root/usr/src/uts/sparc/fpu/compare.c
/*
 * 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);
}