/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8   -*-│
│ vi: set noet ft=c ts=8 sw=8 fenc=utf-8                                   :vi │
╚──────────────────────────────────────────────────────────────────────────────╝
│                                                                              │
│  Musl Libc                                                                   │
│  Copyright © 2005-2014 Rich Felker, et al.                                   │
│                                                                              │
│  Permission is hereby granted, free of charge, to any person obtaining       │
│  a copy of this software and associated documentation files (the             │
│  "Software"), to deal in the Software without restriction, including         │
│  without limitation the rights to use, copy, modify, merge, publish,         │
│  distribute, sublicense, and/or sell copies of the Software, and to          │
│  permit persons to whom the Software is furnished to do so, subject to       │
│  the following conditions:                                                   │
│                                                                              │
│  The above copyright notice and this permission notice shall be              │
│  included in all copies or substantial portions of the Software.             │
│                                                                              │
│  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,             │
│  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF          │
│  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.      │
│  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY        │
│  CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,        │
│  TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE           │
│  SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                      │
│                                                                              │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/complex.h"
#include "libc/math.h"
#include "libc/tinymath/kernel.internal.h"
#include "libc/tinymath/ldshape.internal.h"
#if !(LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024)
__static_yoink("musl_libc_notice");

/**
 * Returns cosine of 𝑥.
 */
long double cosl(long double x)
{
	union ldshape u = {x};
	unsigned n;
	long double y[2], hi, lo;

	u.i.se &= 0x7fff;
	if (u.i.se == 0x7fff)
		return x - x;
	x = u.f;
	if (x < M_PI_4) {
		if (u.i.se < 0x3fff - LDBL_MANT_DIG)
			/* raise inexact if x!=0 */
			return 1.0 + x;
		return __cosl(x, 0);
	}
	n = __rem_pio2l(x, y);
	hi = y[0];
	lo = y[1];
	switch (n & 3) {
	case 0:
		return __cosl(hi, lo);
	case 1:
		return -__sinl(hi, lo, 1);
	case 2:
		return -__cosl(hi, lo);
	case 3:
	default:
		return __sinl(hi, lo, 1);
	}
}

#endif /* long double is long */
