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/* Copyright (C) 2009 Wildfire Games.
* This file is part of 0 A.D.
*
* 0 A.D. is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* 0 A.D. 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with 0 A.D. If not, see <http://www.gnu.org/licenses/>.
*/
#include "lib/self_test.h"
#include "maths/Sqrt.h"
#include <boost/random/mersenne_twister.hpp>
#include <boost/random/uniform_int.hpp>
#include <boost/random/variate_generator.hpp>
class TestSqrt : public CxxTest::TestSuite
{
public:
void t(u32 n)
{
TS_ASSERT_EQUALS(isqrt64((u64)n*(u64)n), n);
}
void s(u64 n, u64 exp)
{
TS_ASSERT_EQUALS((u64)isqrt64(n), exp);
}
void test_sqrt()
{
t(0);
t(1);
t(2);
t(255);
t(256);
t(257);
t(65535);
t(65536);
t(65537);
t(16777215);
t(16777216);
t(16777217);
t(2147483647);
t(2147483648u);
t(2147483649u);
t(4294967295u);
s(2, 1);
s(3, 1);
s(4, 2);
s(255, 15);
s(256, 16);
s(257, 16);
s(65535, 255);
s(65536, 256);
s(65537, 256);
s(999999, 999);
s(1000000, 1000);
s(1000001, 1000);
s((u64)-1, 4294967295u);
}
void test_random()
{
// Test with some random u64s, to make sure the output agrees with floor(sqrt(double))
// (TODO: This might be making non-portable assumptions about sqrt(double))
boost::mt19937 rng;
boost::uniform_int<u64> ints(0, (u64)-1);
boost::variate_generator<boost::mt19937&, boost::uniform_int<u64> > gen(rng, ints);
for (size_t i = 0; i < 1024; ++i)
{
u64 n = gen();
s(n, (u64)sqrt((double)n));
}
}
};
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