i386: move math-emu

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

1 files changed, 0 insertions, 1845 deletions

diff --git a/arch/i386/math-emu/fpu_trig.c b/arch/i386/math-emu/fpu_trig.c
deleted file mode 100644
index 403cbde1d42..00000000000
--- a/arch/i386/math-emu/fpu_trig.c
+++ /dev/null
@@ -1,1845 +0,0 @@
-/*---------------------------------------------------------------------------+
- |  fpu_trig.c                                                               |
- |                                                                           |
- | Implementation of the FPU "transcendental" functions.                     |
- |                                                                           |
- | Copyright (C) 1992,1993,1994,1997,1999                                    |
- |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
- |                       Australia.  E-mail   billm@melbpc.org.au            |
- |                                                                           |
- |                                                                           |
- +---------------------------------------------------------------------------*/
-
-#include "fpu_system.h"
-#include "exception.h"
-#include "fpu_emu.h"
-#include "status_w.h"
-#include "control_w.h"
-#include "reg_constant.h"	
-
-static void rem_kernel(unsigned long long st0, unsigned long long *y,
-		       unsigned long long st1,
-		       unsigned long long q, int n);
-
-#define BETTER_THAN_486
-
-#define FCOS  4
-
-/* Used only by fptan, fsin, fcos, and fsincos. */
-/* This routine produces very accurate results, similar to
-   using a value of pi with more than 128 bits precision. */
-/* Limited measurements show no results worse than 64 bit precision
-   except for the results for arguments close to 2^63, where the
-   precision of the result sometimes degrades to about 63.9 bits */
-static int trig_arg(FPU_REG *st0_ptr, int even)
-{
-  FPU_REG tmp;
-  u_char tmptag;
-  unsigned long long q;
-  int old_cw = control_word, saved_status = partial_status;
-  int tag, st0_tag = TAG_Valid;
-
-  if ( exponent(st0_ptr) >= 63 )
-    {
-      partial_status |= SW_C2;     /* Reduction incomplete. */
-      return -1;
-    }
-
-  control_word &= ~CW_RC;
-  control_word |= RC_CHOP;
-
-  setpositive(st0_ptr);
-  tag = FPU_u_div(st0_ptr, &CONST_PI2, &tmp, PR_64_BITS | RC_CHOP | 0x3f,
-		  SIGN_POS);
-
-  FPU_round_to_int(&tmp, tag);  /* Fortunately, this can't overflow
-				   to 2^64 */
-  q = significand(&tmp);
-  if ( q )
-    {
-      rem_kernel(significand(st0_ptr),
-		 &significand(&tmp),
-		 significand(&CONST_PI2),
-		 q, exponent(st0_ptr) - exponent(&CONST_PI2));
-      setexponent16(&tmp, exponent(&CONST_PI2));
-      st0_tag = FPU_normalize(&tmp);
-      FPU_copy_to_reg0(&tmp, st0_tag);
-    }
-
-  if ( (even && !(q & 1)) || (!even && (q & 1)) )
-    {
-      st0_tag = FPU_sub(REV|LOADED|TAG_Valid, (int)&CONST_PI2, FULL_PRECISION);
-
-#ifdef BETTER_THAN_486
-      /* So far, the results are exact but based upon a 64 bit
-	 precision approximation to pi/2. The technique used
-	 now is equivalent to using an approximation to pi/2 which
-	 is accurate to about 128 bits. */
-      if ( (exponent(st0_ptr) <= exponent(&CONST_PI2extra) + 64) || (q > 1) )
-	{
-	  /* This code gives the effect of having pi/2 to better than
-	     128 bits precision. */
-
-	  significand(&tmp) = q + 1;
-	  setexponent16(&tmp, 63);
-	  FPU_normalize(&tmp);
-	  tmptag =
-	    FPU_u_mul(&CONST_PI2extra, &tmp, &tmp, FULL_PRECISION, SIGN_POS,
-		      exponent(&CONST_PI2extra) + exponent(&tmp));
-	  setsign(&tmp, getsign(&CONST_PI2extra));
-	  st0_tag = FPU_add(&tmp, tmptag, 0, FULL_PRECISION);
-	  if ( signnegative(st0_ptr) )
-	    {
-	      /* CONST_PI2extra is negative, so the result of the addition
-		 can be negative. This means that the argument is actually
-		 in a different quadrant. The correction is always < pi/2,
-		 so it can't overflow into yet another quadrant. */
-	      setpositive(st0_ptr);
-	      q++;
-	    }
-	}
-#endif /* BETTER_THAN_486 */
-    }
-#ifdef BETTER_THAN_486
-  else
-    {
-      /* So far, the results are exact but based upon a 64 bit
-	 precision approximation to pi/2. The technique used
-	 now is equivalent to using an approximation to pi/2 which
-	 is accurate to about 128 bits. */
-      if ( ((q > 0) && (exponent(st0_ptr) <= exponent(&CONST_PI2extra) + 64))
-	   || (q > 1) )
-	{
-	  /* This code gives the effect of having p/2 to better than
-	     128 bits precision. */
-
-	  significand(&tmp) = q;
-	  setexponent16(&tmp, 63);
-	  FPU_normalize(&tmp);         /* This must return TAG_Valid */
-	  tmptag = FPU_u_mul(&CONST_PI2extra, &tmp, &tmp, FULL_PRECISION,
-			     SIGN_POS,
-			     exponent(&CONST_PI2extra) + exponent(&tmp));
-	  setsign(&tmp, getsign(&CONST_PI2extra));
-	  st0_tag = FPU_sub(LOADED|(tmptag & 0x0f), (int)&tmp,
-			    FULL_PRECISION);
-	  if ( (exponent(st0_ptr) == exponent(&CONST_PI2)) &&
-	      ((st0_ptr->sigh > CONST_PI2.sigh)
-	       || ((st0_ptr->sigh == CONST_PI2.sigh)
-		   && (st0_ptr->sigl > CONST_PI2.sigl))) )
-	    {
-	      /* CONST_PI2extra is negative, so the result of the
-		 subtraction can be larger than pi/2. This means
-		 that the argument is actually in a different quadrant.
