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/*
* Copyright (c) 2020 Daniel R. Carvalho
* Copyright (c) 2008 The Hewlett-Packard Development Company
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef __BASE_FLAGS_HH__
#define __BASE_FLAGS_HH__
#include <type_traits>
namespace gem5
{
/**
* Wrapper that groups a few flag bits under the same undelying container.
*
* @tparam T The type of the underlying container. Must be an unsigned integer.
*/
template <typename T>
class Flags
{
private:
static_assert(std::is_unsigned<T>::value, "Flag type must be unsigned");
/** The undelying container of the flags' bits. */
T _flags;
public:
typedef T Type;
/**
* @ingroup api_flags
* @{
*/
/**
* Initialize flags with a given value. If no value is provided, the
* flag bits are initialized cleared.
*
* @param flags The value to initialize the flags with.
*/
Flags(Type flags=0) : _flags(flags) {}
operator const Type() const { return _flags; }
const Flags<T> &
operator=(T flags)
{
_flags = flags;
return *this;
}
/**
* Verifies whether any bit matching the given mask is set.
*
* @param mask The mask containing the bits to verify.
* @return True if any matching bit is set; false otherwise.
*/
bool isSet(Type mask) const { return (_flags & mask); }
/**
* Verifies whether no bits matching the given mask are set.
*
* @param mask The mask containing the bits to verify.
* @return True if matching bits are set; false otherwise.
*/
bool allSet(Type mask) const { return (_flags & mask) == mask; }
/**
* Verifies whether no bits matching the given mask are set.
*
* @param mask The mask containing the bits to verify.
* @return True if matching bits are cleared; false otherwise.
*/
bool noneSet(Type mask) const { return (_flags & mask) == 0; }
/** Clear all flag's bits. */
void clear() { _flags = 0; }
/**
* Clear all flag's bits matching the given mask.
*
* @param mask The mask containing the bits to be cleared.
*/
void clear(Type mask) { _flags &= ~mask; }
/**
* Set all flag's bits matching the given mask.
*
* @param mask The mask containing the bits to be set.
*/
void set(Type mask) { _flags |= mask; }
/**
* Conditionally set or clear some bits of the flag, given a mask.
*
* @param mask The mask containing the bits to be modified.
* @param condition If true, set masked bits; otherwise, clear them.
*/
void
set(Type mask, bool condition)
{
condition ? set(mask) : clear(mask);
}
/**
* Replace the contents of the bits matching the mask with the
* corresponding bits in the provided flags.
*
* This is equivalent to:
* flags.clear(mask); flags.set(flags & mask);
*
* @param flags Flags to extract new bits from.
* @param mask Mask used to determine which bits are replaced.
*/
void
replace(Type flags, Type mask)
{
_flags = (_flags & ~mask) | (flags & mask);
}
/** @} */ // end of api_flags
};
} // namespace gem5
#endif // __BASE_FLAGS_HH__