i386: move math-emu

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1375 insertions, 0 deletions

diff --git a/arch/x86/math-emu/reg_ld_str.c b/arch/x86/math-emu/reg_ld_str.c
new file mode 100644
index 000000000000..e976caef6498
--- /dev/null
+++ b/arch/x86/math-emu/reg_ld_str.c
@@ -0,0 +1,1375 @@
+/*---------------------------------------------------------------------------+
+ |  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;
+
+  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[0] = 0x00000000;        /* Set to */
+              l[1] = 0x7ff00000;        /* + 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 */
+      l[0] = 0;
+      l[1] = 0;
+    }
+  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[0] = 0;
+          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[0] = 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();
+}
+
+/*===========================================================================*/