Ejemplo n.º 1
0
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);
    }
}
Ejemplo n.º 2
0
static void f2xm1(FPU_REG *st0_ptr, u_char tag)
{
	FPU_REG a;

	clear_C1();

	if (tag == TAG_Valid) {
		
		if (exponent(st0_ptr) < 0) {
		      denormal_arg:

			FPU_to_exp16(st0_ptr, &a);

			
			poly_2xm1(getsign(st0_ptr), &a, st0_ptr);
		}
		set_precision_flag_up();	
		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)) {
			
			FPU_copy_to_reg0(&CONST_1, TAG_Valid);
			setnegative(st0_ptr);
		}
		return;
	default:
		single_arg_error(st0_ptr, tag);
	}
}
Ejemplo n.º 3
0
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;	

	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);	
		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) {
		
		if (control_word & EX_Invalid) {
			FPU_stack_underflow();
			push();
			FPU_stack_underflow();
		} else
			EXCEPTION(EX_StackUnder);
	}
#ifdef PARANOID
	else
		EXCEPTION(EX_INTERNAL | 0x119);
#endif 
}
Ejemplo n.º 4
0
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);

	
	if (st0_tag == TAG_Empty) {
		FPU_stack_underflow();	
		if (control_word & CW_Invalid) {
			st_new_ptr = &st(-1);
			push();
			FPU_stack_underflow();	
		}
		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) {
				
				return;
			}

			poly_tan(st0_ptr);
			setsign(st0_ptr, (q & 1) ^ (arg_sign != 0));
			set_precision_flag_up();	
		} else {
			
			

		      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) {
		
		if (arith_invalid(0) >= 0) {
			st_new_ptr = &st(-1);
			push();
			arith_invalid(0);
		}
		return;
	}

	single_arg_2_error(st0_ptr, st0_tag);
}
int FPU_add(FPU_REG const *b, u_char tagb, int deststnr, int control_w)
{
	FPU_REG *a = &st(0);
	FPU_REG *dest = &st(deststnr);
	u_char signb = getsign(b);
	u_char taga = FPU_gettag0();
	u_char signa = getsign(a);
	u_char saved_sign = getsign(dest);
	int diff, tag, expa, expb;

	if (!(taga | tagb)) {
		expa = exponent(a);
		expb = exponent(b);

	      valid_add:
		
		if (!(signa ^ signb)) {
			
			tag =
			    FPU_u_add(a, b, dest, control_w, signa, expa, expb);
		} else {
			
			diff = expa - expb;
			if (!diff) {
				diff = a->sigh - b->sigh;	
				if (!diff) {
					diff = a->sigl > b->sigl;
					if (!diff)
						diff = -(a->sigl < b->sigl);
				}
			}

			if (diff > 0) {
				tag =
				    FPU_u_sub(a, b, dest, control_w, signa,
					      expa, expb);
			} else if (diff < 0) {
				tag =
				    FPU_u_sub(b, a, dest, control_w, signb,
					      expb, expa);
			} else {
				FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
				
				setsign(dest, ((control_w & CW_RC) != RC_DOWN)
					? SIGN_POS : SIGN_NEG);
				return TAG_Zero;
			}
		}

		if (tag < 0) {
			setsign(dest, saved_sign);
			return tag;
		}
		FPU_settagi(deststnr, tag);
		return tag;
	}

	if (taga == TAG_Special)
		taga = FPU_Special(a);
	if (tagb == TAG_Special)
		tagb = FPU_Special(b);

	if (((taga == TAG_Valid) && (tagb == TW_Denormal))
	    || ((taga == TW_Denormal) && (tagb == TAG_Valid))
	    || ((taga == TW_Denormal) && (tagb == TW_Denormal))) {
		FPU_REG x, y;

		if (denormal_operand() < 0)
			return FPU_Exception;

		FPU_to_exp16(a, &x);
		FPU_to_exp16(b, &y);
		a = &x;
		b = &y;
		expa = exponent16(a);
		expb = exponent16(b);
		goto valid_add;
	}

	if ((taga == TW_NaN) || (tagb == TW_NaN)) {
		if (deststnr == 0)
			return real_2op_NaN(b, tagb, deststnr, a);
		else
			return real_2op_NaN(a, taga, deststnr, a);
	}

	return add_sub_specials(a, taga, signa, b, tagb, signb,
				dest, deststnr, control_w);
}
int FPU_sub(int flags, int rm, int control_w)
{
	FPU_REG const *a, *b;
	FPU_REG *dest;
	u_char taga, tagb, signa, signb, saved_sign, sign;
	int diff, tag = 0, expa, expb, deststnr;

	a = &st(0);
	taga = FPU_gettag0();

	deststnr = 0;
	if (flags & LOADED) {
		b = (FPU_REG *) rm;
		tagb = flags & 0x0f;
	} else {
		b = &st(rm);
		tagb = FPU_gettagi(rm);

		if (flags & DEST_RM)
			deststnr = rm;
	}

	signa = getsign(a);
	signb = getsign(b);

