X-Git-Url: https://oss.titaniummirror.com/gitweb?a=blobdiff_plain;f=gmp%2Fmpz%2Fcdiv_qr_ui.c;fp=gmp%2Fmpz%2Fcdiv_qr_ui.c;h=67e80b7ac72ead438723740771f38051e10362b3;hb=6fed43773c9b0ce596dca5686f37ac3fc0fa11c0;hp=0000000000000000000000000000000000000000;hpb=27b11d56b743098deb193d510b337ba22dc52e5c;p=msp430-gcc.git diff --git a/gmp/mpz/cdiv_qr_ui.c b/gmp/mpz/cdiv_qr_ui.c new file mode 100644 index 00000000..67e80b7a --- /dev/null +++ b/gmp/mpz/cdiv_qr_ui.c @@ -0,0 +1,110 @@ +/* mpz_cdiv_qr_ui -- Division rounding the quotient towards +infinity. The + remainder gets the opposite sign as the denominator. In order to make it + always fit into the return type, the negative of the true remainder is + returned. + +Copyright 1994, 1995, 1996, 1999, 2001, 2002, 2004 Free Software Foundation, +Inc. + +This file is part of the GNU MP Library. + +The GNU MP Library is free software; you can redistribute it and/or modify +it under the terms of the GNU Lesser General Public License as published by +the Free Software Foundation; either version 3 of the License, or (at your +option) any later version. + +The GNU MP Library is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY +or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public +License for more details. + +You should have received a copy of the GNU Lesser General Public License +along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */ + +#include "gmp.h" +#include "gmp-impl.h" + +unsigned long int +mpz_cdiv_qr_ui (mpz_ptr quot, mpz_ptr rem, mpz_srcptr dividend, unsigned long int divisor) +{ + mp_size_t ns, nn, qn; + mp_ptr np, qp; + mp_limb_t rl; + + if (divisor == 0) + DIVIDE_BY_ZERO; + + ns = SIZ(dividend); + if (ns == 0) + { + SIZ(quot) = 0; + SIZ(rem) = 0; + return 0; + } + + nn = ABS(ns); + MPZ_REALLOC (quot, nn); + qp = PTR(quot); + np = PTR(dividend); + +#if BITS_PER_ULONG > GMP_NUMB_BITS /* avoid warnings about shift amount */ + if (divisor > GMP_NUMB_MAX) + { + mp_limb_t dp[2]; + mp_ptr rp; + mp_size_t rn; + + MPZ_REALLOC (rem, 2); + rp = PTR(rem); + + if (nn == 1) /* tdiv_qr requirements; tested above for 0 */ + { + qp[0] = 0; + qn = 1; /* a white lie, fixed below */ + rl = np[0]; + rp[0] = rl; + } + else + { + dp[0] = divisor & GMP_NUMB_MASK; + dp[1] = divisor >> GMP_NUMB_BITS; + mpn_tdiv_qr (qp, rp, (mp_size_t) 0, np, nn, dp, (mp_size_t) 2); + rl = rp[0] + (rp[1] << GMP_NUMB_BITS); + qn = nn - 2 + 1; + } + + if (rl != 0 && ns >= 0) + { + mpn_incr_u (qp, (mp_limb_t) 1); + rl = divisor - rl; + rp[0] = rl & GMP_NUMB_MASK; + rp[1] = rl >> GMP_NUMB_BITS; + } + + qn -= qp[qn - 1] == 0; qn -= qn != 0 && qp[qn - 1] == 0; + rn = 1 + (rl > GMP_NUMB_MAX); rn -= (rp[rn - 1] == 0); + SIZ(rem) = -rn; + } + else +#endif + { + rl = mpn_divrem_1 (qp, (mp_size_t) 0, np, nn, (mp_limb_t) divisor); + if (rl == 0) + SIZ(rem) = 0; + else + { + if (ns >= 0) + { + mpn_incr_u (qp, (mp_limb_t) 1); + rl = divisor - rl; + } + + PTR(rem)[0] = rl; + SIZ(rem) = -(rl != 0); + } + qn = nn - (qp[nn - 1] == 0); + } + + SIZ(quot) = ns >= 0 ? qn : -qn; + return rl; +}