-		 The correction is always < pi/2, so it can't overflow
-		 into yet another quadrant. */
-	      st0_tag = FPU_sub(REV|LOADED|TAG_Valid, (int)&CONST_PI2,
-				FULL_PRECISION);
-	      q++;
-	    }
-	}
-    }
-#endif /* BETTER_THAN_486 */
-
-  FPU_settag0(st0_tag);
-  control_word = old_cw;
-  partial_status = saved_status & ~SW_C2;     /* Reduction complete. */
-
-  return (q & 3) | even;
-}
-
-
-/* Convert a long to register */
-static void convert_l2reg(long const *arg, int deststnr)
-{
-  int tag;
-  long num = *arg;
-  u_char sign;
-  FPU_REG *dest = &st(deststnr);
-
-  if (num == 0)
-    {
-      FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
-      return;
-    }
-
-  if (num > 0)
-    { sign = SIGN_POS; }
-  else
-    { num = -num; sign = SIGN_NEG; }
-
-  dest->sigh = num;
-  dest->sigl = 0;
-  setexponent16(dest, 31);
-  tag = FPU_normalize(dest);
-  FPU_settagi(deststnr, tag);
-  setsign(dest, sign);
-  return;
-}
-
-
-static void single_arg_error(FPU_REG *st0_ptr, u_char st0_tag)
-{
-  if ( st0_tag == TAG_Empty )
-    FPU_stack_underflow();  /* Puts a QNaN in st(0) */
-  else if ( st0_tag == TW_NaN )
-    real_1op_NaN(st0_ptr);       /* return with a NaN in st(0) */
-#ifdef PARANOID
-  else
-    EXCEPTION(EX_INTERNAL|0x0112);
-#endif /* PARANOID */
-}
-
-
-static void single_arg_2_error(FPU_REG *st0_ptr, u_char st0_tag)
-{
-  int isNaN;
-
-  switch ( st0_tag )
-    {
-    case TW_NaN:
-      isNaN = (exponent(st0_ptr) == EXP_OVER) && (st0_ptr->sigh & 0x80000000);
-      if ( isNaN && !(st0_ptr->sigh & 0x40000000) )   /* Signaling ? */
-	{
-	  EXCEPTION(EX_Invalid);
-	  if ( control_word & CW_Invalid )
-	    {
-	      /* The masked response */
-	      /* Convert to a QNaN */
-	      st0_ptr->sigh |= 0x40000000;
-	      push();
-	      FPU_copy_to_reg0(st0_ptr, TAG_Special);
-	    }
-	}
-      else if ( isNaN )
-	{
-	  /* A QNaN */
-	  push();
-	  FPU_copy_to_reg0(st0_ptr, TAG_Special);
-	}
-      else
-	{
-	  /* pseudoNaN or other unsupported */
-	  EXCEPTION(EX_Invalid);
-	  if ( control_word & CW_Invalid )
-	    {
-	      /* The masked response */
-	      FPU_copy_to_reg0(&CONST_QNaN, TAG_Special);
-	      push();
-	      FPU_copy_to_reg0(&CONST_QNaN, TAG_Special);
-	    }
-	}
-      break;              /* return with a NaN in st(0) */
-#ifdef PARANOID
-    default:
-      EXCEPTION(EX_INTERNAL|0x0112);
-#endif /* PARANOID */
-    }
-}
-
-
-/*---------------------------------------------------------------------------*/
-
-static void f2xm1(FPU_REG *st0_ptr, u_char tag)
-{
-  FPU_REG a;
-
-  clear_C1();
-
-  if ( tag == TAG_Valid )
-    {
-      /* For an 80486 FPU, the result is undefined if the arg is >= 1.0 */
-      if ( exponent(st0_ptr) < 0 )
-	{
-	denormal_arg:
-
-	  FPU_to_exp16(st0_ptr, &a);
-
-	  /* poly_2xm1(x) requires 0 < st(0) < 1. */
-	  poly_2xm1(getsign(st0_ptr), &a, st0_ptr);
-	}
-      set_precision_flag_up();   /* 80486 appears to always do this */
-      return;
-    }
-
-  if ( tag == TAG_Zero )
-    return;
-
-  if ( tag == TAG_Special )
-    tag = FPU_Special(st0_ptr);
-
-  switch ( tag )
-    {
-    case TW_Denormal:
-      if ( denormal_operand() < 0 )
-	return;
-      goto denormal_arg;
-    case TW_Infinity:
-      if ( signnegative(st0_ptr) )
-	{
-	  /* -infinity gives -1 (p16-10) */
-	  FPU_copy_to_reg0(&CONST_1, TAG_Valid);
-	  setnegative(st0_ptr);
-	}
-      return;
-    default:
-      single_arg_error(st0_ptr, tag);
-    }
-}
-
-
-static void fptan(FPU_REG *st0_ptr, u_char st0_tag)
-{
-  FPU_REG *st_new_ptr;
-  int q;
-  u_char arg_sign = getsign(st0_ptr);
-
-  /* Stack underflow has higher priority */
-  if ( st0_tag == TAG_Empty )
-    {
-      FPU_stack_underflow();  /* Puts a QNaN in st(0) */
-      if ( control_word & CW_Invalid )
-	{
-	  st_new_ptr = &st(-1);
-	  push();
-	  FPU_stack_underflow();  /* Puts a QNaN in the new st(0) */
-	}
-      return;
-    }
-
-  if ( STACK_OVERFLOW )
-    { FPU_stack_overflow(); return; }
-
-  if ( st0_tag == TAG_Valid )
-    {
-      if ( exponent(st0_ptr) > -40 )
-	{
-	  if ( (q = trig_arg(st0_ptr, 0)) == -1 )
-	    {
-	      /* Operand is out of range */
-	      return;
-	    }
-
-	  poly_tan(st0_ptr);
-	  setsign(st0_ptr, (q & 1) ^ (arg_sign != 0));
-	  set_precision_flag_up();  /* We do not really know if up or down */
-	}
-      else
-	{
-	  /* For a small arg, the result == the argument */
-	  /* Underflow may happen */
-
-	denormal_arg:
-
-	  FPU_to_exp16(st0_ptr, st0_ptr);
-      
-	  st0_tag = FPU_round(st0_ptr, 1, 0, FULL_PRECISION, arg_sign);
-	  FPU_settag0(st0_tag);
-	}
-      push();
-      FPU_copy_to_reg0(&CONST_1, TAG_Valid);
-      return;
-    }
-
-  if ( st0_tag == TAG_Zero )
-    {
-      push();
-      FPU_copy_to_reg0(&CONST_1, TAG_Valid);
-      setcc(0);
-      return;
-    }
-
-  if ( st0_tag == TAG_Special )
-    st0_tag = FPU_Special(st0_ptr);
-
-  if ( st0_tag == TW_Denormal )
-    {
-      if ( denormal_operand() < 0 )
-	return;
-
-      goto denormal_arg;
-    }
-
-  if ( st0_tag == TW_Infinity )
-    {
-      /* The 80486 treats infinity as an invalid operand */
-      if ( arith_invalid(0) >= 0 )
-	{
-	  st_new_ptr = &st(-1);
-	  push();
-	  arith_invalid(0);
-	}
-      return;
-    }
-
-  single_arg_2_error(st0_ptr, st0_tag);
-}
-
-
-static void fxtract(FPU_REG *st0_ptr, u_char st0_tag)
-{
-  FPU_REG *st_new_ptr;
-  u_char sign;
-  register FPU_REG *st1_ptr = st0_ptr;  /* anticipate */
-
-  if ( STACK_OVERFLOW )
-    {  FPU_stack_overflow(); return; }
-
-  clear_C1();
-
-  if ( st0_tag == TAG_Valid )
-    {
-      long e;
-
-      push();
-      sign = getsign(st1_ptr);
-      reg_copy(st1_ptr, st_new_ptr);
-      setexponent16(st_new_ptr, exponent(st_new_ptr));
-
-    denormal_arg:
-
-      e = exponent16(st_new_ptr);
-      convert_l2reg(&e, 1);
-      setexponentpos(st_new_ptr, 0);
-      setsign(st_new_ptr, sign);
-      FPU_settag0(TAG_Valid);       /* Needed if arg was a denormal */
-      return;
-    }
-  else if ( st0_tag == TAG_Zero )
-    {
-      sign = getsign(st0_ptr);
-
-      if ( FPU_divide_by_zero(0, SIGN_NEG) < 0 )
-	return;
-
-      push();
-      FPU_copy_to_reg0(&CONST_Z, TAG_Zero);
-      setsign(st_new_ptr, sign);
-      return;
-    }
-
-  if ( st0_tag == TAG_Special )
-    st0_tag = FPU_Special(st0_ptr);
-
-  if ( st0_tag == TW_Denormal )
