/* mpz_sqrtrem(root,rem,x) -- Set ROOT to floor(sqrt(X)) and REM to the remainder, i.e. X - ROOT**2. Copyright (C) 1991, 1993, 1994, 1996, 2000 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 2.1 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; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include /* for NULL */ #include "gmp.h" #include "gmp-impl.h" #ifdef BERKELEY_MP #include "mp.h" #endif #ifndef BERKELEY_MP void #if __STDC__ mpz_sqrtrem (mpz_ptr root, mpz_ptr rem, mpz_srcptr op) #else mpz_sqrtrem (root, rem, op) mpz_ptr root; mpz_ptr rem; mpz_srcptr op; #endif #else /* BERKELEY_MP */ void #if __STDC__ msqrt (mpz_srcptr op, mpz_ptr root, mpz_ptr rem) #else msqrt (op, root, rem) mpz_srcptr op; mpz_ptr root; mpz_ptr rem; #endif #endif /* BERKELEY_MP */ { mp_size_t op_size, root_size, rem_size; mp_ptr root_ptr, op_ptr; mp_ptr free_me = NULL; mp_size_t free_me_size; TMP_DECL (marker); TMP_MARK (marker); op_size = op->_mp_size; if (op_size < 0) SQRT_OF_NEGATIVE; if (rem->_mp_alloc < op_size) _mpz_realloc (rem, op_size); /* The size of the root is accurate after this simple calculation. */ root_size = (op_size + 1) / 2; root_ptr = root->_mp_d; op_ptr = op->_mp_d; if (root->_mp_alloc < root_size) { if (root_ptr == op_ptr) { free_me = root_ptr; free_me_size = root->_mp_alloc; } else (*_mp_free_func) (root_ptr, root->_mp_alloc * BYTES_PER_MP_LIMB); root->_mp_alloc = root_size; root_ptr = (mp_ptr) (*_mp_allocate_func) (root_size * BYTES_PER_MP_LIMB); root->_mp_d = root_ptr; } else { /* Make OP not overlap with ROOT. */ if (root_ptr == op_ptr) { /* ROOT and OP are identical. Allocate temporary space for OP. */ op_ptr = (mp_ptr) TMP_ALLOC (op_size * BYTES_PER_MP_LIMB); /* Copy to the temporary space. Hack: Avoid temporary variable by using ROOT_PTR. */ MPN_COPY (op_ptr, root_ptr, op_size); } } rem_size = mpn_sqrtrem (root_ptr, rem->_mp_d, op_ptr, op_size); root->_mp_size = root_size; /* Write remainder size last, to enable us to define this function to give only the square root remainder, if the user calls if with ROOT == REM. */ rem->_mp_size = rem_size; if (free_me != NULL) (*_mp_free_func) (free_me, free_me_size * BYTES_PER_MP_LIMB); TMP_FREE (marker); }