/*
 * 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 fmal = __fmal

#include "libm.h"
#include "fma.h"
#include "fenv_inlines.h"

#if defined(__sparc)

static const union {
        unsigned i[2];
        double d;
} C[] = {
        { 0x3fe00000u, 0 },
        { 0x40000000u, 0 },
        { 0x3ef00000u, 0 },
        { 0x3e700000u, 0 },
        { 0x41300000u, 0 },
        { 0x3e300000u, 0 },
        { 0x3b300000u, 0 },
        { 0x38300000u, 0 },
        { 0x42300000u, 0 },
        { 0x3df00000u, 0 },
        { 0x7fe00000u, 0 },
        { 0x00100000u, 0 },
        { 0x00100001u, 0 },
        { 0, 0 },
        { 0x7ff00000u, 0 },
        { 0x7ff00001u, 0 }
};

#define half    C[0].d
#define two     C[1].d
#define twom16  C[2].d
#define twom24  C[3].d
#define two20   C[4].d
#define twom28  C[5].d
#define twom76  C[6].d
#define twom124 C[7].d
#define two36   C[8].d
#define twom32  C[9].d
#define huge    C[10].d
#define tiny    C[11].d
#define tiny2   C[12].d
#define zero    C[13].d
#define inf     C[14].d
#define snan    C[15].d

static const unsigned int fsr_rm = 0xc0000000u;

/*
 * fmal for SPARC: 128-bit quad precision, big-endian
 */
long double
__fmal(long double x, long double y, long double z) {
        union {
                unsigned int i[4];
                long double q;
        } xx, yy, zz;
        union {
                unsigned int i[2];
                double d;
        } u;
        double dx[5], dy[5], dxy[9], c, s;
        unsigned int xy0, xy1, xy2, xy3, xy4, xy5, xy6, xy7;
        unsigned int z0, z1, z2, z3, z4, z5, z6, z7;
        unsigned int rm, sticky;
        unsigned int fsr;
        int hx, hy, hz, ex, ey, ez, exy, sxy, sz, e, ibit;
        int cx, cy, cz;
        volatile double dummy;

        /* extract the high order words of the arguments */
        xx.q = x;
        yy.q = y;
        zz.q = z;
        hx = xx.i[0] & ~0x80000000;
        hy = yy.i[0] & ~0x80000000;
        hz = zz.i[0] & ~0x80000000;

        /*
         * distinguish zero, finite nonzero, infinite, and quiet nan
         * arguments; raise invalid and return for signaling nans
         */
        if (hx >= 0x7fff0000) {
                if ((hx & 0xffff) | xx.i[1] | xx.i[2] | xx.i[3]) {
                        if (!(hx & 0x8000)) {
                                /* signaling nan, raise invalid */
                                dummy = snan;
                                dummy += snan;
                                xx.i[0] |= 0x8000;
                                return (xx.q);
                        }
                        cx = 3; /* quiet nan */
                } else
                        cx = 2; /* inf */
        } else if (hx == 0) {
                cx = (xx.i[1] | xx.i[2] | xx.i[3]) ? 1 : 0;
                                /* subnormal or zero */
        } else
                cx = 1;         /* finite nonzero */

        if (hy >= 0x7fff0000) {
                if ((hy & 0xffff) | yy.i[1] | yy.i[2] | yy.i[3]) {
                        if (!(hy & 0x8000)) {
                                dummy = snan;
                                dummy += snan;
                                yy.i[0] |= 0x8000;
                                return (yy.q);
                        }
                        cy = 3;
                } else
                        cy = 2;
        } else if (hy == 0) {
                cy = (yy.i[1] | yy.i[2] | yy.i[3]) ? 1 : 0;
        } else
                cy = 1;

        if (hz >= 0x7fff0000) {
                if ((hz & 0xffff) | zz.i[1] | zz.i[2] | zz.i[3]) {
                        if (!(hz & 0x8000)) {
                                dummy = snan;
                                dummy += snan;
                                zz.i[0] |= 0x8000;
                                return (zz.q);
                        }
                        cz = 3;
                } else
                        cz = 2;
        } else if (hz == 0) {
                cz = (zz.i[1] | zz.i[2] | zz.i[3]) ? 1 : 0;
        } else
                cz = 1;

        /* get the fsr and clear current exceptions */
        __fenv_getfsr32(&fsr);
        fsr &= ~FSR_CEXC;

        /* handle all other zero, inf, and nan cases */
        if (cx != 1 || cy != 1 || cz != 1) {
                /* if x or y is a quiet nan, return it */
                if (cx == 3) {
                        __fenv_setfsr32(&fsr);
                        return (x);
                }
                if (cy == 3) {
                        __fenv_setfsr32(&fsr);
                        return (y);
                }

                /* if x*y is 0*inf, raise invalid and return the default nan */
                if ((cx == 0 && cy == 2) || (cx == 2 && cy == 0)) {
                        dummy = zero;
                        dummy *= inf;
                        zz.i[0] = 0x7fffffff;
                        zz.i[1] = zz.i[2] = zz.i[3] = 0xffffffff;
                        return (zz.q);
                }

                /* if z is a quiet nan, return it */
                if (cz == 3) {
                        __fenv_setfsr32(&fsr);
                        return (z);
                }

