// SPDX-License-Identifier: GPL-2.0
/*---------------------------------------------------------------------------+
 |  reg_ld_str.c                                                             |
 |                                                                           |
 | All of the functions which transfer data between user memory and FPU_REGs.|
 |                                                                           |
 | Copyright (C) 1992,1993,1994,1996,1997                                    |
 |                  W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
 |                  E-mail   billm@suburbia.net                              |
 |                                                                           |
 |                                                                           |
 +---------------------------------------------------------------------------*/

/*---------------------------------------------------------------------------+
 | Note:                                                                     |
 |    The file contains code which accesses user memory.                     |
 |    Emulator static data may change when user memory is accessed, due to   |
 |    other processes using the emulator while swapping is in progress.      |
 +---------------------------------------------------------------------------*/

#include "fpu_emu.h"

#include <linux/uaccess.h>

#include "fpu_system.h"
#include "exception.h"
#include "reg_constant.h"
#include "control_w.h"
#include "status_w.h"

#define DOUBLE_Emax 1023        /* largest valid exponent */
#define DOUBLE_Ebias 1023
#define DOUBLE_Emin (-1022)     /* smallest valid exponent */

#define SINGLE_Emax 127         /* largest valid exponent */
#define SINGLE_Ebias 127
#define SINGLE_Emin (-126)      /* smallest valid exponent */

static u_char normalize_no_excep(FPU_REG *r, int exp, int sign)
{
        u_char tag;

        setexponent16(r, exp);

        tag = FPU_normalize_nuo(r);
        stdexp(r);
        if (sign)
                setnegative(r);

        return tag;
}

int FPU_tagof(FPU_REG *ptr)
{
        int exp;

        exp = exponent16(ptr) & 0x7fff;
        if (exp == 0) {
                if (!(ptr->sigh | ptr->sigl)) {
                        return TAG_Zero;
                }
                /* The number is a de-normal or pseudodenormal. */
                return TAG_Special;
        }

        if (exp == 0x7fff) {
                /* Is an Infinity, a NaN, or an unsupported data type. */
                return TAG_Special;
        }

        if (!(ptr->sigh & 0x80000000)) {
                /* Unsupported data type. */
                /* Valid numbers have the ms bit set to 1. */
                /* Unnormal. */
                return TAG_Special;
        }

        return TAG_Valid;
}

/* Get a long double from user memory */
int FPU_load_extended(long double __user *s, int stnr)
{
        FPU_REG *sti_ptr = &st(stnr);

        RE_ENTRANT_CHECK_OFF;
        FPU_access_ok(s, 10);
        FPU_copy_from_user(sti_ptr, s, 10);
        RE_ENTRANT_CHECK_ON;

        return FPU_tagof(sti_ptr);
}

/* Get a double from user memory */
int FPU_load_double(double __user *dfloat, FPU_REG *loaded_data)
{
        int exp, tag, negative;
        unsigned m64, l64;

        RE_ENTRANT_CHECK_OFF;
        FPU_access_ok(dfloat, 8);
        FPU_get_user(m64, 1 + (unsigned long __user *)dfloat);
        FPU_get_user(l64, (unsigned long __user *)dfloat);
        RE_ENTRANT_CHECK_ON;

        negative = (m64 & 0x80000000) ? SIGN_Negative : SIGN_Positive;
        exp = ((m64 & 0x7ff00000) >> 20) - DOUBLE_Ebias + EXTENDED_Ebias;
        m64 &= 0xfffff;
        if (exp > DOUBLE_Emax + EXTENDED_Ebias) {
                /* Infinity or NaN */
                if ((m64 == 0) && (l64 == 0)) {
                        /* +- infinity */
                        loaded_data->sigh = 0x80000000;
                        loaded_data->sigl = 0x00000000;
                        exp = EXP_Infinity + EXTENDED_Ebias;
                        tag = TAG_Special;
                } else {
                        /* Must be a signaling or quiet NaN */
                        exp = EXP_NaN + EXTENDED_Ebias;
                        loaded_data->sigh = (m64 << 11) | 0x80000000;
                        loaded_data->sigh |= l64 >> 21;
                        loaded_data->sigl = l64 << 11;
                        tag = TAG_Special;      /* The calling function must look for NaNs */
                }
        } else if (exp < DOUBLE_Emin + EXTENDED_Ebias) {
                /* Zero or de-normal */
                if ((m64 == 0) && (l64 == 0)) {
                        /* Zero */
                        reg_copy(&CONST_Z, loaded_data);
                        exp = 0;
                        tag = TAG_Zero;
                } else {
                        /* De-normal */
                        loaded_data->sigh = m64 << 11;
                        loaded_data->sigh |= l64 >> 21;
                        loaded_data->sigl = l64 << 11;

                        return normalize_no_excep(loaded_data, DOUBLE_Emin,
                                                  negative)
                            | (denormal_operand() < 0 ? FPU_Exception : 0);
                }
        } else {
                loaded_data->sigh = (m64 << 11) | 0x80000000;
                loaded_data->sigh |= l64 >> 21;
                loaded_data->sigl = l64 << 11;

                tag = TAG_Valid;
        }

        setexponent16(loaded_data, exp | negative);

        return tag;
}

/* Get a float from user memory */
int FPU_load_single(float __user *single, FPU_REG *loaded_data)
{
        unsigned m32;
        int exp, tag, negative;

