1/* mpz_cdiv_r_ui -- Division rounding the quotient towards +infinity. The 2 remainder gets the opposite sign as the denominator. In order to make it 3 always fit into the return type, the negative of the true remainder is 4 returned. 5 6Copyright 1994-1996, 2001, 2002, 2004, 2005, 2012, 2015 Free Software 7Foundation, Inc. 8 9This file is part of the GNU MP Library. 10 11The GNU MP Library is free software; you can redistribute it and/or modify 12it under the terms of either: 13 14 * the GNU Lesser General Public License as published by the Free 15 Software Foundation; either version 3 of the License, or (at your 16 option) any later version. 17 18or 19 20 * the GNU General Public License as published by the Free Software 21 Foundation; either version 2 of the License, or (at your option) any 22 later version. 23 24or both in parallel, as here. 25 26The GNU MP Library is distributed in the hope that it will be useful, but 27WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 28or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 29for more details. 30 31You should have received copies of the GNU General Public License and the 32GNU Lesser General Public License along with the GNU MP Library. If not, 33see https://www.gnu.org/licenses/. */ 34 35#include "gmp-impl.h" 36 37unsigned long int 38mpz_cdiv_r_ui (mpz_ptr rem, mpz_srcptr dividend, unsigned long int divisor) 39{ 40 mp_size_t ns, nn; 41 mp_ptr np; 42 mp_limb_t rl; 43 44 if (UNLIKELY (divisor == 0)) 45 DIVIDE_BY_ZERO; 46 47 ns = SIZ(dividend); 48 if (ns == 0) 49 { 50 SIZ(rem) = 0; 51 return 0; 52 } 53 54 nn = ABS(ns); 55 np = PTR(dividend); 56#if BITS_PER_ULONG > GMP_NUMB_BITS /* avoid warnings about shift amount */ 57 if (divisor > GMP_NUMB_MAX) 58 { 59 mp_limb_t dp[2]; 60 mp_ptr rp, qp; 61 mp_size_t rn; 62 TMP_DECL; 63 64 rp = MPZ_REALLOC (rem, 2); 65 66 if (nn == 1) /* tdiv_qr requirements; tested above for 0 */ 67 { 68 rl = np[0]; 69 rp[0] = rl; 70 } 71 else 72 { 73 TMP_MARK; 74 dp[0] = divisor & GMP_NUMB_MASK; 75 dp[1] = divisor >> GMP_NUMB_BITS; 76 qp = TMP_ALLOC_LIMBS (nn - 2 + 1); 77 mpn_tdiv_qr (qp, rp, (mp_size_t) 0, np, nn, dp, (mp_size_t) 2); 78 TMP_FREE; 79 rl = rp[0] + (rp[1] << GMP_NUMB_BITS); 80 } 81 82 if (rl != 0 && ns >= 0) 83 { 84 rl = divisor - rl; 85 rp[0] = rl & GMP_NUMB_MASK; 86 rp[1] = rl >> GMP_NUMB_BITS; 87 } 88 89 rn = 1 + (rl > GMP_NUMB_MAX); rn -= (rp[rn - 1] == 0); 90 SIZ(rem) = -rn; 91 } 92 else 93#endif 94 { 95 rl = mpn_mod_1 (np, nn, (mp_limb_t) divisor); 96 if (rl == 0) 97 SIZ(rem) = 0; 98 else 99 { 100 if (ns >= 0) 101 rl = divisor - rl; 102 103 MPZ_NEWALLOC (rem, 1)[0] = rl; 104 SIZ(rem) = -1; 105 } 106 } 107 108 return rl; 109} 110