                /*
                 * now none of x, y, or z is nan; handle cases where x or y
                 * is inf
                 */
                if (cx == 2 || cy == 2) {
                        /*
                         * if z is also inf, either we have inf-inf or
                         * the result is the same as z depending on signs
                         */
                        if (cz == 2) {
                                if ((int) ((xx.i[0] ^ yy.i[0]) ^ zz.i[0]) < 0) {
                                        dummy = inf;
                                        dummy -= inf;
                                        zz.i[0] = 0x7fffffff;
                                        zz.i[1] = zz.i[2] = zz.i[3] =
                                                0xffffffff;
                                        return (zz.q);
                                }
                                __fenv_setfsr32(&fsr);
                                return (z);
                        }

                        /* otherwise the result is inf with appropriate sign */
                        zz.i[0] = ((xx.i[0] ^ yy.i[0]) & 0x80000000) |
                                0x7fff0000;
                        zz.i[1] = zz.i[2] = zz.i[3] = 0;
                        __fenv_setfsr32(&fsr);
                        return (zz.q);
                }

                /* if z is inf, return it */
                if (cz == 2) {
                        __fenv_setfsr32(&fsr);
                        return (z);
                }

                /*
                 * now x, y, and z are all finite; handle cases where x or y
                 * is zero
                 */
                if (cx == 0 || cy == 0) {
                        /* either we have 0-0 or the result is the same as z */
                        if (cz == 0 && (int) ((xx.i[0] ^ yy.i[0]) ^ zz.i[0]) <
                                0) {
                                zz.i[0] = (fsr >> 30) == FSR_RM ? 0x80000000 :
                                        0;
                                __fenv_setfsr32(&fsr);
                                return (zz.q);
                        }
                        __fenv_setfsr32(&fsr);
                        return (z);
                }

                /* if we get here, x and y are nonzero finite, z must be zero */
                return (x * y);
        }

        /*
         * now x, y, and z are all finite and nonzero; set round-to-
         * negative-infinity mode
         */
        __fenv_setfsr32(&fsr_rm);

        /*
         * get the signs and exponents and normalize the significands
         * of x and y
         */
        sxy = (xx.i[0] ^ yy.i[0]) & 0x80000000;
        ex = hx >> 16;
        hx &= 0xffff;
        if (!ex) {
                if (hx | (xx.i[1] & 0xfffe0000)) {
                        ex = 1;
                } else if (xx.i[1] | (xx.i[2] & 0xfffe0000)) {
                        hx = xx.i[1];
                        xx.i[1] = xx.i[2];
                        xx.i[2] = xx.i[3];
                        xx.i[3] = 0;
                        ex = -31;
                } else if (xx.i[2] | (xx.i[3] & 0xfffe0000)) {
                        hx = xx.i[2];
                        xx.i[1] = xx.i[3];
                        xx.i[2] = xx.i[3] = 0;
                        ex = -63;
                } else {
                        hx = xx.i[3];
                        xx.i[1] = xx.i[2] = xx.i[3] = 0;
                        ex = -95;
                }
                while ((hx & 0x10000) == 0) {
                        hx = (hx << 1) | (xx.i[1] >> 31);
                        xx.i[1] = (xx.i[1] << 1) | (xx.i[2] >> 31);
                        xx.i[2] = (xx.i[2] << 1) | (xx.i[3] >> 31);
                        xx.i[3] <<= 1;
                        ex--;
                }
        } else
                hx |= 0x10000;
        ey = hy >> 16;
        hy &= 0xffff;
        if (!ey) {
                if (hy | (yy.i[1] & 0xfffe0000)) {
                        ey = 1;
                } else if (yy.i[1] | (yy.i[2] & 0xfffe0000)) {
                        hy = yy.i[1];
                        yy.i[1] = yy.i[2];
                        yy.i[2] = yy.i[3];
                        yy.i[3] = 0;
                        ey = -31;
                } else if (yy.i[2] | (yy.i[3] & 0xfffe0000)) {
                        hy = yy.i[2];
                        yy.i[1] = yy.i[3];
                        yy.i[2] = yy.i[3] = 0;
                        ey = -63;
                } else {
                        hy = yy.i[3];
                        yy.i[1] = yy.i[2] = yy.i[3] = 0;
                        ey = -95;
                }
                while ((hy & 0x10000) == 0) {
                        hy = (hy << 1) | (yy.i[1] >> 31);
                        yy.i[1] = (yy.i[1] << 1) | (yy.i[2] >> 31);
                        yy.i[2] = (yy.i[2] << 1) | (yy.i[3] >> 31);
                        yy.i[3] <<= 1;
                        ey--;
                }
        } else
                hy |= 0x10000;
        exy = ex + ey - 0x3fff;

        /* convert the significands of x and y to doubles */
        c = twom16;
        dx[0] = (double) ((int) hx) * c;
        dy[0] = (double) ((int) hy) * c;

        c *= twom24;
        dx[1] = (double) ((int) (xx.i[1] >> 8)) * c;
        dy[1] = (double) ((int) (yy.i[1] >> 8)) * c;

        c *= twom24;
        dx[2] = (double) ((int) (((xx.i[1] << 16) | (xx.i[2] >> 16)) &
            0xffffff)) * c;
        dy[2] = (double) ((int) (((yy.i[1] << 16) | (yy.i[2] >> 16)) &
            0xffffff)) * c;

        c *= twom24;
        dx[3] = (double) ((int) (((xx.i[2] << 8) | (xx.i[3] >> 24)) &
            0xffffff)) * c;
        dy[3] = (double) ((int) (((yy.i[2] << 8) | (yy.i[3] >> 24)) &
            0xffffff)) * c;

        c *= twom24;
        dx[4] = (double) ((int) (xx.i[3] & 0xffffff)) * c;
        dy[4] = (double) ((int) (yy.i[3] & 0xffffff)) * c;

