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/*
Copyright (C) 2020 Fredrik Johansson
This file is part of FLINT.
FLINT is free software: you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License (LGPL) as published
by the Free Software Foundation; either version 3 of the License, or
(at your option) any later version. See <https://www.gnu.org/licenses/>.
*/
#include "ca.h"
void
ca_sgn(ca_t res, const ca_t x, ca_ctx_t ctx)
{
if (CA_IS_SPECIAL(x))
{
if (CA_IS_SIGNED_INF(x))
{
ca_set(res, x, ctx);
res->field &= ~CA_INF;
}
else if (CA_IS_UNKNOWN(x))
{
ca_unknown(res, ctx);
}
else
{
ca_undefined(res, ctx);
}
return;
}
else if (CA_IS_QQ(x, ctx))
{
ca_set_si(res, fmpz_sgn(fmpq_numref(CA_FMPQ(x))), ctx);
}
else
{
qqbar_t t;
qqbar_init(t);
if (ca_get_qqbar(t, x, ctx))
{
qqbar_sgn(t, t);
if (qqbar_within_limits(t, ctx->options[CA_OPT_QQBAR_DEG_LIMIT], 0))
ca_set_qqbar(res, t, ctx);
else
_ca_function_fx(res, CA_Sign, x, ctx);
}
else
{
_ca_function_fx(res, CA_Sign, x, ctx);
}
qqbar_clear(t);
}
}