xref: /illumos-gate/usr/src/uts/sparc/fpu/compare.c (revision 7c478bd9)

/*
 * 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) 1986 by Sun Microsystems, Inc.
 */
#ident	"%Z%%M%	%I%	%E% SMI"	/* SunOS-4.1 1.7 88/12/06 */

#include <sys/fpu/fpu_simulator.h>
#include <sys/fpu/globals.h>

enum fcc_type
_fp_compare(pfpsd, px, py, strict)
	fp_simd_type	*pfpsd;	/* simulator data */
	unpacked	*px, *py;
	int		strict;
				/*
				 * 0 if quiet NaN unexceptional, 1 if
				 * exceptional
				 */
{
	enum fcc_type   cc;
	int  n;

	if ((px->fpclass == fp_quiet) || (py->fpclass == fp_quiet) ||
	    (px->fpclass == fp_signaling) || (py->fpclass == fp_signaling)) {
		if (strict)				/* NaN */
			fpu_set_exception(pfpsd, fp_invalid);
		cc = fcc_unordered;
	} else if ((px->fpclass == fp_zero) && (py->fpclass == fp_zero))
		cc = fcc_equal;
	/* both zeros */
	else if (px->sign < py->sign)
		cc = fcc_greater;
	else if (px->sign > py->sign)
		cc = fcc_less;
	else {			/* signs the same, compute magnitude cc */
		if ((int) px->fpclass > (int) py->fpclass)
			cc = fcc_greater;
		else if ((int) px->fpclass < (int) py->fpclass)
			cc = fcc_less;
		else
		/* same classes */ if (px->fpclass == fp_infinity)
			cc = fcc_equal;	/* same infinity */
		else if (px->exponent > py->exponent)
			cc = fcc_greater;
		else if (px->exponent < py->exponent)
			cc = fcc_less;
		else {	/* equal exponents */
			n = fpu_cmpli(px->significand, py->significand, 4);
			if (n > 0) cc = fcc_greater;
			else if (n < 0) cc = fcc_less;
			else cc = fcc_equal;
		}
		if (px->sign)
			switch (cc) {	/* negative numbers */
			case fcc_less:
				cc = fcc_greater;
				break;
			case fcc_greater:
				cc = fcc_less;
				break;
			}
	}
	return (cc);
}