        RE_ENTRANT_CHECK_OFF;
        FPU_access_ok(single, 4);
        FPU_get_user(m32, (unsigned long __user *)single);
        RE_ENTRANT_CHECK_ON;

        negative = (m32 & 0x80000000) ? SIGN_Negative : SIGN_Positive;

        if (!(m32 & 0x7fffffff)) {
                /* Zero */
                reg_copy(&CONST_Z, loaded_data);
                addexponent(loaded_data, negative);
                return TAG_Zero;
        }
        exp = ((m32 & 0x7f800000) >> 23) - SINGLE_Ebias + EXTENDED_Ebias;
        m32 = (m32 & 0x7fffff) << 8;
        if (exp < SINGLE_Emin + EXTENDED_Ebias) {
                /* De-normals */
                loaded_data->sigh = m32;
                loaded_data->sigl = 0;

                return normalize_no_excep(loaded_data, SINGLE_Emin, negative)
                    | (denormal_operand() < 0 ? FPU_Exception : 0);
        } else if (exp > SINGLE_Emax + EXTENDED_Ebias) {
                /* Infinity or NaN */
                if (m32 == 0) {
                        /* +- infinity */
                        loaded_data->sigh = 0x80000000;
                        loaded_data->sigl = 0x00000000;
                        exp = EXP_Infinity + EXTENDED_Ebias;
                        tag = TAG_Special;
                } else {
                        /* Must be a signaling or quiet NaN */
                        exp = EXP_NaN + EXTENDED_Ebias;
                        loaded_data->sigh = m32 | 0x80000000;
                        loaded_data->sigl = 0;
                        tag = TAG_Special;      /* The calling function must look for NaNs */
                }
        } else {
                loaded_data->sigh = m32 | 0x80000000;
                loaded_data->sigl = 0;
                tag = TAG_Valid;
        }

        setexponent16(loaded_data, exp | negative);     /* Set the sign. */

        return tag;
}

/* Get a long long from user memory */
int FPU_load_int64(long long __user *_s)
{
        long long s;
        int sign;
        FPU_REG *st0_ptr = &st(0);

        RE_ENTRANT_CHECK_OFF;
        FPU_access_ok(_s, 8);
        if (copy_from_user(&s, _s, 8))
                FPU_abort;
        RE_ENTRANT_CHECK_ON;

        if (s == 0) {
                reg_copy(&CONST_Z, st0_ptr);
                return TAG_Zero;
        }

        if (s > 0)
                sign = SIGN_Positive;
        else {
                s = -s;
                sign = SIGN_Negative;
        }

        significand(st0_ptr) = s;

        return normalize_no_excep(st0_ptr, 63, sign);
}

/* Get a long from user memory */
int FPU_load_int32(long __user *_s, FPU_REG *loaded_data)
{
        long s;
        int negative;

        RE_ENTRANT_CHECK_OFF;
        FPU_access_ok(_s, 4);
        FPU_get_user(s, _s);
        RE_ENTRANT_CHECK_ON;

        if (s == 0) {
                reg_copy(&CONST_Z, loaded_data);
                return TAG_Zero;
        }

        if (s > 0)
                negative = SIGN_Positive;
        else {
                s = -s;
                negative = SIGN_Negative;
        }

        loaded_data->sigh = s;
        loaded_data->sigl = 0;

        return normalize_no_excep(loaded_data, 31, negative);
}

/* Get a short from user memory */
int FPU_load_int16(short __user *_s, FPU_REG *loaded_data)
{
        int s, negative;

        RE_ENTRANT_CHECK_OFF;
        FPU_access_ok(_s, 2);
        /* Cast as short to get the sign extended. */
        FPU_get_user(s, _s);
        RE_ENTRANT_CHECK_ON;

        if (s == 0) {
                reg_copy(&CONST_Z, loaded_data);
                return TAG_Zero;
        }

        if (s > 0)
                negative = SIGN_Positive;
        else {
                s = -s;
                negative = SIGN_Negative;
        }

        loaded_data->sigh = s << 16;
        loaded_data->sigl = 0;

        return normalize_no_excep(loaded_data, 15, negative);
}

/* Get a packed bcd array from user memory */
int FPU_load_bcd(u_char __user *s)
{
        FPU_REG *st0_ptr = &st(0);
        int pos;
        u_char bcd;
        long long l = 0;
        int sign;

        RE_ENTRANT_CHECK_OFF;
        FPU_access_ok(s, 10);
        RE_ENTRANT_CHECK_ON;
        for (pos = 8; pos >= 0; pos--) {
                l *= 10;
                RE_ENTRANT_CHECK_OFF;
                FPU_get_user(bcd, s + pos);
                RE_ENTRANT_CHECK_ON;
                l += bcd >> 4;
                l *= 10;
                l += bcd & 0x0f;
        }

        RE_ENTRANT_CHECK_OFF;
        FPU_get_user(sign, s + 9);
        sign = sign & 0x80 ? SIGN_Negative : SIGN_Positive;
        RE_ENTRANT_CHECK_ON;

        if (l == 0) {
                reg_copy(&CONST_Z, st0_ptr);
                addexponent(st0_ptr, sign);     /* Set the sign. */
                return TAG_Zero;
        } else {
                significand(st0_ptr) = l;
                return normalize_no_excep(st0_ptr, 63, sign);
        }
}

