xref: /freebsd/contrib/arm-optimized-routines/math/sincosf.c (revision dd21556857e8d40f66bf5ad54754d9d52669ebf7)
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
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