1*86d7f5d3SJohn Marino /* mpz_fdiv_r_ui -- Division rounding the quotient towards -infinity.
2*86d7f5d3SJohn Marino The remainder gets the same sign as the denominator.
3*86d7f5d3SJohn Marino
4*86d7f5d3SJohn Marino Copyright 1994, 1995, 1996, 2001, 2002, 2004, 2005 Free Software Foundation,
5*86d7f5d3SJohn Marino Inc.
6*86d7f5d3SJohn Marino
7*86d7f5d3SJohn Marino This file is part of the GNU MP Library.
8*86d7f5d3SJohn Marino
9*86d7f5d3SJohn Marino The GNU MP Library is free software; you can redistribute it and/or modify
10*86d7f5d3SJohn Marino it under the terms of the GNU Lesser General Public License as published by
11*86d7f5d3SJohn Marino the Free Software Foundation; either version 3 of the License, or (at your
12*86d7f5d3SJohn Marino option) any later version.
13*86d7f5d3SJohn Marino
14*86d7f5d3SJohn Marino The GNU MP Library is distributed in the hope that it will be useful, but
15*86d7f5d3SJohn Marino WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
16*86d7f5d3SJohn Marino or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
17*86d7f5d3SJohn Marino License for more details.
18*86d7f5d3SJohn Marino
19*86d7f5d3SJohn Marino You should have received a copy of the GNU Lesser General Public License
20*86d7f5d3SJohn Marino along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */
21*86d7f5d3SJohn Marino
22*86d7f5d3SJohn Marino #include "gmp.h"
23*86d7f5d3SJohn Marino #include "gmp-impl.h"
24*86d7f5d3SJohn Marino
25*86d7f5d3SJohn Marino unsigned long int
mpz_fdiv_r_ui(mpz_ptr rem,mpz_srcptr dividend,unsigned long int divisor)26*86d7f5d3SJohn Marino mpz_fdiv_r_ui (mpz_ptr rem, mpz_srcptr dividend, unsigned long int divisor)
27*86d7f5d3SJohn Marino {
28*86d7f5d3SJohn Marino mp_size_t ns, nn;
29*86d7f5d3SJohn Marino mp_ptr np;
30*86d7f5d3SJohn Marino mp_limb_t rl;
31*86d7f5d3SJohn Marino
32*86d7f5d3SJohn Marino if (divisor == 0)
33*86d7f5d3SJohn Marino DIVIDE_BY_ZERO;
34*86d7f5d3SJohn Marino
35*86d7f5d3SJohn Marino ns = SIZ(dividend);
36*86d7f5d3SJohn Marino if (ns == 0)
37*86d7f5d3SJohn Marino {
38*86d7f5d3SJohn Marino SIZ(rem) = 0;
39*86d7f5d3SJohn Marino return 0;
40*86d7f5d3SJohn Marino }
41*86d7f5d3SJohn Marino
42*86d7f5d3SJohn Marino nn = ABS(ns);
43*86d7f5d3SJohn Marino np = PTR(dividend);
44*86d7f5d3SJohn Marino #if BITS_PER_ULONG > GMP_NUMB_BITS /* avoid warnings about shift amount */
45*86d7f5d3SJohn Marino if (divisor > GMP_NUMB_MAX)
46*86d7f5d3SJohn Marino {
47*86d7f5d3SJohn Marino mp_limb_t dp[2];
48*86d7f5d3SJohn Marino mp_ptr rp, qp;
49*86d7f5d3SJohn Marino mp_size_t rn;
50*86d7f5d3SJohn Marino TMP_DECL;
51*86d7f5d3SJohn Marino
52*86d7f5d3SJohn Marino MPZ_REALLOC (rem, 2);
53*86d7f5d3SJohn Marino rp = PTR(rem);
54*86d7f5d3SJohn Marino
55*86d7f5d3SJohn Marino if (nn == 1) /* tdiv_qr requirements; tested above for 0 */
56*86d7f5d3SJohn Marino {
57*86d7f5d3SJohn Marino rl = np[0];
58*86d7f5d3SJohn Marino rp[0] = rl;
59*86d7f5d3SJohn Marino }
60*86d7f5d3SJohn Marino else
61*86d7f5d3SJohn Marino {
62*86d7f5d3SJohn Marino TMP_MARK;
63*86d7f5d3SJohn Marino dp[0] = divisor & GMP_NUMB_MASK;
64*86d7f5d3SJohn Marino dp[1] = divisor >> GMP_NUMB_BITS;
65*86d7f5d3SJohn Marino qp = TMP_ALLOC_LIMBS (nn - 2 + 1);
66*86d7f5d3SJohn Marino mpn_tdiv_qr (qp, rp, (mp_size_t) 0, np, nn, dp, (mp_size_t) 2);
67*86d7f5d3SJohn Marino TMP_FREE;
68*86d7f5d3SJohn Marino rl = rp[0] + (rp[1] << GMP_NUMB_BITS);
69*86d7f5d3SJohn Marino }
70*86d7f5d3SJohn Marino
71*86d7f5d3SJohn Marino if (rl != 0 && ns < 0)
72*86d7f5d3SJohn Marino {
73*86d7f5d3SJohn Marino rl = divisor - rl;
74*86d7f5d3SJohn Marino rp[0] = rl & GMP_NUMB_MASK;
75*86d7f5d3SJohn Marino rp[1] = rl >> GMP_NUMB_BITS;
76*86d7f5d3SJohn Marino }
77*86d7f5d3SJohn Marino
78*86d7f5d3SJohn Marino rn = 1 + (rl > GMP_NUMB_MAX); rn -= (rp[rn - 1] == 0);
79*86d7f5d3SJohn Marino SIZ(rem) = rn;
80*86d7f5d3SJohn Marino }
81*86d7f5d3SJohn Marino else
82*86d7f5d3SJohn Marino #endif
83*86d7f5d3SJohn Marino {
84*86d7f5d3SJohn Marino rl = mpn_mod_1 (np, nn, (mp_limb_t) divisor);
85*86d7f5d3SJohn Marino if (rl == 0)
86*86d7f5d3SJohn Marino SIZ(rem) = 0;
87*86d7f5d3SJohn Marino else
88*86d7f5d3SJohn Marino {
89*86d7f5d3SJohn Marino if (ns < 0)
90*86d7f5d3SJohn Marino rl = divisor - rl;
91*86d7f5d3SJohn Marino
92*86d7f5d3SJohn Marino PTR(rem)[0] = rl;
93*86d7f5d3SJohn Marino SIZ(rem) = 1;
94*86d7f5d3SJohn Marino }
95*86d7f5d3SJohn Marino }
96*86d7f5d3SJohn Marino
97*86d7f5d3SJohn Marino return rl;
98*86d7f5d3SJohn Marino }
99