op-common.h

优龙2410linux2.6.8内核源代码

    _FP_FRAC_SET_##wc(R, _FP_NANFRAC_##fs);		\
    break;						\
							\
  default:						\
    abort();						\
  }							\
} while (0)


/*
 * Main division routine.  The input values should be cooked.
 */

#define _FP_DIV(fs, wc, R, X, Y)			\
do {							\
  R##_s = X##_s ^ Y##_s;				\
  switch (_FP_CLS_COMBINE(X##_c, Y##_c))		\
  {							\
  case _FP_CLS_COMBINE(FP_CLS_NORMAL,FP_CLS_NORMAL):	\
    R##_c = FP_CLS_NORMAL;				\
    R##_e = X##_e - Y##_e;				\
							\
    _FP_DIV_MEAT_##fs(R,X,Y);				\
    break;						\
							\
  case _FP_CLS_COMBINE(FP_CLS_NAN,FP_CLS_NAN):		\
    _FP_CHOOSENAN(fs, wc, R, X, Y);			\
    break;						\
							\
  case _FP_CLS_COMBINE(FP_CLS_NAN,FP_CLS_NORMAL):	\
  case _FP_CLS_COMBINE(FP_CLS_NAN,FP_CLS_INF):		\
  case _FP_CLS_COMBINE(FP_CLS_NAN,FP_CLS_ZERO):		\
    R##_s = X##_s;					\
    _FP_FRAC_COPY_##wc(R, X);				\
    R##_c = X##_c;					\
    break;						\
							\
  case _FP_CLS_COMBINE(FP_CLS_NORMAL,FP_CLS_NAN):	\
  case _FP_CLS_COMBINE(FP_CLS_INF,FP_CLS_NAN):		\
  case _FP_CLS_COMBINE(FP_CLS_ZERO,FP_CLS_NAN):		\
    R##_s = Y##_s;					\
    _FP_FRAC_COPY_##wc(R, Y);				\
    R##_c = Y##_c;					\
    break;						\
							\
  case _FP_CLS_COMBINE(FP_CLS_NORMAL,FP_CLS_INF):	\
  case _FP_CLS_COMBINE(FP_CLS_ZERO,FP_CLS_INF):		\
  case _FP_CLS_COMBINE(FP_CLS_ZERO,FP_CLS_NORMAL):	\
    R##_c = FP_CLS_ZERO;				\
    break;						\
							\
  case _FP_CLS_COMBINE(FP_CLS_NORMAL,FP_CLS_ZERO):	\
  case _FP_CLS_COMBINE(FP_CLS_INF,FP_CLS_ZERO):		\
  case _FP_CLS_COMBINE(FP_CLS_INF,FP_CLS_NORMAL):	\
    R##_c = FP_CLS_INF;					\
    break;						\
							\
  case _FP_CLS_COMBINE(FP_CLS_INF,FP_CLS_INF):		\
  case _FP_CLS_COMBINE(FP_CLS_ZERO,FP_CLS_ZERO):	\
    R##_c = FP_CLS_NAN;					\
    _FP_FRAC_SET_##wc(R, _FP_NANFRAC_##fs);		\
    break;						\
							\
  default:						\
    abort();						\
  }							\
} while (0)


/*
 * Main differential comparison routine.  The inputs should be raw not
 * cooked.  The return is -1,0,1 for normal values, 2 otherwise.
 */

#define _FP_CMP(fs, wc, ret, X, Y, un)					\
  do {									\
    /* NANs are unordered */						\
    if ((X##_e == _FP_EXPMAX_##fs && !_FP_FRAC_ZEROP_##wc(X))		\
	|| (Y##_e == _FP_EXPMAX_##fs && !_FP_FRAC_ZEROP_##wc(Y)))	\
      {									\
	ret = un;							\
      }									\
    else								\
      {									\
        int __x_zero = (!X##_e && _FP_FRAC_ZEROP_##wc(X)) ? 1 : 0;	\
        int __y_zero = (!Y##_e && _FP_FRAC_ZEROP_##wc(Y)) ? 1 : 0;	\
									\
	if (__x_zero && __y_zero)					\
	  ret = 0;							\
	else if (__x_zero)						\
	  ret = Y##_s ? 1 : -1;						\
	else if (__y_zero)						\
	  ret = X##_s ? -1 : 1;						\
	else if (X##_s != Y##_s)					\
	  ret = X##_s ? -1 : 1;						\
	else if (X##_e > Y##_e)						\
	  ret = X##_s ? -1 : 1;						\
	else if (X##_e < Y##_e)						\
	  ret = X##_s ? 1 : -1;						\
	else if (_FP_FRAC_GT_##wc(X, Y))				\
	  ret = X##_s ? -1 : 1;						\
	else if (_FP_FRAC_GT_##wc(Y, X))				\
	  ret = X##_s ? 1 : -1;						\
	else								\
	  ret = 0;							\
      }									\
  } while (0)