/*===========================================================================*/

/* Put a long double into user memory */
int FPU_store_extended(FPU_REG *st0_ptr, u_char st0_tag,
                       long double __user * d)
{
        /*
           The only exception raised by an attempt to store to an
           extended format is the Invalid Stack exception, i.e.
           attempting to store from an empty register.
         */

        if (st0_tag != TAG_Empty) {
                RE_ENTRANT_CHECK_OFF;
                FPU_access_ok(d, 10);

                FPU_put_user(st0_ptr->sigl, (unsigned long __user *)d);
                FPU_put_user(st0_ptr->sigh,
                             (unsigned long __user *)((u_char __user *) d + 4));
                FPU_put_user(exponent16(st0_ptr),
                             (unsigned short __user *)((u_char __user *) d +
                                                       8));
                RE_ENTRANT_CHECK_ON;

                return 1;
        }

        /* Empty register (stack underflow) */
        EXCEPTION(EX_StackUnder);
        if (control_word & CW_Invalid) {
                /* The masked response */
                /* Put out the QNaN indefinite */
                RE_ENTRANT_CHECK_OFF;
                FPU_access_ok(d, 10);
                FPU_put_user(0, (unsigned long __user *)d);
                FPU_put_user(0xc0000000, 1 + (unsigned long __user *)d);
                FPU_put_user(0xffff, 4 + (short __user *)d);
                RE_ENTRANT_CHECK_ON;
                return 1;
        } else
                return 0;

}

/* Put a double into user memory */
int FPU_store_double(FPU_REG *st0_ptr, u_char st0_tag, double __user *dfloat)
{
        unsigned long l[2];
        unsigned long increment = 0;    /* avoid gcc warnings */
        int precision_loss;
        int exp;
        FPU_REG tmp;

        l[0] = 0;
        l[1] = 0;
        if (st0_tag == TAG_Valid) {
                reg_copy(st0_ptr, &tmp);
                exp = exponent(&tmp);

                if (exp < DOUBLE_Emin) {        /* It may be a denormal */
                        addexponent(&tmp, -DOUBLE_Emin + 52);   /* largest exp to be 51 */
denormal_arg:
                        if ((precision_loss = FPU_round_to_int(&tmp, st0_tag))) {
#ifdef PECULIAR_486
                                /* Did it round to a non-denormal ? */
                                /* This behaviour might be regarded as peculiar, it appears
                                   that the 80486 rounds to the dest precision, then
                                   converts to decide underflow. */
                                if (!
                                    ((tmp.sigh == 0x00100000) && (tmp.sigl == 0)
                                     && (st0_ptr->sigl & 0x000007ff)))
#endif /* PECULIAR_486 */
                                {
                                        EXCEPTION(EX_Underflow);
                                        /* This is a special case: see sec 16.2.5.1 of
                                           the 80486 book */
                                        if (!(control_word & CW_Underflow))
                                                return 0;
                                }
                                EXCEPTION(precision_loss);
                                if (!(control_word & CW_Precision))
                                        return 0;
                        }
                        l[0] = tmp.sigl;
                        l[1] = tmp.sigh;
                } else {
                        if (tmp.sigl & 0x000007ff) {
                                precision_loss = 1;
                                switch (control_word & CW_RC) {
                                case RC_RND:
                                        /* Rounding can get a little messy.. */
                                        increment = ((tmp.sigl & 0x7ff) > 0x400) |      /* nearest */
                                            ((tmp.sigl & 0xc00) == 0xc00);      /* odd -> even */
                                        break;
                                case RC_DOWN:   /* towards -infinity */
                                        increment =
                                            signpositive(&tmp) ? 0 : tmp.
                                            sigl & 0x7ff;
                                        break;
                                case RC_UP:     /* towards +infinity */
                                        increment =
                                            signpositive(&tmp) ? tmp.
                                            sigl & 0x7ff : 0;
                                        break;
                                case RC_CHOP:
                                        increment = 0;
                                        break;
                                }

                                /* Truncate the mantissa */
                                tmp.sigl &= 0xfffff800;

                                if (increment) {
                                        if (tmp.sigl >= 0xfffff800) {
                                                /* the sigl part overflows */
                                                if (tmp.sigh == 0xffffffff) {
                                                        /* The sigh part overflows */
                                                        tmp.sigh = 0x80000000;
                                                        exp++;
                                                        if (exp >= EXP_OVER)
                                                                goto overflow;
                                                } else {
                                                        tmp.sigh++;
                                                }
                                                tmp.sigl = 0x00000000;
                                        } else {
                                                /* We only need to increment sigl */
                                                tmp.sigl += 0x00000800;
                                        }
                                }
                        } else
                                precision_loss = 0;

                        l[0] = (tmp.sigl >> 11) | (tmp.sigh << 21);
                        l[1] = ((tmp.sigh >> 11) & 0xfffff);

                        if (exp > DOUBLE_Emax) {
                              overflow:
                                EXCEPTION(EX_Overflow);
                                if (!(control_word & CW_Overflow))
                                        return 0;
                                set_precision_flag_up();
                                if (!(control_word & CW_Precision))
                                        return 0;

