1 files changed, 65 insertions, 0 deletions
diff --git a/src/zencore/intmath.cpp b/src/zencore/intmath.cpp
new file mode 100644
index 000000000..5a686dc8e
--- /dev/null
+++ b/src/zencore/intmath.cpp
@@ -0,0 +1,65 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#include <zencore/endian.h>
+#include <zencore/intmath.h>
+
+#include <zencore/testing.h>
+
+namespace zen {
+
+//////////////////////////////////////////////////////////////////////////
+//
+// Testing related code follows...
+//
+
+#if ZEN_WITH_TESTS
+
+void
+intmath_forcelink()
+{
+}
+
+TEST_CASE("intmath")
+{
+	CHECK(FloorLog2(0x00) == 0);
+	CHECK(FloorLog2(0x01) == 0);
+	CHECK(FloorLog2(0x0f) == 3);
+	CHECK(FloorLog2(0x10) == 4);
+	CHECK(FloorLog2(0x11) == 4);
+	CHECK(FloorLog2(0x12) == 4);
+	CHECK(FloorLog2(0x22) == 5);
+	CHECK(FloorLog2(0x0001'0000) == 16);
+	CHECK(FloorLog2(0x0001'000f) == 16);
+	CHECK(FloorLog2(0x8000'0000) == 31);
+
+	CHECK(FloorLog2_64(0x00ull) == 0);
+	CHECK(FloorLog2_64(0x01ull) == 0);
+	CHECK(FloorLog2_64(0x0full) == 3);
+	CHECK(FloorLog2_64(0x10ull) == 4);
+	CHECK(FloorLog2_64(0x11ull) == 4);
+	CHECK(FloorLog2_64(0x0001'0000ull) == 16);
+	CHECK(FloorLog2_64(0x0001'000full) == 16);
+	CHECK(FloorLog2_64(0x8000'0000ull) == 31);
+	CHECK(FloorLog2_64(0x0000'0001'0000'0000ull) == 32);
+	CHECK(FloorLog2_64(0x8000'0000'0000'0000ull) == 63);
+
+	CHECK(CountLeadingZeros64(0x8000'0000'0000'0000ull) == 0);
+	CHECK(CountLeadingZeros64(0x0000'0000'0000'0000ull) == 64);
+	CHECK(CountLeadingZeros64(0x0000'0000'0000'0001ull) == 63);
+	CHECK(CountLeadingZeros64(0x0000'0000'8000'0000ull) == 32);
+	CHECK(CountLeadingZeros64(0x0000'0001'0000'0000ull) == 31);
+
+	CHECK(CountTrailingZeros64(0x8000'0000'0000'0000ull) == 63);
+	CHECK(CountTrailingZeros64(0x0000'0000'0000'0000ull) == 64);
+	CHECK(CountTrailingZeros64(0x0000'0000'0000'0001ull) == 0);
+	CHECK(CountTrailingZeros64(0x0000'0000'8000'0000ull) == 31);
+	CHECK(CountTrailingZeros64(0x0000'0001'0000'0000ull) == 32);
+
+	CHECK(ByteSwap(uint16_t(0x6d72)) == 0x726d);
+	CHECK(ByteSwap(uint32_t(0x2741'3965)) == 0x6539'4127);
+	CHECK(ByteSwap(uint64_t(0x214d'6172'7469'6e21ull)) == 0x216e'6974'7261'4d21ull);
+}
+
+#endif
+
+}  // namespace zen