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

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:
                      5: Copyright (C) 1993, 1994, 1996 Free Software Foundation, Inc.
                      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
                     10: it under the terms of the GNU Library General Public License as published by
                     11: the Free Software Foundation; either version 2 of the License, or (at your
                     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
                     16: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
                     17: License for more details.
                     18:
                     19: You should have received a copy of the GNU Library General Public License
                     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: /* gmp.h defines a macro for mpq_cmp_ui.  */
                     28: #undef mpq_cmp_ui
                     29:
                     30: int
                     31: #if __STDC__
                     32: mpq_cmp_ui (const MP_RAT *op1, unsigned long int num2, unsigned long int den2)
                     33: #else
                     34: mpq_cmp_ui (op1, num2, den2)
                     35:      const MP_RAT *op1;
                     36:      unsigned long int num2;
                     37:      unsigned long int den2;
                     38: #endif
                     39: {
                     40:   mp_size_t num1_size = op1->_mp_num._mp_size;
                     41:   mp_size_t den1_size = op1->_mp_den._mp_size;
                     42:   mp_size_t tmp1_size, tmp2_size;
                     43:   mp_ptr tmp1_ptr, tmp2_ptr;
                     44:   mp_size_t num1_sign;
                     45:   mp_limb_t cy_limb;
                     46:   int cc;
                     47:   TMP_DECL (marker);
                     48:
                     49:   if (num1_size == 0)
                     50:     return -(num2 != 0);
                     51:   if (num1_size < 0)
                     52:     return num1_size;
                     53:   if (num2 == 0)
                     54:     return num1_size;
                     55:
                     56:   num1_sign = num1_size;
                     57:   num1_size = ABS (num1_size);
                     58:
                     59:   /* NUM1 x DEN2 is either TMP1_SIZE limbs or TMP1_SIZE-1 limbs.
                     60:      Same for NUM1 x DEN1 with respect to TMP2_SIZE.  */
                     61:   if (num1_size > den1_size + 1)
                     62:     /* NUM1 x DEN2 is surely larger in magnitude than NUM2 x DEN1.  */
                     63:     return num1_sign;
                     64:   if (den1_size > num1_sign + 1)
                     65:     /* NUM1 x DEN2 is surely smaller in magnitude than NUM2 x DEN1.  */
                     66:     return -num1_sign;
                     67:
                     68:   TMP_MARK (marker);
                     69:   tmp1_ptr = (mp_ptr) TMP_ALLOC ((num1_size + 1) * BYTES_PER_MP_LIMB);
                     70:   tmp2_ptr = (mp_ptr) TMP_ALLOC ((den1_size + 1) * BYTES_PER_MP_LIMB);
                     71:
                     72:   cy_limb = mpn_mul_1 (tmp1_ptr, op1->_mp_num._mp_d, num1_size, den2);
                     73:   tmp1_ptr[num1_size] = cy_limb;
                     74:   tmp1_size = num1_size + (cy_limb != 0);
                     75:
                     76:   cy_limb = mpn_mul_1 (tmp2_ptr, op1->_mp_den._mp_d, den1_size, num2);
                     77:   tmp2_ptr[den1_size] = cy_limb;
                     78:   tmp2_size = den1_size + (cy_limb != 0);
                     79:
                     80:   cc = tmp1_size - tmp2_size != 0
                     81:     ? tmp1_size - tmp2_size : mpn_cmp (tmp1_ptr, tmp2_ptr, tmp1_size);
                     82:   TMP_FREE (marker);
                     83:   return (num1_sign < 0) ? -cc : cc;
                     84: }