Swap.h

// Copyright (c) 2012- PPSSPP Project / Dolphin Project.

// 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, version 2.0 or later versions.

// 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 2.0 for more details.

// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/

// Official git repository and contact information can be found at
// https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.

#pragma once

#include <cstdlib>

#include "CommonTypes.h"

// Android
#if defined(__ANDROID__)
#include <sys/endian.h>

#if _BYTE_ORDER == _LITTLE_ENDIAN && !defined(COMMON_LITTLE_ENDIAN)
#define COMMON_LITTLE_ENDIAN 1
#elif _BYTE_ORDER == _BIG_ENDIAN && !defined(COMMON_BIG_ENDIAN)
#define COMMON_BIG_ENDIAN 1
#endif

// GCC 4.6+
#elif __GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)

#if __BYTE_ORDER__ && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) && !defined(COMMON_LITTLE_ENDIAN)
#define COMMON_LITTLE_ENDIAN 1
#elif __BYTE_ORDER__ && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) && !defined(COMMON_BIG_ENDIAN)
#define COMMON_BIG_ENDIAN 1
#endif

// LLVM/clang
#elif __clang__

#if __LITTLE_ENDIAN__ && !defined(COMMON_LITTLE_ENDIAN)
#define COMMON_LITTLE_ENDIAN 1
#elif __BIG_ENDIAN__ && !defined(COMMON_BIG_ENDIAN)
#define COMMON_BIG_ENDIAN 1
#endif

// MSVC
#elif defined(_MSC_VER) && !defined(COMMON_BIG_ENDIAN) && !defined(COMMON_LITTLE_ENDIAN)

#define COMMON_LITTLE_ENDIAN 1

#endif

// Worst case, default to little endian.
#if !COMMON_BIG_ENDIAN && !COMMON_LITTLE_ENDIAN
#define COMMON_LITTLE_ENDIAN 1
#endif

#ifdef _MSC_VER
inline unsigned long long bswap64(unsigned long long x) { return _byteswap_uint64(x); }
inline unsigned int bswap32(unsigned int x) { return _byteswap_ulong(x); }
inline unsigned short bswap16(unsigned short x) { return _byteswap_ushort(x); }
#elif defined(__DragonFly__) || defined(__FreeBSD__) || \
      defined(__NetBSD__) || defined(__OpenBSD__)
#include <sys/endian.h>
# ifdef __OpenBSD__
#define bswap16 swap16
#define bswap32 swap32
#define bswap64 swap64
# endif
#else
// TODO: speedup
inline unsigned short bswap16(unsigned short x) { return (x << 8) | (x >> 8); }
inline unsigned int bswap32(unsigned int x) { return (x >> 24) | ((x & 0xFF0000) >> 8) | ((x & 0xFF00) << 8) | (x << 24); }
inline unsigned long long bswap64(unsigned long long x) { return ((unsigned long long)bswap32(x) << 32) | bswap32(x >> 32); }
#endif

inline float bswapf(float f) {
	union {
		float f;
		unsigned int u32;
	} dat1, dat2;

	dat1.f = f;
	dat2.u32 = bswap32(dat1.u32);

	return dat2.f;
}

inline double bswapd(double f) {
	union {
		double f;
		unsigned long long u64;
	} dat1, dat2;

	dat1.f = f;
	dat2.u64 = bswap64(dat1.u64);

	return dat2.f;
}

template <typename T, typename F>
struct swap_struct_t {
	typedef swap_struct_t<T, F> swapped_t;

protected:
	T value;

	static T swap(T v) {
		return F::swap(v);
	}
public:
	T const swap() const {
		return swap(value);
	}
	swap_struct_t() : value((T)0) {}
	swap_struct_t(const T &v): value(swap(v)) {}

	template <typename S>
	swapped_t& operator=(const S &source) {
		value = swap((T)source);
		return *this;
	}

	operator unsigned long() const { return (unsigned long)swap(); }
	operator long() const { return (long)swap(); }	
	operator s8() const { return (s8)swap(); }
	operator u8() const { return (u8)swap(); }
	operator s16() const { return (s16)swap(); }
	operator u16() const { return (u16)swap(); }
	operator s32() const { return (s32)swap(); }
	operator u32() const { return (u32)swap(); }
	operator s64() const { return (s64)swap(); }
	operator u64() const { return (u64)swap(); }
	operator float() const { return (float)swap(); }
	operator double() const { return (double)swap(); }

