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

asm(".ident\t\"\\n\\n\
Musl libc (MIT License)\\n\
Copyright 2005-2014 Rich Felker, et. al.\"");
asm(".include \"libc/disclaimer.inc\"");
// clang-format off

#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
long double modfl(long double x, long double *iptr)
{
	double d;
	long double r;

	r = modf(x, &d);
	*iptr = d;
	return r;
}
#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384

static const long double toint = 1/LDBL_EPSILON;

long double modfl(long double x, long double *iptr)
{
	union {
		long double f;
		struct {
			uint64_t m;
			uint16_t se;
		} i;
	} u = {x};
	int e = (u.i.se & 0x7fff) - 0x3fff;
	int s = u.i.se >> 15;
	long double absx;
	long double y;

	/* no fractional part */
	if (e >= LDBL_MANT_DIG-1) {
		*iptr = x;
		if (isnan(x))
			return x;
		return s ? -0.0 : 0.0;
	}

	/* no integral part*/
	if (e < 0) {
		*iptr = s ? -0.0 : 0.0;
		return x;
	}

	/* raises spurious inexact */
	absx = s ? -x : x;
	y = absx + toint - toint - absx;
	if (y == 0) {
		*iptr = x;
		return s ? -0.0 : 0.0;
	}
	if (y > 0)
		y -= 1;
	if (s)
		y = -y;
	*iptr = x + y;
	return -y;
}

#else
#error "architecture unsupported"
#endif
