diff --git a/include/ircd/simt/math.h b/include/ircd/simt/math.h
new file mode 100644
index 000000000..5bbcacfd0
--- /dev/null
+++ b/include/ircd/simt/math.h
@@ -0,0 +1,20 @@
+// Matrix Construct
+//
+// Copyright (C) Matrix Construct Developers, Authors & Contributors
+// Copyright (C) 2016-2022 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_SIMT_MATH_H
+
+#ifdef __OPENCL_VERSION__
+inline bool
+ircd_math_is_pow2(const uint val)
+{
+	return val > 0 && (val & (val - 1)) == 0;
+}
+#endif
diff --git a/include/ircd/simt/reduce_add.h b/include/ircd/simt/reduce_add.h
index eb2406325..ff7203e36 100644
--- a/include/ircd/simt/reduce_add.h
+++ b/include/ircd/simt/reduce_add.h
@@ -11,14 +11,6 @@
 #pragma once
 #define HAVE_IRCD_SIMT_REDUCE_ADD_H
 
-#ifdef __OPENCL_VERSION__
-inline bool
-ircd_math_is_pow2(const uint val)
-{
-	return val > 0 && (val & (val - 1)) == 0;
-}
-#endif
-
 #ifdef __OPENCL_VERSION__
 /// Sum all elements in the buffer. All threads in the group participate;
 /// result is placed in index [0], the rest of the buffer is trashed.
diff --git a/include/ircd/simt/simt.h b/include/ircd/simt/simt.h
index d9148858e..e86433514 100644
--- a/include/ircd/simt/simt.h
+++ b/include/ircd/simt/simt.h
@@ -14,6 +14,7 @@
 #include "portable.h"
 #include "assert.h"
 #include "cycles.h"
+#include "math.h"
 #include "broadcast.h"
 #include "reduce_add.h"
 #include "reduce_max.h"
diff --git a/include/ircd/simt/sort.h b/include/ircd/simt/sort.h
index d969cbf54..83e5fbf8d 100644
--- a/include/ircd/simt/sort.h
+++ b/include/ircd/simt/sort.h
@@ -66,6 +66,8 @@ ircd_simt_sort_idx16_flldr(__local ushort *const idx,
                            const uint ln,
                            const uint li)
 {
+	assert(ircd_math_is_pow2(ln));
+
 	#pragma clang loop unroll(disable)
 	for(uint up = 1; up < ln; up <<= 1)
 	{