op-4.h

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  } while (0)

/*
 * Helper utility for _FP_DIV_MEAT_4_udiv:
 * pppp = m * nnn
 */
#define umul_ppppmnnn(p3,p2,p1,p0,m,n2,n1,n0)				    \
  do {									    \
    UWtype _t;								    \
    umul_ppmm(p1,p0,m,n0);						    \
    umul_ppmm(p2,_t,m,n1);						    \
    __FP_FRAC_ADDI_2(p2,p1,_t);						    \
    umul_ppmm(p3,_t,m,n2);						    \
    __FP_FRAC_ADDI_2(p3,p2,_t);						    \
  } while (0)

/*
 * Division algorithms:
 */

#define _FP_DIV_MEAT_4_udiv(fs, R, X, Y)				    \
  do {									    \
    int _i;								    \
    _FP_FRAC_DECL_4(_n); _FP_FRAC_DECL_4(_m);				    \
    _FP_FRAC_SET_4(_n, _FP_ZEROFRAC_4);					    \
    if (_FP_FRAC_GT_4(X, Y))						    \
      {									    \
	_n_f[3] = X##_f[0] << (_FP_W_TYPE_SIZE - 1);			    \
	_FP_FRAC_SRL_4(X, 1);						    \
      }									    \
    else								    \
      R##_e--;								    \
									    \
    /* Normalize, i.e. make the most significant bit of the 		    \
       denominator set. */						    \
    _FP_FRAC_SLL_4(Y, _FP_WFRACXBITS_##fs);				    \
									    \
    for (_i = 3; ; _i--)						    \
      {									    \
        if (X##_f[3] == Y##_f[3])					    \
          {								    \
            /* This is a special case, not an optimization		    \
               (X##_f[3]/Y##_f[3] would not fit into UWtype).		    \
               As X## is guaranteed to be < Y,  R##_f[_i] can be either	    \
               (UWtype)-1 or (UWtype)-2.  */				    \
            R##_f[_i] = -1;						    \
            if (!_i)							    \
	      break;							    \
            __FP_FRAC_SUB_4(X##_f[3], X##_f[2], X##_f[1], X##_f[0],	    \
			    Y##_f[2], Y##_f[1], Y##_f[0], 0,		    \
			    X##_f[2], X##_f[1], X##_f[0], _n_f[_i]);	    \
            _FP_FRAC_SUB_4(X, Y, X);					    \
            if (X##_f[3] > Y##_f[3])					    \
              {								    \
                R##_f[_i] = -2;						    \
                _FP_FRAC_ADD_4(X, Y, X);				    \
              }								    \
          }								    \
        else								    \
          {								    \
            udiv_qrnnd(R##_f[_i], X##_f[3], X##_f[3], X##_f[2], Y##_f[3]);  \
            umul_ppppmnnn(_m_f[3], _m_f[2], _m_f[1], _m_f[0],		    \
			  R##_f[_i], Y##_f[2], Y##_f[1], Y##_f[0]);	    \
            X##_f[2] = X##_f[1];					    \
            X##_f[1] = X##_f[0];					    \
            X##_f[0] = _n_f[_i];					    \
            if (_FP_FRAC_GT_4(_m, X))					    \
              {								    \
                R##_f[_i]--;						    \
                _FP_FRAC_ADD_4(X, Y, X);				    \
                if (_FP_FRAC_GE_4(X, Y) && _FP_FRAC_GT_4(_m, X))	    \
                  {							    \
		    R##_f[_i]--;					    \
		    _FP_FRAC_ADD_4(X, Y, X);				    \
                  }							    \
              }								    \
            _FP_FRAC_DEC_4(X, _m);					    \
            if (!_i)							    \
	      {								    \
		if (!_FP_FRAC_EQ_4(X, _m))				    \
		  R##_f[0] |= _FP_WORK_STICKY;				    \
		break;							    \
	      }								    \
          }								    \
      }									    \
  } while (0)


/*
 * Square root algorithms:
 * We have just one right now, maybe Newton approximation
 * should be added for those machines where division is fast.
 */
 