                                /* This is a special case: see sec 16.2.5.1 of the 80486 book */
                                /* Overflow to infinity */
                                l[1] = 0x7ff00000;      /* Set to + INF */
                        } else {
                                if (precision_loss) {
                                        if (increment)
                                                set_precision_flag_up();
                                        else
                                                set_precision_flag_down();
                                }
                                /* Add the exponent */
                                l[1] |= (((exp + DOUBLE_Ebias) & 0x7ff) << 20);
                        }
                }
        } else if (st0_tag == TAG_Zero) {
                /* Number is zero */
        } else if (st0_tag == TAG_Special) {
                st0_tag = FPU_Special(st0_ptr);
                if (st0_tag == TW_Denormal) {
                        /* A denormal will always underflow. */
#ifndef PECULIAR_486
                        /* An 80486 is supposed to be able to generate
                           a denormal exception here, but... */
                        /* Underflow has priority. */
                        if (control_word & CW_Underflow)
                                denormal_operand();
#endif /* PECULIAR_486 */
                        reg_copy(st0_ptr, &tmp);
                        goto denormal_arg;
                } else if (st0_tag == TW_Infinity) {
                        l[1] = 0x7ff00000;
                } else if (st0_tag == TW_NaN) {
                        /* Is it really a NaN ? */
                        if ((exponent(st0_ptr) == EXP_OVER)
                            && (st0_ptr->sigh & 0x80000000)) {
                                /* See if we can get a valid NaN from the FPU_REG */
                                l[0] =
                                    (st0_ptr->sigl >> 11) | (st0_ptr->
                                                             sigh << 21);
                                l[1] = ((st0_ptr->sigh >> 11) & 0xfffff);
                                if (!(st0_ptr->sigh & 0x40000000)) {
                                        /* It is a signalling NaN */
                                        EXCEPTION(EX_Invalid);
                                        if (!(control_word & CW_Invalid))
                                                return 0;
                                        l[1] |= (0x40000000 >> 11);
                                }
                                l[1] |= 0x7ff00000;
                        } else {
                                /* It is an unsupported data type */
                                EXCEPTION(EX_Invalid);
                                if (!(control_word & CW_Invalid))
                                        return 0;
                                l[1] = 0xfff80000;
                        }
                }
        } else if (st0_tag == TAG_Empty) {
                /* Empty register (stack underflow) */
                EXCEPTION(EX_StackUnder);
                if (control_word & CW_Invalid) {
                        /* The masked response */
                        /* Put out the QNaN indefinite */
                        RE_ENTRANT_CHECK_OFF;
                        FPU_access_ok(dfloat, 8);
                        FPU_put_user(0, (unsigned long __user *)dfloat);
                        FPU_put_user(0xfff80000,
                                     1 + (unsigned long __user *)dfloat);
                        RE_ENTRANT_CHECK_ON;
                        return 1;
                } else
                        return 0;
        }
        if (getsign(st0_ptr))
                l[1] |= 0x80000000;

        RE_ENTRANT_CHECK_OFF;
        FPU_access_ok(dfloat, 8);
        FPU_put_user(l[0], (unsigned long __user *)dfloat);
        FPU_put_user(l[1], 1 + (unsigned long __user *)dfloat);
        RE_ENTRANT_CHECK_ON;

        return 1;
}

/* Put a float into user memory */
int FPU_store_single(FPU_REG *st0_ptr, u_char st0_tag, float __user *single)
{
        long templ = 0;
        unsigned long increment = 0;    /* avoid gcc warnings */
        int precision_loss;
        int exp;
        FPU_REG tmp;

        if (st0_tag == TAG_Valid) {

                reg_copy(st0_ptr, &tmp);
                exp = exponent(&tmp);

                if (exp < SINGLE_Emin) {
                        addexponent(&tmp, -SINGLE_Emin + 23);   /* largest exp to be 22 */

                      denormal_arg:

                        if ((precision_loss = FPU_round_to_int(&tmp, st0_tag))) {
#ifdef PECULIAR_486
                                /* Did it round to a non-denormal ? */
                                /* This behaviour might be regarded as peculiar, it appears
                                   that the 80486 rounds to the dest precision, then
                                   converts to decide underflow. */
                                if (!((tmp.sigl == 0x00800000) &&
                                      ((st0_ptr->sigh & 0x000000ff)
                                       || st0_ptr->sigl)))
#endif /* PECULIAR_486 */
                                {
                                        EXCEPTION(EX_Underflow);
                                        /* This is a special case: see sec 16.2.5.1 of
                                           the 80486 book */
                                        if (!(control_word & CW_Underflow))
                                                return 0;
                                }
                                EXCEPTION(precision_loss);
                                if (!(control_word & CW_Precision))
                                        return 0;
                        }
                        templ = tmp.sigl;
                } else {
                        if (tmp.sigl | (tmp.sigh & 0x000000ff)) {
                                unsigned long sigh = tmp.sigh;
                                unsigned long sigl = tmp.sigl;

                                precision_loss = 1;
                                switch (control_word & CW_RC) {
                                case RC_RND:
                                        increment = ((sigh & 0xff) > 0x80)      /* more than half */
                                            ||(((sigh & 0xff) == 0x80) && sigl) /* more than half */
                                            ||((sigh & 0x180) == 0x180);        /* round to even */
                                        break;
                                case RC_DOWN:   /* towards -infinity */
                                        increment = signpositive(&tmp)
                                            ? 0 : (sigl | (sigh & 0xff));
                                        break;
                                case RC_UP:     /* towards +infinity */
                                        increment = signpositive(&tmp)
                                            ? (sigl | (sigh & 0xff)) : 0;
                                        break;
                                case RC_CHOP:
                                        increment = 0;
                                        break;
                                }