	if (flags & REV) {
		signa ^= SIGN_NEG;
		signb ^= SIGN_NEG;
	}

	dest = &st(deststnr);
	saved_sign = getsign(dest);

	if (!(taga | tagb)) {
		expa = exponent(a);
		expb = exponent(b);

	      valid_subtract:
		

		diff = expa - expb;

		if (!diff) {
			diff = a->sigh - b->sigh;	
			if (!diff) {
				diff = a->sigl > b->sigl;
				if (!diff)
					diff = -(a->sigl < b->sigl);
			}
		}

		switch ((((int)signa) * 2 + signb) / SIGN_NEG) {
		case 0:	
		case 3:	
			if (diff > 0) {
				
				tag =
				    FPU_u_sub(a, b, dest, control_w, signa,
					      expa, expb);
			} else if (diff == 0) {
				FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);

				
				setsign(dest, ((control_w & CW_RC) != RC_DOWN)
					? SIGN_POS : SIGN_NEG);
				return TAG_Zero;
			} else {
				sign = signa ^ SIGN_NEG;
				tag =
				    FPU_u_sub(b, a, dest, control_w, sign, expb,
					      expa);
			}
			break;
		case 1:	
			tag =
			    FPU_u_add(a, b, dest, control_w, SIGN_POS, expa,
				      expb);
			break;
		case 2:	
			tag =
			    FPU_u_add(a, b, dest, control_w, SIGN_NEG, expa,
				      expb);
			break;
#ifdef PARANOID
		default:
			EXCEPTION(EX_INTERNAL | 0x111);
			return -1;
#endif
		}
		if (tag < 0) {
			setsign(dest, saved_sign);
			return tag;
		}
		FPU_settagi(deststnr, tag);
		return tag;
	}

	if (taga == TAG_Special)
		taga = FPU_Special(a);
	if (tagb == TAG_Special)
		tagb = FPU_Special(b);

	if (((taga == TAG_Valid) && (tagb == TW_Denormal))
	    || ((taga == TW_Denormal) && (tagb == TAG_Valid))
	    || ((taga == TW_Denormal) && (tagb == TW_Denormal))) {
		FPU_REG x, y;

		if (denormal_operand() < 0)
			return FPU_Exception;

		FPU_to_exp16(a, &x);
		FPU_to_exp16(b, &y);
		a = &x;
		b = &y;
		expa = exponent16(a);
		expb = exponent16(b);

		goto valid_subtract;
	}

	if ((taga == TW_NaN) || (tagb == TW_NaN)) {
		FPU_REG const *d1, *d2;
		if (flags & REV) {
			d1 = b;
			d2 = a;
		} else {
			d1 = a;
			d2 = b;
		}
		if (flags & LOADED)
			return real_2op_NaN(b, tagb, deststnr, d1);
		if (flags & DEST_RM)
			return real_2op_NaN(a, taga, deststnr, d2);
		else
			return real_2op_NaN(b, tagb, deststnr, d2);
	}

	return add_sub_specials(a, taga, signa, b, tagb, signb ^ SIGN_NEG,
				dest, deststnr, control_w);
}
Ejemplo n.º 7
0
/*--- poly_atan() -----------------------------------------------------------+
 |                                                                           |
 +---------------------------------------------------------------------------*/
void	poly_atan(FPU_REG *st0_ptr, u_char st0_tag,
		  FPU_REG *st1_ptr, u_char st1_tag)
{
  u_char	transformed, inverted,
                sign1, sign2;
  int           exponent;
  long int   	dummy_exp;
  Xsig          accumulator, Numer, Denom, accumulatore, argSignif,
                argSq, argSqSq;
  u_char        tag;
  
  sign1 = getsign(st0_ptr);
  sign2 = getsign(st1_ptr);
  if ( st0_tag == TAG_Valid )
    {
      exponent = exponent(st0_ptr);
    }
  else
    {
      /* This gives non-compatible stack contents... */
      FPU_to_exp16(st0_ptr, st0_ptr);
      exponent = exponent16(st0_ptr);
    }
  if ( st1_tag == TAG_Valid )
    {
      exponent -= exponent(st1_ptr);
    }
  else
    {
      /* This gives non-compatible stack contents... */
      FPU_to_exp16(st1_ptr, st1_ptr);
      exponent -= exponent16(st1_ptr);
    }

  if ( (exponent < 0) || ((exponent == 0) &&
			  ((st0_ptr->sigh < st1_ptr->sigh) ||
			   ((st0_ptr->sigh == st1_ptr->sigh) &&
			    (st0_ptr->sigl < st1_ptr->sigl))) ) )
    {
      inverted = 1;
      Numer.lsw = Denom.lsw = 0;
      XSIG_LL(Numer) = significand(st0_ptr);
      XSIG_LL(Denom) = significand(st1_ptr);
    }
  else
    {
      inverted = 0;
      exponent = -exponent;
      Numer.lsw = Denom.lsw = 0;
      XSIG_LL(Numer) = significand(st1_ptr);
      XSIG_LL(Denom) = significand(st0_ptr);
     }
  div_Xsig(&Numer, &Denom, &argSignif);
  exponent += norm_Xsig(&argSignif);

