utility.hpp

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/* Copyright 2025 René Widera
 * SPDX-License-Identifier: MPL-2.0
 */
 
#pragma once
 
#include <cstdint>
#include <type_traits>
 
namespace alpaka::internal
{
 
    /** Convert a bool value into a mask type for SIMD
     *
     * @return
     */
    template<typename T>
    constexpr auto valueMaskCast(bool condition)
    {
        return condition;
    }
 
    /** specialization for 4 and 8 byte types
     *
     * @return value type where all bits are 1 if condition is true, else all bit are zero
     */
    template<typename T>
    requires(sizeof(T) == 4u || sizeof(T) == 8u)
    constexpr auto valueMaskCast(bool condition)
    {
        using ValueMaskType = std::conditional_t<sizeof(T) == 4u, uint32_t, uint64_t>;
        // if condition is true value will be 1 and negated to set all bits
        return -static_cast<ValueMaskType>(condition);
    }
} // namespace alpaka::internal