double_cpdo.c

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/*
    NetWinder Floating Point Emulator
    (c) Rebel.COM, 1998,1999

    Direct questions, comments to Scott Bambrough <[email protected]>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

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

union float64_components {
    float64 f64;
    unsigned int i[2];
};

float64 float64_exp(float64 Fm);
float64 float64_ln(float64 Fm);
float64 float64_sin(float64 rFm);
float64 float64_cos(float64 rFm);
float64 float64_arcsin(float64 rFm);
float64 float64_arctan(float64 rFm);
float64 float64_log(float64 rFm);
float64 float64_tan(float64 rFm);
float64 float64_arccos(float64 rFm);
float64 float64_pow(float64 rFn, float64 rFm);
float64 float64_pol(float64 rFn, float64 rFm);

static float64 float64_rsf(struct roundingData *roundData, float64 rFn, float64 rFm)
{
    return float64_sub(roundData, rFm, rFn);
}

static float64 float64_rdv(struct roundingData *roundData, float64 rFn, float64 rFm)
{
    return float64_div(roundData, rFm, rFn);
}

static float64 (*const dyadic_double[16])(struct roundingData*, float64 rFn, float64 rFm) = {
    [ADF_CODE >> 20] = float64_add,
    [MUF_CODE >> 20] = float64_mul,
    [SUF_CODE >> 20] = float64_sub,
    [RSF_CODE >> 20] = float64_rsf,
    [DVF_CODE >> 20] = float64_div,
    [RDF_CODE >> 20] = float64_rdv,
    [RMF_CODE >> 20] = float64_rem,

    /* strictly, these opcodes should not be implemented */
    [FML_CODE >> 20] = float64_mul,
    [FDV_CODE >> 20] = float64_div,
    [FRD_CODE >> 20] = float64_rdv,
};

static float64 float64_mvf(struct roundingData *roundData,float64 rFm)
{
    return rFm;
}

static float64 float64_mnf(struct roundingData *roundData,float64 rFm)
{
    union float64_components u;

    u.f64 = rFm;
#ifdef __ARMEB__
    u.i[0] ^= 0x80000000;
#else
    u.i[1] ^= 0x80000000;
#endif

    return u.f64;
}

static float64 float64_abs(struct roundingData *roundData,float64 rFm)
{
    union float64_components u;

    u.f64 = rFm;
#ifdef __ARMEB__
    u.i[0] &= 0x7fffffff;
#else
    u.i[1] &= 0x7fffffff;
#endif

    return u.f64;
}

static float64 (*const monadic_double[16])(struct roundingData *, float64 rFm) = {
    [MVF_CODE >> 20] = float64_mvf,
    [MNF_CODE >> 20] = float64_mnf,
    [ABS_CODE >> 20] = float64_abs,
    [RND_CODE >> 20] = float64_round_to_int,
    [URD_CODE >> 20] = float64_round_to_int,
    [SQT_CODE >> 20] = float64_sqrt,
    [NRM_CODE >> 20] = float64_mvf,
};

unsigned int DoubleCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd)
{
    FPA11 *fpa11 = GET_FPA11();
    float64 rFm;
    unsigned int Fm, opc_mask_shift;

    Fm = getFm(opcode);
    if (CONSTANT_FM(opcode)) {
        rFm = getDoubleConstant(Fm);
    } else {
        switch (fpa11->fType[Fm]) {
        case typeSingle:
            rFm = float32_to_float64(fpa11->fpreg[Fm].fSingle);
            break;

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

        default:
            return 0;
        }
    }

    opc_mask_shift = (opcode & MASK_ARITHMETIC_OPCODE) >> 20;
    if (!MONADIC_INSTRUCTION(opcode)) {
        unsigned int Fn = getFn(opcode);
        float64 rFn;

        switch (fpa11->fType[Fn]) {
        case typeSingle:
            rFn = float32_to_float64(fpa11->fpreg[Fn].fSingle);
            break;

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

        default:
            return 0;
        }

        if (dyadic_double[opc_mask_shift]) {
            rFd->fDouble = dyadic_double[opc_mask_shift](roundData, rFn, rFm);
        } else {
            return 0;
        }
    } else {
        if (monadic_double[opc_mask_shift]) {
            rFd->fDouble = monadic_double[opc_mask_shift](roundData, rFm);
        } else {
            return 0;
        }
    }

    return 1;
}