                                /* Truncate part of the mantissa */
                                tmp.sigl = 0;

                                if (increment) {
                                        if (sigh >= 0xffffff00) {
                                                /* The sigh part overflows */
                                                tmp.sigh = 0x80000000;
                                                exp++;
                                                if (exp >= EXP_OVER)
                                                        goto overflow;
                                        } else {
                                                tmp.sigh &= 0xffffff00;
                                                tmp.sigh += 0x100;
                                        }
                                } else {
                                        tmp.sigh &= 0xffffff00; /* Finish the truncation */
                                }
                        } else
                                precision_loss = 0;

                        templ = (tmp.sigh >> 8) & 0x007fffff;

                        if (exp > SINGLE_Emax) {
                              overflow:
                                EXCEPTION(EX_Overflow);
                                if (!(control_word & CW_Overflow))
                                        return 0;
                                set_precision_flag_up();
                                if (!(control_word & CW_Precision))
                                        return 0;

                                /* This is a special case: see sec 16.2.5.1 of the 80486 book. */
                                /* Masked response is overflow to infinity. */
                                templ = 0x7f800000;
                        } else {
                                if (precision_loss) {
                                        if (increment)
                                                set_precision_flag_up();
                                        else
                                                set_precision_flag_down();
                                }
                                /* Add the exponent */
                                templ |= ((exp + SINGLE_Ebias) & 0xff) << 23;
                        }
                }
        } else if (st0_tag == TAG_Zero) {
                templ = 0;
        } else if (st0_tag == TAG_Special) {
                st0_tag = FPU_Special(st0_ptr);
                if (st0_tag == TW_Denormal) {
                        reg_copy(st0_ptr, &tmp);

                        /* A denormal will always underflow. */
#ifndef PECULIAR_486
                        /* An 80486 is supposed to be able to generate
                           a denormal exception here, but... */
                        /* Underflow has priority. */
                        if (control_word & CW_Underflow)
                                denormal_operand();
#endif /* PECULIAR_486 */
                        goto denormal_arg;
                } else if (st0_tag == TW_Infinity) {
                        templ = 0x7f800000;
                } else if (st0_tag == TW_NaN) {
                        /* Is it really a NaN ? */
                        if ((exponent(st0_ptr) == EXP_OVER)
                            && (st0_ptr->sigh & 0x80000000)) {
                                /* See if we can get a valid NaN from the FPU_REG */
                                templ = st0_ptr->sigh >> 8;
                                if (!(st0_ptr->sigh & 0x40000000)) {
                                        /* It is a signalling NaN */
                                        EXCEPTION(EX_Invalid);
                                        if (!(control_word & CW_Invalid))
                                                return 0;
                                        templ |= (0x40000000 >> 8);
                                }
                                templ |= 0x7f800000;
                        } else {
                                /* It is an unsupported data type */
                                EXCEPTION(EX_Invalid);
                                if (!(control_word & CW_Invalid))
                                        return 0;
                                templ = 0xffc00000;
                        }
                }
#ifdef PARANOID
                else {
                        EXCEPTION(EX_INTERNAL | 0x164);
                        return 0;
                }
#endif
        } else if (st0_tag == TAG_Empty) {
                /* Empty register (stack underflow) */
                EXCEPTION(EX_StackUnder);
                if (control_word & EX_Invalid) {
                        /* The masked response */
                        /* Put out the QNaN indefinite */
                        RE_ENTRANT_CHECK_OFF;
                        FPU_access_ok(single, 4);
                        FPU_put_user(0xffc00000,
                                     (unsigned long __user *)single);
                        RE_ENTRANT_CHECK_ON;
                        return 1;
                } else
                        return 0;
        }
#ifdef PARANOID
        else {
                EXCEPTION(EX_INTERNAL | 0x163);
                return 0;
        }
#endif
        if (getsign(st0_ptr))
                templ |= 0x80000000;

        RE_ENTRANT_CHECK_OFF;
        FPU_access_ok(single, 4);
        FPU_put_user(templ, (unsigned long __user *)single);
        RE_ENTRANT_CHECK_ON;

        return 1;
}

/* Put a long long into user memory */
int FPU_store_int64(FPU_REG *st0_ptr, u_char st0_tag, long long __user *d)
{
        FPU_REG t;
        long long tll;
        int precision_loss;

        if (st0_tag == TAG_Empty) {
                /* Empty register (stack underflow) */
                EXCEPTION(EX_StackUnder);
                goto invalid_operand;
        } else if (st0_tag == TAG_Special) {
                st0_tag = FPU_Special(st0_ptr);
                if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
                        EXCEPTION(EX_Invalid);
                        goto invalid_operand;
                }
        }

        reg_copy(st0_ptr, &t);
        precision_loss = FPU_round_to_int(&t, st0_tag);
        ((long *)&tll)[0] = t.sigl;
        ((long *)&tll)[1] = t.sigh;
        if ((precision_loss == 1) ||
            ((t.sigh & 0x80000000) &&
             !((t.sigh == 0x80000000) && (t.sigl == 0) && signnegative(&t)))) {
                EXCEPTION(EX_Invalid);
                /* This is a special case: see sec 16.2.5.1 of the 80486 book */
              invalid_operand:
                if (control_word & EX_Invalid) {
                        /* Produce something like QNaN "indefinite" */
                        tll = 0x8000000000000000LL;
                } else
                        return 0;
        } else {
                if (precision_loss)
                        set_precision_flag(precision_loss);
                if (signnegative(&t))
                        tll = -tll;
        }

