aa9bc17601
BMakefiles and other bits will follow. Requested by: Andrey Chernov Made world by: Chuck Robey
86 lines
2.4 KiB
C
86 lines
2.4 KiB
C
/* mpz_sqrt(root, u) -- Set ROOT to floor(sqrt(U)).
|
|
|
|
Copyright (C) 1991, 1993, 1994, 1996 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 Library General Public License as published by
|
|
the Free Software Foundation; either version 2 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 Library General Public
|
|
License for more details.
|
|
|
|
You should have received a copy of the GNU Library 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 "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)
|
|
op_size = 1 / (op_size > 0); /* Divide by zero for negative OP. */
|
|
|
|
/* 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);
|
|
}
|