        /* form the "digits" of the product */
        dxy[0] = dx[0] * dy[0];
        dxy[1] = dx[0] * dy[1] + dx[1] * dy[0];
        dxy[2] = dx[0] * dy[2] + dx[1] * dy[1] + dx[2] * dy[0];
        dxy[3] = dx[0] * dy[3] + dx[1] * dy[2] + dx[2] * dy[1] +
            dx[3] * dy[0];
        dxy[4] = dx[0] * dy[4] + dx[1] * dy[3] + dx[2] * dy[2] +
            dx[3] * dy[1] + dx[4] * dy[0];
        dxy[5] = dx[1] * dy[4] + dx[2] * dy[3] + dx[3] * dy[2] +
            dx[4] * dy[1];
        dxy[6] = dx[2] * dy[4] + dx[3] * dy[3] + dx[4] * dy[2];
        dxy[7] = dx[3] * dy[4] + dx[4] * dy[3];
        dxy[8] = dx[4] * dy[4];

        /* split odd-numbered terms and combine into even-numbered terms */
        c = (dxy[1] + two20) - two20;
        dxy[0] += c;
        dxy[1] -= c;
        c = (dxy[3] + twom28) - twom28;
        dxy[2] += c + dxy[1];
        dxy[3] -= c;
        c = (dxy[5] + twom76) - twom76;
        dxy[4] += c + dxy[3];
        dxy[5] -= c;
        c = (dxy[7] + twom124) - twom124;
        dxy[6] += c + dxy[5];
        dxy[8] += (dxy[7] - c);

        /* propagate carries, adjusting the exponent if need be */
        dxy[7] = dxy[6] + dxy[8];
        dxy[5] = dxy[4] + dxy[7];
        dxy[3] = dxy[2] + dxy[5];
        dxy[1] = dxy[0] + dxy[3];
        if (dxy[1] >= two) {
                dxy[0] *= half;
                dxy[1] *= half;
                dxy[2] *= half;
                dxy[3] *= half;
                dxy[4] *= half;
                dxy[5] *= half;
                dxy[6] *= half;
                dxy[7] *= half;
                dxy[8] *= half;
                exy++;
        }

        /* extract the significand of x*y */
        s = two36;
        u.d = c = dxy[1] + s;
        xy0 = u.i[1];
        c -= s;
        dxy[1] -= c;
        dxy[0] -= c;

        s *= twom32;
        u.d = c = dxy[1] + s;
        xy1 = u.i[1];
        c -= s;
        dxy[2] += (dxy[0] - c);
        dxy[3] = dxy[2] + dxy[5];

        s *= twom32;
        u.d = c = dxy[3] + s;
        xy2 = u.i[1];
        c -= s;
        dxy[4] += (dxy[2] - c);
        dxy[5] = dxy[4] + dxy[7];

        s *= twom32;
        u.d = c = dxy[5] + s;
        xy3 = u.i[1];
        c -= s;
        dxy[4] -= c;
        dxy[5] = dxy[4] + dxy[7];

        s *= twom32;
        u.d = c = dxy[5] + s;
        xy4 = u.i[1];
        c -= s;
        dxy[6] += (dxy[4] - c);
        dxy[7] = dxy[6] + dxy[8];

        s *= twom32;
        u.d = c = dxy[7] + s;
        xy5 = u.i[1];
        c -= s;
        dxy[8] += (dxy[6] - c);

        s *= twom32;
        u.d = c = dxy[8] + s;
        xy6 = u.i[1];
        c -= s;
        dxy[8] -= c;

        s *= twom32;
        u.d = c = dxy[8] + s;
        xy7 = u.i[1];

        /* extract the sign, exponent, and significand of z */
        sz = zz.i[0] & 0x80000000;
        ez = hz >> 16;
        z0 = hz & 0xffff;
        if (!ez) {
                if (z0 | (zz.i[1] & 0xfffe0000)) {
                        z1 = zz.i[1];
                        z2 = zz.i[2];
                        z3 = zz.i[3];
                        ez = 1;
                } else if (zz.i[1] | (zz.i[2] & 0xfffe0000)) {
                        z0 = zz.i[1];
                        z1 = zz.i[2];
                        z2 = zz.i[3];
                        z3 = 0;
                        ez = -31;
                } else if (zz.i[2] | (zz.i[3] & 0xfffe0000)) {
                        z0 = zz.i[2];
                        z1 = zz.i[3];
                        z2 = z3 = 0;
                        ez = -63;
                } else {
                        z0 = zz.i[3];
                        z1 = z2 = z3 = 0;
                        ez = -95;
                }
                while ((z0 & 0x10000) == 0) {
                        z0 = (z0 << 1) | (z1 >> 31);
                        z1 = (z1 << 1) | (z2 >> 31);
                        z2 = (z2 << 1) | (z3 >> 31);
                        z3 <<= 1;
                        ez--;
                }
        } else {
                z0 |= 0x10000;
                z1 = zz.i[1];
                z2 = zz.i[2];
                z3 = zz.i[3];
        }
        z4 = z5 = z6 = z7 = 0;

