BigFloat.h

#pragma once
#include <stdint.h>
#include <string>
#include <memory>

#define YCL_BIGFLOAT_EXTRA_PRECISION    2

class BigFloat {
public:
	BigFloat(BigFloat&& x);
	BigFloat(const BigFloat& x);
	BigFloat& operator=(BigFloat&& x);
	BigFloat& operator=(const BigFloat& x);

	BigFloat();
	BigFloat(uint32_t x, bool sign = true);

	std::string to_string_dec(size_t digits = 0) const;
	std::string to_string_hex(size_t digits = 0) const;
	size_t get_precision() const { return L; }
	int64_t get_exponent() const { return exp; }
	uint32_t word_at(int64_t mag) const;

	void negate();
	BigFloat mul(uint32_t x) const;
	BigFloat add(const BigFloat& x, size_t p = 0) const;
	BigFloat sub(const BigFloat& x, size_t p = 0) const;
	BigFloat mul(const BigFloat& x, size_t p = 0, int threads=1) const;
	BigFloat rcp(size_t p, int threads=1) const;
	BigFloat div(const BigFloat& x, size_t p, int threads=1) const;

private:
	bool sign;      //  true = positive or zero, false = negative
	int64_t exp;    //  Exponent
	size_t L;       //  Length
	std::unique_ptr<uint32_t[]> T;

	//  Internal helpers
	int ucmp(const BigFloat& x) const;
	BigFloat uadd(const BigFloat& x, size_t p) const;
	BigFloat usub(const BigFloat& x, size_t p) const;

	friend BigFloat invsqrt(uint32_t x, size_t p, int threads);
};

BigFloat invsqrt(uint32_t x, size_t p, int threads=1);