#define _FP_SQRT_MEAT_4(R, S, T, X, q)				\
  do {								\
    while (q)							\
      {								\
	T##_f[3] = S##_f[3] + q;				\
	if (T##_f[3] <= X##_f[3])				\
	  {							\
	    S##_f[3] = T##_f[3] + q;				\
	    X##_f[3] -= T##_f[3];				\
	    R##_f[3] += q;					\
	  }							\
	_FP_FRAC_SLL_4(X, 1);					\
	q >>= 1;						\
      }								\
    q = (_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE - 1);			\
    while (q)							\
      {								\
	T##_f[2] = S##_f[2] + q;				\
	T##_f[3] = S##_f[3];					\
	if (T##_f[3] < X##_f[3] || 				\
	    (T##_f[3] == X##_f[3] && T##_f[2] <= X##_f[2]))	\
	  {							\
	    S##_f[2] = T##_f[2] + q;				\
	    S##_f[3] += (T##_f[2] > S##_f[2]);			\
	    __FP_FRAC_DEC_2(X##_f[3], X##_f[2],			\
			    T##_f[3], T##_f[2]);		\
	    R##_f[2] += q;					\
	  }							\
	_FP_FRAC_SLL_4(X, 1);					\
	q >>= 1;						\
      }								\
    q = (_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE - 1);			\
    while (q)							\
      {								\
	T##_f[1] = S##_f[1] + q;				\
	T##_f[2] = S##_f[2];					\
	T##_f[3] = S##_f[3];					\
	if (T##_f[3] < X##_f[3] || 				\
	    (T##_f[3] == X##_f[3] && (T##_f[2] < X##_f[2] ||	\
	     (T##_f[2] == X##_f[2] && T##_f[1] <= X##_f[1]))))	\
	  {							\
	    S##_f[1] = T##_f[1] + q;				\
	    S##_f[2] += (T##_f[1] > S##_f[1]);			\
	    S##_f[3] += (T##_f[2] > S##_f[2]);			\
	    __FP_FRAC_DEC_3(X##_f[3], X##_f[2], X##_f[1],	\
	    		    T##_f[3], T##_f[2], T##_f[1]);	\
	    R##_f[1] += q;					\
	  }							\
	_FP_FRAC_SLL_4(X, 1);					\
	q >>= 1;						\
      }								\
    q = (_FP_W_TYPE)1 << (_FP_W_TYPE_SIZE - 1);			\
    while (q != _FP_WORK_ROUND)					\
      {								\
	T##_f[0] = S##_f[0] + q;				\
	T##_f[1] = S##_f[1];					\
	T##_f[2] = S##_f[2];					\
	T##_f[3] = S##_f[3];					\
	if (_FP_FRAC_GE_4(X,T))					\
	  {							\
	    S##_f[0] = T##_f[0] + q;				\
	    S##_f[1] += (T##_f[0] > S##_f[0]);			\
	    S##_f[2] += (T##_f[1] > S##_f[1]);			\
	    S##_f[3] += (T##_f[2] > S##_f[2]);			\
	    _FP_FRAC_DEC_4(X, T);				\
	    R##_f[0] += q;					\
	  }							\
	_FP_FRAC_SLL_4(X, 1);					\
	q >>= 1;						\
      }								\
    if (!_FP_FRAC_ZEROP_4(X))					\
      {								\
	if (_FP_FRAC_GT_4(X,S))					\
	  R##_f[0] |= _FP_WORK_ROUND;				\
	R##_f[0] |= _FP_WORK_STICKY;				\
      }								\
  } while (0)


/*
 * Internals 
 */

#define __FP_FRAC_SET_4(X,I3,I2,I1,I0)					\
  (X##_f[3] = I3, X##_f[2] = I2, X##_f[1] = I1, X##_f[0] = I0)

#ifndef __FP_FRAC_ADD_3
#define __FP_FRAC_ADD_3(r2,r1,r0,x2,x1,x0,y2,y1,y0)			\
  (r0 = x0 + y0,							\
   r1 = x1 + y1 + (r0 < x0),						\
   r2 = x2 + y2 + (r1 < x1))
#endif

#ifndef __FP_FRAC_ADD_4
#define __FP_FRAC_ADD_4(r3,r2,r1,r0,x3,x2,x1,x0,y3,y2,y1,y0)		\
  (r0 = x0 + y0,							\
   r1 = x1 + y1 + (r0 < x0),						\
   r2 = x2 + y2 + (r1 < x1),						\
   r3 = x3 + y3 + (r2 < x2))
#endif

#ifndef __FP_FRAC_SUB_3
#define __FP_FRAC_SUB_3(r2,r1,r0,x2,x1,x0,y2,y1,y0)			\
  (r0 = x0 - y0,							\
   r1 = x1 - y1 - (r0 > x0),						\
   r2 = x2 - y2 - (r1 > x1))
#endif

#ifndef __FP_FRAC_SUB_4
#define __FP_FRAC_SUB_4(r3,r2,r1,r0,x3,x2,x1,x0,y3,y2,y1,y0)		\
  (r0 = x0 - y0,							\
   r1 = x1 - y1 - (r0 > x0),						\
   r2 = x2 - y2 - (r1 > x1),						\
   r3 = x3 - y3 - (r2 > x2))
#endif

#ifndef __FP_FRAC_DEC_3
#define __FP_FRAC_DEC_3(x2,x1,x0,y2,y1,y0)				\
  do {									\
    UWtype _t0, _t1;							\
    _t0 = x0;								\
    x0 -= y0;								\
    _t1 = x1;								\
    x1 -= y1 + (x0 > _t0);						\
    x2 -= y2 + (x1 > _t1);						\
  } while (0)
#endif

