Force underflow for tiny y. */
52 if (__glibc_unlikely (abstop12 (y) < abstop12 (0x1p-126f)))
53 math_force_eval ((float)x2);
54 *sinp = y;
55 *cosp = 1.0f;
56 return;
57 }
58
59 sincosf_poly (x, x2, p, 0, sinp, cosp);
60 }
61 else if (abstop12 (y) < abstop12 (120.0f))
62 {
63 x = reduce_fast (x, p, &n);
64
65 /* Setup the signs for sin and cos. */
66 s = p->sign[n & 3];
67
68 if (n & 2)
69 p = &__sincosf_table[1];
70
71 sincosf_poly (x * s, x * x, p, n, sinp, cosp);
72 }
73 else if (__glibc_likely (abstop12 (y) < abstop12 (INFINITY)))
74 {
75 uint32_t xi = asuint (y);
76 int sign = xi >> 31;
77
78 x = reduce_large (xi, &n);
79
80 /* Setup signs for sin and cos - include original sign. */
81 s = p->sign[(n + sign) & 3];
82
83 if ((n + sign) & 2)
84 p = &__sincosf_table[1];
85
86 sincosf_poly (x * s, x * x, p, n, sinp, cosp);
87 }
88 else
89 {
90 /* Return NaN if Inf or NaN for both sin and cos. */
91 *sinp = *cosp = y - y;
92 #if WANT_ERRNO
93 /* Needed to set errno for +-Inf, the add is a hack to work
94 around a gcc register allocation issue: just passing y
95 affects code generation in the fast path (PR86901). */
96 __math_invalidf (y + y);
97 #endif
98 }
99 }
100
101 #ifndef SINCOSF
102 libm_alias_float (__sincos, sincos)
103 #endif
104