  if ( (exponent >= -1)
      || ((exponent == -2) && (argSignif.msw > 0xd413ccd0)) )
    {
      /* The argument is greater than sqrt(2)-1 (=0.414213562...) */
      /* Convert the argument by an identity for atan */
      transformed = 1;

      if ( exponent >= 0 )
	{
#ifdef PARANOID
	  if ( !( (exponent == 0) && 
		 (argSignif.lsw == 0) && (argSignif.midw == 0) &&
		 (argSignif.msw == 0x80000000) ) )
	    {
	      EXCEPTION(EX_INTERNAL|0x104);  /* There must be a logic error */
	      return;
	    }
#endif /* PARANOID */
	  argSignif.msw = 0;   /* Make the transformed arg -> 0.0 */
	}
      else
	{
	  Numer.lsw = Denom.lsw = argSignif.lsw;
	  XSIG_LL(Numer) = XSIG_LL(Denom) = XSIG_LL(argSignif);

	  if ( exponent < -1 )
	    shr_Xsig(&Numer, -1-exponent);
	  negate_Xsig(&Numer);
      
	  shr_Xsig(&Denom, -exponent);
	  Denom.msw |= 0x80000000;
      
	  div_Xsig(&Numer, &Denom, &argSignif);

	  exponent = -1 + norm_Xsig(&argSignif);
	}
    }
  else
    {
      transformed = 0;
    }

  argSq.lsw = argSignif.lsw; argSq.midw = argSignif.midw;
  argSq.msw = argSignif.msw;
  mul_Xsig_Xsig(&argSq, &argSq);
  
  argSqSq.lsw = argSq.lsw; argSqSq.midw = argSq.midw; argSqSq.msw = argSq.msw;
  mul_Xsig_Xsig(&argSqSq, &argSqSq);

  accumulatore.lsw = argSq.lsw;
  XSIG_LL(accumulatore) = XSIG_LL(argSq);

  shr_Xsig(&argSq, 2*(-1-exponent-1));
  shr_Xsig(&argSqSq, 4*(-1-exponent-1));

  /* Now have argSq etc with binary point at the left
     .1xxxxxxxx */

  /* Do the basic fixed point polynomial evaluation */
  accumulator.msw = accumulator.midw = accumulator.lsw = 0;
  polynomial_Xsig(&accumulator, &XSIG_LL(argSqSq),
		   oddplterms, HIPOWERop-1);
  mul64_Xsig(&accumulator, &XSIG_LL(argSq));
  negate_Xsig(&accumulator);
  polynomial_Xsig(&accumulator, &XSIG_LL(argSqSq), oddnegterms, HIPOWERon-1);
  negate_Xsig(&accumulator);
  add_two_Xsig(&accumulator, &fixedpterm, &dummy_exp);

  mul64_Xsig(&accumulatore, &denomterm);
  shr_Xsig(&accumulatore, 1 + 2*(-1-exponent));
  accumulatore.msw |= 0x80000000;

  div_Xsig(&accumulator, &accumulatore, &accumulator);

  mul_Xsig_Xsig(&accumulator, &argSignif);
  mul_Xsig_Xsig(&accumulator, &argSq);

  shr_Xsig(&accumulator, 3);
  negate_Xsig(&accumulator);
  add_Xsig_Xsig(&accumulator, &argSignif);

  if ( transformed )
    {
      /* compute pi/4 - accumulator */
      shr_Xsig(&accumulator, -1-exponent);
      negate_Xsig(&accumulator);
      add_Xsig_Xsig(&accumulator, &pi_signif);
      exponent = -1;
    }

  if ( inverted )
    {
      /* compute pi/2 - accumulator */
      shr_Xsig(&accumulator, -exponent);
      negate_Xsig(&accumulator);
      add_Xsig_Xsig(&accumulator, &pi_signif);
      exponent = 0;
    }

  if ( sign1 )
    {
      /* compute pi - accumulator */
      shr_Xsig(&accumulator, 1 - exponent);
      negate_Xsig(&accumulator);
      add_Xsig_Xsig(&accumulator, &pi_signif);
      exponent = 1;
    }

  exponent += round_Xsig(&accumulator);

  significand(st1_ptr) = XSIG_LL(accumulator);
  setexponent16(st1_ptr, exponent);

  tag = FPU_round(st1_ptr, 1, 0, FULL_PRECISION, sign2);
  FPU_settagi(1, tag);

  set_precision_flag_up();  /* We do not really know if up or down,
			       use this as the default. */

}
Ejemplo n.º 8
0
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);
}
void poly_atan(FPU_REG *st0_ptr, u_char st0_tag,
	       FPU_REG *st1_ptr, u_char st1_tag)
{
	u_char transformed, inverted, sign1, sign2;
	int exponent;
	long int dummy_exp;
	Xsig accumulator, Numer, Denom, accumulatore, argSignif, argSq, argSqSq;
	u_char tag;

	sign1 = getsign(st0_ptr);
	sign2 = getsign(st1_ptr);
	if (st0_tag == TAG_Valid) {
		exponent = exponent(st0_ptr);
	} else {
		
