1/* origin: FreeBSD /usr/src/lib/msun/src/s_sinf.c */
2/*
3 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
4 * Optimized by Bruce D. Evans.
5 */
6/*
7 * ====================================================
8 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
9 *
10 * Developed at SunPro, a Sun Microsystems, Inc. business.
11 * Permission to use, copy, modify, and distribute this
12 * software is freely granted, provided that this notice
13 * is preserved.
14 * ====================================================
15 */
16
17#define _GNU_SOURCE
18#include "libm.h"
19
20/* Small multiples of pi/2 rounded to double precision. */
21static const double
22s1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */
23s2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */
24s3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */
25s4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */
26
27void sincosf(float x, float *sin, float *cos)
28{
29	double y;
30	float_t s, c;
31	uint32_t ix;
32	unsigned n, sign;
33
34	GET_FLOAT_WORD(ix, x);
35	sign = ix >> 31;
36	ix &= 0x7fffffff;
37
38	/* |x| ~<= pi/4 */
39	if (ix <= 0x3f490fda) {
40		/* |x| < 2**-12 */
41		if (ix < 0x39800000) {
42			/* raise inexact if x!=0 and underflow if subnormal */
43			FORCE_EVAL(ix < 0x00100000 ? x/0x1p120f : x+0x1p120f);
44			*sin = x;
45			*cos = 1.0f;
46			return;
47		}
48		*sin = __sindf(x);
49		*cos = __cosdf(x);
50		return;
51	}
52
53	/* |x| ~<= 5*pi/4 */
54	if (ix <= 0x407b53d1) {
55		if (ix <= 0x4016cbe3) {  /* |x| ~<= 3pi/4 */
56			if (sign) {
57				*sin = -__cosdf(x + s1pio2);
58				*cos = __sindf(x + s1pio2);
59			} else {
60				*sin = __cosdf(s1pio2 - x);
61				*cos = __sindf(s1pio2 - x);
62			}
63			return;
64		}
65		/* -sin(x+c) is not correct if x+c could be 0: -0 vs +0 */
66		*sin = -__sindf(sign ? x + s2pio2 : x - s2pio2);
67		*cos = -__cosdf(sign ? x + s2pio2 : x - s2pio2);
68		return;
69	}
70
71	/* |x| ~<= 9*pi/4 */
72	if (ix <= 0x40e231d5) {
73		if (ix <= 0x40afeddf) {  /* |x| ~<= 7*pi/4 */
74			if (sign) {
75				*sin = __cosdf(x + s3pio2);
76				*cos = -__sindf(x + s3pio2);
77			} else {
78				*sin = -__cosdf(x - s3pio2);
79				*cos = __sindf(x - s3pio2);
80			}
81			return;
82		}
83		*sin = __sindf(sign ? x + s4pio2 : x - s4pio2);
84		*cos = __cosdf(sign ? x + s4pio2 : x - s4pio2);
85		return;
86	}
87
88	/* sin(Inf or NaN) is NaN */
89	if (ix >= 0x7f800000) {
90		*sin = *cos = x - x;
91		return;
92	}
93
94	/* general argument reduction needed */
95	n = __rem_pio2f(x, &y);
96	s = __sindf(y);
97	c = __cosdf(y);
98	switch (n&3) {
99	case 0:
100		*sin = s;
101		*cos = c;
102		break;
103	case 1:
104		*sin = c;
105		*cos = -s;
106		break;
107	case 2:
108		*sin = -s;
109		*cos = -c;
110		break;
111	case 3:
112	default:
113		*sin = -c;
114		*cos = s;
115		break;
116	}
117}
118