Logo Search packages:      
Sourcecode: glibc version File versions

op-4.h

/* Software floating-point emulation.
   Basic four-word fraction declaration and manipulation.
   Copyright (C) 1997,1998,1999 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Richard Henderson (rth@cygnus.com),
              Jakub Jelinek (jj@ultra.linux.cz),
              David S. Miller (davem@redhat.com) and
              Peter Maydell (pmaydell@chiark.greenend.org.uk).

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#define _FP_FRAC_DECL_4(X)    _FP_W_TYPE X##_f[4]
#define _FP_FRAC_COPY_4(D,S)              \
  (D##_f[0] = S##_f[0], D##_f[1] = S##_f[1],    \
   D##_f[2] = S##_f[2], D##_f[3] = S##_f[3])
#define _FP_FRAC_SET_4(X,I)   __FP_FRAC_SET_4(X, I)
#define _FP_FRAC_HIGH_4(X)    (X##_f[3])
#define _FP_FRAC_LOW_4(X)     (X##_f[0])
#define _FP_FRAC_WORD_4(X,w)  (X##_f[w])

#define _FP_FRAC_SLL_4(X,N)                                 \
  do {                                                      \
    _FP_I_TYPE _up, _down, _skip, _i;                             \
    _skip = (N) / _FP_W_TYPE_SIZE;                          \
    _up = (N) % _FP_W_TYPE_SIZE;                            \
    _down = _FP_W_TYPE_SIZE - _up;                          \
    if (!_up)                                               \
      for (_i = 3; _i >= _skip; --_i)                             \
      X##_f[_i] = X##_f[_i-_skip];                          \
    else                                              \
      {                                                     \
      for (_i = 3; _i > _skip; --_i)                              \
        X##_f[_i] = X##_f[_i-_skip] << _up                        \
                  | X##_f[_i-_skip-1] >> _down;             \
      X##_f[_i--] = X##_f[0] << _up;                              \
      }                                                     \
    for (; _i >= 0; --_i)                                   \
      X##_f[_i] = 0;                                        \
  } while (0)

/* This one was broken too */
#define _FP_FRAC_SRL_4(X,N)                                 \
  do {                                                      \
    _FP_I_TYPE _up, _down, _skip, _i;                             \
    _skip = (N) / _FP_W_TYPE_SIZE;                          \
    _down = (N) % _FP_W_TYPE_SIZE;                          \
    _up = _FP_W_TYPE_SIZE - _down;                          \
    if (!_down)                                             \
      for (_i = 0; _i <= 3-_skip; ++_i)                           \
      X##_f[_i] = X##_f[_i+_skip];                          \
    else                                              \
      {                                                     \
      for (_i = 0; _i < 3-_skip; ++_i)                      \
        X##_f[_i] = X##_f[_i+_skip] >> _down                      \
                  | X##_f[_i+_skip+1] << _up;               \
      X##_f[_i++] = X##_f[3] >> _down;                      \
      }                                                     \
    for (; _i < 4; ++_i)                                    \
      X##_f[_i] = 0;                                        \
  } while (0)


/* Right shift with sticky-lsb. 
 * What this actually means is that we do a standard right-shift,
 * but that if any of the bits that fall off the right hand side
 * were one then we always set the LSbit.
 */
#define _FP_FRAC_SRS_4(X,N,size)                            \
  do {                                                      \
    _FP_I_TYPE _up, _down, _skip, _i;                             \
    _FP_W_TYPE _s;                                          \
    _skip = (N) / _FP_W_TYPE_SIZE;                          \
    _down = (N) % _FP_W_TYPE_SIZE;                          \
    _up = _FP_W_TYPE_SIZE - _down;                          \
    for (_s = _i = 0; _i < _skip; ++_i)                           \
      _s |= X##_f[_i];                                      \
    _s |= X##_f[_i] << _up;                                 \
/* s is now != 0 if we want to set the LSbit */                   \
    if (!_down)                                             \
      for (_i = 0; _i <= 3-_skip; ++_i)                           \
      X##_f[_i] = X##_f[_i+_skip];                          \
    else                                              \
      {                                                     \
      for (_i = 0; _i < 3-_skip; ++_i)                      \
        X##_f[_i] = X##_f[_i+_skip] >> _down                      \
                  | X##_f[_i+_skip+1] << _up;               \
      X##_f[_i++] = X##_f[3] >> _down;                      \
      }                                                     \
    for (; _i < 4; ++_i)                                    \
      X##_f[_i] = 0;                                        \
    /* don't fix the LSB until the very end when we're sure f[0] is stable */ \
    X##_f[0] |= (_s != 0);                                  \
  } while (0)