	// +v
	swapped_t operator +() const {
		return +swap();
	}
	// -v
	swapped_t operator -() const {
		return -swap();
	}

	// v / 5
	swapped_t operator/(const swapped_t &i) const {
		return swap() / i.swap();
	}
	template <typename S>
	swapped_t operator/(const S &i) const {
		return swap() / i;
	}

	// v * 5
	swapped_t operator*(const swapped_t &i) const {
		return swap() * i.swap();
	}
	template <typename S>
	swapped_t operator*(const S &i) const {
		return swap() * i;
	}

	// v + 5
	swapped_t operator+(const swapped_t &i) const {
		return swap() + i.swap();
	}
	template <typename S>
	swapped_t operator+(const S &i) const {
		return swap() + (T)i;
	}
	// v - 5
	swapped_t operator-(const swapped_t &i) const {
		return swap() - i.swap();
	}
	template <typename S>
	swapped_t operator-(const S &i) const {
		return swap() - (T)i;
	}

	// v += 5
	swapped_t& operator+=(const swapped_t &i) {
		value = swap(swap() + i.swap());
		return *this;
	}
	template <typename S>
	swapped_t& operator+=(const S &i) {
		value = swap(swap() + (T)i);
		return *this;
	}
	// v -= 5
	swapped_t& operator-=(const swapped_t &i) {
		value = swap(swap() - i.swap());
		return *this;
	}
	template <typename S>
	swapped_t& operator-=(const S &i) {
		value = swap(swap() - (T)i);
		return *this;
	}

	// ++v
	swapped_t& operator++() {
		value = swap(swap()+1);
		return *this;
	}
	// --v
	swapped_t& operator--()  {
		value = swap(swap()-1);
		return *this;
	}

	// v++
	swapped_t operator++(int) {
		swapped_t old = *this;
		value = swap(swap()+1);
		return old;
	}
	// v--
	swapped_t operator--(int) {
		swapped_t old = *this;
		value = swap(swap()-1);
		return old;
	}
	// Comparaison
	// v == i
	bool operator==(const swapped_t &i) const {
		return swap() == i.swap();
	}
	template <typename S>
	bool operator==(const S &i) const {
		return swap() == i;
	}

	// v != i
	bool operator!=(const swapped_t &i) const {
		return swap() != i.swap();
	}
	template <typename S>
	bool operator!=(const S &i) const {
		return swap() != i;
	}

	// v > i
	bool operator>(const swapped_t &i) const {
		return swap() > i.swap();
	}
	template <typename S>
	bool operator>(const S &i) const {
		return swap() > i;
	}

	// v < i
	bool operator<(const swapped_t &i) const {
		return swap() < i.swap();
	}
	template <typename S>
	bool operator<(const S &i) const {
		return swap() < i;
	}

	// v >= i
	bool operator>=(const swapped_t &i) const {
		return swap() >= i.swap();
	}
	template <typename S>
	bool operator>=(const S &i) const {
		return swap() >= i;
	}

	// v <= i
	bool operator<=(const swapped_t &i) const {
		return swap() <= i.swap();
	}
	template <typename S>
	bool operator<=(const S &i) const {
		return swap() <= i;
	}

	// logical
	swapped_t operator !() const {
		return !swap();
	}
	
	bool operator ||(const swapped_t  & b) const {
		return swap() || b.swap();
	}
	template <typename S>
	bool operator ||(const S & b) const {
		return swap() || b;
	}

