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author | tege <tege@gmplib.org> | 2002-05-07 03:14:34 +0200 |
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committer | tege <tege@gmplib.org> | 2002-05-07 03:14:34 +0200 |
commit | a0997b6571f3bfb7a924ba7acae869393c148eff (patch) | |
tree | 43c22f4736872484ed1d49f0e8d53d52c4b92513 | |
parent | cc3837b9dd50794d585bc9a6cc42fced37f2e555 (diff) | |
download | gmp-a0997b6571f3bfb7a924ba7acae869393c148eff.tar.gz |
*** empty log message ***
-rw-r--r-- | ChangeLog | 2 | ||||
-rw-r--r-- | mpz/ui_sub.c | 87 |
2 files changed, 89 insertions, 0 deletions
@@ -21,6 +21,8 @@ MA 02111-1307, USA. 2002-05-07 Torbjorn Granlund <tege@swox.com> + * mpz/aors_ui.h: Nailify. + * tests/mpz/t-addsub.c: New file. * tests/mpz/Makefile.am (check_PROGRAMS): Add t-addsub. diff --git a/mpz/ui_sub.c b/mpz/ui_sub.c new file mode 100644 index 000000000..9e2478484 --- /dev/null +++ b/mpz/ui_sub.c @@ -0,0 +1,87 @@ +/* mpz_ui_sub -- Subtract an unsigned one-word integer and an mpz_t. + +Copyright 2002 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 2.1 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; 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 +mpz_ui_sub (mpz_ptr w, unsigned long int uval, mpz_srcptr v) +{ + mp_ptr vp, wp; + mp_size_t vn, wn; + mp_limb_t cy; + +#if GMP_NAIL_BITS != 0 + if (uval > GMP_NUMB_MAX) + { + mpz_t u; + mp_limb_t ul[2]; + PTR(u) = ul; + ul[0] = uval & GMP_NUMB_MASK; + ul[1] = uval >> GMP_NUMB_BITS; + SIZ(u) = 2; + mpz_sub (w, u, v); + return; + } +#endif + + vp = PTR(v); + vn = SIZ(v); + + wp = PTR(w); + + if (vn > 1) + { + wp = MPZ_REALLOC (w, vn); + vp = PTR(v); + mpn_sub_1 (wp, vp, vn, (mp_limb_t) uval); + wn = -(vn - (wp[vn - 1] == 0)); + } + else if (vn == 1) + { + if (uval >= vp[0]) + { + wp[0] = uval - vp[0]; + wn = wp[0] != 0; + } + else + { + wp[0] = vp[0] - uval; + wn = -1; + } + } + else if (vn == 0) + { + wp[0] = uval; + wn = uval != 0; + } + else /* (vn < 0) */ + { + vn = -vn; + wp = MPZ_REALLOC (w, vn + 1); + vp = PTR(v); + cy = mpn_add_1 (wp, vp, vn, (mp_limb_t) uval); + wp[vn] = cy; + wn = vn + (cy != 0); + } + + SIZ(w) = wn; +} |