construct/include/ircd/simd/traits.h

// The Construct
//
// Copyright (C) The Construct Developers, Authors & Contributors
// Copyright (C) 2016-2020 Jason Volk <jason@zemos.net>
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice is present in all copies. The
// full license for this software is available in the LICENSE file.

#pragma once
#define HAVE_IRCD_SIMD_TRAITS_H

namespace ircd::simd
{
	template<class T>
	using lane_type = typename std::remove_reference<decltype(T{}[0])>::type;

	template<class T>
	constexpr size_t sizeof_lane();

	template<class T>
	constexpr size_t lanes();

	// lane number convenience constants
	extern const u8x64    u8x64_lane_id;
	extern const u8x32    u8x32_lane_id;
	extern const u16x32  u16x32_lane_id;
	extern const u8x16    u8x16_lane_id;
	extern const u16x16  u16x16_lane_id;
	extern const u32x16  u32x16_lane_id;
	extern const u16x8    u16x8_lane_id;
	extern const u32x8    u32x8_lane_id;
	extern const u64x8    u64x8_lane_id;
	extern const u32x4    u32x4_lane_id;
	extern const u64x4    u64x4_lane_id;
	extern const u64x2    u64x2_lane_id;
	extern const u128x1  u128x1_lane_id;
	extern const u256x1  u256x1_lane_id;
	extern const u512x1  u512x1_lane_id;

	constexpr auto alignment
	{
		support::avx512f?  64:
		support::avx?      32:
		support::sse?      16:
		                    8
	};
}

/// Get number of lanes for vector type (the number after the x in the
/// type name).
template<class T>
[[gnu::always_inline]]
inline constexpr size_t
ircd::simd::lanes()
{
	constexpr size_t ret
	{
		sizeof(T) / sizeof_lane<T>()
	};

	static_assert
	(
		sizeof(T) <= 64 && ret <= 64 && ret > 0
	);

	return ret;
}

/// Get the size of each lane; i.e the size of one integral element.
template<class T>
[[gnu::always_inline]]
inline constexpr size_t
ircd::simd::sizeof_lane()
{
	constexpr size_t ret
	{
		sizeof(T{}[0])
	};

	static_assert
	(
		ret >= 1 && ret <= 64
	);

	return ret;
}

template<>
constexpr size_t
ircd::simd::sizeof_lane<ircd::u128x1>()
{
	return 16;
};

template<>
constexpr size_t
ircd::simd::sizeof_lane<ircd::f128x1>()
{
	return 16;
};

template<>
constexpr size_t
ircd::simd::sizeof_lane<ircd::d128x1>()
{
	return 16;
};

template<>
constexpr size_t
ircd::simd::sizeof_lane<ircd::u256x1>()
{
	return 32;
};

template<>
constexpr size_t
ircd::simd::sizeof_lane<ircd::f256x1>()
{
	return 32;
};

template<>
constexpr size_t
ircd::simd::sizeof_lane<ircd::d256x1>()
{
	return 32;
};

template<>
constexpr size_t
ircd::simd::sizeof_lane<ircd::u512x1>()
{
	return 64;
};

template<>
constexpr size_t
ircd::simd::sizeof_lane<ircd::f512x1>()
{
	return 64;
};

template<>
constexpr size_t
ircd::simd::sizeof_lane<ircd::d512x1>()
{
	return 64;
};