42 lines
935 B
C++
42 lines
935 B
C++
/*
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* \brief Square root of integer values
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* \date 2010-09-27
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* \author Norman Feske
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*/
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/*
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* Copyright (C) 2010-2017 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU Affero General Public License version 3.
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*/
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#ifndef _INCLUDE__NANO3D__SQRT_H_
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#define _INCLUDE__NANO3D__SQRT_H_
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namespace Nano3d {
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/**
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* Calculate square root of an integer value
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*/
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template <typename T>
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T sqrt(T value)
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{
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/*
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* Calculate square root using nested intervalls. The range of values
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* is log(x) with x being the maximum value of type T. We narrow the
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* result bit by bit starting with the most significant bit.
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*/
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T result = 0;
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for (T i = sizeof(T)*8 / 2; i > 0; i--) {
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T const bit = i - 1;
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T const test = result + (1 << bit);
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if (test*test <= value)
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result = test;
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}
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return result;
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}
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}
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#endif /* _INCLUDE__NANO3D__SQRT_H_ */
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