        RE_ENTRANT_CHECK_OFF;
        FPU_access_ok(d, 8);
        if (copy_to_user(d, &tll, 8))
                FPU_abort;
        RE_ENTRANT_CHECK_ON;

        return 1;
}

/* Put a long into user memory */
int FPU_store_int32(FPU_REG *st0_ptr, u_char st0_tag, long __user *d)
{
        FPU_REG t;
        int precision_loss;

        if (st0_tag == TAG_Empty) {
                /* Empty register (stack underflow) */
                EXCEPTION(EX_StackUnder);
                goto invalid_operand;
        } else if (st0_tag == TAG_Special) {
                st0_tag = FPU_Special(st0_ptr);
                if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
                        EXCEPTION(EX_Invalid);
                        goto invalid_operand;
                }
        }

        reg_copy(st0_ptr, &t);
        precision_loss = FPU_round_to_int(&t, st0_tag);
        if (t.sigh ||
            ((t.sigl & 0x80000000) &&
             !((t.sigl == 0x80000000) && signnegative(&t)))) {
                EXCEPTION(EX_Invalid);
                /* This is a special case: see sec 16.2.5.1 of the 80486 book */
              invalid_operand:
                if (control_word & EX_Invalid) {
                        /* Produce something like QNaN "indefinite" */
                        t.sigl = 0x80000000;
                } else
                        return 0;
        } else {
                if (precision_loss)
                        set_precision_flag(precision_loss);
                if (signnegative(&t))
                        t.sigl = -(long)t.sigl;
        }

        RE_ENTRANT_CHECK_OFF;
        FPU_access_ok(d, 4);
        FPU_put_user(t.sigl, (unsigned long __user *)d);
        RE_ENTRANT_CHECK_ON;

        return 1;
}

/* Put a short into user memory */
int FPU_store_int16(FPU_REG *st0_ptr, u_char st0_tag, short __user *d)
{
        FPU_REG t;
        int precision_loss;

        if (st0_tag == TAG_Empty) {
                /* Empty register (stack underflow) */
                EXCEPTION(EX_StackUnder);
                goto invalid_operand;
        } else if (st0_tag == TAG_Special) {
                st0_tag = FPU_Special(st0_ptr);
                if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
                        EXCEPTION(EX_Invalid);
                        goto invalid_operand;
                }
        }

        reg_copy(st0_ptr, &t);
        precision_loss = FPU_round_to_int(&t, st0_tag);
        if (t.sigh ||
            ((t.sigl & 0xffff8000) &&
             !((t.sigl == 0x8000) && signnegative(&t)))) {
                EXCEPTION(EX_Invalid);
                /* This is a special case: see sec 16.2.5.1 of the 80486 book */
              invalid_operand:
                if (control_word & EX_Invalid) {
                        /* Produce something like QNaN "indefinite" */
                        t.sigl = 0x8000;
                } else
                        return 0;
        } else {
                if (precision_loss)
                        set_precision_flag(precision_loss);
                if (signnegative(&t))
                        t.sigl = -t.sigl;
        }

        RE_ENTRANT_CHECK_OFF;
        FPU_access_ok(d, 2);
        FPU_put_user((short)t.sigl, d);
        RE_ENTRANT_CHECK_ON;

        return 1;
}

/* Put a packed bcd array into user memory */
int FPU_store_bcd(FPU_REG *st0_ptr, u_char st0_tag, u_char __user *d)
{
        FPU_REG t;
        unsigned long long ll;
        u_char b;
        int i, precision_loss;
        u_char sign = (getsign(st0_ptr) == SIGN_NEG) ? 0x80 : 0;

        if (st0_tag == TAG_Empty) {
                /* Empty register (stack underflow) */
                EXCEPTION(EX_StackUnder);
                goto invalid_operand;
        } else if (st0_tag == TAG_Special) {
                st0_tag = FPU_Special(st0_ptr);
                if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
                        EXCEPTION(EX_Invalid);
                        goto invalid_operand;
                }
        }

        reg_copy(st0_ptr, &t);
        precision_loss = FPU_round_to_int(&t, st0_tag);
        ll = significand(&t);

        /* Check for overflow, by comparing with 999999999999999999 decimal. */
        if ((t.sigh > 0x0de0b6b3) ||
            ((t.sigh == 0x0de0b6b3) && (t.sigl > 0xa763ffff))) {
                EXCEPTION(EX_Invalid);
                /* This is a special case: see sec 16.2.5.1 of the 80486 book */
              invalid_operand:
                if (control_word & CW_Invalid) {
                        /* Produce the QNaN "indefinite" */
                        RE_ENTRANT_CHECK_OFF;
                        FPU_access_ok(d, 10);
                        for (i = 0; i < 7; i++)
                                FPU_put_user(0, d + i); /* These bytes "undefined" */
                        FPU_put_user(0xc0, d + 7);      /* This byte "undefined" */
                        FPU_put_user(0xff, d + 8);
                        FPU_put_user(0xff, d + 9);
                        RE_ENTRANT_CHECK_ON;
                        return 1;
                } else
                        return 0;
        } else if (precision_loss) {
                /* Precision loss doesn't stop the data transfer */
                set_precision_flag(precision_loss);
        }

