/*      $NetBSD: fcnvff.c,v 1.6 2012/02/04 17:03:09 skrll Exp $ */

/*      $OpenBSD: fcnvff.c,v 1.5 2001/03/29 03:58:18 mickey Exp $       */

/*
 * Copyright 1996 1995 by Open Software Foundation, Inc.
 *              All Rights Reserved
 *
 * Permission to use, copy, modify, and distribute this software and
 * its documentation for any purpose and without fee is hereby granted,
 * provided that the above copyright notice appears in all copies and
 * that both the copyright notice and this permission notice appear in
 * supporting documentation.
 *
 * OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE.
 *
 * IN NO EVENT SHALL OSF BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
 * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 */
/*
 * pmk1.1
 */
/*
 * (c) Copyright 1986 HEWLETT-PACKARD COMPANY
 *
 * To anyone who acknowledges that this file is provided "AS IS"
 * without any express or implied warranty:
 *     permission to use, copy, modify, and distribute this file
 * for any purpose is hereby granted without fee, provided that
 * the above copyright notice and this notice appears in all
 * copies, and that the name of Hewlett-Packard Company not be
 * used in advertising or publicity pertaining to distribution
 * of the software without specific, written prior permission.
 * Hewlett-Packard Company makes no representations about the
 * suitability of this software for any purpose.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: fcnvff.c,v 1.6 2012/02/04 17:03:09 skrll Exp $");

#include "../spmath/float.h"
#include "../spmath/sgl_float.h"
#include "../spmath/dbl_float.h"
#include "../spmath/cnv_float.h"

/*
 *  Single Floating-point to Double Floating-point
 */
/*ARGSUSED*/
int
sgl_to_dbl_fcnvff(sgl_floating_point *srcptr, dbl_floating_point *dstptr,
    unsigned int *status)
{
        register unsigned int src, resultp1, resultp2;
        register int src_exponent;

        src = *srcptr;
        src_exponent = Sgl_exponent(src);
        Dbl_allp1(resultp1) = Sgl_all(src);  /* set sign of result */
        /*
         * Test for NaN or infinity
         */
        if (src_exponent == SGL_INFINITY_EXPONENT) {
                /*
                 * determine if NaN or infinity
                 */
                if (Sgl_iszero_mantissa(src)) {
                        /*
                         * is infinity; want to return double infinity
                         */
                        Dbl_setinfinity_exponentmantissa(resultp1,resultp2);
                        Dbl_copytoptr(resultp1,resultp2,dstptr);
                        return(NOEXCEPTION);
                }
                else {
                        /*
                         * is NaN; signaling or quiet?
                         */
                        if (Sgl_isone_signaling(src)) {
                                /* trap if INVALIDTRAP enabled */
                                if (Is_invalidtrap_enabled())
                                        return(INVALIDEXCEPTION);
                                /* make NaN quiet */
                                else {
                                        Set_invalidflag();
                                        Sgl_set_quiet(src);
                                }
                        }
                        /*
                         * NaN is quiet, return as double NaN
                         */
                        Dbl_setinfinity_exponent(resultp1);
                        Sgl_to_dbl_mantissa(src,resultp1,resultp2);
                        Dbl_copytoptr(resultp1,resultp2,dstptr);
                        return(NOEXCEPTION);
                }
        }
        /*
         * Test for zero or denormalized
         */
        if (src_exponent == 0) {
                /*
                 * determine if zero or denormalized
                 */
                if (Sgl_isnotzero_mantissa(src)) {
                        /*
                         * is denormalized; want to normalize
                         */
                        Sgl_clear_signexponent(src);
                        Sgl_leftshiftby1(src);
                        Sgl_normalize(src,src_exponent);
                        Sgl_to_dbl_exponent(src_exponent,resultp1);
                        Sgl_to_dbl_mantissa(src,resultp1,resultp2);
                }
                else {
                        Dbl_setzero_exponentmantissa(resultp1,resultp2);
                }
                Dbl_copytoptr(resultp1,resultp2,dstptr);
                return(NOEXCEPTION);
        }
        /*
         * No special cases, just complete the conversion
         */
        Sgl_to_dbl_exponent(src_exponent, resultp1);
        Sgl_to_dbl_mantissa(Sgl_mantissa(src), resultp1,resultp2);
        Dbl_copytoptr(resultp1,resultp2,dstptr);
        return(NOEXCEPTION);
}

/*
 *  Double Floating-point to Single Floating-point
 */
/*ARGSUSED*/
int
dbl_to_sgl_fcnvff(dbl_floating_point *srcptr, sgl_floating_point *dstptr,
    unsigned int *status)
{
        register unsigned int srcp1, srcp2, result;
        register int src_exponent, dest_exponent, dest_mantissa;
        register int inexact = false, guardbit = false, stickybit = false;
        register int lsb_odd = false;
        int is_tiny = false;