/* Simplification for strict equality.  */

#define _FP_CMP_EQ(fs, wc, ret, X, Y)					  \
  do {									  \
    /* NANs are unordered */						  \
    if ((X##_e == _FP_EXPMAX_##fs && !_FP_FRAC_ZEROP_##wc(X))		  \
	|| (Y##_e == _FP_EXPMAX_##fs && !_FP_FRAC_ZEROP_##wc(Y)))	  \
      {									  \
	ret = 1;							  \
      }									  \
    else								  \
      {									  \
	ret = !(X##_e == Y##_e						  \
		&& _FP_FRAC_EQ_##wc(X, Y)				  \
		&& (X##_s == Y##_s || !X##_e && _FP_FRAC_ZEROP_##wc(X))); \
      }									  \
  } while (0)

/*
 * Main square root routine.  The input value should be cooked.
 */

#define _FP_SQRT(fs, wc, R, X)						\
do {									\
    _FP_FRAC_DECL_##wc(T); _FP_FRAC_DECL_##wc(S);			\
    _FP_W_TYPE q;							\
    switch (X##_c)							\
    {									\
    case FP_CLS_NAN:							\
    	R##_s = 0;							\
    	R##_c = FP_CLS_NAN;						\
    	_FP_FRAC_SET_##wc(X, _FP_ZEROFRAC_##wc);			\
    	break;								\
    case FP_CLS_INF:							\
    	if (X##_s)							\
    	  {								\
    	    R##_s = 0;							\
	    R##_c = FP_CLS_NAN; /* sNAN */				\
    	  }								\
    	else								\
    	  {								\
    	    R##_s = 0;							\
    	    R##_c = FP_CLS_INF; /* sqrt(+inf) = +inf */			\
    	  }								\
    	break;								\
    case FP_CLS_ZERO:							\
	R##_s = X##_s;							\
    	R##_c = FP_CLS_ZERO; /* sqrt(+-0) = +-0 */			\
	break;								\
    case FP_CLS_NORMAL:							\
    	R##_s = 0;							\
        if (X##_s)							\
          {								\
	    R##_c = FP_CLS_NAN; /* sNAN */				\
	    break;							\
          }								\
    	R##_c = FP_CLS_NORMAL;						\
        if (X##_e & 1)							\
          _FP_FRAC_SLL_##wc(X, 1);					\
        R##_e = X##_e >> 1;						\
        _FP_FRAC_SET_##wc(S, _FP_ZEROFRAC_##wc);			\
        _FP_FRAC_SET_##wc(R, _FP_ZEROFRAC_##wc);			\
        q = _FP_OVERFLOW_##fs;						\
        _FP_FRAC_SLL_##wc(X, 1);					\
        _FP_SQRT_MEAT_##wc(R, S, T, X, q);				\
        _FP_FRAC_SRL_##wc(R, 1);					\
    }									\
  } while (0)

/*
 * Convert from FP to integer
 */

/* "When a NaN, infinity, large positive argument >= 2147483648.0, or
 * large negative argument <= -2147483649.0 is converted to an integer,
 * the invalid_current bit...should be set and fp_exception_IEEE_754 should
 * be raised. If the floating point invalid trap is disabled, no trap occurs
 * and a numerical result is generated: if the sign bit of the operand
 * is 0, the result is 2147483647; if the sign bit of the operand is 1,
 * the result is -2147483648."
 * Similarly for conversion to extended ints, except that the boundaries
 * are >= 2^63, <= -(2^63 + 1), and the results are 2^63 + 1 for s=0 and
 * -2^63 for s=1.
 * -- SPARC Architecture Manual V9, Appendix B, which specifies how
 * SPARCs resolve implementation dependencies in the IEEE-754 spec.
 * I don't believe that the code below follows this. I'm not even sure
 * it's right!
 * It doesn't cope with needing to convert to an n bit integer when there
 * is no n bit integer type. Fortunately gcc provides long long so this
 * isn't a problem for sparc32.
 * I have, however, fixed its NaN handling to conform as above.
 *         -- PMM 02/1998
 * NB: rsigned is not 'is r declared signed?' but 'should the value stored
 * in r be signed or unsigned?'. r is always(?) declared unsigned.
 * Comments below are mine, BTW -- PMM
 */
#define _FP_TO_INT(fs, wc, r, X, rsize, rsigned)			\
  do {									\
    switch (X##_c)							\
      {									\
      case FP_CLS_NORMAL:						\
	if (X##_e < 0)							\
	  {								\
	  /* case FP_CLS_NAN: see above! */				\
	  case FP_CLS_ZERO:						\
	    r = 0;							\
	  }								\
	else if (X##_e >= rsize - (rsigned != 0))			\
	  {	/* overflow */						\
	  case FP_CLS_NAN:                                              \
          case FP_CLS_INF:						\
	    if (rsigned)						\
	      {								\
		r = 1;							\
		r <<= rsize - 1;					\
		r -= 1 - X##_s;						\
	      }								\
	    else							\
	      {								\
		r = 0;							\
		if (!X##_s)						\
		  r = ~r;						\
	      }								\
	  }								\
	else								\
	  {								\
	    if (_FP_W_TYPE_SIZE*wc < rsize)				\
	      {								\
		_FP_FRAC_ASSEMBLE_##wc(r, X, rsize);			\
		r <<= X##_e - _FP_WFRACBITS_##fs;			\
	      }								\
	    else							\
	      {								\
		if (X##_e >= _FP_WFRACBITS_##fs)			\
		  _FP_FRAC_SLL_##wc(X, (X##_e - _FP_WFRACBITS_##fs + 1));\
		else							\
		  _FP_FRAC_SRL_##wc(X, (_FP_WFRACBITS_##fs - X##_e - 1));\
		_FP_FRAC_ASSEMBLE_##wc(r, X, rsize);			\
	      }								\
	    if (rsigned && X##_s)					\
	      r = -r;							\
	  }								\
	break;								\
      }									\
  } while (0)

