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Revision 1.4, Sat Apr 26 23:49:50 2008 UTC (6 years, 4 months ago) by christos
Branch: MAIN
CVS Tags: yamt-pf42-base4, yamt-pf42-base3, yamt-pf42-base2, yamt-pagecache-tag8, yamt-pagecache-base9, yamt-pagecache-base8, yamt-pagecache-base7, yamt-pagecache-base6, yamt-pagecache-base5, yamt-pagecache-base4, yamt-pagecache-base3, yamt-pagecache-base2, yamt-pagecache-base, yamt-pagecache, wrstuden-revivesa-base-3, wrstuden-revivesa-base-2, wrstuden-revivesa-base-1, wrstuden-revivesa-base, wrstuden-revivesa, tls-maxphys-base, tls-maxphys, tls-earlyentropy-base, tls-earlyentropy, riastradh-xf86-video-intel-2-7-1-pre-2-21-15, riastradh-drm2-base3, riastradh-drm2-base2, riastradh-drm2-base1, riastradh-drm2-base, riastradh-drm2, netbsd-7-base, netbsd-7, netbsd-6-base, netbsd-6-1-RELEASE, netbsd-6-1-RC4, netbsd-6-1-RC3, netbsd-6-1-RC2, netbsd-6-1-RC1, netbsd-6-1-4-RELEASE, netbsd-6-1-3-RELEASE, netbsd-6-1-2-RELEASE, netbsd-6-1-1-RELEASE, netbsd-6-1, netbsd-6-0-RELEASE, netbsd-6-0-RC2, netbsd-6-0-RC1, netbsd-6-0-5-RELEASE, netbsd-6-0-4-RELEASE, netbsd-6-0-3-RELEASE, netbsd-6-0-2-RELEASE, netbsd-6-0-1-RELEASE, netbsd-6-0, netbsd-6, netbsd-5-base, netbsd-5-2-RELEASE, netbsd-5-2-RC1, netbsd-5-2-2-RELEASE, netbsd-5-2-1-RELEASE, netbsd-5-2, netbsd-5-1-RELEASE, netbsd-5-1-RC4, netbsd-5-1-RC3, netbsd-5-1-RC2, netbsd-5-1-RC1, netbsd-5-1-4-RELEASE, netbsd-5-1-3-RELEASE, netbsd-5-1-2-RELEASE, netbsd-5-1-1-RELEASE, netbsd-5-1, netbsd-5-0-RELEASE, netbsd-5-0-RC4, netbsd-5-0-RC3, netbsd-5-0-RC2, netbsd-5-0-RC1, netbsd-5-0-2-RELEASE, netbsd-5-0-1-RELEASE, netbsd-5-0, netbsd-5, matt-premerge-20091211, matt-nb6-plus-nbase, matt-nb6-plus-base, matt-nb6-plus, matt-nb5-pq3-base, matt-nb5-pq3, matt-nb5-mips64-u2-k2-k4-k7-k8-k9, matt-nb5-mips64-u1-k1-k5, matt-nb5-mips64-premerge-20101231, matt-nb5-mips64-premerge-20091211, matt-nb5-mips64-k15, matt-nb5-mips64, matt-nb4-mips64-k7-u2a-k9b, matt-mips64-premerge-20101231, matt-mips64-base2, jym-xensuspend-nbase, jym-xensuspend-base, jym-xensuspend, hpcarm-cleanup-nbase, cherry-xenmp-base, cherry-xenmp, bouyer-quota2-nbase, bouyer-quota2-base, bouyer-quota2, agc-symver-base, agc-symver, HEAD
Changes since 1.3: +2 -2 lines

pass a little lint.

/* $NetBSD: lrint.c,v 1.4 2008/04/26 23:49:50 christos Exp $ */

/*-
 * Copyright (c) 2004
 *	Matthias Drochner. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <math.h>
#include <sys/ieee754.h>
#include <machine/limits.h>
#include "math_private.h"

#ifndef LRINTNAME
#define LRINTNAME lrint
#define RESTYPE long int
#define RESTYPE_MIN LONG_MIN
#define RESTYPE_MAX LONG_MAX
#endif

#define RESTYPE_BITS (sizeof(RESTYPE) * 8)

static const double
TWO52[2]={
  4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
 -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */
};

RESTYPE
LRINTNAME(double x)
{
	u_int32_t i0, i1;
	int e, s, shift;
	RESTYPE res;

	GET_HIGH_WORD(i0, x);
	e = i0 >> 20;
	s = (uint32_t)e >> DBL_EXPBITS;
	e = (e & 0x7ff) - DBL_EXP_BIAS;

	/* 1.0 x 2^-1 is the smallest number which can be rounded to 1 */
	if (e < -1)
		return (0);
	/* 1.0 x 2^31 (or 2^63) is already too large */
	if (e >= (int)RESTYPE_BITS - 1)
		return (s ? RESTYPE_MIN : RESTYPE_MAX); /* ??? unspecified */

	/* >= 2^52 is already an exact integer */
	if (e < DBL_FRACBITS) {
		/* round, using current direction */
		x += TWO52[s];
		x -= TWO52[s];
	}

	EXTRACT_WORDS(i0, i1, x);
	e = ((i0 >> 20) & 0x7ff) - DBL_EXP_BIAS;
	i0 &= 0xfffff;
	i0 |= (1 << 20);

	shift = e - DBL_FRACBITS;
	if (shift >=0)
		res = (shift < 32 ? (RESTYPE)i1 << shift : 0);
	else
		res = (shift > -32 ? i1 >> -shift : 0);
	shift += 32;
	if (shift >=0)
		res |= (shift < 32 ? (RESTYPE)i0 << shift : 0);
	else
		res |= (shift > -32 ? i0 >> -shift : 0);

	return (s ? -res : res);
}