-    {
-      if (denormal_operand() < 0 )
-	return;
-
-      push();
-      sign = getsign(st1_ptr);
-      FPU_to_exp16(st1_ptr, st_new_ptr);
-      goto denormal_arg;
-    }
-  else if ( st0_tag == TW_Infinity )
-    {
-      sign = getsign(st0_ptr);
-      setpositive(st0_ptr);
-      push();
-      FPU_copy_to_reg0(&CONST_INF, TAG_Special);
-      setsign(st_new_ptr, sign);
-      return;
-    }
-  else if ( st0_tag == TW_NaN )
-    {
-      if ( real_1op_NaN(st0_ptr) < 0 )
-	return;
-
-      push();
-      FPU_copy_to_reg0(st0_ptr, TAG_Special);
-      return;
-    }
-  else if ( st0_tag == TAG_Empty )
-    {
-      /* Is this the correct behaviour? */
-      if ( control_word & EX_Invalid )
-	{
-	  FPU_stack_underflow();
-	  push();
-	  FPU_stack_underflow();
-	}
-      else
-	EXCEPTION(EX_StackUnder);
-    }
-#ifdef PARANOID
-  else
-    EXCEPTION(EX_INTERNAL | 0x119);
-#endif /* PARANOID */
-}
-
-
-static void fdecstp(void)
-{
-  clear_C1();
-  top--;
-}
-
-static void fincstp(void)
-{
-  clear_C1();
-  top++;
-}
-
-
-static void fsqrt_(FPU_REG *st0_ptr, u_char st0_tag)
-{
-  int expon;
-
-  clear_C1();
-
-  if ( st0_tag == TAG_Valid )
-    {
-      u_char tag;
-      
-      if (signnegative(st0_ptr))
-	{
-	  arith_invalid(0);  /* sqrt(negative) is invalid */
-	  return;
-	}
-
-      /* make st(0) in  [1.0 .. 4.0) */
-      expon = exponent(st0_ptr);
-
-    denormal_arg:
-
-      setexponent16(st0_ptr, (expon & 1));
-
-      /* Do the computation, the sign of the result will be positive. */
-      tag = wm_sqrt(st0_ptr, 0, 0, control_word, SIGN_POS);
-      addexponent(st0_ptr, expon >> 1);
-      FPU_settag0(tag);
-      return;
-    }
-
-  if ( st0_tag == TAG_Zero )
-    return;
-
-  if ( st0_tag == TAG_Special )
-    st0_tag = FPU_Special(st0_ptr);
-
-  if ( st0_tag == TW_Infinity )
-    {
-      if ( signnegative(st0_ptr) )
-	arith_invalid(0);  /* sqrt(-Infinity) is invalid */
-      return;
-    }
-  else if ( st0_tag == TW_Denormal )
-    {
-      if (signnegative(st0_ptr))
-	{
-	  arith_invalid(0);  /* sqrt(negative) is invalid */
-	  return;
-	}
-
-      if ( denormal_operand() < 0 )
-	return;
-
-      FPU_to_exp16(st0_ptr, st0_ptr);
-
-      expon = exponent16(st0_ptr);
-
-      goto denormal_arg;
-    }
-
-  single_arg_error(st0_ptr, st0_tag);
-
-}
-
-
-static void frndint_(FPU_REG *st0_ptr, u_char st0_tag)
-{
-  int flags, tag;
-
-  if ( st0_tag == TAG_Valid )
-    {
-      u_char sign;
-
-    denormal_arg:
-
-      sign = getsign(st0_ptr);
-
-      if (exponent(st0_ptr) > 63)
-	return;
-
-      if ( st0_tag == TW_Denormal )
-	{
-	  if (denormal_operand() < 0 )
-	    return;
-	}
-
-      /* Fortunately, this can't overflow to 2^64 */
-      if ( (flags = FPU_round_to_int(st0_ptr, st0_tag)) )
-	set_precision_flag(flags);
-
-      setexponent16(st0_ptr, 63);
-      tag = FPU_normalize(st0_ptr);
-      setsign(st0_ptr, sign);
-      FPU_settag0(tag);
-      return;
-    }
-
-  if ( st0_tag == TAG_Zero )
-    return;
-
-  if ( st0_tag == TAG_Special )
-    st0_tag = FPU_Special(st0_ptr);
-
-  if ( st0_tag == TW_Denormal )
-    goto denormal_arg;
-  else if ( st0_tag == TW_Infinity )
-    return;
-  else
-    single_arg_error(st0_ptr, st0_tag);
-}
-
-
-static int fsin(FPU_REG *st0_ptr, u_char tag)
-{
-  u_char arg_sign = getsign(st0_ptr);
-
-  if ( tag == TAG_Valid )
-    {
-      int q;
-
-      if ( exponent(st0_ptr) > -40 )
-	{
-	  if ( (q = trig_arg(st0_ptr, 0)) == -1 )
-	    {
-	      /* Operand is out of range */
-	      return 1;
-	    }
-
-	  poly_sine(st0_ptr);
-	  
-	  if (q & 2)
-	    changesign(st0_ptr);
-
-	  setsign(st0_ptr, getsign(st0_ptr) ^ arg_sign);
-
-	  /* We do not really know if up or down */
-	  set_precision_flag_up();
-	  return 0;
-	}
-      else
-	{
-	  /* For a small arg, the result == the argument */
-	  set_precision_flag_up();  /* Must be up. */
-	  return 0;
-	}
-    }
-
-  if ( tag == TAG_Zero )
-    {
-      setcc(0);
-      return 0;
-    }
-
-  if ( tag == TAG_Special )
-    tag = FPU_Special(st0_ptr);
-
-  if ( tag == TW_Denormal )
-    {
-      if ( denormal_operand() < 0 )
-	return 1;
-
-      /* For a small arg, the result == the argument */
-      /* Underflow may happen */
-      FPU_to_exp16(st0_ptr, st0_ptr);
-      
-      tag = FPU_round(st0_ptr, 1, 0, FULL_PRECISION, arg_sign);
-
-      FPU_settag0(tag);
-
-      return 0;
-    }
-  else if ( tag == TW_Infinity )
-    {
-      /* The 80486 treats infinity as an invalid operand */
-      arith_invalid(0);
-      return 1;
-    }
-  else
-    {
-      single_arg_error(st0_ptr, tag);
-      return 1;
-    }
-}
-
-
-static int f_cos(FPU_REG *st0_ptr, u_char tag)
-{
-  u_char st0_sign;
-
-  st0_sign = getsign(st0_ptr);
-
-  if ( tag == TAG_Valid )
-    {
-      int q;
-
-      if ( exponent(st0_ptr) > -40 )
-	{
-	  if ( (exponent(st0_ptr) < 0)
-	      || ((exponent(st0_ptr) == 0)
-		  && (significand(st0_ptr) <= 0xc90fdaa22168c234LL)) )
-	    {
-	      poly_cos(st0_ptr);
-
-	      /* We do not really know if up or down */
-	      set_precision_flag_down();
-	  
-	      return 0;
-	    }
-	  else if ( (q = trig_arg(st0_ptr, FCOS)) != -1 )
-	    {
-	      poly_sine(st0_ptr);
-
-	      if ((q+1) & 2)
-		changesign(st0_ptr);
-
-	      /* We do not really know if up or down */
-	      set_precision_flag_down();
-	  
-	      return 0;
-	    }
-	  else
-	    {
-	      /* Operand is out of range */
-	      return 1;
-	    }
-	}
-      else
-	{
-	denormal_arg:
-
-	  setcc(0);
-	  FPU_copy_to_reg0(&CONST_1, TAG_Valid);
-#ifdef PECULIAR_486
-	  set_precision_flag_down();  /* 80486 appears to do this. */
-#else
-	  set_precision_flag_up();  /* Must be up. */
-#endif /* PECULIAR_486 */
-	  return 0;
-	}
-    }
-  else if ( tag == TAG_Zero )
-    {
-      FPU_copy_to_reg0(&CONST_1, TAG_Valid);
-      setcc(0);
-      return 0;
-    }
-
-  if ( tag == TAG_Special )
-    tag = FPU_Special(st0_ptr);
-
-  if ( tag == TW_Denormal )
-    {
-      if ( denormal_operand() < 0 )
-	return 1;
-
-      goto denormal_arg;
-    }
-  else if ( tag == TW_Infinity )
-    {
-      /* The 80486 treats infinity as an invalid operand */
-      arith_invalid(0);
-      return 1;
-    }
-  else
-    {
-      single_arg_error(st0_ptr, tag);  /* requires st0_ptr == &st(0) */
-      return 1;
-    }
-}
-
