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, 1995, 1996, 2001, 2002, 2004, 2005 Free Software Foundation, 7Inc. 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 the GNU Lesser General Public License as published by 13the Free Software Foundation; either version 3 of the License, or (at your 14option) any later version. 15 16The GNU MP Library is distributed in the hope that it will be useful, but 17WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 18or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 19License for more details. 20 21You should have received a copy of the GNU Lesser General Public License 22along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */ 23 24#include "gmp.h" 25#include "gmp-impl.h" 26 27unsigned long int 28mpz_cdiv_r_ui (mpz_ptr rem, mpz_srcptr dividend, unsigned long int divisor) 29{ 30 mp_size_t ns, nn; 31 mp_ptr np; 32 mp_limb_t rl; 33 34 if (divisor == 0) 35 DIVIDE_BY_ZERO; 36 37 ns = SIZ(dividend); 38 if (ns == 0) 39 { 40 SIZ(rem) = 0; 41 return 0; 42 } 43 44 nn = ABS(ns); 45 np = PTR(dividend); 46#if BITS_PER_ULONG > GMP_NUMB_BITS /* avoid warnings about shift amount */ 47 if (divisor > GMP_NUMB_MAX) 48 { 49 mp_limb_t dp[2]; 50 mp_ptr rp, qp; 51 mp_size_t rn; 52 TMP_DECL; 53 54 MPZ_REALLOC (rem, 2); 55 rp = PTR(rem); 56 57 if (nn == 1) /* tdiv_qr requirements; tested above for 0 */ 58 { 59 rl = np[0]; 60 rp[0] = rl; 61 } 62 else 63 { 64 TMP_MARK; 65 dp[0] = divisor & GMP_NUMB_MASK; 66 dp[1] = divisor >> GMP_NUMB_BITS; 67 qp = TMP_ALLOC_LIMBS (nn - 2 + 1); 68 mpn_tdiv_qr (qp, rp, (mp_size_t) 0, np, nn, dp, (mp_size_t) 2); 69 TMP_FREE; 70 rl = rp[0] + (rp[1] << GMP_NUMB_BITS); 71 } 72 73 if (rl != 0 && ns >= 0) 74 { 75 rl = divisor - rl; 76 rp[0] = rl & GMP_NUMB_MASK; 77 rp[1] = rl >> GMP_NUMB_BITS; 78 } 79 80 rn = 1 + (rl > GMP_NUMB_MAX); rn -= (rp[rn - 1] == 0); 81 SIZ(rem) = -rn; 82 } 83 else 84#endif 85 { 86 rl = mpn_mod_1 (np, nn, (mp_limb_t) divisor); 87 if (rl == 0) 88 SIZ(rem) = 0; 89 else 90 { 91 if (ns >= 0) 92 rl = divisor - rl; 93 94 PTR(rem)[0] = rl; 95 SIZ(rem) = -1; 96 } 97 } 98 99 return rl; 100} 101