1*39f28e1eSmrg /* trootofunity -- test file for mpc_rootofunity.
2*39f28e1eSmrg
3*39f28e1eSmrg Copyright (C) 2012, 2016 INRIA
4*39f28e1eSmrg
5*39f28e1eSmrg This file is part of GNU MPC.
6*39f28e1eSmrg
7*39f28e1eSmrg GNU MPC is free software; you can redistribute it and/or modify it under
8*39f28e1eSmrg the terms of the GNU Lesser General Public License as published by the
9*39f28e1eSmrg Free Software Foundation; either version 3 of the License, or (at your
10*39f28e1eSmrg option) any later version.
11*39f28e1eSmrg
12*39f28e1eSmrg GNU MPC is distributed in the hope that it will be useful, but WITHOUT ANY
13*39f28e1eSmrg WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
14*39f28e1eSmrg FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
15*39f28e1eSmrg more details.
16*39f28e1eSmrg
17*39f28e1eSmrg You should have received a copy of the GNU Lesser General Public License
18*39f28e1eSmrg along with this program. If not, see http://www.gnu.org/licenses/ .
19*39f28e1eSmrg */
20*39f28e1eSmrg
21*39f28e1eSmrg #include "mpc-tests.h"
22*39f28e1eSmrg
23*39f28e1eSmrg #define MPC_FUNCTION_CALL \
24*39f28e1eSmrg P[0].mpc_inex = mpc_rootofunity (P[1].mpc, P[2].ui, P[3].ui, P[4].mpc_rnd)
25*39f28e1eSmrg
26*39f28e1eSmrg #include "data_check.tpl"
27*39f28e1eSmrg #include "tgeneric.tpl"
28*39f28e1eSmrg
29*39f28e1eSmrg static void
check(unsigned long int n)30*39f28e1eSmrg check (unsigned long int n)
31*39f28e1eSmrg /* checks whether zeta_n^n = 1, which is somewhat dangerous in floating
32*39f28e1eSmrg point */
33*39f28e1eSmrg {
34*39f28e1eSmrg mpc_t z, zero;
35*39f28e1eSmrg mpfr_prec_t prec;
36*39f28e1eSmrg
37*39f28e1eSmrg mpc_init2 (z, 2);
38*39f28e1eSmrg mpc_init2 (zero, 2);
39*39f28e1eSmrg
40*39f28e1eSmrg for (prec = 2*n; prec < 1000; prec = (mpfr_prec_t) (prec * 1.1 + 1)) {
41*39f28e1eSmrg mpc_set_prec (z, prec);
42*39f28e1eSmrg mpc_set_prec (zero, prec);
43*39f28e1eSmrg
44*39f28e1eSmrg mpc_rootofunity (z, n, 1, MPC_RNDNN);
45*39f28e1eSmrg mpc_pow_ui (zero, z, n, MPC_RNDNN);
46*39f28e1eSmrg mpc_sub_ui (zero, zero, 1u, MPC_RNDNN);
47*39f28e1eSmrg if (MPC_MAX (mpfr_get_exp (mpc_realref (zero)), mpfr_get_exp (mpc_imagref (zero)))
48*39f28e1eSmrg > - ((long int) prec - (long int) n)) {
49*39f28e1eSmrg fprintf (stderr, "rootofunity too imprecise for n=%lu\n", n);
50*39f28e1eSmrg MPC_OUT (z);
51*39f28e1eSmrg MPC_OUT (zero);
52*39f28e1eSmrg exit (1);
53*39f28e1eSmrg }
54*39f28e1eSmrg }
55*39f28e1eSmrg
56*39f28e1eSmrg mpc_clear (z);
57*39f28e1eSmrg mpc_clear (zero);
58*39f28e1eSmrg }
59*39f28e1eSmrg
60*39f28e1eSmrg
61*39f28e1eSmrg int
main(void)62*39f28e1eSmrg main (void)
63*39f28e1eSmrg {
64*39f28e1eSmrg unsigned long int n;
65*39f28e1eSmrg
66*39f28e1eSmrg for (n = 1; n < 10000; n += 10)
67*39f28e1eSmrg check (n);
68*39f28e1eSmrg
69*39f28e1eSmrg test_start ();
70*39f28e1eSmrg
71*39f28e1eSmrg data_check_template ("rootofunity.dsc", "rootofunity.dat");
72*39f28e1eSmrg
73*39f28e1eSmrg /* Avoid checking roots of unity of high order at very low precision,
74*39f28e1eSmrg so start only at 20. */
75*39f28e1eSmrg tgeneric_template ("rootofunity.dsc", 20, 512, 7, 256);
76*39f28e1eSmrg
77*39f28e1eSmrg test_end ();
78*39f28e1eSmrg
79*39f28e1eSmrg return 0;
80*39f28e1eSmrg }
81