-
-static void fcos(FPU_REG *st0_ptr, u_char st0_tag)
-{
-  f_cos(st0_ptr, st0_tag);
-}
-
-
-static void fsincos(FPU_REG *st0_ptr, u_char st0_tag)
-{
-  FPU_REG *st_new_ptr;
-  FPU_REG arg;
-  u_char tag;
-
-  /* Stack underflow has higher priority */
-  if ( st0_tag == TAG_Empty )
-    {
-      FPU_stack_underflow();  /* Puts a QNaN in st(0) */
-      if ( control_word & CW_Invalid )
-	{
-	  st_new_ptr = &st(-1);
-	  push();
-	  FPU_stack_underflow();  /* Puts a QNaN in the new st(0) */
-	}
-      return;
-    }
-
-  if ( STACK_OVERFLOW )
-    { FPU_stack_overflow(); return; }
-
-  if ( st0_tag == TAG_Special )
-    tag = FPU_Special(st0_ptr);
-  else
-    tag = st0_tag;
-
-  if ( tag == TW_NaN )
-    {
-      single_arg_2_error(st0_ptr, TW_NaN);
-      return;
-    }
-  else if ( tag == TW_Infinity )
-    {
-      /* The 80486 treats infinity as an invalid operand */
-      if ( arith_invalid(0) >= 0 )
-	{
-	  /* Masked response */
-	  push();
-	  arith_invalid(0);
-	}
-      return;
-    }
-
-  reg_copy(st0_ptr, &arg);
-  if ( !fsin(st0_ptr, st0_tag) )
-    {
-      push();
-      FPU_copy_to_reg0(&arg, st0_tag);
-      f_cos(&st(0), st0_tag);
-    }
-  else
-    {
-      /* An error, so restore st(0) */
-      FPU_copy_to_reg0(&arg, st0_tag);
-    }
-}
-
-
-/*---------------------------------------------------------------------------*/
-/* The following all require two arguments: st(0) and st(1) */
-
-/* A lean, mean kernel for the fprem instructions. This relies upon
-   the division and rounding to an integer in do_fprem giving an
-   exact result. Because of this, rem_kernel() needs to deal only with
-   the least significant 64 bits, the more significant bits of the
-   result must be zero.
- */
-static void rem_kernel(unsigned long long st0, unsigned long long *y,
-		       unsigned long long st1,
-		       unsigned long long q, int n)
-{
-  int dummy;
-  unsigned long long x;
-
-  x = st0 << n;
-
-  /* Do the required multiplication and subtraction in the one operation */
-
-  /* lsw x -= lsw st1 * lsw q */
-  asm volatile ("mull %4; subl %%eax,%0; sbbl %%edx,%1"
-		:"=m" (((unsigned *)&x)[0]), "=m" (((unsigned *)&x)[1]),
-		"=a" (dummy)
-		:"2" (((unsigned *)&st1)[0]), "m" (((unsigned *)&q)[0])
-		:"%dx");
-  /* msw x -= msw st1 * lsw q */
-  asm volatile ("mull %3; subl %%eax,%0"
-		:"=m" (((unsigned *)&x)[1]), "=a" (dummy)
-		:"1" (((unsigned *)&st1)[1]), "m" (((unsigned *)&q)[0])
-		:"%dx");
-  /* msw x -= lsw st1 * msw q */
-  asm volatile ("mull %3; subl %%eax,%0"
-		:"=m" (((unsigned *)&x)[1]), "=a" (dummy)
-		:"1" (((unsigned *)&st1)[0]), "m" (((unsigned *)&q)[1])
-		:"%dx");
-
-  *y = x;
-}
-
-
-/* Remainder of st(0) / st(1) */
-/* This routine produces exact results, i.e. there is never any
-   rounding or truncation, etc of the result. */
-static void do_fprem(FPU_REG *st0_ptr, u_char st0_tag, int round)
-{
-  FPU_REG *st1_ptr = &st(1);
-  u_char st1_tag = FPU_gettagi(1);
-
-  if ( !((st0_tag ^ TAG_Valid) | (st1_tag ^ TAG_Valid)) )
-    {
-      FPU_REG tmp, st0, st1;
-      u_char st0_sign, st1_sign;
-      u_char tmptag;
-      int tag;
-      int old_cw;
-      int expdif;
-      long long q;
-      unsigned short saved_status;
-      int cc;
-
-    fprem_valid:
-      /* Convert registers for internal use. */
-      st0_sign = FPU_to_exp16(st0_ptr, &st0);
-      st1_sign = FPU_to_exp16(st1_ptr, &st1);
-      expdif = exponent16(&st0) - exponent16(&st1);
-
-      old_cw = control_word;
-      cc = 0;
-
-      /* We want the status following the denorm tests, but don't want
-	 the status changed by the arithmetic operations. */
-      saved_status = partial_status;
-      control_word &= ~CW_RC;
-      control_word |= RC_CHOP;
-
-      if ( expdif < 64 )
-	{
-	  /* This should be the most common case */
-
-	  if ( expdif > -2 )
-	    {
-	      u_char sign = st0_sign ^ st1_sign;
-	      tag = FPU_u_div(&st0, &st1, &tmp,
-			      PR_64_BITS | RC_CHOP | 0x3f,
-			      sign);
-	      setsign(&tmp, sign);
-
-	      if ( exponent(&tmp) >= 0 )
-		{
-		  FPU_round_to_int(&tmp, tag);  /* Fortunately, this can't
-						   overflow to 2^64 */
-		  q = significand(&tmp);
-
-		  rem_kernel(significand(&st0),
-			     &significand(&tmp),
-			     significand(&st1),
-			     q, expdif);
-
-		  setexponent16(&tmp, exponent16(&st1));
-		}
-	      else
-		{
-		  reg_copy(&st0, &tmp);
-		  q = 0;
-		}
-
-	      if ( (round == RC_RND) && (tmp.sigh & 0xc0000000) )
-		{
-		  /* We may need to subtract st(1) once more,
-		     to get a result <= 1/2 of st(1). */
-		  unsigned long long x;
-		  expdif = exponent16(&st1) - exponent16(&tmp);
-		  if ( expdif <= 1 )
-		    {
-		      if ( expdif == 0 )
-			x = significand(&st1) - significand(&tmp);
-		      else /* expdif is 1 */
-			x = (significand(&st1) << 1) - significand(&tmp);
-		      if ( (x < significand(&tmp)) ||
-			  /* or equi-distant (from 0 & st(1)) and q is odd */
-			  ((x == significand(&tmp)) && (q & 1) ) )
-			{
-			  st0_sign = ! st0_sign;
-			  significand(&tmp) = x;
-			  q++;
-			}
-		    }
-		}
-
-	      if (q & 4) cc |= SW_C0;
-	      if (q & 2) cc |= SW_C3;
-	      if (q & 1) cc |= SW_C1;
-	    }
-	  else
-	    {
-	      control_word = old_cw;
-	      setcc(0);
-	      return;
-	    }
-	}
-      else
-	{
-	  /* There is a large exponent difference ( >= 64 ) */
-	  /* To make much sense, the code in this section should
-	     be done at high precision. */
-	  int exp_1, N;
-	  u_char sign;
-
-	  /* prevent overflow here */
-	  /* N is 'a number between 32 and 63' (p26-113) */
-	  reg_copy(&st0, &tmp);
-	  tmptag = st0_tag;
-	  N = (expdif & 0x0000001f) + 32;  /* This choice gives results
-					      identical to an AMD 486 */
-	  setexponent16(&tmp, N);
-	  exp_1 = exponent16(&st1);
-	  setexponent16(&st1, 0);
-	  expdif -= N;
-
-	  sign = getsign(&tmp) ^ st1_sign;
-	  tag = FPU_u_div(&tmp, &st1, &tmp, PR_64_BITS | RC_CHOP | 0x3f,
-			  sign);
-	  setsign(&tmp, sign);
-
-	  FPU_round_to_int(&tmp, tag);  /* Fortunately, this can't
-					   overflow to 2^64 */
-
-	  rem_kernel(significand(&st0),
-		     &significand(&tmp),
-		     significand(&st1),
-		     significand(&tmp),
-		     exponent(&tmp)
-		     ); 
-	  setexponent16(&tmp, exp_1 + expdif);
-
-	  /* It is possible for the operation to be complete here.
