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

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

*/

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

floatx80 floatx80_exp(floatx80 Fm);
floatx80 floatx80_ln(floatx80 Fm);
floatx80 floatx80_sin(floatx80 rFm);
floatx80 floatx80_cos(floatx80 rFm);
floatx80 floatx80_arcsin(floatx80 rFm);
floatx80 floatx80_arctan(floatx80 rFm);
floatx80 floatx80_log(floatx80 rFm);
floatx80 floatx80_tan(floatx80 rFm);
floatx80 floatx80_arccos(floatx80 rFm);
floatx80 floatx80_pow(floatx80 rFn, floatx80 rFm);
floatx80 floatx80_pol(floatx80 rFn, floatx80 rFm);

static floatx80 floatx80_rsf(struct roundingData *roundData, floatx80 rFn, floatx80 rFm)
{
        return floatx80_sub(roundData, rFm, rFn);
}

static floatx80 floatx80_rdv(struct roundingData *roundData, floatx80 rFn, floatx80 rFm)
{
        return floatx80_div(roundData, rFm, rFn);
}

static floatx80 (*const dyadic_extended[16])(struct roundingData*, floatx80 rFn, floatx80 rFm) = {
        [ADF_CODE >> 20] = floatx80_add,
        [MUF_CODE >> 20] = floatx80_mul,
        [SUF_CODE >> 20] = floatx80_sub,
        [RSF_CODE >> 20] = floatx80_rsf,
        [DVF_CODE >> 20] = floatx80_div,
        [RDF_CODE >> 20] = floatx80_rdv,
        [RMF_CODE >> 20] = floatx80_rem,

        /* strictly, these opcodes should not be implemented */
        [FML_CODE >> 20] = floatx80_mul,
        [FDV_CODE >> 20] = floatx80_div,
        [FRD_CODE >> 20] = floatx80_rdv,
};

static floatx80 floatx80_mvf(struct roundingData *roundData, floatx80 rFm)
{
        return rFm;
}

static floatx80 floatx80_mnf(struct roundingData *roundData, floatx80 rFm)
{
        rFm.high ^= 0x8000;
        return rFm;
}

static floatx80 floatx80_abs(struct roundingData *roundData, floatx80 rFm)
{
        rFm.high &= 0x7fff;
        return rFm;
}

static floatx80 (*const monadic_extended[16])(struct roundingData*, floatx80 rFm) = {
        [MVF_CODE >> 20] = floatx80_mvf,
        [MNF_CODE >> 20] = floatx80_mnf,
        [ABS_CODE >> 20] = floatx80_abs,
        [RND_CODE >> 20] = floatx80_round_to_int,
        [URD_CODE >> 20] = floatx80_round_to_int,
        [SQT_CODE >> 20] = floatx80_sqrt,
        [NRM_CODE >> 20] = floatx80_mvf,
};

unsigned int ExtendedCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd)
{
        FPA11 *fpa11 = GET_FPA11();
        floatx80 rFm;
        unsigned int Fm, opc_mask_shift;

        Fm = getFm(opcode);
        if (CONSTANT_FM(opcode)) {
                rFm = getExtendedConstant(Fm);
        } else {
                switch (fpa11->fType[Fm]) {
                case typeSingle:
                        rFm = float32_to_floatx80(fpa11->fpreg[Fm].fSingle);
                        break;

                case typeDouble:
                        rFm = float64_to_floatx80(fpa11->fpreg[Fm].fDouble);
                        break;

                case typeExtended:
                        rFm = fpa11->fpreg[Fm].fExtended;
                        break;

                default:
                        return 0;
                }
        }

        opc_mask_shift = (opcode & MASK_ARITHMETIC_OPCODE) >> 20;
        if (!MONADIC_INSTRUCTION(opcode)) {
                unsigned int Fn = getFn(opcode);
                floatx80 rFn;

                switch (fpa11->fType[Fn]) {
                case typeSingle:
                        rFn = float32_to_floatx80(fpa11->fpreg[Fn].fSingle);
                        break;

                case typeDouble:
                        rFn = float64_to_floatx80(fpa11->fpreg[Fn].fDouble);
                        break;

                case typeExtended:
                        rFn = fpa11->fpreg[Fn].fExtended;
                        break;

                default:
                        return 0;
                }

                if (dyadic_extended[opc_mask_shift]) {
                        rFd->fExtended = dyadic_extended[opc_mask_shift](roundData, rFn, rFm);
                } else {
                        return 0;
                }
        } else {
                if (monadic_extended[opc_mask_shift]) {
                        rFd->fExtended = monadic_extended[opc_mask_shift](roundData, rFm);
                } else {
                        return 0;
                }
        }

        return 1;
}