        /*
         * now x*y is represented by sxy, exy, and xy[0-7], and z is
         * represented likewise; swap if need be so |xy| <= |z|
         */
        if (exy > ez || (exy == ez && (xy0 > z0 || (xy0 == z0 && (xy1 > z1 ||
                (xy1 == z1 && (xy2 > z2 || (xy2 == z2 && (xy3 > z3 ||
                (xy3 == z3 && (xy4 | xy5 | xy6 | xy7) != 0)))))))))) {
                e = sxy; sxy = sz; sz = e;
                e = exy; exy = ez; ez = e;
                e = xy0; xy0 = z0; z0 = e;
                e = xy1; xy1 = z1; z1 = e;
                e = xy2; xy2 = z2; z2 = e;
                e = xy3; xy3 = z3; z3 = e;
                z4 = xy4; xy4 = 0;
                z5 = xy5; xy5 = 0;
                z6 = xy6; xy6 = 0;
                z7 = xy7; xy7 = 0;
        }

        /* shift the significand of xy keeping a sticky bit */
        e = ez - exy;
        if (e > 236) {
                xy0 = xy1 = xy2 = xy3 = xy4 = xy5 = xy6 = 0;
                xy7 = 1;
        } else if (e >= 224) {
                sticky = xy7 | xy6 | xy5 | xy4 | xy3 | xy2 | xy1 |
                        ((xy0 << 1) << (255 - e));
                xy7 = xy0 >> (e - 224);
                if (sticky)
                        xy7 |= 1;
                xy0 = xy1 = xy2 = xy3 = xy4 = xy5 = xy6 = 0;
        } else if (e >= 192) {
                sticky = xy7 | xy6 | xy5 | xy4 | xy3 | xy2 |
                        ((xy1 << 1) << (223 - e));
                xy7 = (xy1 >> (e - 192)) | ((xy0 << 1) << (223 - e));
                if (sticky)
                        xy7 |= 1;
                xy6 = xy0 >> (e - 192);
                xy0 = xy1 = xy2 = xy3 = xy4 = xy5 = 0;
        } else if (e >= 160) {
                sticky = xy7 | xy6 | xy5 | xy4 | xy3 |
                        ((xy2 << 1) << (191 - e));
                xy7 = (xy2 >> (e - 160)) | ((xy1 << 1) << (191 - e));
                if (sticky)
                        xy7 |= 1;
                xy6 = (xy1 >> (e - 160)) | ((xy0 << 1) << (191 - e));
                xy5 = xy0 >> (e - 160);
                xy0 = xy1 = xy2 = xy3 = xy4 = 0;
        } else if (e >= 128) {
                sticky = xy7 | xy6 | xy5 | xy4 | ((xy3 << 1) << (159 - e));
                xy7 = (xy3 >> (e - 128)) | ((xy2 << 1) << (159 - e));
                if (sticky)
                        xy7 |= 1;
                xy6 = (xy2 >> (e - 128)) | ((xy1 << 1) << (159 - e));
                xy5 = (xy1 >> (e - 128)) | ((xy0 << 1) << (159 - e));
                xy4 = xy0 >> (e - 128);
                xy0 = xy1 = xy2 = xy3 = 0;
        } else if (e >= 96) {
                sticky = xy7 | xy6 | xy5 | ((xy4 << 1) << (127 - e));
                xy7 = (xy4 >> (e - 96)) | ((xy3 << 1) << (127 - e));
                if (sticky)
                        xy7 |= 1;
                xy6 = (xy3 >> (e - 96)) | ((xy2 << 1) << (127 - e));
                xy5 = (xy2 >> (e - 96)) | ((xy1 << 1) << (127 - e));
                xy4 = (xy1 >> (e - 96)) | ((xy0 << 1) << (127 - e));
                xy3 = xy0 >> (e - 96);
                xy0 = xy1 = xy2 = 0;
        } else if (e >= 64) {
                sticky = xy7 | xy6 | ((xy5 << 1) << (95 - e));
                xy7 = (xy5 >> (e - 64)) | ((xy4 << 1) << (95 - e));
                if (sticky)
                        xy7 |= 1;
                xy6 = (xy4 >> (e - 64)) | ((xy3 << 1) << (95 - e));
                xy5 = (xy3 >> (e - 64)) | ((xy2 << 1) << (95 - e));
                xy4 = (xy2 >> (e - 64)) | ((xy1 << 1) << (95 - e));
                xy3 = (xy1 >> (e - 64)) | ((xy0 << 1) << (95 - e));
                xy2 = xy0 >> (e - 64);
                xy0 = xy1 = 0;
        } else if (e >= 32) {
                sticky = xy7 | ((xy6 << 1) << (63 - e));
                xy7 = (xy6 >> (e - 32)) | ((xy5 << 1) << (63 - e));
                if (sticky)
                        xy7 |= 1;
                xy6 = (xy5 >> (e - 32)) | ((xy4 << 1) << (63 - e));
                xy5 = (xy4 >> (e - 32)) | ((xy3 << 1) << (63 - e));
                xy4 = (xy3 >> (e - 32)) | ((xy2 << 1) << (63 - e));
                xy3 = (xy2 >> (e - 32)) | ((xy1 << 1) << (63 - e));
                xy2 = (xy1 >> (e - 32)) | ((xy0 << 1) << (63 - e));
                xy1 = xy0 >> (e - 32);
                xy0 = 0;
        } else if (e) {
                sticky = (xy7 << 1) << (31 - e);
                xy7 = (xy7 >> e) | ((xy6 << 1) << (31 - e));
                if (sticky)
                        xy7 |= 1;
                xy6 = (xy6 >> e) | ((xy5 << 1) << (31 - e));
                xy5 = (xy5 >> e) | ((xy4 << 1) << (31 - e));
                xy4 = (xy4 >> e) | ((xy3 << 1) << (31 - e));
                xy3 = (xy3 >> e) | ((xy2 << 1) << (31 - e));
                xy2 = (xy2 >> e) | ((xy1 << 1) << (31 - e));
                xy1 = (xy1 >> e) | ((xy0 << 1) << (31 - e));
                xy0 >>= e;
        }

