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Annotation of OpenXM_contrib/gmp/mpz/cmp_d.c, Revision 1.1.1.1

1.1       ohara       1: /* mpz_cmpabs_d -- compare absolute values of mpz and double.
                      2:
                      3: Copyright 2001, 2002 Free Software Foundation, Inc.
                      4:
                      5: This file is part of the GNU MP Library.
                      6:
                      7: The GNU MP Library is free software; you can redistribute it and/or modify
                      8: it under the terms of the GNU Lesser General Public License as published by
                      9: the Free Software Foundation; either version 2.1 of the License, or (at your
                     10: option) any later version.
                     11:
                     12: The GNU MP Library is distributed in the hope that it will be useful, but
                     13: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
                     14: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
                     15: License for more details.
                     16:
                     17: You should have received a copy of the GNU Lesser General Public License
                     18: along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
                     19: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
                     20: MA 02111-1307, USA.
                     21: */
                     22:
                     23: #include "gmp.h"
                     24: #include "gmp-impl.h"
                     25:
                     26:
                     27: #define RETURN_CMP(zl, dl)                      \
                     28:   do {                                          \
                     29:     zlimb = (zl);                               \
                     30:     dlimb = (dl);                               \
                     31:     if (zlimb != dlimb)                         \
                     32:       return (zlimb >= dlimb ? ret : -ret);     \
                     33:   } while (0)
                     34:
                     35: #define RETURN_NONZERO(ptr, size, val)          \
                     36:   do {                                          \
                     37:     mp_size_t __i;                              \
                     38:     for (__i = (size)-1; __i >= 0; __i--)       \
                     39:       if ((ptr)[__i] != 0)                      \
                     40:         return val;                             \
                     41:     return 0;                                   \
                     42:   } while (0)
                     43:
                     44:
                     45: int
                     46: mpz_cmp_d (mpz_srcptr z, double d)
                     47: {
                     48:   mp_limb_t  darray[LIMBS_PER_DOUBLE], zlimb, dlimb;
                     49:   mp_srcptr  zp;
                     50:   mp_size_t  zsize;
                     51:   int        dexp, ret;
                     52:
                     53:   /* 1. Either operand zero. */
                     54:   zsize = SIZ(z);
                     55:   if (d == 0.0)
                     56:     return zsize;
                     57:   if (zsize == 0)
                     58:     return (d < 0.0 ? 1 : -1);
                     59:
                     60:   /* 2. Opposite signs. */
                     61:   if (zsize >= 0)
                     62:     {
                     63:       if (d < 0.0)
                     64:         return 1;    /* >=0 cmp <0 */
                     65:       ret = 1;
                     66:     }
                     67:   else
                     68:     {
                     69:       if (d >= 0.0)
                     70:         return -1;   /* <0 cmp >=0 */
                     71:       ret = -1;
                     72:       d = -d;
                     73:       zsize = -zsize;
                     74:     }
                     75:
                     76:   /* 3. Small d, knowing abs(z) >= 1. */
                     77:   if (d < 1.0)
                     78:     return ret;
                     79:
                     80:   dexp = __gmp_extract_double (darray, d);
                     81:   ASSERT (dexp >= 1);
                     82:
                     83:   /* 4. Different high limb positions. */
                     84:   if (zsize != dexp)
                     85:     return (zsize >= dexp ? ret : -ret);
                     86:
                     87:   /* 5. Limb data. */
                     88:   zp = PTR(z);
                     89:
                     90: #if LIMBS_PER_DOUBLE == 2
                     91:   RETURN_CMP (zp[zsize-1], darray[1]);
                     92:   if (zsize == 1)
                     93:     return (darray[0] != 0 ? -ret : 0);
                     94:
                     95:   RETURN_CMP (zp[zsize-2], darray[0]);
                     96:   RETURN_NONZERO (zp, zsize-2, ret);
                     97:
                     98: #else
                     99: #if LIMBS_PER_DOUBLE == 3
                    100:   RETURN_CMP (zp[zsize-1], darray[2]);
                    101:   if (zsize == 1)
                    102:     return ((darray[0] | darray[1]) != 0 ? -ret : 0);
                    103:
                    104:   RETURN_CMP (zp[zsize-2], darray[1]);
                    105:   if (zsize == 2)
                    106:     return (darray[0] != 0 ? -ret : 0);
                    107:
                    108:   RETURN_CMP (zp[zsize-3], darray[0]);
                    109:   RETURN_NONZERO (zp, zsize-3, ret);
                    110:
                    111: #else
                    112:   for (i = 1; i <= LIMBS_PER_DOUBLE; i++)
                    113:     {
                    114:       RETURN_CMP (zp[zsize-i], darray[LIMBS_PER_DOUBLE-i]);
                    115:       if (i >= zsize)
                    116:         RETURN_NONZERO (darray, LIMBS_PER_DOUBLE-i, -ret);
                    117:     }
                    118:   RETURN_NONZERO (zp, zsize-LIMBS_PER_DOUBLE, ret);
                    119: #endif
                    120: #endif
                    121: }