        RE_ENTRANT_CHECK_OFF;
        FPU_access_ok(d, 10);
        RE_ENTRANT_CHECK_ON;
        for (i = 0; i < 9; i++) {
                b = FPU_div_small(&ll, 10);
                b |= (FPU_div_small(&ll, 10)) << 4;
                RE_ENTRANT_CHECK_OFF;
                FPU_put_user(b, d + i);
                RE_ENTRANT_CHECK_ON;
        }
        RE_ENTRANT_CHECK_OFF;
        FPU_put_user(sign, d + 9);
        RE_ENTRANT_CHECK_ON;

        return 1;
}

/*===========================================================================*/

/* r gets mangled such that sig is int, sign: 
   it is NOT normalized */
/* The return value (in eax) is zero if the result is exact,
   if bits are changed due to rounding, truncation, etc, then
   a non-zero value is returned */
/* Overflow is signaled by a non-zero return value (in eax).
   In the case of overflow, the returned significand always has the
   largest possible value */
int FPU_round_to_int(FPU_REG *r, u_char tag)
{
        u_char very_big;
        unsigned eax;

        if (tag == TAG_Zero) {
                /* Make sure that zero is returned */
                significand(r) = 0;
                return 0;       /* o.k. */
        }

        if (exponent(r) > 63) {
                r->sigl = r->sigh = ~0; /* The largest representable number */
                return 1;       /* overflow */
        }

        eax = FPU_shrxs(&r->sigl, 63 - exponent(r));
        very_big = !(~(r->sigh) | ~(r->sigl));  /* test for 0xfff...fff */
#define half_or_more    (eax & 0x80000000)
#define frac_part       (eax)
#define more_than_half  ((eax & 0x80000001) == 0x80000001)
        switch (control_word & CW_RC) {
        case RC_RND:
                if (more_than_half      /* nearest */
                    || (half_or_more && (r->sigl & 1))) {       /* odd -> even */
                        if (very_big)
                                return 1;       /* overflow */
                        significand(r)++;
                        return PRECISION_LOST_UP;
                }
                break;

        case RC_DOWN:
                if (frac_part && getsign(r)) {
                        if (very_big)
                                return 1;       /* overflow */
                        significand(r)++;
                        return PRECISION_LOST_UP;
                }
                break;
        case RC_UP:
                if (frac_part && !getsign(r)) {
                        if (very_big)
                                return 1;       /* overflow */
                        significand(r)++;
                        return PRECISION_LOST_UP;
                }
                break;
        case RC_CHOP:
                break;
        }

        return eax ? PRECISION_LOST_DOWN : 0;

}

/*===========================================================================*/

u_char __user *fldenv(fpu_addr_modes addr_modes, u_char __user *s)
{
        unsigned short tag_word = 0;
        u_char tag;
        int i;

        if ((addr_modes.default_mode == VM86) ||
            ((addr_modes.default_mode == PM16)
             ^ (addr_modes.override.operand_size == OP_SIZE_PREFIX))) {
                RE_ENTRANT_CHECK_OFF;
                FPU_access_ok(s, 0x0e);
                FPU_get_user(control_word, (unsigned short __user *)s);
                FPU_get_user(partial_status, (unsigned short __user *)(s + 2));
                FPU_get_user(tag_word, (unsigned short __user *)(s + 4));
                FPU_get_user(instruction_address.offset,
                             (unsigned short __user *)(s + 6));
                FPU_get_user(instruction_address.selector,
                             (unsigned short __user *)(s + 8));
                FPU_get_user(operand_address.offset,
                             (unsigned short __user *)(s + 0x0a));
                FPU_get_user(operand_address.selector,
                             (unsigned short __user *)(s + 0x0c));
                RE_ENTRANT_CHECK_ON;
                s += 0x0e;
                if (addr_modes.default_mode == VM86) {
                        instruction_address.offset
                            += (instruction_address.selector & 0xf000) << 4;
                        operand_address.offset +=
                            (operand_address.selector & 0xf000) << 4;
                }
        } else {
                RE_ENTRANT_CHECK_OFF;
                FPU_access_ok(s, 0x1c);
                FPU_get_user(control_word, (unsigned short __user *)s);
                FPU_get_user(partial_status, (unsigned short __user *)(s + 4));
                FPU_get_user(tag_word, (unsigned short __user *)(s + 8));
                FPU_get_user(instruction_address.offset,
                             (unsigned long __user *)(s + 0x0c));
                FPU_get_user(instruction_address.selector,
                             (unsigned short __user *)(s + 0x10));
                FPU_get_user(instruction_address.opcode,
                             (unsigned short __user *)(s + 0x12));
                FPU_get_user(operand_address.offset,
                             (unsigned long __user *)(s + 0x14));
                FPU_get_user(operand_address.selector,
                             (unsigned long __user *)(s + 0x18));
                RE_ENTRANT_CHECK_ON;
                s += 0x1c;
        }

