bits.h

Go to the documentation of this file.

// Copyright Microsoft and CHERIoT Contributors.
// SPDX-License-Identifier: MIT
 
/**
 * @file
 * \brief Bit manipulation utilities
 */
 
#pragma once
 
#include <concepts>
 
namespace ds::bits
{
 
    /**
     * Isolate the least significant set bit.  That is, clear all bits to the
     * left of the first set bit.
     */
    template<typename T>
    __always_inline T isolate_least(T v)
    {
        return v & -v;
    }
 
    /**
     * Mask of all bits above and including the least significant set bit.
     */
    template<typename T>
    __always_inline T above_or_least(T v)
    {
        return v | -v;
    }
 
    /**
     * Mask of all bits above the least significant set bit.
     */
    template<typename T>
    __always_inline T above_least(T v)
    {
        return above_or_least(v << 1);
    }
 
} // namespace ds::bits