Add test for sizeclass calculations

src/test/func/sizeclass/sizeclass.cc

@@ -0,0 +1,53 @@
+#include <iostream>
+#include <snmalloc.h>
+
+NOINLINE 
+uint8_t size_to_sizeclass(size_t size)
+{
+  return snmalloc::size_to_sizeclass(size);
+}
+
+int main(int, char**)
+{
+  bool failed = false;
+  size_t size_low = 0;
+
+  std::cout << "0 has sizeclass: " << (size_t)snmalloc::size_to_sizeclass(0)
+            << std::endl;
+
+  std::cout << "sizeclass |-> [size_low, size_high] " << std::endl;
+
+  for (uint8_t sz = 0; sz < snmalloc::NUM_SIZECLASSES; sz++)
+  {
+    // Separate printing for small and medium sizeclasses
+    if (sz == snmalloc::NUM_SMALL_CLASSES)
+      std::cout << std::endl;
+
+    size_t size = snmalloc::sizeclass_to_size(sz);
+    std::cout << (size_t)sz << " |-> "
+              << "[" << size_low + 1 << ", " << size << "]" << std::endl;
+
+    if (size < size_low)
+    {
+      std::cout << "Sizeclass " << (size_t)sz << " is " << size
+                << " which is less than " << size_low << std::endl;
+      failed = true;
+    }
+
+    for (size_t i = size_low + 1; i <= size; i++)
+    {
+      if (size_to_sizeclass(i) != sz)
+      {
+        std::cout << "Size " << i << " has sizeclass "
+                  << (size_t)size_to_sizeclass(i)
+                  << " but expected sizeclass " << (size_t)sz << std::endl;
+        failed = true;
+      }
+    }
+
+    size_low = size;
+  }
+
+  if (failed)
+    abort();
+}