		FPU_to_exp16(st0_ptr, st0_ptr);
		exponent = exponent16(st0_ptr);
	}
	if (st1_tag == TAG_Valid) {
		exponent -= exponent(st1_ptr);
	} else {
		
		FPU_to_exp16(st1_ptr, st1_ptr);
		exponent -= exponent16(st1_ptr);
	}

	if ((exponent < 0) || ((exponent == 0) &&
			       ((st0_ptr->sigh < st1_ptr->sigh) ||
				((st0_ptr->sigh == st1_ptr->sigh) &&
				 (st0_ptr->sigl < st1_ptr->sigl))))) {
		inverted = 1;
		Numer.lsw = Denom.lsw = 0;
		XSIG_LL(Numer) = significand(st0_ptr);
		XSIG_LL(Denom) = significand(st1_ptr);
	} else {
		inverted = 0;
		exponent = -exponent;
		Numer.lsw = Denom.lsw = 0;
		XSIG_LL(Numer) = significand(st1_ptr);
		XSIG_LL(Denom) = significand(st0_ptr);
	}
	div_Xsig(&Numer, &Denom, &argSignif);
	exponent += norm_Xsig(&argSignif);

	if ((exponent >= -1)
	    || ((exponent == -2) && (argSignif.msw > 0xd413ccd0))) {
		
		
		transformed = 1;

		if (exponent >= 0) {
#ifdef PARANOID
			if (!((exponent == 0) &&
			      (argSignif.lsw == 0) && (argSignif.midw == 0) &&
			      (argSignif.msw == 0x80000000))) {
				EXCEPTION(EX_INTERNAL | 0x104);	
				return;
			}
#endif 
			argSignif.msw = 0;	
		} else {
			Numer.lsw = Denom.lsw = argSignif.lsw;
			XSIG_LL(Numer) = XSIG_LL(Denom) = XSIG_LL(argSignif);

			if (exponent < -1)
				shr_Xsig(&Numer, -1 - exponent);
			negate_Xsig(&Numer);

			shr_Xsig(&Denom, -exponent);
			Denom.msw |= 0x80000000;

			div_Xsig(&Numer, &Denom, &argSignif);

			exponent = -1 + norm_Xsig(&argSignif);
		}
	} else {
		transformed = 0;
	}

	argSq.lsw = argSignif.lsw;
	argSq.midw = argSignif.midw;
	argSq.msw = argSignif.msw;
	mul_Xsig_Xsig(&argSq, &argSq);

	argSqSq.lsw = argSq.lsw;
	argSqSq.midw = argSq.midw;
	argSqSq.msw = argSq.msw;
	mul_Xsig_Xsig(&argSqSq, &argSqSq);

	accumulatore.lsw = argSq.lsw;
	XSIG_LL(accumulatore) = XSIG_LL(argSq);

	shr_Xsig(&argSq, 2 * (-1 - exponent - 1));
	shr_Xsig(&argSqSq, 4 * (-1 - exponent - 1));


	
	accumulator.msw = accumulator.midw = accumulator.lsw = 0;
	polynomial_Xsig(&accumulator, &XSIG_LL(argSqSq),
			oddplterms, HIPOWERop - 1);
	mul64_Xsig(&accumulator, &XSIG_LL(argSq));
	negate_Xsig(&accumulator);
	polynomial_Xsig(&accumulator, &XSIG_LL(argSqSq), oddnegterms,
			HIPOWERon - 1);
	negate_Xsig(&accumulator);
	add_two_Xsig(&accumulator, &fixedpterm, &dummy_exp);

	mul64_Xsig(&accumulatore, &denomterm);
	shr_Xsig(&accumulatore, 1 + 2 * (-1 - exponent));
	accumulatore.msw |= 0x80000000;

	div_Xsig(&accumulator, &accumulatore, &accumulator);

	mul_Xsig_Xsig(&accumulator, &argSignif);
	mul_Xsig_Xsig(&accumulator, &argSq);

	shr_Xsig(&accumulator, 3);
	negate_Xsig(&accumulator);
	add_Xsig_Xsig(&accumulator, &argSignif);

	if (transformed) {
		
		shr_Xsig(&accumulator, -1 - exponent);
		negate_Xsig(&accumulator);
		add_Xsig_Xsig(&accumulator, &pi_signif);
		exponent = -1;
	}

	if (inverted) {
		
		shr_Xsig(&accumulator, -exponent);
		negate_Xsig(&accumulator);
		add_Xsig_Xsig(&accumulator, &pi_signif);
		exponent = 0;
	}

	if (sign1) {
		
		shr_Xsig(&accumulator, 1 - exponent);
		negate_Xsig(&accumulator);
		add_Xsig_Xsig(&accumulator, &pi_signif);
		exponent = 1;
	}

	exponent += round_Xsig(&accumulator);

	significand(st1_ptr) = XSIG_LL(accumulator);
	setexponent16(st1_ptr, exponent);

	tag = FPU_round(st1_ptr, 1, 0, FULL_PRECISION, sign2);
	FPU_settagi(1, tag);

	set_precision_flag_up();	