-	     What does the IEEE standard say? The Intel 80486 manual
-	     implies that the operation will never be completed at this
-	     point, and the behaviour of a real 80486 confirms this.
-	   */
-	  if ( !(tmp.sigh | tmp.sigl) )
-	    {
-	      /* The result is zero */
-	      control_word = old_cw;
-	      partial_status = saved_status;
-	      FPU_copy_to_reg0(&CONST_Z, TAG_Zero);
-	      setsign(&st0, st0_sign);
-#ifdef PECULIAR_486
-	      setcc(SW_C2);
-#else
-	      setcc(0);
-#endif /* PECULIAR_486 */
-	      return;
-	    }
-	  cc = SW_C2;
-	}
-
-      control_word = old_cw;
-      partial_status = saved_status;
-      tag = FPU_normalize_nuo(&tmp);
-      reg_copy(&tmp, st0_ptr);
-
-      /* The only condition to be looked for is underflow,
-	 and it can occur here only if underflow is unmasked. */
-      if ( (exponent16(&tmp) <= EXP_UNDER) && (tag != TAG_Zero)
-	  && !(control_word & CW_Underflow) )
-	{
-	  setcc(cc);
-	  tag = arith_underflow(st0_ptr);
-	  setsign(st0_ptr, st0_sign);
-	  FPU_settag0(tag);
-	  return;
-	}
-      else if ( (exponent16(&tmp) > EXP_UNDER) || (tag == TAG_Zero) )
-	{
-	  stdexp(st0_ptr);
-	  setsign(st0_ptr, st0_sign);
-	}
-      else
-	{
-	  tag = FPU_round(st0_ptr, 0, 0, FULL_PRECISION, st0_sign);
-	}
-      FPU_settag0(tag);
-      setcc(cc);
-
-      return;
-    }
-
-  if ( st0_tag == TAG_Special )
-    st0_tag = FPU_Special(st0_ptr);
-  if ( st1_tag == TAG_Special )
-    st1_tag = FPU_Special(st1_ptr);
-
-  if ( ((st0_tag == TAG_Valid) && (st1_tag == TW_Denormal))
-	    || ((st0_tag == TW_Denormal) && (st1_tag == TAG_Valid))
-	    || ((st0_tag == TW_Denormal) && (st1_tag == TW_Denormal)) )
-    {
-      if ( denormal_operand() < 0 )
-	return;
-      goto fprem_valid;
-    }
-  else if ( (st0_tag == TAG_Empty) || (st1_tag == TAG_Empty) )
-    {
-      FPU_stack_underflow();
-      return;
-    }
-  else if ( st0_tag == TAG_Zero )
-    {
-      if ( st1_tag == TAG_Valid )
-	{
-	  setcc(0); return;
-	}
-      else if ( st1_tag == TW_Denormal )
-	{
-	  if ( denormal_operand() < 0 )
-	    return;
-	  setcc(0); return;
-	}
-      else if ( st1_tag == TAG_Zero )
-	{ arith_invalid(0); return; } /* fprem(?,0) always invalid */
-      else if ( st1_tag == TW_Infinity )
-	{ setcc(0); return; }
-    }
-  else if ( (st0_tag == TAG_Valid) || (st0_tag == TW_Denormal) )
-    {
-      if ( st1_tag == TAG_Zero )
-	{
-	  arith_invalid(0); /* fprem(Valid,Zero) is invalid */
-	  return;
-	}
-      else if ( st1_tag != TW_NaN )
-	{
-	  if ( ((st0_tag == TW_Denormal) || (st1_tag == TW_Denormal))
-	       && (denormal_operand() < 0) )
-	    return;
-
-	  if ( st1_tag == TW_Infinity )
-	    {
-	      /* fprem(Valid,Infinity) is o.k. */
-	      setcc(0); return;
-	    }
-	}
-    }
-  else if ( st0_tag == TW_Infinity )
-    {
-      if ( st1_tag != TW_NaN )
-	{
-	  arith_invalid(0); /* fprem(Infinity,?) is invalid */
-	  return;
-	}
-    }
-
-  /* One of the registers must contain a NaN if we got here. */
-
-#ifdef PARANOID
-  if ( (st0_tag != TW_NaN) && (st1_tag != TW_NaN) )
-      EXCEPTION(EX_INTERNAL | 0x118);
-#endif /* PARANOID */
-
-  real_2op_NaN(st1_ptr, st1_tag, 0, st1_ptr);
-
-}
-
-
-/* ST(1) <- ST(1) * log ST;  pop ST */
-static void fyl2x(FPU_REG *st0_ptr, u_char st0_tag)
-{
-  FPU_REG *st1_ptr = &st(1), exponent;
-  u_char st1_tag = FPU_gettagi(1);
-  u_char sign;
-  int e, tag;
-
-  clear_C1();
-
-  if ( (st0_tag == TAG_Valid) && (st1_tag == TAG_Valid) )
-    {
-    both_valid:
-      /* Both regs are Valid or Denormal */
-      if ( signpositive(st0_ptr) )
-	{
-	  if ( st0_tag == TW_Denormal )
-	    FPU_to_exp16(st0_ptr, st0_ptr);
-	  else
-	    /* Convert st(0) for internal use. */
-	    setexponent16(st0_ptr, exponent(st0_ptr));
-
-	  if ( (st0_ptr->sigh == 0x80000000) && (st0_ptr->sigl == 0) )
-	    {
-	      /* Special case. The result can be precise. */
-	      u_char esign;
-	      e = exponent16(st0_ptr);
-	      if ( e >= 0 )
-		{
-		  exponent.sigh = e;
-		  esign = SIGN_POS;
-		}
-	      else
-		{
-		  exponent.sigh = -e;
-		  esign = SIGN_NEG;
-		}
-	      exponent.sigl = 0;
-	      setexponent16(&exponent, 31);
-	      tag = FPU_normalize_nuo(&exponent);
-	      stdexp(&exponent);
-	      setsign(&exponent, esign);
-	      tag = FPU_mul(&exponent, tag, 1, FULL_PRECISION);
-	      if ( tag >= 0 )
-		FPU_settagi(1, tag);
-	    }
-	  else
-	    {
-	      /* The usual case */
-	      sign = getsign(st1_ptr);
-	      if ( st1_tag == TW_Denormal )
-		FPU_to_exp16(st1_ptr, st1_ptr);
-	      else
-		/* Convert st(1) for internal use. */
-		setexponent16(st1_ptr, exponent(st1_ptr));
-	      poly_l2(st0_ptr, st1_ptr, sign);
-	    }
-	}
-      else
-	{
-	  /* negative */
-	  if ( arith_invalid(1) < 0 )
-	    return;
-	}
-
-      FPU_pop();
-
-      return;
-    }
-
-  if ( st0_tag == TAG_Special )
-    st0_tag = FPU_Special(st0_ptr);