	// bitmath
	swapped_t operator ~() const {
		return ~swap();
	}

	swapped_t operator &(const swapped_t &b) const {
		return swap() & b.swap();
	}
	template <typename S>
	swapped_t operator &(const S &b) const {
		return swap() & b;
	}
	swapped_t& operator &=(const swapped_t &b) {
		value = swap(swap() & b.swap());
		return *this;
	}
	template <typename S>
	swapped_t& operator &=(const S b) {
		value = swap(swap() & b);
		return *this;
	}

	swapped_t operator |(const swapped_t &b) const {
		return swap() | b.swap();
	}
	template <typename S>
	swapped_t operator |(const S &b) const {
		return swap() | b;
	}
	swapped_t& operator |=(const swapped_t &b) {
		value = swap(swap() | b.swap());
		return *this;
	}
	template <typename S>
	swapped_t& operator |=(const S &b) {
		value = swap(swap() | b);
		return *this;
	}

	swapped_t operator ^(const swapped_t &b) const {
		return swap() ^ b.swap();
	}
	template <typename S>
	swapped_t operator ^(const S &b) const {
		return swap() ^ b;
	}
	swapped_t& operator ^=(const swapped_t &b) {
		value = swap(swap() ^ b.swap());
		return *this;
	}
	template <typename S>
	swapped_t& operator ^=(const S &b) {
		value = swap(swap() ^ b);
		return *this;
	}

	template <typename S>
	swapped_t operator <<(const S &b) const {
		return swap() << b;
	}
	template <typename S>
	swapped_t& operator <<=(const S &b) const {
		value = swap(swap() << b);
		return *this;
	}

	template <typename S>
	swapped_t operator >>(const S &b) const {
		return swap() >> b;
	}
	template <typename S>
	swapped_t& operator >>=(const S &b) const {
		value = swap(swap() >> b);
		return *this;
	}

	// Member
	/** todo **/


	// Arithmetics
	template <typename S, typename T2, typename F2>
	friend S operator+(const S &p, const swapped_t& v);

	template <typename S, typename T2, typename F2>
	friend S operator-(const S &p, const swapped_t& v);

	template <typename S, typename T2, typename F2>
	friend S operator/(const S &p, const swapped_t& v);

	template <typename S, typename T2, typename F2>
	friend S operator*(const S &p, const swapped_t& v);

	template <typename S, typename T2, typename F2>
	friend S operator%(const S &p, const swapped_t& v);

	// Arithmetics + assignements
	template <typename S, typename T2, typename F2>
	friend S operator+=(const S &p, const swapped_t& v);

	template <typename S, typename T2, typename F2>
	friend S operator-=(const S &p, const swapped_t& v);

	// Bitmath
	template <typename S, typename T2, typename F2>
	friend S operator&(const S &p, const swapped_t& v);

	// Comparison
	template <typename S, typename T2, typename F2>
	friend bool operator<(const S &p, const swapped_t& v);

	template <typename S, typename T2, typename F2>
	friend bool operator>(const S &p, const swapped_t& v);

	template <typename S, typename T2, typename F2>
	friend bool operator<=(const S &p, const swapped_t& v);

	template <typename S, typename T2, typename F2>
	friend bool operator>=(const S &p, const swapped_t& v);

	template <typename S, typename T2, typename F2>
	friend bool operator!=(const S &p, const swapped_t& v);

	template <typename S, typename T2, typename F2>
	friend bool operator==(const S &p, const swapped_t& v);
};


// Arithmetics
template <typename S, typename T, typename F>
S operator+(const S &i, const swap_struct_t<T, F>& v) {
	return i + v.swap();
}

template <typename S, typename T, typename F>
S operator-(const S &i, const swap_struct_t<T, F>& v) {
	return i - v.swap();
}

template <typename S, typename T, typename F>
S operator/(const S &i, const swap_struct_t<T, F>& v) {
	return i / v.swap();
}

template <typename S, typename T, typename F>
S operator*(const S &i, const swap_struct_t<T, F>& v) {
	return i * v.swap();
}

template <typename S, typename T, typename F>
S operator%(const S &i, const swap_struct_t<T, F>& v) {
	return i % v.swap();
}

