reldiff.c
上传用户:qaz666999
上传日期:2022-08-06
资源大小:2570k
文件大小:2k
- /* mpf_reldiff -- Generate the relative difference of two floats.
- Copyright 1996, 2001, 2004, 2005 Free Software Foundation, Inc.
- This file is part of the GNU MP Library.
- The GNU MP Library is free software; you can redistribute it and/or modify
- it under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 3 of the License, or (at your
- option) any later version.
- The GNU MP Library is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
- License for more details.
- You should have received a copy of the GNU Lesser General Public License
- along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */
- #include "gmp.h"
- #include "gmp-impl.h"
- /* The precision we use for d = x-y is based on what mpf_div will want from
- the dividend. It calls mpn_tdiv_qr to produce a quotient of rprec+1
- limbs. So rprec+1 == dsize - xsize + 1, hence dprec = rprec+xsize. */
- void
- mpf_reldiff (mpf_t rdiff, mpf_srcptr x, mpf_srcptr y)
- {
- if (UNLIKELY (SIZ(x) == 0))
- {
- mpf_set_ui (rdiff, (unsigned long int) (mpf_sgn (y) != 0));
- }
- else
- {
- mp_size_t dprec;
- mpf_t d;
- TMP_DECL;
- TMP_MARK;
- dprec = PREC(rdiff) + ABSIZ(x);
- ASSERT (PREC(rdiff)+1 == dprec - ABSIZ(x) + 1);
- PREC(d) = dprec;
- PTR(d) = TMP_ALLOC_LIMBS (dprec + 1);
- mpf_sub (d, x, y);
- SIZ(d) = ABSIZ(d);
- mpf_div (rdiff, d, x);
- TMP_FREE;
- }
- }