source: src/AST/Bitfield.hpp @ 809e058

//
// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// Bitfield.hpp --
//
// Author           : Aaron B. Moss
// Created On       : Thu May 9 10:00:00 2019
// Last Modified By : Andrew Beach
// Last Modified On : Wed Jun 5 10:00:00 2019
// Update Count     : 2
//

#pragma once

#include <strings.h>   // for ffs
#include <type_traits> // for is_unsigned

/// Make a type a bitfield.
/// Include in type definition to add operators. Used to simulate inheritance because union
/// does not allow it. Requires type to have `unsigned val` field
/// @param BFType  Name of containing type
template<typename T>
struct bitfield : public T {
        using T::val;
        using val_t = decltype(val);
        static_assert(sizeof(T) == sizeof(unsigned int), "Type has incorrect size");
        static_assert(std::is_unsigned<val_t>::value, "Bitfield val field is not unsigned.");

        constexpr bitfield() : T( 0 ) {}
        constexpr bitfield( val_t v ) : T( v ) {}

        bool operator[]( val_t i ) const { return val & (1 << i); }
        bool any() const { return val != 0; }
        void reset() { val = 0; }
        int ffs() { return ::ffs( val ) - 1; }

        bitfield operator&=( bitfield other ) {
                val &= other.val; return *this;
        }
        bitfield operator&( bitfield other ) const {
                bitfield q = other;
                q &= *this;
                return q;
        }
        bitfield operator|=( bitfield other ) {
                val |= other.val; return *this;
        }
        bitfield operator|( bitfield other ) const {
                bitfield q = other;
                q |= *this;
                return q;
        }
        bitfield operator-=( bitfield other ) {
                val &= ~other.val; return *this;
        }
};

template<typename T>
inline bool operator== ( const bitfield<T> & a, const bitfield<T> & b ) {
        return a.val == b.val;
}

template<typename T>
inline bool operator!= ( const bitfield<T> & a, const bitfield<T> & b ) {
        return !(a == b);
}

// Local Variables: //
// tab-width: 4 //
// mode: c++ //
// compile-command: "make install" //
// End: //