#define _FP_FRAC_ADD_4(R,X,Y)                               \
  __FP_FRAC_ADD_4(R##_f[3], R##_f[2], R##_f[1], R##_f[0],         \
              X##_f[3], X##_f[2], X##_f[1], X##_f[0],       \
              Y##_f[3], Y##_f[2], Y##_f[1], Y##_f[0])

#define _FP_FRAC_SUB_4(R,X,Y)                               \
  __FP_FRAC_SUB_4(R##_f[3], R##_f[2], R##_f[1], R##_f[0],         \
              X##_f[3], X##_f[2], X##_f[1], X##_f[0],       \
              Y##_f[3], Y##_f[2], Y##_f[1], Y##_f[0])

#define _FP_FRAC_DEC_4(X,Y)                                 \
  __FP_FRAC_DEC_4(X##_f[3], X##_f[2], X##_f[1], X##_f[0],         \
              Y##_f[3], Y##_f[2], Y##_f[1], Y##_f[0])

#define _FP_FRAC_ADDI_4(X,I)                                \
  __FP_FRAC_ADDI_4(X##_f[3], X##_f[2], X##_f[1], X##_f[0], I)

#define _FP_ZEROFRAC_4  0,0,0,0
#define _FP_MINFRAC_4   0,0,0,1
#define _FP_MAXFRAC_4   (~(_FP_WS_TYPE)0), (~(_FP_WS_TYPE)0), (~(_FP_WS_TYPE)0), (~(_FP_WS_TYPE)0)

#define _FP_FRAC_ZEROP_4(X)     ((X##_f[0] | X##_f[1] | X##_f[2] | X##_f[3]) == 0)
#define _FP_FRAC_NEGP_4(X)      ((_FP_WS_TYPE)X##_f[3] < 0)
#define _FP_FRAC_OVERP_4(fs,X)  (_FP_FRAC_HIGH_##fs(X) & _FP_OVERFLOW_##fs)
#define _FP_FRAC_CLEAR_OVERP_4(fs,X)  (_FP_FRAC_HIGH_##fs(X) &= ~_FP_OVERFLOW_##fs)

#define _FP_FRAC_EQ_4(X,Y)                      \
 (X##_f[0] == Y##_f[0] && X##_f[1] == Y##_f[1]        \
  && X##_f[2] == Y##_f[2] && X##_f[3] == Y##_f[3])

#define _FP_FRAC_GT_4(X,Y)                      \
 (X##_f[3] > Y##_f[3] ||                        \
  (X##_f[3] == Y##_f[3] && (X##_f[2] > Y##_f[2] ||    \
   (X##_f[2] == Y##_f[2] && (X##_f[1] > Y##_f[1] ||   \
    (X##_f[1] == Y##_f[1] && X##_f[0] > Y##_f[0])     \
   ))                                     \
  ))                                      \
 )

#define _FP_FRAC_GE_4(X,Y)                      \
 (X##_f[3] > Y##_f[3] ||                        \
  (X##_f[3] == Y##_f[3] && (X##_f[2] > Y##_f[2] ||    \
   (X##_f[2] == Y##_f[2] && (X##_f[1] > Y##_f[1] ||   \
    (X##_f[1] == Y##_f[1] && X##_f[0] >= Y##_f[0])    \
   ))                                     \
  ))                                      \
 )


#define _FP_FRAC_CLZ_4(R,X)         \
  do {                              \
    if (X##_f[3])             \
    {                         \
      __FP_CLZ(R,X##_f[3]);         \
    }                         \
    else if (X##_f[2])              \
    {                         \
      __FP_CLZ(R,X##_f[2]);         \
      R += _FP_W_TYPE_SIZE;         \
    }                         \
    else if (X##_f[1])              \
    {                         \
      __FP_CLZ(R,X##_f[1]);         \
      R += _FP_W_TYPE_SIZE*2;       \
    }                         \
    else                      \
    {                         \
      __FP_CLZ(R,X##_f[0]);         \
      R += _FP_W_TYPE_SIZE*3;       \
    }                         \
  } while(0)


#define _FP_UNPACK_RAW_4(fs, X, val)                        \
  do {                                                \
    union _FP_UNION_##fs _flo; _flo.flt = (val);            \
    X##_f[0] = _flo.bits.frac0;                             \
    X##_f[1] = _flo.bits.frac1;                             \
    X##_f[2] = _flo.bits.frac2;                             \
    X##_f[3] = _flo.bits.frac3;                             \
    X##_e  = _flo.bits.exp;                           \
    X##_s  = _flo.bits.sign;                          \
  } while (0)