-  if ( st1_tag == TAG_Special )
-    st1_tag = FPU_Special(st1_ptr);
-
-  if ( (st0_tag == TAG_Empty) || (st1_tag == TAG_Empty) )
-    {
-      FPU_stack_underflow_pop(1);
-      return;
-    }
-  else if ( (st0_tag <= TW_Denormal) && (st1_tag <= TW_Denormal) )
-    {
-      if ( st0_tag == TAG_Zero )
-	{
-	  if ( st1_tag == TAG_Zero )
-	    {
-	      /* Both args zero is invalid */
-	      if ( arith_invalid(1) < 0 )
-		return;
-	    }
-	  else
-	    {
-	      u_char sign;
-	      sign = getsign(st1_ptr)^SIGN_NEG;
-	      if ( FPU_divide_by_zero(1, sign) < 0 )
-		return;
-
-	      setsign(st1_ptr, sign);
-	    }
-	}
-      else if ( st1_tag == TAG_Zero )
-	{
-	  /* st(1) contains zero, st(0) valid <> 0 */
-	  /* Zero is the valid answer */
-	  sign = getsign(st1_ptr);
-	  
-	  if ( signnegative(st0_ptr) )
-	    {
-	      /* log(negative) */
-	      if ( arith_invalid(1) < 0 )
-		return;
-	    }
-	  else if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
-	    return;
-	  else
-	    {
-	      if ( exponent(st0_ptr) < 0 )
-		sign ^= SIGN_NEG;
-
-	      FPU_copy_to_reg1(&CONST_Z, TAG_Zero);
-	      setsign(st1_ptr, sign);
-	    }
-	}
-      else
-	{
-	  /* One or both operands are denormals. */
-	  if ( denormal_operand() < 0 )
-	    return;
-	  goto both_valid;
-	}
-    }
-  else if ( (st0_tag == TW_NaN) || (st1_tag == TW_NaN) )
-    {
-      if ( real_2op_NaN(st0_ptr, st0_tag, 1, st0_ptr) < 0 )
-	return;
-    }
-  /* One or both arg must be an infinity */
-  else if ( st0_tag == TW_Infinity )
-    {
-      if ( (signnegative(st0_ptr)) || (st1_tag == TAG_Zero) )
-	{
-	  /* log(-infinity) or 0*log(infinity) */
-	  if ( arith_invalid(1) < 0 )
-	    return;
-	}
-      else
-	{
-	  u_char sign = getsign(st1_ptr);
-
-	  if ( (st1_tag == TW_Denormal) && (denormal_operand() < 0) )
-	    return;
-
-	  FPU_copy_to_reg1(&CONST_INF, TAG_Special);
-	  setsign(st1_ptr, sign);
-	}
-    }
-  /* st(1) must be infinity here */
-  else if ( ((st0_tag == TAG_Valid) || (st0_tag == TW_Denormal))
-	    && ( signpositive(st0_ptr) ) )
-    {
-      if ( exponent(st0_ptr) >= 0 )
-	{
-	  if ( (exponent(st0_ptr) == 0) &&
-	      (st0_ptr->sigh == 0x80000000) &&
-	      (st0_ptr->sigl == 0) )
-	    {
-	      /* st(0) holds 1.0 */
-	      /* infinity*log(1) */
-	      if ( arith_invalid(1) < 0 )
-		return;
-	    }
-	  /* else st(0) is positive and > 1.0 */
-	}
-      else
-	{
-	  /* st(0) is positive and < 1.0 */
-
-	  if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
-	    return;
-
-	  changesign(st1_ptr);
-	}
-    }
-  else
-    {
-      /* st(0) must be zero or negative */
-      if ( st0_tag == TAG_Zero )
-	{
-	  /* This should be invalid, but a real 80486 is happy with it. */
-
-#ifndef PECULIAR_486
-	  sign = getsign(st1_ptr);
-	  if ( FPU_divide_by_zero(1, sign) < 0 )
-	    return;
-#endif /* PECULIAR_486 */
-
-	  changesign(st1_ptr);
-	}
-      else if ( arith_invalid(1) < 0 )	  /* log(negative) */
-	return;
-    }
-
-  FPU_pop();
-}
-
-
-static void fpatan(FPU_REG *st0_ptr, u_char st0_tag)
-{
-  FPU_REG *st1_ptr = &st(1);
-  u_char st1_tag = FPU_gettagi(1);
-  int tag;
-
-  clear_C1();
-  if ( !((st0_tag ^ TAG_Valid) | (st1_tag ^ TAG_Valid)) )
-    {
-    valid_atan:
-
-      poly_atan(st0_ptr, st0_tag, st1_ptr, st1_tag);
-
-      FPU_pop();
-
-      return;
-    }
-
-  if ( st0_tag == TAG_Special )
-    st0_tag = FPU_Special(st0_ptr);
-  if ( st1_tag == TAG_Special )
-    st1_tag = FPU_Special(st1_ptr);
-
-  if ( ((st0_tag == TAG_Valid) && (st1_tag == TW_Denormal))
-	    || ((st0_tag == TW_Denormal) && (st1_tag == TAG_Valid))
-	    || ((st0_tag == TW_Denormal) && (st1_tag == TW_Denormal)) )
-    {
-      if ( denormal_operand() < 0 )
-	return;
-
-      goto valid_atan;
-    }
-  else if ( (st0_tag == TAG_Empty) || (st1_tag == TAG_Empty) )
-    {
-      FPU_stack_underflow_pop(1);
-      return;
-    }
-  else if ( (st0_tag == TW_NaN) || (st1_tag == TW_NaN) )
-    {
-      if ( real_2op_NaN(st0_ptr, st0_tag, 1, st0_ptr) >= 0 )
-	  FPU_pop();
-      return;
-    }
-  else if ( (st0_tag == TW_Infinity) || (st1_tag == TW_Infinity) )
-    {
-      u_char sign = getsign(st1_ptr);
-      if ( st0_tag == TW_Infinity )
-	{
-	  if ( st1_tag == TW_Infinity )
-	    {
-	      if ( signpositive(st0_ptr) )
-		{
-		  FPU_copy_to_reg1(&CONST_PI4, TAG_Valid);
-		}
-	      else
-		{
-		  setpositive(st1_ptr);
-		  tag = FPU_u_add(&CONST_PI4, &CONST_PI2, st1_ptr,
-				  FULL_PRECISION, SIGN_POS,
-				  exponent(&CONST_PI4), exponent(&CONST_PI2));
-		  if ( tag >= 0 )
-		    FPU_settagi(1, tag);
-		}
-	    }
-	  else
-	    {
-	      if ( (st1_tag == TW_Denormal) && (denormal_operand() < 0) )
-		return;
-
-	      if ( signpositive(st0_ptr) )
-		{
-		  FPU_copy_to_reg1(&CONST_Z, TAG_Zero);
-		  setsign(st1_ptr, sign);   /* An 80486 preserves the sign */
-		  FPU_pop();
-		  return;
-		}
-	      else
-		{