// Arithmetics + assignements
template <typename S, typename T, typename F>
S &operator+=(S &i, const swap_struct_t<T, F>& v) {
	i += v.swap();
	return i;
}

template <typename S, typename T, typename F>
S &operator-=(S &i, const swap_struct_t<T, F>& v) {
	i -= v.swap();
	return i;
}

// Logical
template <typename S, typename T, typename F>
S operator&(const S &i, const swap_struct_t<T, F>& v) {
	return i & v.swap();
}

template <typename S, typename T, typename F>
S operator&(const swap_struct_t<T, F>& v, const S &i) {
	return (S)(v.swap() & i);
}


// Comparaison
template <typename S, typename T, typename F>
bool operator<(const S &p, const swap_struct_t<T, F>& v) {
	return p < v.swap();
}
template <typename S, typename T, typename F>
bool operator>(const S &p, const swap_struct_t<T, F>& v) {
	return p > v.swap();
}
template <typename S, typename T, typename F>
bool operator<=(const S &p, const swap_struct_t<T, F>& v) {
	return p <= v.swap();
}
template <typename S, typename T, typename F>
bool operator>=(const S &p, const swap_struct_t<T, F>& v) {
	return p >= v.swap();
}
template <typename S, typename T, typename F>
bool operator!=(const S &p, const swap_struct_t<T, F>& v) {
	return p != v.swap();
}
template <typename S, typename T, typename F>
bool operator==(const S &p, const swap_struct_t<T, F>& v) {
	return p == v.swap();
}

template <typename T>
struct swap_64_t {
	static T swap(T x) {
		return (T)bswap64(*(u64 *)&x);
	}
};

template <typename T>
struct swap_32_t {
	static T swap(T x) {
		return (T)bswap32(*(u32 *)&x);
	}
};

template <typename T>
struct swap_16_t {
	static T swap(T x) {
		return (T)bswap16(*(u16 *)&x);
	}
};

template <typename T>
struct swap_float_t {
	static T swap(T x) {
		return (T)bswapf(*(float *)&x);
	}
};

template <typename T>
struct swap_double_t {
	static T swap(T x) {
		return (T)bswapd(*(double *)&x);
	}
};

#if COMMON_LITTLE_ENDIAN
typedef u32 u32_le;
typedef u16 u16_le;
typedef u64 u64_le;

typedef s32 s32_le;
typedef s16 s16_le;
typedef s64 s64_le;

typedef float float_le;
typedef double double_le;

typedef swap_struct_t<u64, swap_64_t<u64>> u64_be;
typedef swap_struct_t<s64, swap_64_t<s64>> s64_be;

typedef swap_struct_t<u32, swap_32_t<u32>> u32_be;
typedef swap_struct_t<s32, swap_32_t<s32>> s32_be;

typedef swap_struct_t<u16, swap_16_t<u16>> u16_be;
typedef swap_struct_t<s16, swap_16_t<s16>> s16_be;

typedef swap_struct_t<float, swap_float_t<float> > float_be;
typedef swap_struct_t<double, swap_double_t<double> > double_be;
#else

typedef swap_struct_t<u64, swap_64_t<u64>> u64_le;
typedef swap_struct_t<s64, swap_64_t<s64>> s64_le;

typedef swap_struct_t<u32, swap_32_t<u32>> u32_le;
typedef swap_struct_t<s32, swap_32_t<s32>> s32_le;

typedef swap_struct_t<u16, swap_16_t<u16>> u16_le;
typedef swap_struct_t<s16, swap_16_t<s16>> s16_le;

typedef swap_struct_t<float, swap_float_t<float> > float_le;
typedef swap_struct_t<double, swap_double_t<double> > double_le;

typedef u32 u32_be;
typedef u16 u16_be;
typedef u64 u64_be;

typedef s32 s32_be;
typedef s16 s16_be;
typedef s64 s64_be;

typedef float float_be;
typedef double double_be;
#endif