genode/repos/base/include/util/misc_math.h
Stefan Kalkowski dc36b63acb base: turn align_addr tool into constexpr
Thereby, the tool can be used to calculate static compile-time values.
Ref 
2015-07-01 14:46:17 +02:00

73 lines
1.5 KiB
C++

/*
* \brief Commonly used math functions
* \author Norman Feske
* \date 2006-04-12
*/
/*
* Copyright (C) 2006-2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _INCLUDE__UTIL__MISC_MATH_H_
#define _INCLUDE__UTIL__MISC_MATH_H_
namespace Genode {
template <typename T1, typename T2>
T1 max(T1 v1, T2 v2) { return v1 > v2 ? v1 : v2; }
template <typename T1, typename T2>
T1 min(T1 v1, T2 v2) { return v1 < v2 ? v1 : v2; }
template <typename T>
T abs(T value) { return value >= 0 ? value : -value; }
/**
* Alignment to the power of two
*/
template <typename T>
static constexpr T _align_mask(T align) {
return ~(((T)1 << align) - (T)1); }
template <typename T>
static constexpr T _align_offset(T align) {
return ((T)1 << align) - (T)1; }
template <typename T>
static constexpr T align_addr(T addr, int align) {
return (addr + _align_offset((T)align)) & _align_mask((T)align); }
/**
* LOG2
*
* Scan for most-significant set bit.
*/
template <typename T>
static inline T log2(T value)
{
if (!value) return -1;
for (int i = 8 * sizeof(value) - 1; i >= 0; --i)
if (((T)1 << i) & value) return i;
return -1;
}
/**
* Align value to next machine-word boundary
*/
template <typename T>
inline T align_natural(T value)
{
T mask = sizeof(long) - 1;
return (value + mask) & ~mask;
}
}
#endif /* _INCLUDE__UTIL__MISC_MATH_H_ */