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/* mpz_fdiv_q_ui -- Division rounding the quotient towards -infinity.
The remainder gets the same sign as the denominator.
Copyright 1994-1996, 1999, 2001, 2002, 2004, 2012 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 https://www.gnu.org/licenses/. */
#include "gmp.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 (UNLIKELY (divisor == 0))
DIVIDE_BY_ZERO;
ns = SIZ(dividend);
if (ns == 0)
{
SIZ(quot) = 0;
return 0;
}
nn = ABS(ns);
qp = MPZ_REALLOC (quot, nn);
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, (mp_size_t) 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;
}
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