ircd::simd: Add horizontal adder template.

include/ircd/simd/hadd.h

@@ -0,0 +1,114 @@
+// 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_HADD_H
+
+// Horizontal add
+namespace ircd::simd
+{
+	template<class T,
+	         class R = T>
+	typename std::enable_if<simd::lanes<T>() == 2, R>::type
+	hadd(const T, const T) noexcept;
+
+	template<class T,
+	         class R = T>
+	typename std::enable_if<simd::lanes<T>() == 4, R>::type
+	hadd(const T, const T) noexcept;
+
+	template<class T,
+	         class R = T>
+	typename std::enable_if<simd::lanes<T>() == 8, R>::type
+	hadd(const T, const T) noexcept;
+
+	template<class T,
+	         class R = T>
+	typename std::enable_if<simd::lanes<T>() == 16, R>::type
+	hadd(const T, const T) noexcept;
+}
+
+template<class T,
+         class R>
+inline typename std::enable_if<ircd::simd::lanes<T>() == 16, R>::type
+ircd::simd::hadd(const T a,
+                 const T b)
+noexcept
+{
+	return R
+	{
+		a[0x01] + a[0x00],
+		a[0x03] + a[0x02],
+		a[0x05] + a[0x04],
+		a[0x07] + a[0x06],
+		b[0x01] + b[0x00],
+		b[0x03] + b[0x02],
+		b[0x05] + b[0x04],
+		b[0x07] + b[0x06],
+		a[0x09] + a[0x08],
+		a[0x0b] + a[0x0a],
+		a[0x0d] + a[0x0c],
+		a[0x0f] + a[0x0e],
+		b[0x09] + b[0x08],
+		b[0x0b] + b[0x0a],
+		b[0x0d] + b[0x0c],
+		b[0x0f] + b[0x0e],
+	};
+}
+
+template<class T,
+         class R>
+inline typename std::enable_if<ircd::simd::lanes<T>() == 8, R>::type
+ircd::simd::hadd(const T a,
+                 const T b)
+noexcept
+{
+	return R
+	{
+		a[0x01] + a[0x00],
+		a[0x03] + a[0x02],
+		b[0x01] + b[0x00],
+		b[0x03] + b[0x02],
+		a[0x05] + a[0x04],
+		a[0x07] + a[0x06],
+		b[0x05] + b[0x04],
+		b[0x07] + b[0x06],
+	};
+}
+
+template<class T,
+         class R>
+inline typename std::enable_if<ircd::simd::lanes<T>() == 4, R>::type
+ircd::simd::hadd(const T a,
+                 const T b)
+noexcept
+{
+	return R
+	{
+		a[0x01] + a[0x00],
+		a[0x03] + a[0x02],
+		b[0x01] + b[0x00],
+		b[0x03] + b[0x02],
+	};
+}
+
+template<class T,
+         class R>
+inline typename std::enable_if<ircd::simd::lanes<T>() == 2, R>::type
+ircd::simd::hadd(const T a,
+                 const T b)
+noexcept
+{
+	return R
+	{
+		a[0x01] + a[0x00],
+		b[0x01] + b[0x00],
+	};
+}

include/ircd/simd/reduce.h

@@ -13,7 +13,7 @@
 
 namespace ircd::simd
 {
-	/// Perform a horizontal operation among lanes. The operation is specified
+	/// Perform a horizontal left-reduce among lanes. The operation is given
 	/// by the caller who supplies a functor template like `std::bit_or` or
 	/// `std::plus` etc. The result resides in lane[0] of the return vector
 	/// while all other lanes of the return vector are undefined/junk as far

include/ircd/simd/simd.h

@@ -32,6 +32,7 @@
 #include "lzcnt.h"
 #include "tzcnt.h"
 #include "reduce.h"
+#include "hadd.h"
 #include "any.h"
 #include "all.h"
 #include "stream.h"