}
Ejemplo n.º 10
0
/*
  Divide one register by another and put the result into a third register.
  */
int FPU_div(int flags, int rm, int control_w)
{
	FPU_REG x, y;
	FPU_REG const *a, *b, *st0_ptr, *st_ptr;
	FPU_REG *dest;
	u_char taga, tagb, signa, signb, sign, saved_sign;
	int tag, deststnr;

	if (flags & DEST_RM)
		deststnr = rm;
	else
		deststnr = 0;

	if (flags & REV) {
		b = &st(0);
		st0_ptr = b;
		tagb = FPU_gettag0();
		if (flags & LOADED) {
			a = (FPU_REG *) rm;
			taga = flags & 0x0f;
		} else {
			a = &st(rm);
			st_ptr = a;
			taga = FPU_gettagi(rm);
		}
	} else {
		a = &st(0);
		st0_ptr = a;
		taga = FPU_gettag0();
		if (flags & LOADED) {
			b = (FPU_REG *) rm;
			tagb = flags & 0x0f;
		} else {
			b = &st(rm);
			st_ptr = b;
			tagb = FPU_gettagi(rm);
		}
	}

	signa = getsign(a);
	signb = getsign(b);

	sign = signa ^ signb;

	dest = &st(deststnr);
	saved_sign = getsign(dest);

	if (!(taga | tagb)) {
		/* Both regs Valid, this should be the most common case. */
		reg_copy(a, &x);
		reg_copy(b, &y);
		setpositive(&x);
		setpositive(&y);
		tag = FPU_u_div(&x, &y, dest, control_w, sign);

		if (tag < 0)
			return tag;

		FPU_settagi(deststnr, tag);
		return tag;
	}

	if (taga == TAG_Special)
		taga = FPU_Special(a);
	if (tagb == TAG_Special)
		tagb = FPU_Special(b);

	if (((taga == TAG_Valid) && (tagb == TW_Denormal))
	    || ((taga == TW_Denormal) && (tagb == TAG_Valid))
	    || ((taga == TW_Denormal) && (tagb == TW_Denormal))) {
		if (denormal_operand() < 0)
			return FPU_Exception;

		FPU_to_exp16(a, &x);
		FPU_to_exp16(b, &y);
		tag = FPU_u_div(&x, &y, dest, control_w, sign);
		if (tag < 0)
			return tag;

		FPU_settagi(deststnr, tag);
		return tag;
	} else if ((taga <= TW_Denormal) && (tagb <= TW_Denormal)) {
		if (tagb != TAG_Zero) {
			/* Want to find Zero/Valid */
			if (tagb == TW_Denormal) {
				if (denormal_operand() < 0)
					return FPU_Exception;
			}

			/* The result is zero. */
			FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
			setsign(dest, sign);
			return TAG_Zero;
		}
		/* We have an exception condition, either 0/0 or Valid/Zero. */
		if (taga == TAG_Zero) {
			/* 0/0 */
			return arith_invalid(deststnr);
		}
		/* Valid/Zero */
		return FPU_divide_by_zero(deststnr, sign);
	}
	/* Must have infinities, NaNs, etc */
	else if ((taga == TW_NaN) || (tagb == TW_NaN)) {
		if (flags & LOADED)
			return real_2op_NaN((FPU_REG *) rm, flags & 0x0f, 0,
					    st0_ptr);

		if (flags & DEST_RM) {
			int tag;
			tag = FPU_gettag0();
			if (tag == TAG_Special)
				tag = FPU_Special(st0_ptr);
			return real_2op_NaN(st0_ptr, tag, rm,
					    (flags & REV) ? st0_ptr : &st(rm));
		} else {
			int tag;
			tag = FPU_gettagi(rm);
			if (tag == TAG_Special)
				tag = FPU_Special(&st(rm));
			return real_2op_NaN(&st(rm), tag, 0,
					    (flags & REV) ? st0_ptr : &st(rm));
		}
	} else if (taga == TW_Infinity) {
		if (tagb == TW_Infinity) {
			/* infinity/infinity */
			return arith_invalid(deststnr);
		} else {
			/* tagb must be Valid or Zero */
			if ((tagb == TW_Denormal) && (denormal_operand() < 0))
				return FPU_Exception;

			/* Infinity divided by Zero or Valid does
			   not raise and exception, but returns Infinity */
			FPU_copy_to_regi(a, TAG_Special, deststnr);
			setsign(dest, sign);
			return taga;
		}
	} else if (tagb == TW_Infinity) {
		if ((taga == TW_Denormal) && (denormal_operand() < 0))
			return FPU_Exception;