#ifdef PECULIAR_486
        control_word &= ~0xe080;
#endif /* PECULIAR_486 */

        top = (partial_status >> SW_Top_Shift) & 7;

        if (partial_status & ~control_word & CW_Exceptions)
                partial_status |= (SW_Summary | SW_Backward);
        else
                partial_status &= ~(SW_Summary | SW_Backward);

        for (i = 0; i < 8; i++) {
                tag = tag_word & 3;
                tag_word >>= 2;

                if (tag == TAG_Empty)
                        /* New tag is empty.  Accept it */
                        FPU_settag(i, TAG_Empty);
                else if (FPU_gettag(i) == TAG_Empty) {
                        /* Old tag is empty and new tag is not empty.  New tag is determined
                           by old reg contents */
                        if (exponent(&fpu_register(i)) == -EXTENDED_Ebias) {
                                if (!
                                    (fpu_register(i).sigl | fpu_register(i).
                                     sigh))
                                        FPU_settag(i, TAG_Zero);
                                else
                                        FPU_settag(i, TAG_Special);
                        } else if (exponent(&fpu_register(i)) ==
                                   0x7fff - EXTENDED_Ebias) {
                                FPU_settag(i, TAG_Special);
                        } else if (fpu_register(i).sigh & 0x80000000)
                                FPU_settag(i, TAG_Valid);
                        else
                                FPU_settag(i, TAG_Special);     /* An Un-normal */
                }
                /* Else old tag is not empty and new tag is not empty.  Old tag
                   remains correct */
        }

        return s;
}

void FPU_frstor(fpu_addr_modes addr_modes, u_char __user *data_address)
{
        int i, regnr;
        u_char __user *s = fldenv(addr_modes, data_address);
        int offset = (top & 7) * 10, other = 80 - offset;

        /* Copy all registers in stack order. */
        RE_ENTRANT_CHECK_OFF;
        FPU_access_ok(s, 80);
        FPU_copy_from_user(register_base + offset, s, other);
        if (offset)
                FPU_copy_from_user(register_base, s + other, offset);
        RE_ENTRANT_CHECK_ON;

        for (i = 0; i < 8; i++) {
                regnr = (i + top) & 7;
                if (FPU_gettag(regnr) != TAG_Empty)
                        /* The loaded data over-rides all other cases. */
                        FPU_settag(regnr, FPU_tagof(&st(i)));
        }

}

u_char __user *fstenv(fpu_addr_modes addr_modes, u_char __user *d)
{
        if ((addr_modes.default_mode == VM86) ||
            ((addr_modes.default_mode == PM16)
             ^ (addr_modes.override.operand_size == OP_SIZE_PREFIX))) {
                RE_ENTRANT_CHECK_OFF;
                FPU_access_ok(d, 14);
#ifdef PECULIAR_486
                FPU_put_user(control_word & ~0xe080, (unsigned long __user *)d);
#else
                FPU_put_user(control_word, (unsigned short __user *)d);
#endif /* PECULIAR_486 */
                FPU_put_user(status_word(), (unsigned short __user *)(d + 2));
                FPU_put_user(fpu_tag_word, (unsigned short __user *)(d + 4));
                FPU_put_user(instruction_address.offset,
                             (unsigned short __user *)(d + 6));
                FPU_put_user(operand_address.offset,
                             (unsigned short __user *)(d + 0x0a));
                if (addr_modes.default_mode == VM86) {
                        FPU_put_user((instruction_address.
                                      offset & 0xf0000) >> 4,
                                     (unsigned short __user *)(d + 8));
                        FPU_put_user((operand_address.offset & 0xf0000) >> 4,
                                     (unsigned short __user *)(d + 0x0c));
                } else {
                        FPU_put_user(instruction_address.selector,
                                     (unsigned short __user *)(d + 8));
                        FPU_put_user(operand_address.selector,
                                     (unsigned short __user *)(d + 0x0c));
                }
                RE_ENTRANT_CHECK_ON;
                d += 0x0e;
        } else {
                RE_ENTRANT_CHECK_OFF;
                FPU_access_ok(d, 7 * 4);
#ifdef PECULIAR_486
                control_word &= ~0xe080;
                /* An 80486 sets nearly all of the reserved bits to 1. */
                control_word |= 0xffff0040;
                partial_status = status_word() | 0xffff0000;
                fpu_tag_word |= 0xffff0000;
                I387->soft.fcs &= ~0xf8000000;
                I387->soft.fos |= 0xffff0000;
#endif /* PECULIAR_486 */
                if (__copy_to_user(d, &control_word, 7 * 4))
                        FPU_abort;
                RE_ENTRANT_CHECK_ON;
                d += 0x1c;
        }

        control_word |= CW_Exceptions;
        partial_status &= ~(SW_Summary | SW_Backward);

        return d;
}

void fsave(fpu_addr_modes addr_modes, u_char __user *data_address)
{
        u_char __user *d;
        int offset = (top & 7) * 10, other = 80 - offset;

        d = fstenv(addr_modes, data_address);

        RE_ENTRANT_CHECK_OFF;
        FPU_access_ok(d, 80);

        /* Copy all registers in stack order. */
        if (__copy_to_user(d, register_base + offset, other))
                FPU_abort;
        if (offset)
                if (__copy_to_user(d + other, register_base, offset))
                        FPU_abort;
        RE_ENTRANT_CHECK_ON;

        finit();
}

/*===========================================================================*/