1 /* mpz_rootrem(root, rem, u, nth) -- Set ROOT to trunc(U^(1/nth)) and 2 set REM to the remainder. 3 4 Copyright 1999-2003, 2005, 2012 Free Software Foundation, Inc. 5 6 This file is part of the GNU MP Library. 7 8 The GNU MP Library is free software; you can redistribute it and/or modify 9 it 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 15 or 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 21 or both in parallel, as here. 22 23 The GNU MP Library is distributed in the hope that it will be useful, but 24 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 25 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 26 for more details. 27 28 You should have received copies of the GNU General Public License and the 29 GNU Lesser General Public License along with the GNU MP Library. If not, 30 see https://www.gnu.org/licenses/. */ 31 32 #include <stdio.h> /* for NULL */ 33 #include "gmp.h" 34 #include "gmp-impl.h" 35 36 void 37 mpz_rootrem (mpz_ptr root, mpz_ptr rem, mpz_srcptr u, unsigned long int nth) 38 { 39 mp_ptr rootp, up, remp; 40 mp_size_t us, un, rootn, remn; 41 TMP_DECL; 42 43 us = SIZ(u); 44 45 /* even roots of negatives provoke an exception */ 46 if (UNLIKELY (us < 0 && (nth & 1) == 0)) 47 SQRT_OF_NEGATIVE; 48 49 /* root extraction interpreted as c^(1/nth) means a zeroth root should 50 provoke a divide by zero, do this even if c==0 */ 51 if (UNLIKELY (nth == 0)) 52 DIVIDE_BY_ZERO; 53 54 if (us == 0) 55 { 56 if (root != NULL) 57 SIZ(root) = 0; 58 SIZ(rem) = 0; 59 return; 60 } 61 62 un = ABS (us); 63 rootn = (un - 1) / nth + 1; 64 65 TMP_MARK; 66 67 /* FIXME: Perhaps disallow root == NULL */ 68 if (root != NULL && u != root) 69 rootp = MPZ_REALLOC (root, rootn); 70 else 71 rootp = TMP_ALLOC_LIMBS (rootn); 72 73 if (u != rem) 74 remp = MPZ_REALLOC (rem, un); 75 else 76 remp = TMP_ALLOC_LIMBS (un); 77 78 up = PTR(u); 79 80 if (nth == 1) 81 { 82 MPN_COPY (rootp, up, un); 83 remn = 0; 84 } 85 else 86 { 87 remn = mpn_rootrem (rootp, remp, up, un, (mp_limb_t) nth); 88 } 89 90 if (root != NULL) 91 { 92 SIZ(root) = us >= 0 ? rootn : -rootn; 93 if (u == root) 94 MPN_COPY (up, rootp, rootn); 95 } 96 97 if (u == rem) 98 MPN_COPY (up, remp, remn); 99 SIZ(rem) = us >= 0 ? remn : -remn; 100 TMP_FREE; 101 } 102