fpa11_cpdt.c

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/*
    NetWinder Floating Point Emulator
    (c) Rebel.com, 1998-1999
    (c) Philip Blundell, 1998, 2001

    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"
#include "fpmodule.h"
#include "fpmodule.inl"

#include <linux/uaccess.h>

static inline void loadSingle(const unsigned int Fn, const unsigned int __user *pMem)
{
    FPA11 *fpa11 = GET_FPA11();
    fpa11->fType[Fn] = typeSingle;
    get_user(fpa11->fpreg[Fn].fSingle, pMem);
}

static inline void loadDouble(const unsigned int Fn, const unsigned int __user *pMem)
{
    FPA11 *fpa11 = GET_FPA11();
    unsigned int *p;
    p = (unsigned int *) &fpa11->fpreg[Fn].fDouble;
    fpa11->fType[Fn] = typeDouble;
#ifdef __ARMEB__
    get_user(p[0], &pMem[0]);   /* sign & exponent */
    get_user(p[1], &pMem[1]);
#else
    get_user(p[0], &pMem[1]);
    get_user(p[1], &pMem[0]);   /* sign & exponent */
#endif
}

#ifdef CONFIG_FPE_NWFPE_XP
static inline void loadExtended(const unsigned int Fn, const unsigned int __user *pMem)
{
    FPA11 *fpa11 = GET_FPA11();
    unsigned int *p;
    p = (unsigned int *) &fpa11->fpreg[Fn].fExtended;
    fpa11->fType[Fn] = typeExtended;
    get_user(p[0], &pMem[0]);   /* sign & exponent */
#ifdef __ARMEB__
    get_user(p[1], &pMem[1]);   /* ms bits */
    get_user(p[2], &pMem[2]);   /* ls bits */
#else
    get_user(p[1], &pMem[2]);   /* ls bits */
    get_user(p[2], &pMem[1]);   /* ms bits */
#endif
}
#endif

static inline void loadMultiple(const unsigned int Fn, const unsigned int __user *pMem)
{
    FPA11 *fpa11 = GET_FPA11();
    register unsigned int *p;
    unsigned long x;

    p = (unsigned int *) &(fpa11->fpreg[Fn]);
    get_user(x, &pMem[0]);
    fpa11->fType[Fn] = (x >> 14) & 0x00000003;

    switch (fpa11->fType[Fn]) {
    case typeSingle:
    case typeDouble:
        {
            get_user(p[0], &pMem[2]);   /* Single */
            get_user(p[1], &pMem[1]);   /* double msw */
            p[2] = 0;           /* empty */
        }
        break;

#ifdef CONFIG_FPE_NWFPE_XP
    case typeExtended:
        {
            get_user(p[1], &pMem[2]);
            get_user(p[2], &pMem[1]);   /* msw */
            p[0] = (x & 0x80003fff);
        }
        break;
#endif
    }
}

static inline void storeSingle(struct roundingData *roundData, const unsigned int Fn, unsigned int __user *pMem)
{
    FPA11 *fpa11 = GET_FPA11();
    union {
        float32 f;
        unsigned int i[1];
    } val;

    switch (fpa11->fType[Fn]) {
    case typeDouble:
        val.f = float64_to_float32(roundData, fpa11->fpreg[Fn].fDouble);
        break;

#ifdef CONFIG_FPE_NWFPE_XP
    case typeExtended:
        val.f = floatx80_to_float32(roundData, fpa11->fpreg[Fn].fExtended);
        break;
#endif

    default:
        val.f = fpa11->fpreg[Fn].fSingle;
    }

    put_user(val.i[0], pMem);
}

static inline void storeDouble(struct roundingData *roundData, const unsigned int Fn, unsigned int __user *pMem)
{
    FPA11 *fpa11 = GET_FPA11();
    union {
        float64 f;
        unsigned int i[2];
    } val;

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

#ifdef CONFIG_FPE_NWFPE_XP
    case typeExtended:
        val.f = floatx80_to_float64(roundData, fpa11->fpreg[Fn].fExtended);
        break;
#endif

    default:
        val.f = fpa11->fpreg[Fn].fDouble;
    }

#ifdef __ARMEB__
    put_user(val.i[0], &pMem[0]);   /* msw */
    put_user(val.i[1], &pMem[1]);   /* lsw */
#else
    put_user(val.i[1], &pMem[0]);   /* msw */
    put_user(val.i[0], &pMem[1]);   /* lsw */
#endif
}

#ifdef CONFIG_FPE_NWFPE_XP
static inline void storeExtended(const unsigned int Fn, unsigned int __user *pMem)
{
    FPA11 *fpa11 = GET_FPA11();
    union {
        floatx80 f;
        unsigned int i[3];
    } val;

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

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

    default:
        val.f = fpa11->fpreg[Fn].fExtended;
    }

    put_user(val.i[0], &pMem[0]);   /* sign & exp */
#ifdef __ARMEB__
    put_user(val.i[1], &pMem[1]);   /* msw */
    put_user(val.i[2], &pMem[2]);
#else
    put_user(val.i[1], &pMem[2]);
    put_user(val.i[2], &pMem[1]);   /* msw */
#endif
}
#endif

static inline void storeMultiple(const unsigned int Fn, unsigned int __user *pMem)
{
    FPA11 *fpa11 = GET_FPA11();
    register unsigned int nType, *p;

    p = (unsigned int *) &(fpa11->fpreg[Fn]);
    nType = fpa11->fType[Fn];

    switch (nType) {
    case typeSingle:
    case typeDouble:
        {
            put_user(p[0], &pMem[2]);   /* single */
            put_user(p[1], &pMem[1]);   /* double msw */
            put_user(nType << 14, &pMem[0]);
        }
        break;

