+++ /dev/null
-/* mpn_perfect_square_p(u,usize) -- Return non-zero if U is a perfect square,
- zero otherwise.
-
-Copyright (C) 1991, 1993, 1994, 1996, 1997, 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"
-#include "longlong.h"
-
-
-/* sq_res_0x100[x mod 0x100] == 1 iff x mod 0x100 is a quadratic residue
- modulo 0x100. */
-static unsigned char const sq_res_0x100[0x100] =
-{
- 1,1,0,0,1,0,0,0,0,1,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,
- 0,1,0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,
- 1,1,0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,
- 0,1,0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,
- 0,1,0,0,1,0,0,0,0,1,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,
- 0,1,0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,
- 0,1,0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,
- 0,1,0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,
-};
-
-int
-#if __STDC__
-mpn_perfect_square_p (mp_srcptr up, mp_size_t usize)
-#else
-mpn_perfect_square_p (up, usize)
- mp_srcptr up;
- mp_size_t usize;
-#endif
-{
- mp_limb_t rem;
- mp_ptr root_ptr;
- int res;
- TMP_DECL (marker);
-
- /* The first test excludes 55/64 (85.9%) of the perfect square candidates
- in O(1) time. */
- if ((sq_res_0x100[(unsigned int) up[0] % 0x100] & 1) == 0)
- return 0;
-
-#if defined (PP)
- /* The second test excludes 30652543/30808063 (99.5%) of the remaining
- perfect square candidates in O(n) time. */
-
- /* Firstly, compute REM = A mod PP. */
- if (UDIV_TIME > (2 * UMUL_TIME + 6))
- rem = mpn_preinv_mod_1 (up, usize, (mp_limb_t) PP, (mp_limb_t) PP_INVERTED);
- else
- rem = mpn_mod_1 (up, usize, (mp_limb_t) PP);
-
- /* Now decide if REM is a quadratic residue modulo the factors in PP. */
-
- /* If A is just a few limbs, computing the square root does not take long
- time, so things might run faster if we limit this loop according to the
- size of A. */
-
-#if BITS_PER_MP_LIMB == 64
- if (((CNST_LIMB(0x12DD703303AED3) >> rem % 53) & 1) == 0)
- return 0;
- if (((CNST_LIMB(0x4351B2753DF) >> rem % 47) & 1) == 0)
- return 0;
- if (((CNST_LIMB(0x35883A3EE53) >> rem % 43) & 1) == 0)
- return 0;
- if (((CNST_LIMB(0x1B382B50737) >> rem % 41) & 1) == 0)
- return 0;
- if (((CNST_LIMB(0x165E211E9B) >> rem % 37) & 1) == 0)
- return 0;
- if (((CNST_LIMB(0x121D47B7) >> rem % 31) & 1) == 0)
- return 0;
-#endif
- if (((0x13D122F3L >> rem % 29) & 1) == 0)
- return 0;
- if (((0x5335FL >> rem % 23) & 1) == 0)
- return 0;
- if (((0x30AF3L >> rem % 19) & 1) == 0)
- return 0;
- if (((0x1A317L >> rem % 17) & 1) == 0)
- return 0;
- if (((0x161BL >> rem % 13) & 1) == 0)
- return 0;
- if (((0x23BL >> rem % 11) & 1) == 0)
- return 0;
- if (((0x017L >> rem % 7) & 1) == 0)
- return 0;
- if (((0x13L >> rem % 5) & 1) == 0)
- return 0;
- if (((0x3L >> rem % 3) & 1) == 0)
- return 0;
-#endif
-
- TMP_MARK (marker);
-
- /* For the third and last test, we finally compute the square root,
- to make sure we've really got a perfect square. */
- root_ptr = (mp_ptr) TMP_ALLOC ((usize + 1) / 2 * BYTES_PER_MP_LIMB);
-
- /* Iff mpn_sqrtrem returns zero, the square is perfect. */
- res = ! mpn_sqrtrem (root_ptr, NULL, up, usize);
- TMP_FREE (marker);
- return res;
-}