#ifndef __FP_FRAC_DEC_4
#define __FP_FRAC_DEC_4(x3,x2,x1,x0,y3,y2,y1,y0)			\
  do {									\
    UWtype _t0, _t1;							\
    _t0 = x0;								\
    x0 -= y0;								\
    _t1 = x1;								\
    x1 -= y1 + (x0 > _t0);						\
    _t0 = x2;								\
    x2 -= y2 + (x1 > _t1);						\
    x3 -= y3 + (x2 > _t0);						\
  } while (0)
#endif

#ifndef __FP_FRAC_ADDI_4
#define __FP_FRAC_ADDI_4(x3,x2,x1,x0,i)					\
  do {									\
    UWtype _t;								\
    _t = ((x0 += i) < i);						\
    x1 += _t; _t = (x1 < _t);						\
    x2 += _t; _t = (x2 < _t);						\
    x3 += _t;								\
  } while (0)
#endif

/* Convert FP values between word sizes. This appears to be more
 * complicated than I'd have expected it to be, so these might be
 * wrong... These macros are in any case somewhat bogus because they
 * use information about what various FRAC_n variables look like 
 * internally [eg, that 2 word vars are X_f0 and x_f1]. But so do
 * the ones in op-2.h and op-1.h. 
 */
#define _FP_FRAC_CONV_1_4(dfs, sfs, D, S)				\
   do {									\
     if (S##_c != FP_CLS_NAN)						\
       _FP_FRAC_SRS_4(S, (_FP_WFRACBITS_##sfs - _FP_WFRACBITS_##dfs),	\
			  _FP_WFRACBITS_##sfs);				\
     else								\
       _FP_FRAC_SRL_4(S, (_FP_WFRACBITS_##sfs - _FP_WFRACBITS_##dfs));	\
     D##_f = S##_f[0];							\
  } while (0)

#define _FP_FRAC_CONV_2_4(dfs, sfs, D, S)				\
   do {									\
     if (S##_c != FP_CLS_NAN)						\
       _FP_FRAC_SRS_4(S, (_FP_WFRACBITS_##sfs - _FP_WFRACBITS_##dfs),	\
		      _FP_WFRACBITS_##sfs);				\
     else								\
       _FP_FRAC_SRL_4(S, (_FP_WFRACBITS_##sfs - _FP_WFRACBITS_##dfs));	\
     D##_f0 = S##_f[0];							\
     D##_f1 = S##_f[1];							\
  } while (0)

/* Assembly/disassembly for converting to/from integral types.  
 * No shifting or overflow handled here.
 */
/* Put the FP value X into r, which is an integer of size rsize. */
#define _FP_FRAC_ASSEMBLE_4(r, X, rsize)				\
  do {									\
    if (rsize <= _FP_W_TYPE_SIZE)					\
      r = X##_f[0];							\
    else if (rsize <= 2*_FP_W_TYPE_SIZE)				\
    {									\
      r = X##_f[1];							\
      r <<= _FP_W_TYPE_SIZE;						\
      r += X##_f[0];							\
    }									\
    else								\
    {									\
      /* I'm feeling lazy so we deal with int == 3words (implausible)*/	\
      /* and int == 4words as a single case.			 */	\
      r = X##_f[3];							\
      r <<= _FP_W_TYPE_SIZE;						\
      r += X##_f[2];							\
      r <<= _FP_W_TYPE_SIZE;						\
      r += X##_f[1];							\
      r <<= _FP_W_TYPE_SIZE;						\
      r += X##_f[0];							\
    }									\
  } while (0)

/* "No disassemble Number Five!" */
/* move an integer of size rsize into X's fractional part. We rely on
 * the _f[] array consisting of words of size _FP_W_TYPE_SIZE to avoid
 * having to mask the values we store into it.
 */
#define _FP_FRAC_DISASSEMBLE_4(X, r, rsize)				\
  do {									\
    X##_f[0] = r;							\
    X##_f[1] = (rsize <= _FP_W_TYPE_SIZE ? 0 : r >> _FP_W_TYPE_SIZE);	\
    X##_f[2] = (rsize <= 2*_FP_W_TYPE_SIZE ? 0 : r >> 2*_FP_W_TYPE_SIZE); \
    X##_f[3] = (rsize <= 3*_FP_W_TYPE_SIZE ? 0 : r >> 3*_FP_W_TYPE_SIZE); \
  } while (0);

#define _FP_FRAC_CONV_4_1(dfs, sfs, D, S)				\
   do {									\
     D##_f[0] = S##_f;							\
     D##_f[1] = D##_f[2] = D##_f[3] = 0;				\
     _FP_FRAC_SLL_4(D, (_FP_WFRACBITS_##dfs - _FP_WFRACBITS_##sfs));	\
   } while (0)

#define _FP_FRAC_CONV_4_2(dfs, sfs, D, S)				\
   do {									\
     D##_f[0] = S##_f0;							\
     D##_f[1] = S##_f1;							\
     D##_f[2] = D##_f[3] = 0;						\
     _FP_FRAC_SLL_4(D, (_FP_WFRACBITS_##dfs - _FP_WFRACBITS_##sfs));	\
   } while (0)

#endif