#ifdef CONFIG_FPE_NWFPE_XP
    case typeExtended:
        {
            put_user(p[2], &pMem[1]);   /* msw */
            put_user(p[1], &pMem[2]);
            put_user((p[0] & 0x80003fff) | (nType << 14), &pMem[0]);
        }
        break;
#endif
    }
}

unsigned int PerformLDF(const unsigned int opcode)
{
    unsigned int __user *pBase, *pAddress, *pFinal;
    unsigned int nRc = 1, write_back = WRITE_BACK(opcode);

    pBase = (unsigned int __user *) readRegister(getRn(opcode));
    if (REG_PC == getRn(opcode)) {
        pBase += 2;
        write_back = 0;
    }

    pFinal = pBase;
    if (BIT_UP_SET(opcode))
        pFinal += getOffset(opcode);
    else
        pFinal -= getOffset(opcode);

    if (PREINDEXED(opcode))
        pAddress = pFinal;
    else
        pAddress = pBase;

    switch (opcode & MASK_TRANSFER_LENGTH) {
    case TRANSFER_SINGLE:
        loadSingle(getFd(opcode), pAddress);
        break;
    case TRANSFER_DOUBLE:
        loadDouble(getFd(opcode), pAddress);
        break;
#ifdef CONFIG_FPE_NWFPE_XP
    case TRANSFER_EXTENDED:
        loadExtended(getFd(opcode), pAddress);
        break;
#endif
    default:
        nRc = 0;
    }

    if (write_back)
        writeRegister(getRn(opcode), (unsigned long) pFinal);
    return nRc;
}

unsigned int PerformSTF(const unsigned int opcode)
{
    unsigned int __user *pBase, *pAddress, *pFinal;
    unsigned int nRc = 1, write_back = WRITE_BACK(opcode);
    struct roundingData roundData;

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

    pBase = (unsigned int __user *) readRegister(getRn(opcode));
    if (REG_PC == getRn(opcode)) {
        pBase += 2;
        write_back = 0;
    }

    pFinal = pBase;
    if (BIT_UP_SET(opcode))
        pFinal += getOffset(opcode);
    else
        pFinal -= getOffset(opcode);

    if (PREINDEXED(opcode))
        pAddress = pFinal;
    else
        pAddress = pBase;

    switch (opcode & MASK_TRANSFER_LENGTH) {
    case TRANSFER_SINGLE:
        storeSingle(&roundData, getFd(opcode), pAddress);
        break;
    case TRANSFER_DOUBLE:
        storeDouble(&roundData, getFd(opcode), pAddress);
        break;
#ifdef CONFIG_FPE_NWFPE_XP
    case TRANSFER_EXTENDED:
        storeExtended(getFd(opcode), pAddress);
        break;
#endif
    default:
        nRc = 0;
    }

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

    if (write_back)
        writeRegister(getRn(opcode), (unsigned long) pFinal);
    return nRc;
}

unsigned int PerformLFM(const unsigned int opcode)
{
    unsigned int __user *pBase, *pAddress, *pFinal;
    unsigned int i, Fd, write_back = WRITE_BACK(opcode);

    pBase = (unsigned int __user *) readRegister(getRn(opcode));
    if (REG_PC == getRn(opcode)) {
        pBase += 2;
        write_back = 0;
    }

    pFinal = pBase;
    if (BIT_UP_SET(opcode))
        pFinal += getOffset(opcode);
    else
        pFinal -= getOffset(opcode);

    if (PREINDEXED(opcode))
        pAddress = pFinal;
    else
        pAddress = pBase;

    Fd = getFd(opcode);
    for (i = getRegisterCount(opcode); i > 0; i--) {
        loadMultiple(Fd, pAddress);
        pAddress += 3;
        Fd++;
        if (Fd == 8)
            Fd = 0;
    }

    if (write_back)
        writeRegister(getRn(opcode), (unsigned long) pFinal);
    return 1;
}

unsigned int PerformSFM(const unsigned int opcode)
{
    unsigned int __user *pBase, *pAddress, *pFinal;
    unsigned int i, Fd, write_back = WRITE_BACK(opcode);

    pBase = (unsigned int __user *) readRegister(getRn(opcode));
    if (REG_PC == getRn(opcode)) {
        pBase += 2;
        write_back = 0;
    }

    pFinal = pBase;
    if (BIT_UP_SET(opcode))
        pFinal += getOffset(opcode);
    else
        pFinal -= getOffset(opcode);

    if (PREINDEXED(opcode))
        pAddress = pFinal;
    else
        pAddress = pBase;

    Fd = getFd(opcode);
    for (i = getRegisterCount(opcode); i > 0; i--) {
        storeMultiple(Fd, pAddress);
        pAddress += 3;
        Fd++;
        if (Fd == 8)
            Fd = 0;
    }

    if (write_back)
        writeRegister(getRn(opcode), (unsigned long) pFinal);
    return 1;
}

unsigned int EmulateCPDT(const unsigned int opcode)
{
    unsigned int nRc = 0;

    if (LDF_OP(opcode)) {
        nRc = PerformLDF(opcode);
    } else if (LFM_OP(opcode)) {
        nRc = PerformLFM(opcode);
    } else if (STF_OP(opcode)) {
        nRc = PerformSTF(opcode);
    } else if (SFM_OP(opcode)) {
        nRc = PerformSFM(opcode);
    } else {
        nRc = 0;
    }

    return nRc;
}