-		  FPU_copy_to_reg1(&CONST_PI, TAG_Valid);
-		}
-	    }
-	}
-      else
-	{
-	  /* st(1) is infinity, st(0) not infinity */
-	  if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
-	    return;
-
-	  FPU_copy_to_reg1(&CONST_PI2, TAG_Valid);
-	}
-      setsign(st1_ptr, sign);
-    }
-  else if ( st1_tag == TAG_Zero )
-    {
-      /* st(0) must be valid or zero */
-      u_char sign = getsign(st1_ptr);
-
-      if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
-	return;
-
-      if ( signpositive(st0_ptr) )
-	{
-	  /* An 80486 preserves the sign */
-	  FPU_pop();
-	  return;
-	}
-
-      FPU_copy_to_reg1(&CONST_PI, TAG_Valid);
-      setsign(st1_ptr, sign);
-    }
-  else if ( st0_tag == TAG_Zero )
-    {
-      /* st(1) must be TAG_Valid here */
-      u_char sign = getsign(st1_ptr);
-
-      if ( (st1_tag == TW_Denormal) && (denormal_operand() < 0) )
-	return;
-
-      FPU_copy_to_reg1(&CONST_PI2, TAG_Valid);
-      setsign(st1_ptr, sign);
-    }
-#ifdef PARANOID
-  else
-    EXCEPTION(EX_INTERNAL | 0x125);
-#endif /* PARANOID */
-
-  FPU_pop();
-  set_precision_flag_up();  /* We do not really know if up or down */
-}
-
-
-static void fprem(FPU_REG *st0_ptr, u_char st0_tag)
-{
-  do_fprem(st0_ptr, st0_tag, RC_CHOP);
-}
-
-
-static void fprem1(FPU_REG *st0_ptr, u_char st0_tag)
-{
-  do_fprem(st0_ptr, st0_tag, RC_RND);
-}
-
-
-static void fyl2xp1(FPU_REG *st0_ptr, u_char st0_tag)
-{
-  u_char sign, sign1;
-  FPU_REG *st1_ptr = &st(1), a, b;
-  u_char st1_tag = FPU_gettagi(1);
-
-  clear_C1();
-  if ( !((st0_tag ^ TAG_Valid) | (st1_tag ^ TAG_Valid)) )
-    {
-    valid_yl2xp1:
-
-      sign = getsign(st0_ptr);
-      sign1 = getsign(st1_ptr);
-
-      FPU_to_exp16(st0_ptr, &a);
-      FPU_to_exp16(st1_ptr, &b);
-
-      if ( poly_l2p1(sign, sign1, &a, &b, st1_ptr) )
-	return;
-
-      FPU_pop();
-      return;
-    }
-
-  if ( st0_tag == TAG_Special )
-    st0_tag = FPU_Special(st0_ptr);
-  if ( st1_tag == TAG_Special )
-    st1_tag = FPU_Special(st1_ptr);
-
-  if ( ((st0_tag == TAG_Valid) && (st1_tag == TW_Denormal))
-	    || ((st0_tag == TW_Denormal) && (st1_tag == TAG_Valid))
-	    || ((st0_tag == TW_Denormal) && (st1_tag == TW_Denormal)) )
-    {
-      if ( denormal_operand() < 0 )
-	return;
-
-      goto valid_yl2xp1;
-    }
-  else if ( (st0_tag == TAG_Empty) | (st1_tag == TAG_Empty) )
-    {
-      FPU_stack_underflow_pop(1);
-      return;
-    }
-  else if ( st0_tag == TAG_Zero )
-    {
-      switch ( st1_tag )
-	{
-	case TW_Denormal:
-	  if ( denormal_operand() < 0 )
-	    return;
-
-	case TAG_Zero:
-	case TAG_Valid:
-	  setsign(st0_ptr, getsign(st0_ptr) ^ getsign(st1_ptr));
-	  FPU_copy_to_reg1(st0_ptr, st0_tag);
-	  break;
-
-	case TW_Infinity:
-	  /* Infinity*log(1) */
-	  if ( arith_invalid(1) < 0 )
-	    return;
-	  break;
-
-	case TW_NaN:
-	  if ( real_2op_NaN(st0_ptr, st0_tag, 1, st0_ptr) < 0 )
-	    return;
-	  break;
-
-	default:
-#ifdef PARANOID
-	  EXCEPTION(EX_INTERNAL | 0x116);
-	  return;
-#endif /* PARANOID */
-	  break;
-	}
-    }
-  else if ( (st0_tag == TAG_Valid) || (st0_tag == TW_Denormal) )
-    {
-      switch ( st1_tag )
-	{
-	case TAG_Zero:
-	  if ( signnegative(st0_ptr) )
-	    {
-	      if ( exponent(st0_ptr) >= 0 )
-		{
-		  /* st(0) holds <= -1.0 */
-#ifdef PECULIAR_486   /* Stupid 80486 doesn't worry about log(negative). */
-		  changesign(st1_ptr);
-#else
-		  if ( arith_invalid(1) < 0 )
-		    return;
-#endif /* PECULIAR_486 */
-		}
-	      else if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
-		return;
-	      else
-		changesign(st1_ptr);
-	    }
-	  else if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
-	    return;
-	  break;
-
-	case TW_Infinity:
-	  if ( signnegative(st0_ptr) )
-	    {
-	      if ( (exponent(st0_ptr) >= 0) &&
-		  !((st0_ptr->sigh == 0x80000000) &&
-		    (st0_ptr->sigl == 0)) )
-		{
-		  /* st(0) holds < -1.0 */
-#ifdef PECULIAR_486   /* Stupid 80486 doesn't worry about log(negative). */
-		  changesign(st1_ptr);
-#else
-		  if ( arith_invalid(1) < 0 ) return;
-#endif /* PECULIAR_486 */
-		}
-	      else if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
-		return;
-	      else
-		changesign(st1_ptr);
-	    }
-	  else if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
-	    return;
-	  break;
-
-	case TW_NaN:
-	  if ( real_2op_NaN(st0_ptr, st0_tag, 1, st0_ptr) < 0 )
-	    return;
-	}
-
-    }
-  else if ( st0_tag == TW_NaN )
-    {
-      if ( real_2op_NaN(st0_ptr, st0_tag, 1, st0_ptr) < 0 )
-	return;
-    }
-  else if ( st0_tag == TW_Infinity )
-    {
-      if ( st1_tag == TW_NaN )
-	{
-	  if ( real_2op_NaN(st0_ptr, st0_tag, 1, st0_ptr) < 0 )
-	    return;
-	}
-      else if ( signnegative(st0_ptr) )
-	{
-#ifndef PECULIAR_486
-	  /* This should have higher priority than denormals, but... */
-	  if ( arith_invalid(1) < 0 )  /* log(-infinity) */
-	    return;
-#endif /* PECULIAR_486 */
