109 lines
2.5 KiB
C
109 lines
2.5 KiB
C
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/* mpf_cmp -- Compare two floats.
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Copyright 1993, 1994, 1996, 2001 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 Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or (at your
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option) any later version.
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The GNU MP Library is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with the GNU MP Library; see the file COPYING.LIB. If not, write to
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the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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MA 02110-1301, USA. */
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#include "gmp.h"
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#include "gmp-impl.h"
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int
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mpf_cmp (mpf_srcptr u, mpf_srcptr v)
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{
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mp_srcptr up, vp;
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mp_size_t usize, vsize;
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mp_exp_t uexp, vexp;
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int cmp;
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int usign;
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uexp = u->_mp_exp;
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vexp = v->_mp_exp;
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usize = u->_mp_size;
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vsize = v->_mp_size;
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/* 1. Are the signs different? */
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if ((usize ^ vsize) >= 0)
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{
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/* U and V are both non-negative or both negative. */
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if (usize == 0)
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/* vsize >= 0 */
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return -(vsize != 0);
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if (vsize == 0)
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/* usize >= 0 */
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return usize != 0;
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/* Fall out. */
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}
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else
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{
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/* Either U or V is negative, but not both. */
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return usize >= 0 ? 1 : -1;
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}
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/* U and V have the same sign and are both non-zero. */
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usign = usize >= 0 ? 1 : -1;
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/* 2. Are the exponents different? */
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if (uexp > vexp)
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return usign;
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if (uexp < vexp)
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return -usign;
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usize = ABS (usize);
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vsize = ABS (vsize);
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up = u->_mp_d;
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vp = v->_mp_d;
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#define STRICT_MPF_NORMALIZATION 0
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#if ! STRICT_MPF_NORMALIZATION
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/* Ignore zeroes at the low end of U and V. */
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while (up[0] == 0)
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{
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up++;
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usize--;
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}
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while (vp[0] == 0)
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{
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vp++;
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vsize--;
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}
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#endif
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if (usize > vsize)
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{
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cmp = mpn_cmp (up + usize - vsize, vp, vsize);
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if (cmp == 0)
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return usign;
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}
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else if (vsize > usize)
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{
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cmp = mpn_cmp (up, vp + vsize - usize, usize);
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if (cmp == 0)
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return -usign;
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}
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else
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{
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cmp = mpn_cmp (up, vp, usize);
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if (cmp == 0)
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return 0;
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}
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return cmp > 0 ? usign : -usign;
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}
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