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