        Dbl_copyfromptr(srcptr,srcp1,srcp2);
        src_exponent = Dbl_exponent(srcp1);
        Sgl_all(result) = Dbl_allp1(srcp1);  /* set sign of result */
        /*
         * Test for NaN or infinity
         */
        if (src_exponent == DBL_INFINITY_EXPONENT) {
                /*
                 * determine if NaN or infinity
                 */
                if (Dbl_iszero_mantissa(srcp1,srcp2)) {
                        /*
                         * is infinity; want to return single infinity
                         */
                        Sgl_setinfinity_exponentmantissa(result);
                        *dstptr = result;
                        return(NOEXCEPTION);
                }
                /*
                 * is NaN; signaling or quiet?
                 */
                if (Dbl_isone_signaling(srcp1)) {
                        /* trap if INVALIDTRAP enabled */
                        if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION);
                        else {
                                Set_invalidflag();
                                /* make NaN quiet */
                                Dbl_set_quiet(srcp1);
                        }
                }
                /*
                 * NaN is quiet, return as single NaN
                 */
                Sgl_setinfinity_exponent(result);
                Sgl_set_mantissa(result,Dallp1(srcp1)<<3 | Dallp2(srcp2)>>29);
                if (Sgl_iszero_mantissa(result)) Sgl_set_quiet(result);
                *dstptr = result;
                return(NOEXCEPTION);
        }
        /*
         * Generate result
         */
        Dbl_to_sgl_exponent(src_exponent,dest_exponent);
        if (dest_exponent > 0) {
                Dbl_to_sgl_mantissa(srcp1,srcp2,dest_mantissa,inexact,guardbit,
                stickybit,lsb_odd);
        }
        else {
                if (Dbl_iszero_exponentmantissa(srcp1,srcp2)){
                        Sgl_setzero_exponentmantissa(result);
                        *dstptr = result;
                        return(NOEXCEPTION);
                }
                if (Is_underflowtrap_enabled()) {
                        Dbl_to_sgl_mantissa(srcp1,srcp2,dest_mantissa,inexact,
                        guardbit,stickybit,lsb_odd);
                }
                else {
                        /* compute result, determine inexact info,
                         * and set Underflowflag if appropriate
                         */
                        Dbl_to_sgl_denormalized(srcp1,srcp2,dest_exponent,
                        dest_mantissa,inexact,guardbit,stickybit,lsb_odd,
                        is_tiny);
                }
        }
        /*
         * Now round result if not exact
         */
        if (inexact) {
                switch (Rounding_mode()) {
                        case ROUNDPLUS:
                                if (Sgl_iszero_sign(result)) dest_mantissa++;
                                break;
                        case ROUNDMINUS:
                                if (Sgl_isone_sign(result)) dest_mantissa++;
                                break;
                        case ROUNDNEAREST:
                                if (guardbit) {
                                   if (stickybit || lsb_odd) dest_mantissa++;
                                   }
                }
        }
        Sgl_set_exponentmantissa(result,dest_mantissa);

        /*
         * check for mantissa overflow after rounding
         */
        if ((dest_exponent>0 || Is_underflowtrap_enabled()) &&
            Sgl_isone_hidden(result)) dest_exponent++;

        /*
         * Test for overflow
         */
        if (dest_exponent >= SGL_INFINITY_EXPONENT) {
                /* trap if OVERFLOWTRAP enabled */
                if (Is_overflowtrap_enabled()) {
                        /*
                         * Check for gross overflow
                         */
                        if (dest_exponent >= SGL_INFINITY_EXPONENT+SGL_WRAP)
                                return(UNIMPLEMENTEDEXCEPTION);

                        /*
                         * Adjust bias of result
                         */
                        Sgl_setwrapped_exponent(result,dest_exponent,ovfl);
                        *dstptr = result;
                        if (inexact) {
                            if (Is_inexacttrap_enabled())
                                return(OVERFLOWEXCEPTION|INEXACTEXCEPTION);
                            else
                                Set_inexactflag();
                        }
                        return(OVERFLOWEXCEPTION);
                }
                Set_overflowflag();
                inexact = true;
                /* set result to infinity or largest number */
                Sgl_setoverflow(result);
        }
        /*
         * Test for underflow
         */
        else if (dest_exponent <= 0) {
                /* trap if UNDERFLOWTRAP enabled */
                if (Is_underflowtrap_enabled()) {
                        /*
                         * Check for gross underflow
                         */
                        if (dest_exponent <= -(SGL_WRAP))
                                return(UNIMPLEMENTEDEXCEPTION);
                        /*
                         * Adjust bias of result
                         */
                        Sgl_setwrapped_exponent(result,dest_exponent,unfl);
                        *dstptr = result;
                        if (inexact) {
                            if (Is_inexacttrap_enabled())
                                return(UNDERFLOWEXCEPTION|INEXACTEXCEPTION);
                            else
                                Set_inexactflag();
                        }
                        return(UNDERFLOWEXCEPTION);
                }
                 /*
                  * result is denormalized or signed zero
                  */
               if (inexact && is_tiny) Set_underflowflag();

        }
        else Sgl_set_exponent(result,dest_exponent);
        *dstptr = result;
        /*
         * Trap if inexact trap is enabled
         */
        if (inexact) {
                if (Is_inexacttrap_enabled())
                        return(INEXACTEXCEPTION);
                else
                        Set_inexactflag();
        }
        return(NOEXCEPTION);
}