Method bcm_decoder

src/core/bcm.cpp:148–155

	counter_t<6> counter_2[2][256][17];

	explicit bcm_decoder(std::span<const uint8_t> input_) : input(input_) {
		bcm_init_counter_2(counter_2);
#pragma unroll
		for (uint32_t i = 0; i < 4; ++i) {
			code = (code << 8u) + input[i];
		}
		input = input.subspan(4);
	}

	template <uint32_t P_LOG> uint32_t decode_bit(const uint32_t p, uint32_t& in_idx) {
		const auto mid = uint32_t(low + ((uint64_t(high - low) * p) >> P_LOG));