        /* if this is a magnitude subtract, negate the significand of xy */
        if (sxy ^ sz) {
                xy0 = ~xy0;
                xy1 = ~xy1;
                xy2 = ~xy2;
                xy3 = ~xy3;
                xy4 = ~xy4;
                xy5 = ~xy5;
                xy6 = ~xy6;
                xy7 = -xy7;
                if (xy7 == 0)
                        if (++xy6 == 0)
                                if (++xy5 == 0)
                                        if (++xy4 == 0)
                                                if (++xy3 == 0)
                                                        if (++xy2 == 0)
                                                                if (++xy1 == 0)
                                                                        xy0++;
        }

        /* add, propagating carries */
        z7 += xy7;
        e = (z7 < xy7);
        z6 += xy6;
        if (e) {
                z6++;
                e = (z6 <= xy6);
        } else
                e = (z6 < xy6);
        z5 += xy5;
        if (e) {
                z5++;
                e = (z5 <= xy5);
        } else
                e = (z5 < xy5);
        z4 += xy4;
        if (e) {
                z4++;
                e = (z4 <= xy4);
        } else
                e = (z4 < xy4);
        z3 += xy3;
        if (e) {
                z3++;
                e = (z3 <= xy3);
        } else
                e = (z3 < xy3);
        z2 += xy2;
        if (e) {
                z2++;
                e = (z2 <= xy2);
        } else
                e = (z2 < xy2);
        z1 += xy1;
        if (e) {
                z1++;
                e = (z1 <= xy1);
        } else
                e = (z1 < xy1);
        z0 += xy0;
        if (e)
                z0++;

        /* postnormalize and collect rounding information into z4 */
        if (ez < 1) {
                /* result is tiny; shift right until exponent is within range */
                e = 1 - ez;
                if (e > 116) {
                        z4 = 1; /* result can't be exactly zero */
                        z0 = z1 = z2 = z3 = 0;
                } else if (e >= 96) {
                        sticky = z7 | z6 | z5 | z4 | z3 | z2 |
                                ((z1 << 1) << (127 - e));
                        z4 = (z1 >> (e - 96)) | ((z0 << 1) << (127 - e));
                        if (sticky)
                                z4 |= 1;
                        z3 = z0 >> (e - 96);
                        z0 = z1 = z2 = 0;
                } else if (e >= 64) {
                        sticky = z7 | z6 | z5 | z4 | z3 |
                                ((z2 << 1) << (95 - e));
                        z4 = (z2 >> (e - 64)) | ((z1 << 1) << (95 - e));
                        if (sticky)
                                z4 |= 1;
                        z3 = (z1 >> (e - 64)) | ((z0 << 1) << (95 - e));
                        z2 = z0 >> (e - 64);
                        z0 = z1 = 0;
                } else if (e >= 32) {
                        sticky = z7 | z6 | z5 | z4 | ((z3 << 1) << (63 - e));
                        z4 = (z3 >> (e - 32)) | ((z2 << 1) << (63 - e));
                        if (sticky)
                                z4 |= 1;
                        z3 = (z2 >> (e - 32)) | ((z1 << 1) << (63 - e));
                        z2 = (z1 >> (e - 32)) | ((z0 << 1) << (63 - e));
                        z1 = z0 >> (e - 32);
                        z0 = 0;
                } else {
                        sticky = z7 | z6 | z5 | (z4 << 1) << (31 - e);
                        z4 = (z4 >> e) | ((z3 << 1) << (31 - e));
                        if (sticky)
                                z4 |= 1;
                        z3 = (z3 >> e) | ((z2 << 1) << (31 - e));
                        z2 = (z2 >> e) | ((z1 << 1) << (31 - e));
                        z1 = (z1 >> e) | ((z0 << 1) << (31 - e));
                        z0 >>= e;
                }
                ez = 1;
        } else if (z0 >= 0x20000) {
                /* carry out; shift right by one */
                sticky = (z4 & 1) | z5 | z6 | z7;
                z4 = (z4 >> 1) | (z3 << 31);
                if (sticky)
                        z4 |= 1;
                z3 = (z3 >> 1) | (z2 << 31);
                z2 = (z2 >> 1) | (z1 << 31);
                z1 = (z1 >> 1) | (z0 << 31);
                z0 >>= 1;
                ez++;
        } else {
                if (z0 < 0x10000 && (z0 | z1 | z2 | z3 | z4 | z5 | z6 | z7)
                        != 0) {
                        /*
                         * borrow/cancellation; shift left as much as
                         * exponent allows
                         */
                        while (!(z0 | (z1 & 0xfffe0000)) && ez >= 33) {
                                z0 = z1;
                                z1 = z2;
                                z2 = z3;
                                z3 = z4;
                                z4 = z5;
                                z5 = z6;
                                z6 = z7;
                                z7 = 0;
                                ez -= 32;
                        }
                        while (z0 < 0x10000 && ez > 1) {
                                z0 = (z0 << 1) | (z1 >> 31);
                                z1 = (z1 << 1) | (z2 >> 31);
                                z2 = (z2 << 1) | (z3 >> 31);
                                z3 = (z3 << 1) | (z4 >> 31);
                                z4 = (z4 << 1) | (z5 >> 31);
                                z5 = (z5 << 1) | (z6 >> 31);
                                z6 = (z6 << 1) | (z7 >> 31);
                                z7 <<= 1;
                                ez--;
                        }
                }
                if (z5 | z6 | z7)
                        z4 |= 1;
        }

