/* mpz_fdiv_q_ui -- Division rounding the quotient towards -infinity. The remainder gets the same sign as the denominator. Copyright 1994, 1995, 1996, 1999, 2001, 2002, 2004 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include "mpir.h" #include "gmp-impl.h" unsigned long int mpz_fdiv_q_ui (mpz_ptr quot, mpz_srcptr dividend, unsigned long int divisor) { mp_size_t ns, nn, qn; mp_ptr np, qp; mp_limb_t rl; if (divisor == 0) DIVIDE_BY_ZERO; ns = SIZ(dividend); if (ns == 0) { SIZ(quot) = 0; return 0; } nn = ABS(ns); MPZ_REALLOC (quot, nn); qp = PTR(quot); np = PTR(dividend); #if BITS_PER_ULONG > GMP_NUMB_BITS /* avoid warnings about shift amount */ if (divisor > GMP_NUMB_MAX) { mp_limb_t dp[2], rp[2]; if (nn == 1) /* tdiv_qr requirements; tested above for 0 */ { qp[0] = 0; rl = np[0]; qn = 1; /* a white lie, fixed below */ } else { dp[0] = divisor & GMP_NUMB_MASK; dp[1] = divisor >> GMP_NUMB_BITS; mpn_tdiv_qr (qp, rp, (mp_size_t) 0, np, nn, dp, (mp_size_t) 2); rl = rp[0] + (rp[1] << GMP_NUMB_BITS); qn = nn - 2 + 1; } if (rl != 0 && ns < 0) { mpn_incr_u (qp, (mp_limb_t) 1); rl = divisor - rl; } qn -= qp[qn - 1] == 0; qn -= qn != 0 && qp[qn - 1] == 0; } else #endif { rl = mpn_divrem_1 (qp, 0, np, nn, (mp_limb_t) divisor); if (rl != 0 && ns < 0) { mpn_incr_u (qp, (mp_limb_t) 1); rl = divisor - rl; } qn = nn - (qp[nn - 1] == 0); } SIZ(quot) = ns >= 0 ? qn : -qn; return rl; }