1/*
2 * Single-precision sin/cos function.
3 *
4 * Copyright (c) 2018-2021, 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
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.  */
17void
18sincosf (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 (pio4f))
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