        /* get the rounding mode */
        rm = fsr >> 30;

        /* strip off the integer bit, if there is one */
        ibit = z0 & 0x10000;
        if (ibit)
                z0 -= 0x10000;
        else {
                ez = 0;
                if (!(z0 | z1 | z2 | z3 | z4)) { /* exact zero */
                        zz.i[0] = rm == FSR_RM ? 0x80000000 : 0;
                        zz.i[1] = zz.i[2] = zz.i[3] = 0;
                        __fenv_setfsr32(&fsr);
                        return (zz.q);
                }
        }

        /*
         * flip the sense of directed roundings if the result is negative;
         * the logic below applies to a positive result
         */
        if (sz)
                rm ^= rm >> 1;

        /* round and raise exceptions */
        if (z4) {
                fsr |= FSR_NXC;

                /* decide whether to round the fraction up */
                if (rm == FSR_RP || (rm == FSR_RN && (z4 > 0x80000000u ||
                        (z4 == 0x80000000u && (z3 & 1))))) {
                        /* round up and renormalize if necessary */
                        if (++z3 == 0)
                                if (++z2 == 0)
                                        if (++z1 == 0)
                                                if (++z0 == 0x10000) {
                                                        z0 = 0;
                                                        ez++;
                                                }
                }
        }

        /* check for under/overflow */
        if (ez >= 0x7fff) {
                if (rm == FSR_RN || rm == FSR_RP) {
                        zz.i[0] = sz | 0x7fff0000;
                        zz.i[1] = zz.i[2] = zz.i[3] = 0;
                } else {
                        zz.i[0] = sz | 0x7ffeffff;
                        zz.i[1] = zz.i[2] = zz.i[3] = 0xffffffff;
                }
                fsr |= FSR_OFC | FSR_NXC;
        } else {
                zz.i[0] = sz | (ez << 16) | z0;
                zz.i[1] = z1;
                zz.i[2] = z2;
                zz.i[3] = z3;

                /*
                 * !ibit => exact result was tiny before rounding,
                 * z4 nonzero => result delivered is inexact
                 */
                if (!ibit) {
                        if (z4)
                                fsr |= FSR_UFC | FSR_NXC;
                        else if (fsr & FSR_UFM)
                                fsr |= FSR_UFC;
                }
        }

        /* restore the fsr and emulate exceptions as needed */
        if ((fsr & FSR_CEXC) & (fsr >> 23)) {
                __fenv_setfsr32(&fsr);
                if (fsr & FSR_OFC) {
                        dummy = huge;
                        dummy *= huge;
                } else if (fsr & FSR_UFC) {
                        dummy = tiny;
                        if (fsr & FSR_NXC)
                                dummy *= tiny;
                        else
                                dummy -= tiny2;
                } else {
                        dummy = huge;
                        dummy += tiny;
                }
        } else {
                fsr |= (fsr & 0x1f) << 5;
                __fenv_setfsr32(&fsr);
        }
        return (zz.q);
}

#elif defined(__x86)

static const union {
        unsigned i[2];
        double d;
} C[] = {
        { 0, 0x3fe00000u },
        { 0, 0x40000000u },
        { 0, 0x3df00000u },
        { 0, 0x3bf00000u },
        { 0, 0x41f00000u },
        { 0, 0x43e00000u },
        { 0, 0x7fe00000u },
        { 0, 0x00100000u },
        { 0, 0x00100001u }
};

#define half    C[0].d
#define two     C[1].d
#define twom32  C[2].d
#define twom64  C[3].d
#define two32   C[4].d
#define two63   C[5].d
#define huge    C[6].d
#define tiny    C[7].d
#define tiny2   C[8].d

#if defined(__amd64)
#define NI      4
#else
#define NI      3
#endif

/*
 * fmal for x86: 80-bit extended double precision, little-endian
 */
long double
__fmal(long double x, long double y, long double z) {
        union {
                unsigned i[NI];
                long double e;
        } xx, yy, zz;
        long double xhi, yhi, xlo, ylo, t;
        unsigned xy0, xy1, xy2, xy3, xy4, z0, z1, z2, z3, z4;
        unsigned oldcwsw, cwsw, rm, sticky, carry;
        int ex, ey, ez, exy, sxy, sz, e, tinyafter;
        volatile double dummy;

        /* extract the exponents of the arguments */
        xx.e = x;
        yy.e = y;
        zz.e = z;
        ex = xx.i[2] & 0x7fff;
        ey = yy.i[2] & 0x7fff;
        ez = zz.i[2] & 0x7fff;

        /* dispense with inf, nan, and zero cases */
        if (ex == 0x7fff || ey == 0x7fff || (ex | xx.i[1] | xx.i[0]) == 0 ||
                (ey | yy.i[1] | yy.i[0]) == 0)  /* x or y is inf, nan, or 0 */
                return (x * y + z);

        if (ez == 0x7fff)                       /* z is inf or nan */
                return (x + z); /* avoid spurious under/overflow in x * y */

        if ((ez | zz.i[1] | zz.i[0]) == 0)      /* z is zero */
                /*
                 * x * y isn't zero but could underflow to zero,
                 * so don't add z, lest we perturb the sign
                 */
                return (x * y);