#define _FP_UNPACK_RAW_4_P(fs, X, val)                      \
  do {                                                \
    union _FP_UNION_##fs *_flo =                      \
      (union _FP_UNION_##fs *)(val);                        \
                                                \
    X##_f[0] = _flo->bits.frac0;                      \
    X##_f[1] = _flo->bits.frac1;                      \
    X##_f[2] = _flo->bits.frac2;                      \
    X##_f[3] = _flo->bits.frac3;                      \
    X##_e  = _flo->bits.exp;                          \
    X##_s  = _flo->bits.sign;                         \
  } while (0)

#define _FP_PACK_RAW_4(fs, val, X)                    \
  do {                                                \
    union _FP_UNION_##fs _flo;                              \
    _flo.bits.frac0 = X##_f[0];                             \
    _flo.bits.frac1 = X##_f[1];                             \
    _flo.bits.frac2 = X##_f[2];                             \
    _flo.bits.frac3 = X##_f[3];                             \
    _flo.bits.exp   = X##_e;                          \
    _flo.bits.sign  = X##_s;                          \
    (val) = _flo.flt;                                 \
  } while (0)

#define _FP_PACK_RAW_4_P(fs, val, X)                        \
  do {                                                \
    union _FP_UNION_##fs *_flo =                      \
      (union _FP_UNION_##fs *)(val);                        \
                                                \
    _flo->bits.frac0 = X##_f[0];                      \
    _flo->bits.frac1 = X##_f[1];                      \
    _flo->bits.frac2 = X##_f[2];                      \
    _flo->bits.frac3 = X##_f[3];                      \
    _flo->bits.exp   = X##_e;                         \
    _flo->bits.sign  = X##_s;                         \
  } while (0)

