[BACK]Return to floatunditf_ieee754.c CVS log [TXT][DIR] Up to [cvs.NetBSD.org] / src / lib / libc / quad

File: [cvs.NetBSD.org] / src / lib / libc / quad / floatunditf_ieee754.c (download)

Revision 1.4, Sun Aug 5 04:28:58 2012 UTC (8 years, 1 month ago) by matt
Branch: MAIN
CVS Tags: yamt-pagecache-base9, yamt-pagecache-base8, yamt-pagecache-base7, yamt-pagecache-base6, 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, prg-localcount2-base3, prg-localcount2-base2, prg-localcount2-base1, prg-localcount2-base, prg-localcount2, phil-wifi-base, phil-wifi-20200421, phil-wifi-20200411, phil-wifi-20200406, phil-wifi-20191119, phil-wifi-20190609, phil-wifi, pgoyette-localcount-base, pgoyette-localcount-20170426, pgoyette-localcount-20170320, pgoyette-localcount-20170107, pgoyette-localcount-20161104, pgoyette-localcount-20160806, pgoyette-localcount-20160726, pgoyette-localcount, pgoyette-compat-merge-20190127, pgoyette-compat-base, pgoyette-compat-20190127, pgoyette-compat-20190118, pgoyette-compat-1226, pgoyette-compat-1126, pgoyette-compat-1020, pgoyette-compat-0930, pgoyette-compat-0906, pgoyette-compat-0728, pgoyette-compat-0625, pgoyette-compat-0521, pgoyette-compat-0502, pgoyette-compat-0422, pgoyette-compat-0415, pgoyette-compat-0407, pgoyette-compat-0330, pgoyette-compat-0322, pgoyette-compat-0315, pgoyette-compat, perseant-stdc-iso10646-base, perseant-stdc-iso10646, netbsd-9-base, netbsd-9-0-RELEASE, netbsd-9-0-RC2, netbsd-9-0-RC1, netbsd-9, netbsd-8-base, netbsd-8-2-RELEASE, netbsd-8-1-RELEASE, netbsd-8-1-RC1, netbsd-8-0-RELEASE, netbsd-8-0-RC2, netbsd-8-0-RC1, netbsd-8, netbsd-7-nhusb-base-20170116, netbsd-7-nhusb-base, netbsd-7-nhusb, netbsd-7-base, netbsd-7-2-RELEASE, netbsd-7-1-RELEASE, netbsd-7-1-RC2, netbsd-7-1-RC1, netbsd-7-1-2-RELEASE, netbsd-7-1-1-RELEASE, netbsd-7-1, netbsd-7-0-RELEASE, netbsd-7-0-RC3, netbsd-7-0-RC2, netbsd-7-0-RC1, netbsd-7-0-2-RELEASE, netbsd-7-0-1-RELEASE, netbsd-7-0, netbsd-7, matt-nb8-mediatek-base, matt-nb8-mediatek, localcount-20160914, is-mlppp-base, is-mlppp, bouyer-socketcan-base1, bouyer-socketcan-base, bouyer-socketcan, agc-symver-base, agc-symver, HEAD
Changes since 1.3: +6 -2 lines

If compiling for SOFTFLOAT, include "softfloat/softfloat-for-gcc.h" so we
can pick any redefinitions of the function (for ARM EABI).

/*	$NetBSD: floatunditf_ieee754.c,v 1.4 2012/08/05 04:28:58 matt Exp $	*/

/*-
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This software was developed by the Computer Systems Engineering group
 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
 * contributed to Berkeley.
 *
 * 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)floatunsdidf.c	8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: floatunditf_ieee754.c,v 1.4 2012/08/05 04:28:58 matt Exp $");
#endif
#endif /* LIBC_SCCS and not lint */

#ifdef SOFTFLOAT
#include "softfloat/softfloat-for-gcc.h"
#endif

#include "quad.h"
#ifdef __vax__
#error vax does not support a distinct long double
#endif
#include <machine/ieee.h>

/*
 * Convert (unsigned) quad to long double.
 * This is exactly like floatdidf.c except that negatives never occur.
 */
long double
__floatunditf(u_quad_t x)
{
#if 0
	long double ld;
	union uu u;

	u.uq = x;
	ld = (long double)u.ul[H] * (((int)1 << (INT_BITS - 2)) * 4.0);
	ld += u.ul[L];
	return (ld);
#else
	union ieee_ext_u extu;
	quad_t tmp = x;		/* must be signed */
	unsigned int width = 64;
	unsigned int bit = 0;
	quad_t mask = ~(quad_t)0;

	if (x == 0)
		return 0.0L;
	if (x == 1)
		return 1.0L;

	while (mask != 0 && (tmp >= 0)) {
		width >>= 1;
		mask <<= width;
		if ((tmp & mask) == 0) {
			tmp <<= width;
			bit += width;
		}
	}

	x <<= (bit + 1);
	extu.extu_sign = 0;
	extu.extu_exp = EXT_EXP_BIAS + (64 - (bit + 1));
	extu.extu_frach = (unsigned int)(x >> (64 - EXT_FRACHBITS));
	x <<= EXT_FRACHBITS;
#ifdef EXT_FRACHMBITS
	extu.extu_frachm =(unsigned int)(x >> (64 - EXT_FRACHMBITS));
	x <<= EXT_FRACHMBITS;
#endif
#ifdef EXT_FRACLMBITS
	extu.extu_fraclm =(unsigned int)(x >> (64 - EXT_FRACLMBITS));
	x <<= EXT_FRACLMBITS;
#endif
	extu.extu_fracl =(unsigned int)(x >> (64 - EXT_FRACLBITS));

	return extu.extu_ld;
#endif
}