// SPDX-License-Identifier: GPL-2.0-or-later
/*
    NetWinder Floating Point Emulator
    (c) Rebel.COM, 1998,1999
    (c) Philip Blundell, 2001

    Direct questions, comments to Scott Bambrough <scottb@netwinder.org>

*/

#include "fpa11.h"
#include "fpopcode.h"

unsigned int SingleCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd);
unsigned int DoubleCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd);
unsigned int ExtendedCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd);

unsigned int EmulateCPDO(const unsigned int opcode)
{
        FPA11 *fpa11 = GET_FPA11();
        FPREG *rFd;
        unsigned int nType, nDest, nRc;
        struct roundingData roundData;

        /* Get the destination size.  If not valid let Linux perform
           an invalid instruction trap. */
        nDest = getDestinationSize(opcode);
        if (typeNone == nDest)
                return 0;

        roundData.mode = SetRoundingMode(opcode);
        roundData.precision = SetRoundingPrecision(opcode);
        roundData.exception = 0;

        /* Compare the size of the operands in Fn and Fm.
           Choose the largest size and perform operations in that size,
           in order to make use of all the precision of the operands.
           If Fm is a constant, we just grab a constant of a size
           matching the size of the operand in Fn. */
        if (MONADIC_INSTRUCTION(opcode))
                nType = nDest;
        else
                nType = fpa11->fType[getFn(opcode)];

        if (!CONSTANT_FM(opcode)) {
                register unsigned int Fm = getFm(opcode);
                if (nType < fpa11->fType[Fm]) {
                        nType = fpa11->fType[Fm];
                }
        }

        rFd = &fpa11->fpreg[getFd(opcode)];

        switch (nType) {
        case typeSingle:
                nRc = SingleCPDO(&roundData, opcode, rFd);
                break;
        case typeDouble:
                nRc = DoubleCPDO(&roundData, opcode, rFd);
                break;
#ifdef CONFIG_FPE_NWFPE_XP
        case typeExtended:
                nRc = ExtendedCPDO(&roundData, opcode, rFd);
                break;
#endif
        default:
                nRc = 0;
        }

        /* The CPDO functions used to always set the destination type
           to be the same as their working size. */

        if (nRc != 0) {
                /* If the operation succeeded, check to see if the result in the
                   destination register is the correct size.  If not force it
                   to be. */

                fpa11->fType[getFd(opcode)] = nDest;

#ifdef CONFIG_FPE_NWFPE_XP
                if (nDest != nType) {
                        switch (nDest) {
                        case typeSingle:
                                {
                                        if (typeDouble == nType)
                                                rFd->fSingle = float64_to_float32(&roundData, rFd->fDouble);
                                        else
                                                rFd->fSingle = floatx80_to_float32(&roundData, rFd->fExtended);
                                }
                                break;

                        case typeDouble:
                                {
                                        if (typeSingle == nType)
                                                rFd->fDouble = float32_to_float64(rFd->fSingle);
                                        else
                                                rFd->fDouble = floatx80_to_float64(&roundData, rFd->fExtended);
                                }
                                break;

                        case typeExtended:
                                {
                                        if (typeSingle == nType)
                                                rFd->fExtended = float32_to_floatx80(rFd->fSingle);
                                        else
                                                rFd->fExtended = float64_to_floatx80(rFd->fDouble);
                                }
                                break;
                        }
                }
#else
                if (nDest != nType) {
                        if (nDest == typeSingle)
                                rFd->fSingle = float64_to_float32(&roundData, rFd->fDouble);
                        else
                                rFd->fDouble = float32_to_float64(rFd->fSingle);
                }
#endif
        }

        if (roundData.exception)
                float_raise(roundData.exception);

        return nRc;
}