		/* The result is zero. */
		FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
		setsign(dest, sign);
		return TAG_Zero;
	}
#ifdef PARANOID
	else {
		EXCEPTION(EX_INTERNAL | 0x102);
		return FPU_Exception;
	}
#endif /* PARANOID */

	return 0;
}
Ejemplo n.º 11
0
int FPU_mul(FPU_REG const *b, u_char tagb, int deststnr, int control_w)
{
	FPU_REG *a = &st(deststnr);
	FPU_REG *dest = a;
	u_char taga = FPU_gettagi(deststnr);
	u_char saved_sign = getsign(dest);
	u_char sign = (getsign(a) ^ getsign(b));
	int tag;

	if (!(taga | tagb)) {
		

		tag =
		    FPU_u_mul(a, b, dest, control_w, sign,
			      exponent(a) + exponent(b));
		if (tag < 0) {
			setsign(dest, saved_sign);
			return tag;
		}
		FPU_settagi(deststnr, tag);
		return tag;
	}

	if (taga == TAG_Special)
		taga = FPU_Special(a);
	if (tagb == TAG_Special)
		tagb = FPU_Special(b);

	if (((taga == TAG_Valid) && (tagb == TW_Denormal))
	    || ((taga == TW_Denormal) && (tagb == TAG_Valid))
	    || ((taga == TW_Denormal) && (tagb == TW_Denormal))) {
		FPU_REG x, y;
		if (denormal_operand() < 0)
			return FPU_Exception;

		FPU_to_exp16(a, &x);
		FPU_to_exp16(b, &y);
		tag = FPU_u_mul(&x, &y, dest, control_w, sign,
				exponent16(&x) + exponent16(&y));
		if (tag < 0) {
			setsign(dest, saved_sign);
			return tag;
		}
		FPU_settagi(deststnr, tag);
		return tag;
	} else if ((taga <= TW_Denormal) && (tagb <= TW_Denormal)) {
		if (((tagb == TW_Denormal) || (taga == TW_Denormal))
		    && (denormal_operand() < 0))
			return FPU_Exception;

		FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
		setsign(dest, sign);
		return TAG_Zero;
	}
	
	else if ((taga == TW_NaN) || (tagb == TW_NaN)) {
		return real_2op_NaN(b, tagb, deststnr, &st(0));
	} else if (((taga == TW_Infinity) && (tagb == TAG_Zero))
		   || ((tagb == TW_Infinity) && (taga == TAG_Zero))) {
		return arith_invalid(deststnr);	
	} else if (((taga == TW_Denormal) || (tagb == TW_Denormal))
		   && (denormal_operand() < 0)) {
		return FPU_Exception;
	} else if (taga == TW_Infinity) {
		FPU_copy_to_regi(a, TAG_Special, deststnr);
		setsign(dest, sign);
		return TAG_Special;
	} else if (tagb == TW_Infinity) {
		FPU_copy_to_regi(b, TAG_Special, deststnr);
		setsign(dest, sign);
		return TAG_Special;
	}
#ifdef PARANOID
	else {
		EXCEPTION(EX_INTERNAL | 0x102);
		return FPU_Exception;
	}
#endif 

	return 0;
}
Ejemplo n.º 12
0
static int compare(FPU_REG const *b, int tagb)
{
	int diff, exp0, expb;
	u_char st0_tag;
	FPU_REG *st0_ptr;
	FPU_REG x, y;
	u_char st0_sign, signb = getsign(b);

	st0_ptr = &st(0);
	st0_tag = FPU_gettag0();
	st0_sign = getsign(st0_ptr);

	if (tagb == TAG_Special)
		tagb = FPU_Special(b);
	if (st0_tag == TAG_Special)
		st0_tag = FPU_Special(st0_ptr);

	if (((st0_tag != TAG_Valid) && (st0_tag != TW_Denormal))
	    || ((tagb != TAG_Valid) && (tagb != TW_Denormal))) {
		if (st0_tag == TAG_Zero) {
			if (tagb == TAG_Zero)
				return COMP_A_eq_B;
			if (tagb == TAG_Valid)
				return ((signb ==
					 SIGN_POS) ? COMP_A_lt_B : COMP_A_gt_B);
			if (tagb == TW_Denormal)
				return ((signb ==
					 SIGN_POS) ? COMP_A_lt_B : COMP_A_gt_B)
				    | COMP_Denormal;
		} else if (tagb == TAG_Zero) {
			if (st0_tag == TAG_Valid)
				return ((st0_sign ==
					 SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B);
			if (st0_tag == TW_Denormal)
				return ((st0_sign ==
					 SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B)
				    | COMP_Denormal;
		}

		if (st0_tag == TW_Infinity) {
			if ((tagb == TAG_Valid) || (tagb == TAG_Zero))
				return ((st0_sign ==
					 SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B);
			else if (tagb == TW_Denormal)
				return ((st0_sign ==
					 SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B)
				    | COMP_Denormal;
			else if (tagb == TW_Infinity) {
				/*                                                   */
				return (st0_sign == signb) ? COMP_A_eq_B :
				    ((st0_sign ==
				      SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B);
			}
			/*                              */
		} else if (tagb == TW_Infinity) {
			if ((st0_tag == TAG_Valid) || (st0_tag == TAG_Zero))
				return ((signb ==
					 SIGN_POS) ? COMP_A_lt_B : COMP_A_gt_B);
			if (st0_tag == TW_Denormal)
				return ((signb ==
					 SIGN_POS) ? COMP_A_lt_B : COMP_A_gt_B)
				    | COMP_Denormal;
			/*                              */
		}

