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