        /*
         * now x, y, and z are all finite and nonzero; extract signs and
         * normalize the significands (this will raise the denormal operand
         * exception if need be)
         */
        sxy = (xx.i[2] ^ yy.i[2]) & 0x8000;
        sz = zz.i[2] & 0x8000;
        if (!ex) {
                xx.e = x * two63;
                ex = (xx.i[2] & 0x7fff) - 63;
        }
        if (!ey) {
                yy.e = y * two63;
                ey = (yy.i[2] & 0x7fff) - 63;
        }
        if (!ez) {
                zz.e = z * two63;
                ez = (zz.i[2] & 0x7fff) - 63;
        }

        /*
         * save the control and status words, mask all exceptions, and
         * set rounding to 64-bit precision and toward-zero
         */
        __fenv_getcwsw(&oldcwsw);
        cwsw = (oldcwsw & 0xf0c0ffff) | 0x0f3f0000;
        __fenv_setcwsw(&cwsw);

        /* multiply x*y to 128 bits */
        exy = ex + ey - 0x3fff;
        xx.i[2] = 0x3fff;
        yy.i[2] = 0x3fff;
        x = xx.e;
        y = yy.e;
        xhi = ((x + twom32) + two32) - two32;
        yhi = ((y + twom32) + two32) - two32;
        xlo = x - xhi;
        ylo = y - yhi;
        x *= y;
        y = ((xhi * yhi - x) + xhi * ylo + xlo * yhi) + xlo * ylo;
        if (x >= two) {
                x *= half;
                y *= half;
                exy++;
        }

        /* extract the significands */
        xx.e = x;
        xy0 = xx.i[1];
        xy1 = xx.i[0];
        yy.e = t = y + twom32;
        xy2 = yy.i[0];
        yy.e = (y - (t - twom32)) + twom64;
        xy3 = yy.i[0];
        xy4 = 0;
        z0 = zz.i[1];
        z1 = zz.i[0];
        z2 = z3 = z4 = 0;

        /*
         * now x*y is represented by sxy, exy, and xy[0-4], and z is
         * represented likewise; swap if need be so |xy| <= |z|
         */
        if (exy > ez || (exy == ez && (xy0 > z0 || (xy0 == z0 &&
                (xy1 > z1 || (xy1 == z1 && (xy2 | xy3) != 0)))))) {
                e = sxy; sxy = sz; sz = e;
                e = exy; exy = ez; ez = e;
                e = xy0; xy0 = z0; z0 = e;
                e = xy1; xy1 = z1; z1 = e;
                z2 = xy2; xy2 = 0;
                z3 = xy3; xy3 = 0;
        }

        /* shift the significand of xy keeping a sticky bit */
        e = ez - exy;
        if (e > 130) {
                xy0 = xy1 = xy2 = xy3 = 0;
                xy4 = 1;
        } else if (e >= 128) {
                sticky = xy3 | xy2 | xy1 | ((xy0 << 1) << (159 - e));
                xy4 = xy0 >> (e - 128);
                if (sticky)
                        xy4 |= 1;
                xy0 = xy1 = xy2 = xy3 = 0;
        } else if (e >= 96) {
                sticky = xy3 | xy2 | ((xy1 << 1) << (127 - e));
                xy4 = (xy1 >> (e - 96)) | ((xy0 << 1) << (127 - e));
                if (sticky)
                        xy4 |= 1;
                xy3 = xy0 >> (e - 96);
                xy0 = xy1 = xy2 = 0;
        } else if (e >= 64) {
                sticky = xy3 | ((xy2 << 1) << (95 - e));
                xy4 = (xy2 >> (e - 64)) | ((xy1 << 1) << (95 - e));
                if (sticky)
                        xy4 |= 1;
                xy3 = (xy1 >> (e - 64)) | ((xy0 << 1) << (95 - e));
                xy2 = xy0 >> (e - 64);
                xy0 = xy1 = 0;
        } else if (e >= 32) {
                sticky = (xy3 << 1) << (63 - e);
                xy4 = (xy3 >> (e - 32)) | ((xy2 << 1) << (63 - e));
                if (sticky)
                        xy4 |= 1;
                xy3 = (xy2 >> (e - 32)) | ((xy1 << 1) << (63 - e));
                xy2 = (xy1 >> (e - 32)) | ((xy0 << 1) << (63 - e));
                xy1 = xy0 >> (e - 32);
                xy0 = 0;
        } else if (e) {
                xy4 = (xy3 << 1) << (31 - e);
                xy3 = (xy3 >> e) | ((xy2 << 1) << (31 - e));
                xy2 = (xy2 >> e) | ((xy1 << 1) << (31 - e));
                xy1 = (xy1 >> e) | ((xy0 << 1) << (31 - e));
                xy0 >>= e;
        }

        /* if this is a magnitude subtract, negate the significand of xy */
        if (sxy ^ sz) {
                xy0 = ~xy0;
                xy1 = ~xy1;
                xy2 = ~xy2;
                xy3 = ~xy3;
                xy4 = -xy4;
                if (xy4 == 0)
                        if (++xy3 == 0)
                                if (++xy2 == 0)
                                        if (++xy1 == 0)
                                                xy0++;
        }

        /* add, propagating carries */
        z4 += xy4;
        carry = (z4 < xy4);
        z3 += xy3;
        if (carry) {
                z3++;
                carry = (z3 <= xy3);
        } else
                carry = (z3 < xy3);
        z2 += xy2;
        if (carry) {
                z2++;
                carry = (z2 <= xy2);
        } else
                carry = (z2 < xy2);
        z1 += xy1;
        if (carry) {
                z1++;
                carry = (z1 <= xy1);
        } else
                carry = (z1 < xy1);
        z0 += xy0;
        if (carry) {
                z0++;
                carry = (z0 <= xy0);
        } else
                carry = (z0 < xy0);

