diff options
author | Mark Murray <markm@FreeBSD.org> | 1996-10-20 08:49:26 +0000 |
---|---|---|
committer | Mark Murray <markm@FreeBSD.org> | 1996-10-20 08:49:26 +0000 |
commit | aa9bc1760161ab710fbef6eba4c46bafdc84aa75 (patch) | |
tree | ecc4c214d76efa8e1b2fb33ac2f0aab18ea03ebf /contrib/libgmp/mpz/sub_ui.c | |
download | src-aa9bc1760161ab710fbef6eba4c46bafdc84aa75.tar.gz src-aa9bc1760161ab710fbef6eba4c46bafdc84aa75.zip |
Clean import of libgmp 2.0.2, with only the non-x86 bits removed.
BMakefiles and other bits will follow.
Requested by: Andrey Chernov
Made world by: Chuck Robey
Notes
Notes:
svn path=/vendor/libgmp/dist/; revision=19048
Diffstat (limited to 'contrib/libgmp/mpz/sub_ui.c')
-rw-r--r-- | contrib/libgmp/mpz/sub_ui.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/contrib/libgmp/mpz/sub_ui.c b/contrib/libgmp/mpz/sub_ui.c new file mode 100644 index 000000000000..7dea4b6c03ef --- /dev/null +++ b/contrib/libgmp/mpz/sub_ui.c @@ -0,0 +1,84 @@ +/* mpz_sub_ui -- Subtract an unsigned one-word integer from an MP_INT. + +Copyright (C) 1991, 1993, 1994, 1996 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 Library General Public License as published by +the Free Software Foundation; either version 2 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 Library General Public +License for more details. + +You should have received a copy of the GNU Library General Public License +along with the GNU MP Library; see the file COPYING.LIB. If not, write to +the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, +MA 02111-1307, USA. */ + +#include "gmp.h" +#include "gmp-impl.h" + +void +#if __STDC__ +mpz_sub_ui (mpz_ptr w, mpz_srcptr u, unsigned long int v) +#else +mpz_sub_ui (w, u, v) + mpz_ptr w; + mpz_srcptr u; + unsigned long int v; +#endif +{ + mp_srcptr up; + mp_ptr wp; + mp_size_t usize, wsize; + mp_size_t abs_usize; + + usize = u->_mp_size; + abs_usize = ABS (usize); + + /* If not space for W (and possible carry), increase space. */ + wsize = abs_usize + 1; + if (w->_mp_alloc < wsize) + _mpz_realloc (w, wsize); + + /* These must be after realloc (U may be the same as W). */ + up = u->_mp_d; + wp = w->_mp_d; + + if (abs_usize == 0) + { + wp[0] = v; + w->_mp_size = -(v != 0); + return; + } + + if (usize < 0) + { + mp_limb_t cy; + cy = mpn_add_1 (wp, up, abs_usize, v); + wp[abs_usize] = cy; + wsize = -(abs_usize + cy); + } + else + { + /* The signs are different. Need exact comparison to determine + which operand to subtract from which. */ + if (abs_usize == 1 && up[0] < v) + { + wp[0] = v - up[0]; + wsize = -1; + } + else + { + mpn_sub_1 (wp, up, abs_usize, v); + /* Size can decrease with at most one limb. */ + wsize = abs_usize - (wp[abs_usize - 1] == 0); + } + } + + w->_mp_size = wsize; +} |