77 lines
1.8 KiB
C
77 lines
1.8 KiB
C
/* mpq_set_si(dest,ulong_num,ulong_den) -- Set DEST to the retional number
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ULONG_NUM/ULONG_DEN.
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Copyright (C) 1991 Free Software Foundation, Inc.
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This file is part of the GNU MP Library.
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The GNU MP Library is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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The GNU MP Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with the GNU MP Library; see the file COPYING. If not, write to
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the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
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#include "gmp.h"
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#include "gmp-impl.h"
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static unsigned long int
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gcd (x, y)
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unsigned long int x, y;
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{
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for (;;)
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{
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x = x % y;
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if (x == 0)
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return y;
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y = y % x;
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if (y == 0)
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return x;
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}
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}
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void
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#ifdef __STDC__
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mpq_set_si (MP_RAT *dest, signed long int num, unsigned long int den)
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#else
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mpq_set_si (dest, num, den)
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MP_RAT *dest;
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signed long int num;
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unsigned long int den;
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#endif
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{
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unsigned long int g;
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unsigned long int abs_num;
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abs_num = ABS (num);
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if (num == 0)
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{
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/* Canonicalize 0/d to 0/1. */
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den = 1;
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dest->num.size = 0;
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}
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else
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{
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/* Remove any common factor in NUM and DEN. */
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/* Pass DEN as the second argument to gcd, in order to make the
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gcd function divide by zero if DEN is zero. */
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g = gcd (abs_num, den);
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abs_num /= g;
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den /= g;
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dest->num.d[0] = abs_num;
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dest->num.size = num > 0 ? 1 : -1;
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}
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dest->den.d[0] = den;
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dest->den.size = 1;
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}
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