#define _FP_FROM_INT(fs, wc, X, r, rsize, rtype)			\
  do {									\
    if (r)								\
      {									\
	X##_c = FP_CLS_NORMAL;						\
									\
	if ((X##_s = (r < 0)))						\
	  r = -r;							\
	/* Note that `r' is now considered unsigned, so we don't have	\
	   to worry about the single signed overflow case.  */		\
									\
	if (rsize <= _FP_W_TYPE_SIZE)					\
	  __FP_CLZ(X##_e, r);						\
	else								\
	  __FP_CLZ_2(X##_e, (_FP_W_TYPE)(r >> _FP_W_TYPE_SIZE), 	\
		     (_FP_W_TYPE)r);					\
	if (rsize < _FP_W_TYPE_SIZE)					\
		X##_e -= (_FP_W_TYPE_SIZE - rsize);			\
	X##_e = rsize - X##_e - 1;					\
									\
	if (_FP_FRACBITS_##fs < rsize && _FP_WFRACBITS_##fs < X##_e)	\
	  __FP_FRAC_SRS_1(r, (X##_e - _FP_WFRACBITS_##fs), rsize);	\
	r &= ~((_FP_W_TYPE)1 << X##_e);					\
	_FP_FRAC_DISASSEMBLE_##wc(X, ((unsigned rtype)r), rsize);	\
	_FP_FRAC_SLL_##wc(X, (_FP_WFRACBITS_##fs - X##_e - 1));		\
      }									\
    else								\
      {									\
	X##_c = FP_CLS_ZERO, X##_s = 0;					\
      }									\
  } while (0)


#define FP_CONV(dfs,sfs,dwc,swc,D,S)			\
  do {							\
    _FP_FRAC_CONV_##dwc##_##swc(dfs, sfs, D, S);	\
    D##_e = S##_e;					\
    D##_c = S##_c;					\
    D##_s = S##_s;					\
  } while (0)

/*
 * Helper primitives.
 */

/* Count leading zeros in a word.  */

#ifndef __FP_CLZ
#if _FP_W_TYPE_SIZE < 64
/* this is just to shut the compiler up about shifts > word length -- PMM 02/1998 */
#define __FP_CLZ(r, x)				\
  do {						\
    _FP_W_TYPE _t = (x);			\
    r = _FP_W_TYPE_SIZE - 1;			\
    if (_t > 0xffff) r -= 16;			\
    if (_t > 0xffff) _t >>= 16;			\
    if (_t > 0xff) r -= 8;			\
    if (_t > 0xff) _t >>= 8;			\
    if (_t & 0xf0) r -= 4;			\
    if (_t & 0xf0) _t >>= 4;			\
    if (_t & 0xc) r -= 2;			\
    if (_t & 0xc) _t >>= 2;			\
    if (_t & 0x2) r -= 1;			\
  } while (0)
#else /* not _FP_W_TYPE_SIZE < 64 */
#define __FP_CLZ(r, x)				\
  do {						\
    _FP_W_TYPE _t = (x);			\
    r = _FP_W_TYPE_SIZE - 1;			\
    if (_t > 0xffffffff) r -= 32;		\
    if (_t > 0xffffffff) _t >>= 32;		\
    if (_t > 0xffff) r -= 16;			\
    if (_t > 0xffff) _t >>= 16;			\
    if (_t > 0xff) r -= 8;			\
    if (_t > 0xff) _t >>= 8;			\
    if (_t & 0xf0) r -= 4;			\
    if (_t & 0xf0) _t >>= 4;			\
    if (_t & 0xc) r -= 2;			\
    if (_t & 0xc) _t >>= 2;			\
    if (_t & 0x2) r -= 1;			\
  } while (0)
#endif /* not _FP_W_TYPE_SIZE < 64 */
#endif /* ndef __FP_CLZ */

#define _FP_DIV_HELP_imm(q, r, n, d)		\
  do {						\
    q = n / d, r = n % d;			\
  } while (0)