/*---------------------------------------------------------------------------+
   |  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 <asm/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(VERIFY_READ, s, 10);
  	__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(VERIFY_READ, 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(VERIFY_READ, 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(VERIFY_READ, _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(VERIFY_READ, _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(VERIFY_READ, _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(VERIFY_READ, 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(VERIFY_WRITE, 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(VERIFY_WRITE, 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(VERIFY_WRITE, 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(VERIFY_WRITE, 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(VERIFY_WRITE, 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(VERIFY_WRITE, 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(VERIFY_WRITE, 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(VERIFY_WRITE, 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(VERIFY_WRITE, 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(VERIFY_WRITE, 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(VERIFY_WRITE, 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 signalled 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(VERIFY_READ, 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(VERIFY_READ, 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 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(VERIFY_READ, s, 80);
  	__copy_from_user(register_base + offset, s, other);
  	if (offset)
  		__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(VERIFY_WRITE, 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(VERIFY_WRITE, 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(VERIFY_WRITE, 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();

  }
  
  /*===========================================================================*/