10c567daee
This function simplifies the sanity checking of values that are expected to be aligned, e.g., data offsets within packet streams.
77 lines
1.7 KiB
C++
77 lines
1.7 KiB
C++
/*
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* \brief Commonly used math functions
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* \author Norman Feske
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* \date 2006-04-12
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*/
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/*
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* Copyright (C) 2006-2017 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__UTIL__MISC_MATH_H_
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#define _INCLUDE__UTIL__MISC_MATH_H_
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namespace Genode {
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template <typename T1, typename T2>
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static constexpr T1 max(T1 v1, T2 v2) { return v1 > v2 ? v1 : v2; }
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template <typename T1, typename T2>
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static constexpr T1 min(T1 v1, T2 v2) { return v1 < v2 ? v1 : v2; }
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template <typename T>
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static constexpr T abs(T value) { return value >= 0 ? value : -value; }
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/*
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* Alignment to the power of two
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*/
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template <typename T>
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static constexpr T _align_mask(T align) {
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return ~(((T)1 << align) - (T)1); }
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template <typename T>
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static constexpr T _align_offset(T align) {
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return ((T)1 << align) - (T)1; }
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template <typename T>
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static constexpr T align_addr(T addr, int align) {
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return (addr + _align_offset((T)align)) & _align_mask((T)align); }
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template <typename T>
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static constexpr bool aligned(T value, unsigned align_log2) {
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return (_align_offset(align_log2) & value) == 0; }
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/**
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* LOG2
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*
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* Scan for most-significant set bit.
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*/
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template <typename T>
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static inline T log2(T value)
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{
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if (!value) return -1;
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for (int i = 8 * sizeof(value) - 1; i >= 0; --i)
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if (((T)1 << i) & value) return i;
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return -1;
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}
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/**
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* Align value to next machine-word boundary
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*/
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template <typename T>
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inline T align_natural(T value)
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{
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T mask = sizeof(long) - 1;
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return (value + mask) & ~mask;
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}
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}
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#endif /* _INCLUDE__UTIL__MISC_MATH_H_ */
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