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Annotation of OpenXM_contrib/gmp/mpf/cmp_ui.c, Revision 1.1.1.1

1.1       maekawa     1: /* mpf_cmp_ui -- Compare a float with an unsigned integer.
                      2:
                      3: Copyright (C) 1993, 1994, 1995 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 Library General Public License as published by
                      9: the Free Software Foundation; either version 2 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 Library General Public
                     15: License for more details.
                     16:
                     17: You should have received a copy of the GNU Library 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: #include "gmp.h"
                     23: #include "gmp-impl.h"
                     24:
                     25: int
                     26: #if __STDC__
                     27: mpf_cmp_ui (mpf_srcptr u, unsigned long int vlimb)
                     28: #else
                     29: mpf_cmp_ui (u, vlimb)
                     30:      mpf_srcptr u;
                     31:      unsigned long int vlimb;
                     32: #endif
                     33: {
                     34:   mp_srcptr up;
                     35:   mp_size_t usize;
                     36:   mp_exp_t uexp;
                     37:
                     38:   uexp = u->_mp_exp;
                     39:   usize = u->_mp_size;
                     40:
                     41:   /* 1. Is U negative?  */
                     42:   if (usize < 0)
                     43:     return -1;
                     44:   /* We rely on usize being non-negative in the code that follows.  */
                     45:
                     46:   if (vlimb == 0)
                     47:     return usize != 0;
                     48:
                     49:   /* 2. Are the exponents different (V's exponent == 1)?  */
                     50:   if (uexp > 1)
                     51:     return 1;
                     52:   if (uexp < 1)
                     53:     return -1;
                     54:
                     55:   up = u->_mp_d;
                     56:
                     57: #define STRICT_MPF_NORMALIZATION 0
                     58: #if ! STRICT_MPF_NORMALIZATION
                     59:   /* Ignore zeroes at the low end of U.  */
                     60:   while (*up == 0)
                     61:     {
                     62:       up++;
                     63:       usize--;
                     64:     }
                     65: #endif
                     66:
                     67:   /* 3. Now, if the number of limbs are different, we have a difference
                     68:      since we have made sure the trailing limbs are not zero.  */
                     69:   if (usize > 1)
                     70:     return 1;
                     71:
                     72:   /* 4. Compare the mantissas.  */
                     73:   if (*up > vlimb)
                     74:     return 1;
                     75:   else if (*up < vlimb)
                     76:     return -1;
                     77:
                     78:   /* Wow, we got zero even if we tried hard to avoid it.  */
                     79:   return 0;
                     80: }