1 /*
2 * Single-precision sin/cos 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 <stdint.h>
9 #include <math.h>
10 #include "math_config.h"
11 #include "sincosf.h"
12 #include "test_defs.h"
13
14 /* Fast sincosf 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 void
sincosf(float y,float * sinp,float * cosp)19 sincosf (float y, float *sinp, float *cosp)
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 double x2 = 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 (x2);
35 *sinp = y;
36 *cosp = 1.0f;
37 return;
38 }
39
40 sincosf_poly (x, x2, p, 0, sinp, cosp);
41 }
42 else if (abstop12 (y) < abstop12 (120.0f))
43 {
44 x = reduce_fast (x, p, &n);
45
46 /* Setup the signs for sin and cos. */
47 s = p->sign[n & 3];
48
49 if (n & 2)
50 p = &__sincosf_table[1];
51
52 sincosf_poly (x * s, x * x, p, n, sinp, cosp);
53 }
54 else if (likely (abstop12 (y) < abstop12 (INFINITY)))
55 {
56 uint32_t xi = asuint (y);
57 int sign = xi >> 31;
58
59 x = reduce_large (xi, &n);
60
61 /* Setup signs for sin and cos - include original sign. */
62 s = p->sign[(n + sign) & 3];
63
64 if ((n + sign) & 2)
65 p = &__sincosf_table[1];
66
67 sincosf_poly (x * s, x * x, p, n, sinp, cosp);
68 }
69 else
70 {
71 /* Return NaN if Inf or NaN for both sin and cos. */
72 *sinp = *cosp = y - y;
73 #if WANT_ERRNO
74 /* Needed to set errno for +-Inf, the add is a hack to work
75 around a gcc register allocation issue: just passing y
76 affects code generation in the fast path. */
77 __math_invalidf (y + y);
78 #endif
79 }
80 }
81
82 TEST_ULP (sincosf_sinf, 0.06)
83 TEST_ULP (sincosf_cosf, 0.06)
84 TEST_ULP_NONNEAREST (sincosf_sinf, 0.5)
85 TEST_ULP_NONNEAREST (sincosf_cosf, 0.5)
86 TEST_INTERVAL (sincosf_sinf, 0, 0xffff0000, 10000)
87 TEST_SYM_INTERVAL (sincosf_sinf, 0x1p-14, 0x1p54, 50000)
88 TEST_INTERVAL (sincosf_cosf, 0, 0xffff0000, 10000)
89 TEST_SYM_INTERVAL (sincosf_cosf, 0x1p-14, 0x1p54, 50000)
90