added insertion sort and regression test

tests/sort_regression_test.cc

@@ -0,0 +1,44 @@
+/*
+Regression Test for the SIMD wrappers sort
+
+Copyright 2024 Ahmet Inan <inan@aicodix.de>
+*/
+
+#include <random>
+#include <cassert>
+#include <iostream>
+#include <algorithm>
+#include <functional>
+#include "simd.hh"
+#include "sort.hh"
+
+int main()
+{
+	const int WIDTH = 32;
+	typedef int32_t TYPE;
+	typedef SIMD<TYPE, WIDTH>::uint_type UINT;
+	std::random_device rd;
+	typedef std::default_random_engine generator;
+	typedef std::uniform_int_distribution<int> distribution;
+	auto rand = std::bind(distribution(0, WIDTH), generator(rd()));
+	for (int loop = 0; loop < 1000000; ++loop) {
+		SIMD<TYPE, WIDTH> a, b, c;
+		for (int i = 0; i < WIDTH; ++i)
+			a.v[i] = rand();
+		b = vsort(a);
+		c = a;
+		std::sort(c.v, c.v+WIDTH);
+		for (int i = 0; i < WIDTH; ++i)
+			assert(b.v[i] == c.v[i]);
+		SIMD<UINT, WIDTH> d, e;
+		d = vorder(a);
+		for (int i = 0; i < WIDTH; ++i)
+			e.v[i] = i;
+		std::stable_sort(e.v, e.v+WIDTH, [a](int i, int j){ return a.v[i] < a.v[j]; });
+		for (int i = 0; i < WIDTH; ++i)
+			assert(d.v[i] == e.v[i]);
+	}
+	std::cerr << "Sort regression test passed!" << std::endl;
+	return 0;
+}
+