-	  if ( (st1_tag == TW_Denormal) && (denormal_operand() < 0) )
-	    return;
-#ifdef PECULIAR_486
-	  /* Denormal operands actually get higher priority */
-	  if ( arith_invalid(1) < 0 )  /* log(-infinity) */
-	    return;
-#endif /* PECULIAR_486 */
-	}
-      else if ( st1_tag == TAG_Zero )
-	{
-	  /* log(infinity) */
-	  if ( arith_invalid(1) < 0 )
-	    return;
-	}
-	
-      /* st(1) must be valid here. */
-
-      else if ( (st1_tag == TW_Denormal) && (denormal_operand() < 0) )
-	return;
-
-      /* The Manual says that log(Infinity) is invalid, but a real
-	 80486 sensibly says that it is o.k. */
-      else
-	{
-	  u_char sign = getsign(st1_ptr);
-	  FPU_copy_to_reg1(&CONST_INF, TAG_Special);
-	  setsign(st1_ptr, sign);
-	}
-    }
-#ifdef PARANOID
-  else
-    {
-      EXCEPTION(EX_INTERNAL | 0x117);
-      return;
-    }
-#endif /* PARANOID */
-
-  FPU_pop();
-  return;
-
-}
-
-
-static void fscale(FPU_REG *st0_ptr, u_char st0_tag)
-{
-  FPU_REG *st1_ptr = &st(1);
-  u_char st1_tag = FPU_gettagi(1);
-  int old_cw = control_word;
-  u_char sign = getsign(st0_ptr);
-
-  clear_C1();
-  if ( !((st0_tag ^ TAG_Valid) | (st1_tag ^ TAG_Valid)) )
-    {
-      long scale;
-      FPU_REG tmp;
-
-      /* Convert register for internal use. */
-      setexponent16(st0_ptr, exponent(st0_ptr));
-
-    valid_scale:
-
-      if ( exponent(st1_ptr) > 30 )
-	{
-	  /* 2^31 is far too large, would require 2^(2^30) or 2^(-2^30) */
-
-	  if ( signpositive(st1_ptr) )
-	    {
-	      EXCEPTION(EX_Overflow);
-	      FPU_copy_to_reg0(&CONST_INF, TAG_Special);
-	    }
-	  else
-	    {
-	      EXCEPTION(EX_Underflow);
-	      FPU_copy_to_reg0(&CONST_Z, TAG_Zero);
-	    }
-	  setsign(st0_ptr, sign);
-	  return;
-	}
-
-      control_word &= ~CW_RC;
-      control_word |= RC_CHOP;
-      reg_copy(st1_ptr, &tmp);
-      FPU_round_to_int(&tmp, st1_tag);      /* This can never overflow here */
-      control_word = old_cw;
-      scale = signnegative(st1_ptr) ? -tmp.sigl : tmp.sigl;
-      scale += exponent16(st0_ptr);
-
-      setexponent16(st0_ptr, scale);
-
-      /* Use FPU_round() to properly detect under/overflow etc */
-      FPU_round(st0_ptr, 0, 0, control_word, sign);
-
-      return;
-    }
-
-  if ( st0_tag == TAG_Special )
-    st0_tag = FPU_Special(st0_ptr);
-  if ( st1_tag == TAG_Special )
-    st1_tag = FPU_Special(st1_ptr);
-
-  if ( (st0_tag == TAG_Valid) || (st0_tag == TW_Denormal) )
-    {
-      switch ( st1_tag )
-	{
-	case TAG_Valid:
-	  /* st(0) must be a denormal */
-	  if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
-	    return;
-
-	  FPU_to_exp16(st0_ptr, st0_ptr);  /* Will not be left on stack */
-	  goto valid_scale;
-
-	case TAG_Zero:
-	  if ( st0_tag == TW_Denormal )
-	    denormal_operand();
-	  return;
-
-	case TW_Denormal:
-	  denormal_operand();
-	  return;
-
-	case TW_Infinity:
-	  if ( (st0_tag == TW_Denormal) && (denormal_operand() < 0) )
-	    return;
-
-	  if ( signpositive(st1_ptr) )
-	    FPU_copy_to_reg0(&CONST_INF, TAG_Special);
-	  else
-	    FPU_copy_to_reg0(&CONST_Z, TAG_Zero);
-	  setsign(st0_ptr, sign);
-	  return;
-
-	case TW_NaN:
-	  real_2op_NaN(st1_ptr, st1_tag, 0, st0_ptr);
-	  return;
-	}
-    }
-  else if ( st0_tag == TAG_Zero )
-    {
-      switch ( st1_tag )
-	{
-	case TAG_Valid:
-	case TAG_Zero:
-	  return;
-
-	case TW_Denormal:
-	  denormal_operand();
-	  return;
-
-	case TW_Infinity:
-	  if ( signpositive(st1_ptr) )
-	    arith_invalid(0); /* Zero scaled by +Infinity */
-	  return;
-
-	case TW_NaN:
-	  real_2op_NaN(st1_ptr, st1_tag, 0, st0_ptr);
-	  return;
-	}
-    }
-  else if ( st0_tag == TW_Infinity )
-    {
-      switch ( st1_tag )
-	{
-	case TAG_Valid:
-	case TAG_Zero:
-	  return;
-
-	case TW_Denormal:
-	  denormal_operand();
-	  return;
-
-	case TW_Infinity:
-	  if ( signnegative(st1_ptr) )
-	    arith_invalid(0); /* Infinity scaled by -Infinity */
-	  return;
-
-	case TW_NaN:
-	  real_2op_NaN(st1_ptr, st1_tag, 0, st0_ptr);
-	  return;
-	}
-    }
-  else if ( st0_tag == TW_NaN )
-    {
-      if ( st1_tag != TAG_Empty )
-	{ real_2op_NaN(st1_ptr, st1_tag, 0, st0_ptr); return; }
-    }
-
-#ifdef PARANOID
-  if ( !((st0_tag == TAG_Empty) || (st1_tag == TAG_Empty)) )
-    {
-      EXCEPTION(EX_INTERNAL | 0x115);
-      return;
-    }
-#endif
-
-  /* At least one of st(0), st(1) must be empty */
-  FPU_stack_underflow();
-
-}
-
-
-/*---------------------------------------------------------------------------*/
-
-static FUNC_ST0 const trig_table_a[] = {
-  f2xm1, fyl2x, fptan, fpatan,
-  fxtract, fprem1, (FUNC_ST0)fdecstp, (FUNC_ST0)fincstp
-};
-
-void FPU_triga(void)
-{
-  (trig_table_a[FPU_rm])(&st(0), FPU_gettag0());
-}
-
-
-static FUNC_ST0 const trig_table_b[] =
-  {
-    fprem, fyl2xp1, fsqrt_, fsincos, frndint_, fscale, (FUNC_ST0)fsin, fcos
-  };
-
-void FPU_trigb(void)
-{
-  (trig_table_b[FPU_rm])(&st(0), FPU_gettag0());
-}