		/*                                                             
              */
		if ((st0_tag == TW_NaN) || (tagb == TW_NaN)) {
			int signalling = 0, unsupported = 0;
			if (st0_tag == TW_NaN) {
				signalling =
				    (st0_ptr->sigh & 0xc0000000) == 0x80000000;
				unsupported = !((exponent(st0_ptr) == EXP_OVER)
						&& (st0_ptr->
						    sigh & 0x80000000));
			}
			if (tagb == TW_NaN) {
				signalling |=
				    (b->sigh & 0xc0000000) == 0x80000000;
				unsupported |= !((exponent(b) == EXP_OVER)
						 && (b->sigh & 0x80000000));
			}
			if (signalling || unsupported)
				return COMP_No_Comp | COMP_SNaN | COMP_NaN;
			else
				/*                            */
				return COMP_No_Comp | COMP_NaN;
		}

		EXCEPTION(EX_Invalid);
	}

	if (st0_sign != signb) {
		return ((st0_sign == SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B)
		    | (((st0_tag == TW_Denormal) || (tagb == TW_Denormal)) ?
		       COMP_Denormal : 0);
	}

	if ((st0_tag == TW_Denormal) || (tagb == TW_Denormal)) {
		FPU_to_exp16(st0_ptr, &x);
		FPU_to_exp16(b, &y);
		st0_ptr = &x;
		b = &y;
		exp0 = exponent16(st0_ptr);
		expb = exponent16(b);
	} else {
		exp0 = exponent(st0_ptr);
		expb = exponent(b);
	}

#ifdef PARANOID
	if (!(st0_ptr->sigh & 0x80000000))
		EXCEPTION(EX_Invalid);
	if (!(b->sigh & 0x80000000))
		EXCEPTION(EX_Invalid);
#endif /*          */

	diff = exp0 - expb;
	if (diff == 0) {
		diff = st0_ptr->sigh - b->sigh;	/*                          
                   */
		if (diff == 0) {
			diff = st0_ptr->sigl > b->sigl;
			if (diff == 0)
				diff = -(st0_ptr->sigl < b->sigl);
		}
	}

	if (diff > 0) {
		return ((st0_sign == SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B)
		    | (((st0_tag == TW_Denormal) || (tagb == TW_Denormal)) ?
		       COMP_Denormal : 0);
	}
	if (diff < 0) {
		return ((st0_sign == SIGN_POS) ? COMP_A_lt_B : COMP_A_gt_B)
		    | (((st0_tag == TW_Denormal) || (tagb == TW_Denormal)) ?
		       COMP_Denormal : 0);
	}

	return COMP_A_eq_B
	    | (((st0_tag == TW_Denormal) || (tagb == TW_Denormal)) ?
	       COMP_Denormal : 0);

}
Ejemplo n.º 13
0
/*
  Operates on st(0) and st(n), or on st(0) and temporary data.
  The destination must be one of the source st(x).
  */
int FPU_add(FPU_REG const *b, u_char tagb, int deststnr, u16 control_w)
{
  FPU_REG *a = &st(0);
  FPU_REG *dest = &st(deststnr);
  u_char signb = getsign(b);
  u_char taga = FPU_gettag0();
  u_char signa = getsign(a);
  u_char saved_sign = getsign(dest);
  int diff, tag, expa, expb;
  
  if ( !(taga | tagb) )
    {
      expa = exponent(a);
      expb = exponent(b);

    valid_add:
      /* Both registers are valid */
      if (!(signa ^ signb))
	{
	  /* signs are the same */
	  tag = FPU_u_add(a, b, dest, control_w, signa, expa, expb);
	}
      else
	{
	  /* The signs are different, so do a subtraction */
	  diff = expa - expb;
	  if (!diff)
	    {
	      diff = a->sigh - b->sigh;  /* This works only if the ms bits
					    are identical. */
	      if (!diff)
		{
		  diff = a->sigl > b->sigl;
		  if (!diff)
		    diff = -(a->sigl < b->sigl);
		}
	    }
      
	  if (diff > 0)
	    {
	      tag = FPU_u_sub(a, b, dest, control_w, signa, expa, expb);
	    }
	  else if ( diff < 0 )
	    {
	      tag = FPU_u_sub(b, a, dest, control_w, signb, expb, expa);
	    }
	  else
	    {
	      FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
	      /* sign depends upon rounding mode */
	      setsign(dest, ((control_w & CW_RC) != RC_DOWN)
		      ? SIGN_POS : SIGN_NEG);
	      return TAG_Zero;
	    }
	}

      if ( tag < 0 )
	{
	  setsign(dest, saved_sign);
	  return tag;
	}
      FPU_settagi(deststnr, tag);
      return tag;
    }

  if ( taga == TAG_Special )
    taga = FPU_Special(a);
  if ( tagb == TAG_Special )
    tagb = FPU_Special(b);

  if ( ((taga == TAG_Valid) && (tagb == TW_Denormal))
	    || ((taga == TW_Denormal) && (tagb == TAG_Valid))
	    || ((taga == TW_Denormal) && (tagb == TW_Denormal)) )
    {
      FPU_REG x, y;

      if ( denormal_operand() < 0 )
	return FPU_Exception;

