1 /*-
2 * Copyright (c) 2017,2023 Steven G. Kargl
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice unmodified, this list of conditions, and the following
10 * disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 /*
28 * See ../src/s_sinpi.c for implementation details.
29 */
30
31 #define INLINE_KERNEL_SINDF
32 #define INLINE_KERNEL_COSDF
33
34 #include "math.h"
35 #include "math_private.h"
36 #include "k_cosf.c"
37 #include "k_sinf.c"
38
39 #define __kernel_cospif(x) (__kernel_cosdf(M_PI * (x)))
40 #define __kernel_sinpif(x) (__kernel_sindf(M_PI * (x)))
41
42 static const float
43 pi_hi = 3.14160156e+00F, /* 0x40491000 */
44 pi_lo = -8.90890988e-06F; /* 0xb715777a */
45
46 volatile static const float vzero = 0;
47
48 float
sinpif(float x)49 sinpif(float x)
50 {
51 float ax, hi, lo, s;
52 uint32_t hx, ix, j0;
53
54 GET_FLOAT_WORD(hx, x);
55 ix = hx & 0x7fffffff;
56 SET_FLOAT_WORD(ax, ix);
57
58 if (ix < 0x3f800000) { /* |x| < 1 */
59 if (ix < 0x3e800000) { /* |x| < 0.25 */
60 if (ix < 0x38800000) { /* |x| < 0x1p-14 */
61 if (x == 0)
62 return (x);
63 SET_FLOAT_WORD(hi, hx & 0xffff0000);
64 hi *= 0x1p23F;
65 lo = x * 0x1p23F - hi;
66 s = (pi_lo + pi_hi) * lo + pi_lo * hi +
67 pi_hi * hi;
68 return (s * 0x1p-23F);
69 }
70
71 s = __kernel_sinpif(ax);
72 return ((hx & 0x80000000) ? -s : s);
73 }
74
75 if (ix < 0x3f000000) /* |x| < 0.5 */
76 s = __kernel_cospif(0.5F - ax);
77 else if (ix < 0x3f400000) /* |x| < 0.75 */
78 s = __kernel_cospif(ax - 0.5F);
79 else
80 s = __kernel_sinpif(1 - ax);
81 return ((hx & 0x80000000) ? -s : s);
82 }
83
84 if (ix < 0x4b000000) { /* 1 <= |x| < 0x1p23 */
85 FFLOORF(x, j0, ix); /* Integer part of ax. */
86 ax -= x;
87 GET_FLOAT_WORD(ix, ax);
88
89 if (ix == 0)
90 s = 0;
91 else {
92 if (ix < 0x3f000000) { /* |x| < 0.5 */
93 if (ix < 0x3e800000) /* |x| < 0.25 */
94 s = __kernel_sinpif(ax);
95 else
96 s = __kernel_cospif(0.5F - ax);
97 } else {
98 if (ix < 0x3f400000) /* |x| < 0.75 */
99 s = __kernel_cospif(ax - 0.5F);
100 else
101 s = __kernel_sinpif(1 - ax);
102 }
103
104 j0 = (uint32_t)x;
105 s = (j0 & 1) ? -s : s;
106 }
107 return ((hx & 0x80000000) ? -s : s);
108 }
109
110 /* x = +-inf or nan. */
111 if (ix >= 0x7f800000)
112 return (vzero / vzero);
113
114 /*
115 * |x| >= 0x1p23 is always an integer, so return +-0.
116 */
117 return (copysignf(0, x));
118 }
119