1 /*
2 * Single-precision sin function.
3 *
4 * Copyright (c) 2018-2024, Arm Limited.
5 * SPDX-License-Identifier: MIT OR Apache-2.0 WITH LLVM-exception
6 */
7
8 #include <math.h>
9 #include "math_config.h"
10 #include "sincosf.h"
11 #include "test_defs.h"
12 #include "test_sig.h"
13
14 /* Fast sinf implementation. Worst-case ULP is 0.5607, maximum relative
15 error is 0.5303 * 2^-23. A single-step range reduction is used for
16 small values. Large inputs have their range reduced using fast integer
17 arithmetic. */
18 float
sinf(float y)19 sinf (float y)
20 {
21 double x = y;
22 double s;
23 int n;
24 const sincos_t *p = &__sincosf_table[0];
25
26 if (abstop12 (y) < abstop12 (pio4f))
27 {
28 s = x * x;
29
30 if (unlikely (abstop12 (y) < abstop12 (0x1p-12f)))
31 {
32 if (unlikely (abstop12 (y) < abstop12 (0x1p-126f)))
33 /* Force underflow for tiny y. */
34 force_eval_float (s);
35 return y;
36 }
37
38 return sinf_poly (x, s, p, 0);
39 }
40 else if (likely (abstop12 (y) < abstop12 (120.0f)))
41 {
42 x = reduce_fast (x, p, &n);
43
44 /* Setup the signs for sin and cos. */
45 s = p->sign[n & 3];
46
47 if (n & 2)
48 p = &__sincosf_table[1];
49
50 return sinf_poly (x * s, x * x, p, n);
51 }
52 else if (abstop12 (y) < abstop12 (INFINITY))
53 {
54 uint32_t xi = asuint (y);
55 int sign = xi >> 31;
56
57 x = reduce_large (xi, &n);
58
59 /* Setup signs for sin and cos - include original sign. */
60 s = p->sign[(n + sign) & 3];
61
62 if ((n + sign) & 2)
63 p = &__sincosf_table[1];
64
65 return sinf_poly (x * s, x * x, p, n);
66 }
67 else
68 return __math_invalidf (y);
69 }
70
71 TEST_SIG (S, F, 1, sin, -3.1, 3.1)
72 TEST_ULP (sinf, 0.06)
73 TEST_ULP_NONNEAREST (sinf, 0.5)
74 TEST_INTERVAL (sinf, 0, 0xffff0000, 10000)
75 TEST_SYM_INTERVAL (sinf, 0x1p-14, 0x1p54, 50000)
76