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
42static const float
43pi_hi =  3.14160156e+00F,	/* 0x40491000 */
44pi_lo = -8.90890988e-06F;	/* 0xb715777a */
45
46volatile static const float vzero = 0;
47
48float
49sinpif(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