        /* for a magnitude subtract, ignore the last carry out */
        if (sxy ^ sz)
                carry = 0;

        /* postnormalize and collect rounding information into z2 */
        if (ez < 1) {
                /* result is tiny; shift right until exponent is within range */
                e = 1 - ez;
                if (e > 67) {
                        z2 = 1; /* result can't be exactly zero */
                        z0 = z1 = 0;
                } else if (e >= 64) {
                        sticky = z4 | z3 | z2 | z1 | ((z0 << 1) << (95 - e));
                        z2 = (z0 >> (e - 64)) | ((carry << 1) << (95 - e));
                        if (sticky)
                                z2 |= 1;
                        z1 = carry >> (e - 64);
                        z0 = 0;
                } else if (e >= 32) {
                        sticky = z4 | z3 | z2 | ((z1 << 1) << (63 - e));
                        z2 = (z1 >> (e - 32)) | ((z0 << 1) << (63 - e));
                        if (sticky)
                                z2 |= 1;
                        z1 = (z0 >> (e - 32)) | ((carry << 1) << (63 - e));
                        z0 = carry >> (e - 32);
                } else {
                        sticky = z4 | z3 | (z2 << 1) << (31 - e);
                        z2 = (z2 >> e) | ((z1 << 1) << (31 - e));
                        if (sticky)
                                z2 |= 1;
                        z1 = (z1 >> e) | ((z0 << 1) << (31 - e));
                        z0 = (z0 >> e) | ((carry << 1) << (31 - e));
                }
                ez = 1;
        } else if (carry) {
                /* carry out; shift right by one */
                sticky = (z2 & 1) | z3 | z4;
                z2 = (z2 >> 1) | (z1 << 31);
                if (sticky)
                        z2 |= 1;
                z1 = (z1 >> 1) | (z0 << 31);
                z0 = (z0 >> 1) | 0x80000000;
                ez++;
        } else {
                if (z0 < 0x80000000u && (z0 | z1 | z2 | z3 | z4) != 0) {
                        /*
                         * borrow/cancellation; shift left as much as
                         * exponent allows
                         */
                        while (!z0 && ez >= 33) {
                                z0 = z1;
                                z1 = z2;
                                z2 = z3;
                                z3 = z4;
                                z4 = 0;
                                ez -= 32;
                        }
                        while (z0 < 0x80000000u && ez > 1) {
                                z0 = (z0 << 1) | (z1 >> 31);
                                z1 = (z1 << 1) | (z2 >> 31);
                                z2 = (z2 << 1) | (z3 >> 31);
                                z3 = (z3 << 1) | (z4 >> 31);
                                z4 <<= 1;
                                ez--;
                        }
                }
                if (z3 | z4)
                        z2 |= 1;
        }

        /* get the rounding mode */
        rm = oldcwsw & 0x0c000000;

        /* adjust exponent if result is subnormal */
        tinyafter = 0;
        if (!(z0 & 0x80000000)) {
                ez = 0;
                tinyafter = 1;
                if (!(z0 | z1 | z2)) { /* exact zero */
                        zz.i[2] = rm == FCW_RM ? 0x8000 : 0;
                        zz.i[1] = zz.i[0] = 0;
                        __fenv_setcwsw(&oldcwsw);
                        return (zz.e);
                }
        }

        /*
         * flip the sense of directed roundings if the result is negative;
         * the logic below applies to a positive result
         */
        if (sz && (rm == FCW_RM || rm == FCW_RP))
                rm = (FCW_RM + FCW_RP) - rm;

        /* round */
        if (z2) {
                if (rm == FCW_RP || (rm == FCW_RN && (z2 > 0x80000000u ||
                        (z2 == 0x80000000u && (z1 & 1))))) {
                        /* round up and renormalize if necessary */
                        if (++z1 == 0) {
                                if (++z0 == 0) {
                                        z0 = 0x80000000;
                                        ez++;
                                } else if (z0 == 0x80000000) {
                                        /* rounded up to smallest normal */
                                        ez = 1;
                                        if ((rm == FCW_RP && z2 >
                                                0x80000000u) || (rm == FCW_RN &&
                                                z2 >= 0xc0000000u))
                                                /*
                                                 * would have rounded up to
                                                 * smallest normal even with
                                                 * unbounded range
                                                 */
                                                tinyafter = 0;
                                }
                        }
                }
        }

        /* restore the control and status words, check for over/underflow */
        __fenv_setcwsw(&oldcwsw);
        if (ez >= 0x7fff) {
                if (rm == FCW_RN || rm == FCW_RP) {
                        zz.i[2] = sz | 0x7fff;
                        zz.i[1] = 0x80000000;
                        zz.i[0] = 0;
                } else {
                        zz.i[2] = sz | 0x7ffe;
                        zz.i[1] = 0xffffffff;
                        zz.i[0] = 0xffffffff;
                }
                dummy = huge;
                dummy *= huge;
        } else {
                zz.i[2] = sz | ez;
                zz.i[1] = z0;
                zz.i[0] = z1;

                /*
                 * tinyafter => result rounded w/ unbounded range would be tiny,
                 * z2 nonzero => result delivered is inexact
                 */
                if (tinyafter) {
                        dummy = tiny;
                        if (z2)
                                dummy *= tiny;
                        else
                                dummy -= tiny2;
                } else if (z2) {
                        dummy = huge;
                        dummy += tiny;
                }
        }

        return (zz.e);
}

#else
#error Unknown architecture
#endif