/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (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 2011 Nexenta Systems, Inc.  All rights reserved.
 */
/*
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma weak __nextafterl = nextafterl

#include "libm.h"
#include <float.h>              /* LDBL_MAX, LDBL_MIN */

#if defined(__sparc)
#define n0      0
#define n1      1
#define n2      2
#define n3      3
#define X86PDNRM1(x)
#define INC(px) { \
                        if (++px[n3] == 0) \
                                if (++px[n2] == 0) \
                                        if (++px[n1] == 0) \
                                                ++px[n0]; \
                }
#define DEC(px) { \
                        if (--px[n3] == 0xffffffff) \
                                if (--px[n2] == 0xffffffff) \
                                        if (--px[n1] == 0xffffffff) \
                                                --px[n0]; \
                }
#elif defined(__x86)
#define n0      2
#define n1      1
#define n2      0
#define n3      0
/*
 * if pseudo-denormal, replace by the equivalent normal
 */
#define X86PDNRM1(x)    if (XBIASED_EXP(x) == 0 && (((int *) &x)[1] & \
                                0x80000000) != 0) \
                                ((int *) &x)[2] |= 1
#define INC(px) { \
                        if (++px[n2] == 0) \
                                if ((++px[n1] & ~0x80000000) == 0) \
                                        px[n1] = 0x80000000, ++px[n0]; \
                }
#define DEC(px) { \
                        if (--px[n2] == 0xffffffff) \
                                if (--px[n1] == 0x7fffffff) \
                                        if ((--px[n0] & 0x7fff) != 0) \
                                                px[n1] |= 0x80000000; \
                }
#endif

long double
nextafterl(long double x, long double y) {
        int *px = (int *) &x;
        int *py = (int *) &y;

        if (x == y)
                return (y);             /* C99 requirement */
        if (x != x || y != y)
                return (x * y);

        if (ISZEROL(x)) {       /* x == 0.0 */
                px[n0] = py[n0] & XSGNMSK;
                px[n1] = px[n2] = 0;
                px[n3] = 1;
        } else {
                X86PDNRM1(x);
                if ((px[n0] & XSGNMSK) == 0) {  /* x > 0.0 */
                        if (x > y)      /* x > y */
                                DEC(px)
                        else
                                INC(px)
                } else {
                        if (x < y)      /* x < y */
                                DEC(px)
                        else
                                INC(px)
                }
        }
#ifndef lint
        {
                volatile long double dummy __unused;
                int k = XBIASED_EXP(x);

                if (k == 0)
                        dummy = LDBL_MIN * copysignl(LDBL_MIN, x);
                else if (k == 0x7fff)
                        dummy = LDBL_MAX * copysignl(LDBL_MAX, x);
        }
#endif
        return (x);
}