diff options
Diffstat (limited to 'rts/gmp/mpz/sqrt.c')
| -rw-r--r-- | rts/gmp/mpz/sqrt.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/rts/gmp/mpz/sqrt.c b/rts/gmp/mpz/sqrt.c new file mode 100644 index 0000000000..fe82fe407a --- /dev/null +++ b/rts/gmp/mpz/sqrt.c @@ -0,0 +1,86 @@ +/* mpz_sqrt(root, u) -- Set ROOT to floor(sqrt(U)). + +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 <stdio.h> /* for NULL */ +#include "gmp.h" +#include "gmp-impl.h" + +void +#if __STDC__ +mpz_sqrt (mpz_ptr root, mpz_srcptr op) +#else +mpz_sqrt (root, op) + mpz_ptr root; + mpz_srcptr op; +#endif +{ + mp_size_t op_size, root_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; + + /* 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); + } + } + + mpn_sqrtrem (root_ptr, NULL, op_ptr, op_size); + + root->_mp_size = root_size; + + if (free_me != NULL) + (*_mp_free_func) (free_me, free_me_size * BYTES_PER_MP_LIMB); + TMP_FREE (marker); +} |