/*
 * Multiplication algorithms:
 */

/* Given a 1W * 1W => 2W primitive, do the extended multiplication.  */

#define _FP_MUL_MEAT_4_wide(wfracbits, R, X, Y, doit)                 \
  do {                                                          \
    _FP_FRAC_DECL_8(_z); _FP_FRAC_DECL_2(_b); _FP_FRAC_DECL_2(_c);          \
    _FP_FRAC_DECL_2(_d); _FP_FRAC_DECL_2(_e); _FP_FRAC_DECL_2(_f);          \
                                                          \
    doit(_FP_FRAC_WORD_8(_z,1), _FP_FRAC_WORD_8(_z,0), X##_f[0], Y##_f[0]); \
    doit(_b_f1, _b_f0, X##_f[0], Y##_f[1]);                           \
    doit(_c_f1, _c_f0, X##_f[1], Y##_f[0]);                           \
    doit(_d_f1, _d_f0, X##_f[1], Y##_f[1]);                           \
    doit(_e_f1, _e_f0, X##_f[0], Y##_f[2]);                           \
    doit(_f_f1, _f_f0, X##_f[2], Y##_f[0]);                           \
    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,3),_FP_FRAC_WORD_8(_z,2),      \
                _FP_FRAC_WORD_8(_z,1), 0,_b_f1,_b_f0,           \
                0,0,_FP_FRAC_WORD_8(_z,1));                           \
    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,3),_FP_FRAC_WORD_8(_z,2),      \
                _FP_FRAC_WORD_8(_z,1), 0,_c_f1,_c_f0,           \
                _FP_FRAC_WORD_8(_z,3),_FP_FRAC_WORD_8(_z,2),          \
                _FP_FRAC_WORD_8(_z,1));                         \
    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,4),_FP_FRAC_WORD_8(_z,3),      \
                _FP_FRAC_WORD_8(_z,2), 0,_d_f1,_d_f0,           \
                0,_FP_FRAC_WORD_8(_z,3),_FP_FRAC_WORD_8(_z,2));       \
    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,4),_FP_FRAC_WORD_8(_z,3),      \
                _FP_FRAC_WORD_8(_z,2), 0,_e_f1,_e_f0,           \
                _FP_FRAC_WORD_8(_z,4),_FP_FRAC_WORD_8(_z,3),          \
                _FP_FRAC_WORD_8(_z,2));                         \
    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,4),_FP_FRAC_WORD_8(_z,3),      \
                _FP_FRAC_WORD_8(_z,2), 0,_f_f1,_f_f0,           \
                _FP_FRAC_WORD_8(_z,4),_FP_FRAC_WORD_8(_z,3),          \
                _FP_FRAC_WORD_8(_z,2));                         \
    doit(_b_f1, _b_f0, X##_f[0], Y##_f[3]);                           \
    doit(_c_f1, _c_f0, X##_f[3], Y##_f[0]);                           \
    doit(_d_f1, _d_f0, X##_f[1], Y##_f[2]);                           \
    doit(_e_f1, _e_f0, X##_f[2], Y##_f[1]);                           \
    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,5),_FP_FRAC_WORD_8(_z,4),      \
                _FP_FRAC_WORD_8(_z,3), 0,_b_f1,_b_f0,           \
                0,_FP_FRAC_WORD_8(_z,4),_FP_FRAC_WORD_8(_z,3));       \
    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,5),_FP_FRAC_WORD_8(_z,4),      \
                _FP_FRAC_WORD_8(_z,3), 0,_c_f1,_c_f0,           \
                _FP_FRAC_WORD_8(_z,5),_FP_FRAC_WORD_8(_z,4),          \
                _FP_FRAC_WORD_8(_z,3));                         \
    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,5),_FP_FRAC_WORD_8(_z,4),      \
                _FP_FRAC_WORD_8(_z,3), 0,_d_f1,_d_f0,           \
                _FP_FRAC_WORD_8(_z,5),_FP_FRAC_WORD_8(_z,4),          \
                _FP_FRAC_WORD_8(_z,3));                         \
    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,5),_FP_FRAC_WORD_8(_z,4),      \
                _FP_FRAC_WORD_8(_z,3), 0,_e_f1,_e_f0,           \
                _FP_FRAC_WORD_8(_z,5),_FP_FRAC_WORD_8(_z,4),          \
                _FP_FRAC_WORD_8(_z,3));                         \
    doit(_b_f1, _b_f0, X##_f[2], Y##_f[2]);                           \
    doit(_c_f1, _c_f0, X##_f[1], Y##_f[3]);                           \
    doit(_d_f1, _d_f0, X##_f[3], Y##_f[1]);                           \
    doit(_e_f1, _e_f0, X##_f[2], Y##_f[3]);                           \
    doit(_f_f1, _f_f0, X##_f[3], Y##_f[2]);                           \
    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,6),_FP_FRAC_WORD_8(_z,5),      \
                _FP_FRAC_WORD_8(_z,4), 0,_b_f1,_b_f0,           \
                0,_FP_FRAC_WORD_8(_z,5),_FP_FRAC_WORD_8(_z,4));       \
    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,6),_FP_FRAC_WORD_8(_z,5),      \
                _FP_FRAC_WORD_8(_z,4), 0,_c_f1,_c_f0,           \
                _FP_FRAC_WORD_8(_z,6),_FP_FRAC_WORD_8(_z,5),          \
                _FP_FRAC_WORD_8(_z,4));                         \
    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,6),_FP_FRAC_WORD_8(_z,5),      \
                _FP_FRAC_WORD_8(_z,4), 0,_d_f1,_d_f0,           \
                _FP_FRAC_WORD_8(_z,6),_FP_FRAC_WORD_8(_z,5),          \
                _FP_FRAC_WORD_8(_z,4));                         \
    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,7),_FP_FRAC_WORD_8(_z,6),      \
                _FP_FRAC_WORD_8(_z,5), 0,_e_f1,_e_f0,           \
                0,_FP_FRAC_WORD_8(_z,6),_FP_FRAC_WORD_8(_z,5));       \
    __FP_FRAC_ADD_3(_FP_FRAC_WORD_8(_z,7),_FP_FRAC_WORD_8(_z,6),      \
                _FP_FRAC_WORD_8(_z,5), 0,_f_f1,_f_f0,           \
                _FP_FRAC_WORD_8(_z,7),_FP_FRAC_WORD_8(_z,6),          \
                _FP_FRAC_WORD_8(_z,5));                         \
    doit(_b_f1, _b_f0, X##_f[3], Y##_f[3]);                           \
    __FP_FRAC_ADD_2(_FP_FRAC_WORD_8(_z,7),_FP_FRAC_WORD_8(_z,6),      \
                _b_f1,_b_f0,                              \
                _FP_FRAC_WORD_8(_z,7),_FP_FRAC_WORD_8(_z,6));         \
                                                          \
    /* Normalize since we know where the msb of the multiplicands     \
       were (bit B), we know that the msb of the of the product is          \
       at either 2B or 2B-1.  */                                \
    _FP_FRAC_SRS_8(_z, wfracbits-1, 2*wfracbits);                     \
    __FP_FRAC_SET_4(R, _FP_FRAC_WORD_8(_z,3), _FP_FRAC_WORD_8(_z,2),        \
                _FP_FRAC_WORD_8(_z,1), _FP_FRAC_WORD_8(_z,0));        \
  } while (0)

