1 /*
2 * Single-precision sin/cos function.
3 *
4 * Copyright (c) 2018-2019, Arm Limited.
5 * SPDX-License-Identifier: MIT
6 */
7
8 #include <stdint.h>
9 #include <math.h>
10 #include "math_config.h"
11 #include "sincosf.h"
12
13 /* Fast sincosf implementation. Worst-case ULP is 0.5607, maximum relative
14 error is 0.5303 * 2^-23. A single-step range reduction is used for
15 small values. Large inputs have their range reduced using fast integer
16 arithmetic. */
17 void
sincosf(float y,float * sinp,float * cosp)18 sincosf (float y, float *sinp, float *cosp)
19 {
20 double x = y;
21 double s;
22 int n;
23 const sincos_t *p = &__sincosf_table[0];
24
25 if (abstop12 (y) < abstop12 (pio4))
26 {
27 double x2 = x * x;
28
29 if (unlikely (abstop12 (y) < abstop12 (0x1p-12f)))
30 {
31 if (unlikely (abstop12 (y) < abstop12 (0x1p-126f)))
32 /* Force underflow for tiny y. */
33 force_eval_float (x2);
34 *sinp = y;
35 *cosp = 1.0f;
36 return;
37 }
38
39 sincosf_poly (x, x2, p, 0, sinp, cosp);
40 }
41 else if (abstop12 (y) < abstop12 (120.0f))
42 {
43 x = reduce_fast (x, p, &n);
44
45 /* Setup the signs for sin and cos. */
46 s = p->sign[n & 3];
47
48 if (n & 2)
49 p = &__sincosf_table[1];
50
51 sincosf_poly (x * s, x * x, p, n, sinp, cosp);
52 }
53 else if (likely (abstop12 (y) < abstop12 (INFINITY)))
54 {
55 uint32_t xi = asuint (y);
56 int sign = xi >> 31;
57
58 x = reduce_large (xi, &n);
59
60 /* Setup signs for sin and cos - include original sign. */
61 s = p->sign[(n + sign) & 3];
62
63 if ((n + sign) & 2)
64 p = &__sincosf_table[1];
65
66 sincosf_poly (x * s, x * x, p, n, sinp, cosp);
67 }
68 else
69 {
70 /* Return NaN if Inf or NaN for both sin and cos. */
71 *sinp = *cosp = y - y;
72 #if WANT_ERRNO
73 /* Needed to set errno for +-Inf, the add is a hack to work
74 around a gcc register allocation issue: just passing y
75 affects code generation in the fast path. */
76 __math_invalidf (y + y);
77 #endif
78 }
79 }
80