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Annotation of OpenXM_contrib/gmp/mpq/cmp_ui.c, Revision 1.1.1.3

1.1       maekawa     1: /* mpq_cmp_ui(u,vn,vd) -- Compare U with Vn/Vd.  Return positive, zero, or
                      2:    negative based on if U > V, U == V, or U < V.  Vn and Vd may have
                      3:    common factors.
                      4:
1.1.1.3 ! ohara       5: Copyright 1993, 1994, 1996, 2000, 2001, 2002 Free Software Foundation, Inc.
1.1       maekawa     6:
                      7: This file is part of the GNU MP Library.
                      8:
                      9: The GNU MP Library is free software; you can redistribute it and/or modify
1.1.1.2   maekawa    10: it under the terms of the GNU Lesser General Public License as published by
                     11: the Free Software Foundation; either version 2.1 of the License, or (at your
1.1       maekawa    12: option) any later version.
                     13:
                     14: The GNU MP Library is distributed in the hope that it will be useful, but
                     15: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
1.1.1.2   maekawa    16: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
1.1       maekawa    17: License for more details.
                     18:
1.1.1.2   maekawa    19: You should have received a copy of the GNU Lesser General Public License
1.1       maekawa    20: along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
                     21: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
                     22: MA 02111-1307, USA. */
                     23:
                     24: #include "gmp.h"
                     25: #include "gmp-impl.h"
                     26:
                     27: int
1.1.1.2   maekawa    28: _mpq_cmp_ui (const MP_RAT *op1, unsigned long int num2, unsigned long int den2)
1.1       maekawa    29: {
                     30:   mp_size_t num1_size = op1->_mp_num._mp_size;
                     31:   mp_size_t den1_size = op1->_mp_den._mp_size;
                     32:   mp_size_t tmp1_size, tmp2_size;
                     33:   mp_ptr tmp1_ptr, tmp2_ptr;
                     34:   mp_limb_t cy_limb;
                     35:   int cc;
                     36:   TMP_DECL (marker);
                     37:
1.1.1.3 ! ohara      38: #if GMP_NAIL_BITS != 0
        !            39:   if ((num2 | den2) > GMP_NUMB_MAX)
        !            40:     {
        !            41:       mpq_t op2;
        !            42:       mpq_init (op2);
        !            43:       mpz_set_ui (mpq_numref (op2), num2);
        !            44:       mpz_set_ui (mpq_denref (op2), den2);
        !            45:       cc = mpq_cmp (op1, op2);
        !            46:       mpq_clear (op2);
        !            47:       return cc;
        !            48:     }
        !            49: #endif
        !            50:
        !            51:   /* need canonical sign to get right result */
        !            52:   ASSERT (den1_size > 0);
        !            53:
        !            54:   if (den2 == 0)
        !            55:     DIVIDE_BY_ZERO;
        !            56:
1.1       maekawa    57:   if (num1_size == 0)
                     58:     return -(num2 != 0);
                     59:   if (num1_size < 0)
                     60:     return num1_size;
                     61:   if (num2 == 0)
                     62:     return num1_size;
                     63:
                     64:   /* NUM1 x DEN2 is either TMP1_SIZE limbs or TMP1_SIZE-1 limbs.
                     65:      Same for NUM1 x DEN1 with respect to TMP2_SIZE.  */
                     66:   if (num1_size > den1_size + 1)
                     67:     /* NUM1 x DEN2 is surely larger in magnitude than NUM2 x DEN1.  */
1.1.1.3 ! ohara      68:     return num1_size;
        !            69:   if (den1_size > num1_size + 1)
1.1       maekawa    70:     /* NUM1 x DEN2 is surely smaller in magnitude than NUM2 x DEN1.  */
1.1.1.3 ! ohara      71:     return -num1_size;
1.1       maekawa    72:
                     73:   TMP_MARK (marker);
                     74:   tmp1_ptr = (mp_ptr) TMP_ALLOC ((num1_size + 1) * BYTES_PER_MP_LIMB);
                     75:   tmp2_ptr = (mp_ptr) TMP_ALLOC ((den1_size + 1) * BYTES_PER_MP_LIMB);
                     76:
                     77:   cy_limb = mpn_mul_1 (tmp1_ptr, op1->_mp_num._mp_d, num1_size, den2);
                     78:   tmp1_ptr[num1_size] = cy_limb;
                     79:   tmp1_size = num1_size + (cy_limb != 0);
                     80:
                     81:   cy_limb = mpn_mul_1 (tmp2_ptr, op1->_mp_den._mp_d, den1_size, num2);
                     82:   tmp2_ptr[den1_size] = cy_limb;
                     83:   tmp2_size = den1_size + (cy_limb != 0);
                     84:
                     85:   cc = tmp1_size - tmp2_size != 0
                     86:     ? tmp1_size - tmp2_size : mpn_cmp (tmp1_ptr, tmp2_ptr, tmp1_size);
                     87:   TMP_FREE (marker);
1.1.1.3 ! ohara      88:   return cc;
1.1       maekawa    89: }