#define _FP_MUL_MEAT_4_gmp(wfracbits, R, X, Y)                        \
  do {                                                          \
    _FP_FRAC_DECL_8(_z);                                        \
                                                          \
    mpn_mul_n(_z_f, _x_f, _y_f, 4);                             \
                                                          \
    /* Normalize since we know where the msb of the multiplicands     \
       were (bit B), we know that the msb of the of the product is          \
       at either 2B or 2B-1.  */                                \
    _FP_FRAC_SRS_8(_z, wfracbits-1, 2*wfracbits);                     \
    __FP_FRAC_SET_4(R, _FP_FRAC_WORD_8(_z,3), _FP_FRAC_WORD_8(_z,2),        \
                _FP_FRAC_WORD_8(_z,1), _FP_FRAC_WORD_8(_z,0));        \
  } 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)         \
  do {                                                \
    int _c1, _c2;                                     \
    r0 = x0 + y0;                               \
    _c1 = r0 < x0;                                    \
    r1 = x1 + y1;                               \
    _c2 = r1 < x1;                                    \
    r1 += _c1;                                        \
    _c2 |= r1 < _c1;                                  \
    r2 = x2 + y2 + _c2;                               \
  } while (0)
#endif

#ifndef __FP_FRAC_ADD_4
#define __FP_FRAC_ADD_4(r3,r2,r1,r0,x3,x2,x1,x0,y3,y2,y1,y0)      \
  do {                                                \
    int _c1, _c2, _c3;                                \
    r0 = x0 + y0;                               \
    _c1 = r0 < x0;                                    \
    r1 = x1 + y1;                               \
    _c2 = r1 < x1;                                    \
    r1 += _c1;                                        \
    _c2 |= r1 < _c1;                                  \
    r2 = x2 + y2;                               \
    _c3 = r2 < x2;                                    \
    r2 += _c2;                                        \
    _c3 |= r2 < _c2;                                  \
    r3 = x3 + y3 + _c3;                               \
  } while (0)
#endif

#ifndef __FP_FRAC_SUB_3
#define __FP_FRAC_SUB_3(r2,r1,r0,x2,x1,x0,y2,y1,y0)         \
  do {                                                \
    int _c1, _c2;                                     \
    r0 = x0 - y0;                               \
    _c1 = r0 > x0;                                    \
    r1 = x1 - y1;                               \
    _c2 = r1 > x1;                                    \
    r1 -= _c1;                                        \
    _c2 |= r1 > _c1;                                  \
    r2 = x2 - y2 - _c2;                               \
  } while (0)
#endif

#ifndef __FP_FRAC_SUB_4
#define __FP_FRAC_SUB_4(r3,r2,r1,r0,x3,x2,x1,x0,y3,y2,y1,y0)      \
  do {                                                \
    int _c1, _c2, _c3;                                \
    r0 = x0 - y0;                               \
    _c1 = r0 > x0;                                    \
    r1 = x1 - y1;                               \
    _c2 = r1 > x1;                                    \
    r1 -= _c1;                                        \
    _c2 |= r1 > _c1;                                  \
    r2 = x2 - y2;                               \
    _c3 = r2 > x2;                                    \
    r2 -= _c2;                                        \
    _c3 |= r2 > _c2;                                  \
    r3 = x3 - y3 - _c3;                               \
  } while (0)
#endif

#ifndef __FP_FRAC_DEC_3
#define __FP_FRAC_DEC_3(x2,x1,x0,y2,y1,y0)                        \
  do {                                                      \
    UWtype _t0, _t1, _t2;                                   \
    _t0 = x0, _t1 = x1, _t2 = x2;                           \
    __FP_FRAC_SUB_3 (x2, x1, x0, _t2, _t1, _t0, y2, y1, y0);            \
  } 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, _t2, _t3;                                    \
    _t0 = x0, _t1 = x1, _t2 = x2, _t3 = x3;                       \
    __FP_FRAC_SUB_4 (x3,x2,x1,x0,_t3,_t2,_t1,_t0, y3,y2,y1,y0);         \
  } 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)


Generated by  Doxygen 1.6.0   Back to index