diff options
Diffstat (limited to 'gmp/mpz/cong.c')
| -rw-r--r-- | gmp/mpz/cong.c | 117 |
1 files changed, 53 insertions, 64 deletions
diff --git a/gmp/mpz/cong.c b/gmp/mpz/cong.c index 1855b5052a..7fcd6e8d52 100644 --- a/gmp/mpz/cong.c +++ b/gmp/mpz/cong.c @@ -5,28 +5,17 @@ Copyright 2001, 2002, 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 either: - - * 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. - -or - - * the GNU General Public License as published by the Free Software - Foundation; either version 2 of the License, or (at your option) any - later version. - -or both in parallel, as here. +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 General Public License -for more details. +or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public +License for more details. -You should have received copies of the GNU General Public License and the -GNU Lesser General Public License along with the GNU MP Library. If not, -see https://www.gnu.org/licenses/. */ +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" @@ -105,53 +94,53 @@ mpz_congruent_p (mpz_srcptr a, mpz_srcptr c, mpz_srcptr d) if (csize == 1) { if (dsize == 1) - { - cong_1: - if (sign < 0) - NEG_MOD (clow, clow, dlow); - - if (ABOVE_THRESHOLD (asize, BMOD_1_TO_MOD_1_THRESHOLD)) - { - r = mpn_mod_1 (ap, asize, dlow); - if (clow < dlow) - return r == clow; - else - return r == (clow % dlow); - } - - if ((dlow & 1) == 0) - { - /* Strip low zero bits to get odd d required by modexact. If - d==e*2^n then a==c mod d if and only if both a==c mod e and - a==c mod 2^n, the latter having been done above. */ - unsigned twos; - count_trailing_zeros (twos, dlow); - dlow >>= twos; - } - - r = mpn_modexact_1c_odd (ap, asize, dlow, clow); - return r == 0 || r == dlow; - } + { + cong_1: + if (sign < 0) + NEG_MOD (clow, clow, dlow); + + if (BELOW_THRESHOLD (asize, MODEXACT_1_ODD_THRESHOLD)) + { + r = mpn_mod_1 (ap, asize, dlow); + if (clow < dlow) + return r == clow; + else + return r == (clow % dlow); + } + + if ((dlow & 1) == 0) + { + /* Strip low zero bits to get odd d required by modexact. If + d==e*2^n then a==c mod d if and only if both a==c mod e and + a==c mod 2^n, the latter having been done above. */ + unsigned twos; + count_trailing_zeros (twos, dlow); + dlow >>= twos; + } + + r = mpn_modexact_1c_odd (ap, asize, dlow, clow); + return r == 0 || r == dlow; + } /* dlow==0 is avoided since we don't want to bother handling extra low - zero bits if dsecond is even (would involve borrow if a,c differ in - sign and alow,clow!=0). */ + zero bits if dsecond is even (would involve borrow if a,c differ in + sign and alow,clow!=0). */ if (dsize == 2 && dlow != 0) - { - mp_limb_t dsecond = dp[1]; - - if (dsecond <= dmask) - { - unsigned twos; - count_trailing_zeros (twos, dlow); - dlow = (dlow >> twos) | (dsecond << (GMP_NUMB_BITS-twos)); - ASSERT_LIMB (dlow); - - /* dlow will be odd here, so the test for it even under cong_1 - is unnecessary, but the rest of that code is wanted. */ - goto cong_1; - } - } + { + mp_limb_t dsecond = dp[1]; + + if (dsecond <= dmask) + { + unsigned twos; + count_trailing_zeros (twos, dlow); + dlow = (dlow >> twos) | (dsecond << (GMP_NUMB_BITS-twos)); + ASSERT_LIMB (dlow); + + /* dlow will be odd here, so the test for it even under cong_1 + is unnecessary, but the rest of that code is wanted. */ + goto cong_1; + } + } } TMP_MARK; @@ -162,9 +151,9 @@ mpz_congruent_p (mpz_srcptr a, mpz_srcptr c, mpz_srcptr d) { /* same signs, subtract */ if (asize > csize || mpn_cmp (ap, cp, asize) >= 0) - ASSERT_NOCARRY (mpn_sub (xp, ap, asize, cp, csize)); + ASSERT_NOCARRY (mpn_sub (xp, ap, asize, cp, csize)); else - ASSERT_NOCARRY (mpn_sub_n (xp, cp, ap, asize)); + ASSERT_NOCARRY (mpn_sub_n (xp, cp, ap, asize)); MPN_NORMALIZE (xp, asize); } else |