1/* mpz_rootrem(root, rem, u, nth) -- Set ROOT to trunc(U^(1/nth)) and 2 set REM to the remainder. 3 4Copyright 1999-2003, 2005, 2012 Free Software Foundation, Inc. 5 6This file is part of the GNU MP Library. 7 8The GNU MP Library is free software; you can redistribute it and/or modify 9it under the terms of either: 10 11 * the GNU Lesser General Public License as published by the Free 12 Software Foundation; either version 3 of the License, or (at your 13 option) any later version. 14 15or 16 17 * the GNU General Public License as published by the Free Software 18 Foundation; either version 2 of the License, or (at your option) any 19 later version. 20 21or both in parallel, as here. 22 23The GNU MP Library is distributed in the hope that it will be useful, but 24WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 25or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 26for more details. 27 28You should have received copies of the GNU General Public License and the 29GNU Lesser General Public License along with the GNU MP Library. If not, 30see https://www.gnu.org/licenses/. */ 31 32#include <stdio.h> /* for NULL */ 33#include "gmp-impl.h" 34 35void 36mpz_rootrem (mpz_ptr root, mpz_ptr rem, mpz_srcptr u, unsigned long int nth) 37{ 38 mp_ptr rootp, up, remp; 39 mp_size_t us, un, rootn, remn; 40 TMP_DECL; 41 42 us = SIZ(u); 43 44 /* even roots of negatives provoke an exception */ 45 if (UNLIKELY (us < 0 && (nth & 1) == 0)) 46 SQRT_OF_NEGATIVE; 47 48 /* root extraction interpreted as c^(1/nth) means a zeroth root should 49 provoke a divide by zero, do this even if c==0 */ 50 if (UNLIKELY (nth == 0)) 51 DIVIDE_BY_ZERO; 52 53 if (us == 0) 54 { 55 if (root != NULL) 56 SIZ(root) = 0; 57 SIZ(rem) = 0; 58 return; 59 } 60 61 un = ABS (us); 62 rootn = (un - 1) / nth + 1; 63 64 TMP_MARK; 65 66 /* FIXME: Perhaps disallow root == NULL */ 67 if (root != NULL && u != root) 68 rootp = MPZ_NEWALLOC (root, rootn); 69 else 70 rootp = TMP_ALLOC_LIMBS (rootn); 71 72 if (u != rem) 73 remp = MPZ_NEWALLOC (rem, un); 74 else 75 remp = TMP_ALLOC_LIMBS (un); 76 77 up = PTR(u); 78 79 if (nth == 1) 80 { 81 MPN_COPY (rootp, up, un); 82 remn = 0; 83 } 84 else 85 { 86 remn = mpn_rootrem (rootp, remp, up, un, (mp_limb_t) nth); 87 } 88 89 if (root != NULL) 90 { 91 SIZ(root) = us >= 0 ? rootn : -rootn; 92 if (u == root) 93 MPN_COPY (up, rootp, rootn); 94 } 95 96 if (u == rem) 97 MPN_COPY (up, remp, remn); 98 SIZ(rem) = us >= 0 ? remn : -remn; 99 TMP_FREE; 100} 101