      FPU_to_exp16(a, &x);
      FPU_to_exp16(b, &y);
      a = &x;
      b = &y;
      expa = exponent16(a);
      expb = exponent16(b);
      goto valid_add;
    }

  if ( (taga == TW_NaN) || (tagb == TW_NaN) )
    {
      if ( deststnr == 0 )
	return real_2op_NaN(b, tagb, deststnr, a);
      else
	return real_2op_NaN(a, taga, deststnr, a);
    }

  return add_sub_specials(a, taga, signa, b, tagb, signb,
			  dest, deststnr, control_w);
}
Ejemplo n.º 14
0
int FPU_div(int flags, int rm, int control_w)
{
	FPU_REG x, y;
	FPU_REG const *a, *b, *st0_ptr, *st_ptr;
	FPU_REG *dest;
	u_char taga, tagb, signa, signb, sign, saved_sign;
	int tag, deststnr;

	if (flags & DEST_RM)
		deststnr = rm;
	else
		deststnr = 0;

	if (flags & REV) {
		b = &st(0);
		st0_ptr = b;
		tagb = FPU_gettag0();
		if (flags & LOADED) {
			a = (FPU_REG *) rm;
			taga = flags & 0x0f;
		} else {
			a = &st(rm);
			st_ptr = a;
			taga = FPU_gettagi(rm);
		}
	} else {
		a = &st(0);
		st0_ptr = a;
		taga = FPU_gettag0();
		if (flags & LOADED) {
			b = (FPU_REG *) rm;
			tagb = flags & 0x0f;
		} else {
			b = &st(rm);
			st_ptr = b;
			tagb = FPU_gettagi(rm);
		}
	}

	signa = getsign(a);
	signb = getsign(b);

	sign = signa ^ signb;

	dest = &st(deststnr);
	saved_sign = getsign(dest);

	if (!(taga | tagb)) {
		
		reg_copy(a, &x);
		reg_copy(b, &y);
		setpositive(&x);
		setpositive(&y);
		tag = FPU_u_div(&x, &y, dest, control_w, sign);

		if (tag < 0)
			return tag;

		FPU_settagi(deststnr, tag);
		return tag;
	}

	if (taga == TAG_Special)
		taga = FPU_Special(a);
	if (tagb == TAG_Special)
		tagb = FPU_Special(b);

	if (((taga == TAG_Valid) && (tagb == TW_Denormal))
	    || ((taga == TW_Denormal) && (tagb == TAG_Valid))
	    || ((taga == TW_Denormal) && (tagb == TW_Denormal))) {
		if (denormal_operand() < 0)
			return FPU_Exception;

		FPU_to_exp16(a, &x);
		FPU_to_exp16(b, &y);
		tag = FPU_u_div(&x, &y, dest, control_w, sign);
		if (tag < 0)
			return tag;

		FPU_settagi(deststnr, tag);
		return tag;
	} else if ((taga <= TW_Denormal) && (tagb <= TW_Denormal)) {
		if (tagb != TAG_Zero) {
			
			if (tagb == TW_Denormal) {
				if (denormal_operand() < 0)
					return FPU_Exception;
			}

			
			FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
			setsign(dest, sign);
			return TAG_Zero;
		}
		
		if (taga == TAG_Zero) {
			
			return arith_invalid(deststnr);
		}
		
		return FPU_divide_by_zero(deststnr, sign);
	}
	
	else if ((taga == TW_NaN) || (tagb == TW_NaN)) {
		if (flags & LOADED)
			return real_2op_NaN((FPU_REG *) rm, flags & 0x0f, 0,
					    st0_ptr);

		if (flags & DEST_RM) {
			int tag;
			tag = FPU_gettag0();
			if (tag == TAG_Special)
				tag = FPU_Special(st0_ptr);
			return real_2op_NaN(st0_ptr, tag, rm,
					    (flags & REV) ? st0_ptr : &st(rm));
		} else {
			int tag;
			tag = FPU_gettagi(rm);
			if (tag == TAG_Special)
				tag = FPU_Special(&st(rm));
			return real_2op_NaN(&st(rm), tag, 0,
					    (flags & REV) ? st0_ptr : &st(rm));
		}
	} else if (taga == TW_Infinity) {
		if (tagb == TW_Infinity) {
			
			return arith_invalid(deststnr);
		} else {
			
			if ((tagb == TW_Denormal) && (denormal_operand() < 0))
				return FPU_Exception;

			
			FPU_copy_to_regi(a, TAG_Special, deststnr);
			setsign(dest, sign);
			return taga;
		}
	} else if (tagb == TW_Infinity) {
		if ((taga == TW_Denormal) && (denormal_operand() < 0))
			return FPU_Exception;

		
		FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
		setsign(dest, sign);
		return TAG_Zero;
	}
#ifdef PARANOID
	else {
		EXCEPTION(EX_INTERNAL | 0x102);
		return FPU_Exception;
	}
#endif 

	return 0;
}