xref: /illumos-gate/usr/src/lib/libc/sparcv9/fp/_Qp_uxtoq.c (revision 1da57d55)

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 1994-1997, by Sun Microsystems, Inc.
 * All rights reserved.
 */

#include "quad.h"

/*
 * _Qp_uxtoq(pz, x) sets *pz = (long double)x.
 */
void
_Qp_uxtoq(union longdouble *pz, unsigned long x)
{
	unsigned int	e;

	/* test for zero */
	if (x == 0) {
		Z.l.msw = Z.l.frac2 = Z.l.frac3 = Z.l.frac4 = 0;
		QUAD_RETURN(Z);
	}

	/* find the most significant bit */
	for (e = 63; (x & (1l << e)) == 0; e--)
		;

	if (e > 48) {
		Z.l.msw = (x >> (e - 16)) & 0xffff;
		Z.l.frac2 = x >> (e - 48);
		Z.l.frac3 = x << (80 - e);
	} else if (e > 16) {
		Z.l.msw = (x >> (e - 16)) & 0xffff;
		Z.l.frac2 = x << (48 - e);
		Z.l.frac3 = 0;
	} else {
		Z.l.msw = (x << (16 - e)) & 0xffff;
		Z.l.frac2 = Z.l.frac3 = 0;
	}
	Z.l.frac4 = 0;
	Z.l.msw |= ((e + 0x3fff) << 16);
	QUAD_RETURN(Z);
}