bits.h

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// =====================================================================================================================
//  fennec, a free and open source game engine
//  Copyright © 2025  Medusa Slockbower
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <https://www.gnu.org/licenses/>.
// =====================================================================================================================
 
 
#ifndef FENNEC_LANG_BITS_H
#define FENNEC_LANG_BITS_H
 
 
#include <fennec/lang/intrinsics.h>
#include <fennec/memory/common.h>
#include <fennec/lang/detail/_bits.h>
 
namespace fennec
{
 
template<typename ToT, typename FromT> requires(sizeof(ToT) == sizeof(FromT))
constexpr ToT bit_cast(const FromT& from) {
    if constexpr(FENNEC_HAS_BUILTIN_BIT_CAST) {
        return FENNEC_BUILTIN_BIT_CAST(ToT, from);
    } else {
        ToT to;
        fennec::memcpy(&to, &from, sizeof(ToT));
        return to;
    }
}
 
 
 
 
 
constexpr void* bit_and(void* arr, const void* mask, size_t n) {
    if (arr == mask) {
        return arr;
    }
 
    uint8_t*       d = static_cast<uint8_t*>(arr);
    const uint8_t* s = static_cast<const uint8_t*>(mask);
 
    while (n > 0) {
        const size_t step = detail::_bit_and(d, s, n);
        d += step; s += step; n -= step;
    }
 
    return arr;
}
 
constexpr void* bit_and_s(void* arr, size_t n0, const void* mask, size_t n1) {
    return bit_and(arr, mask, n0 < n1 ? n0 : n1);
}
 
 
 
 
 
constexpr void* bit_or(void* arr, const void* mask, size_t n) {
    if (arr == mask) {
        return arr;
    }
 
    uint8_t*       d = static_cast<uint8_t*>(arr);
    const uint8_t* s = static_cast<const uint8_t*>(mask);
    while (n > 0)
    {
        const size_t step = detail::_bit_or(d, s, n);
        d += step; s += step; n -= step;
    }
 
    return arr;
}
 
constexpr void* bit_or_s(void* arr, size_t n0, const void* mask, size_t n1) {
    return bit_or(arr, mask, n0 < n1 ? n0 : n1);
}
 
 
 
 
 
constexpr void* bit_xor(void* arr, const void* mask, size_t n) {
    if (arr == mask) {
        return arr;
    }
 
    uint8_t*       d = static_cast<uint8_t*>(arr);
    const uint8_t* s = static_cast<const uint8_t*>(mask);
    while (n > 0) {
        const size_t step = detail::_bit_xor(d, s, n);
        d += step; s += step; n -= step;
    }
 
    return arr;
}
 
constexpr void* bit_xor_s(void* arr, size_t n0, const void* mask, size_t n1) {
    return bit_xor(arr, mask, n0 < n1 ? n0 : n1);
}
 
}
 
#endif // FENNEC_LANG_BITS_H