From b7decb3923548ed2e0b9b15231ddbfc1e53f0957 Mon Sep 17 00:00:00 2001
From: Madeline Busig <madeline.busig@outlook.com>
Date: Thu, 29 Aug 2024 22:07:08 -0700
Subject: [PATCH] Add fixed point multiplication tests

---
 CMakeLists.txt              |  2 +-
 include/mtl/tests/fixed.hpp | 41 ++++++++++++++++++++++
 src/tests/fixed.cpp         | 69 +++++++++++++++++++++++++++++++++++++
 3 files changed, 111 insertions(+), 1 deletion(-)
 create mode 100644 include/mtl/tests/fixed.hpp
 create mode 100644 src/tests/fixed.cpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 712f259..366925e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -9,7 +9,7 @@ message("Compiling MTL for ${CMAKE_SYSTEM_PROCESSOR}")
 # build system to automatically re-run CMake if the glob changes, solving the
 # major issue with globbing. May have a performance impact, but it should be
 # negligible compared to the time spent building.
-file(GLOB mtl_sources_common LIST_DIRECTORIES false CONFIGURE_DEPENDS src/*.cpp src/*.c src/*.s)
+file(GLOB mtl_sources_common LIST_DIRECTORIES false CONFIGURE_DEPENDS src/*.cpp src/*.c src/*.s src/tests/*.cpp)
 file(GLOB mtl_sources_armv4t LIST_DIRECTORIES false CONFIGURE_DEPENDS src/armv4t/*.cpp src/armv4t/*.c src/armv4t/*.s)
 file(GLOB mtl_sources_gba LIST_DIRECTORIES false CONFIGURE_DEPENDS src/gba/*.cpp src/gba/*.c src/gba/*.s)
 
diff --git a/include/mtl/tests/fixed.hpp b/include/mtl/tests/fixed.hpp
new file mode 100644
index 0000000..63b5774
--- /dev/null
+++ b/include/mtl/tests/fixed.hpp
@@ -0,0 +1,41 @@
+#pragma once
+
+#include "mtl/test.hpp"
+
+#include "mtl/fixed.hpp"
+
+namespace mtl {
+
+namespace test {
+
+class fixed_suite : public suite<fixed_suite> {
+public:
+	fixed_suite() {
+		add_test(&construction, "construction");
+		add_test(&addition, "addition");
+		add_test(&subtraction, "subtraction");
+		add_test(&multiplication, "multiplication");
+		add_test(&mult_overflow, "mult_overflow");
+		add_test(&division, "division");
+	}
+
+	virtual string_view name() {
+		return "fixed_suite";
+	}
+
+	static bool construction() {
+		return fixed(7).raw() == 7 * 64;
+	}
+
+	// All tests are placed in IWRAM in ARM mode.
+	GBA_IWRAM ARM_MODE static bool addition();
+	GBA_IWRAM ARM_MODE static bool subtraction();
+	GBA_IWRAM ARM_MODE static bool multiplication();
+	GBA_IWRAM ARM_MODE static bool mult_overflow();
+	GBA_IWRAM ARM_MODE static bool division();
+};
+
+} // namespace test
+
+} // namespace mtl
+
diff --git a/src/tests/fixed.cpp b/src/tests/fixed.cpp
new file mode 100644
index 0000000..6f14fef
--- /dev/null
+++ b/src/tests/fixed.cpp
@@ -0,0 +1,69 @@
+#include "mtl/tests/fixed.hpp"
+
+#include "mtl/target.hpp"
+#include "mtl/fixed.hpp"
+
+TARGET_ARM_MODE
+
+namespace mtl {
+namespace test{
+
+bool fixed_suite::addition() {
+	struct {
+		NOINLINE fixed operator()(fixed x, fixed y) {
+			return x + y;
+		}
+	} f;
+
+	return f(3, 4) == fixed(7);
+}
+
+bool fixed_suite::subtraction() {
+	struct {
+		NOINLINE fixed operator()(fixed x, fixed y) {
+			return x - y;
+		}
+	} f;
+
+	return f(8, 3) == fixed(5);
+}
+
+bool fixed_suite::multiplication() {
+	struct {
+		NOINLINE fixed operator()(fixed x, fixed y) {
+			return x * y;
+		}
+	} f;
+
+	return f(3, 4) == fixed(12);
+}
+
+bool fixed_suite::mult_overflow() {
+	// This tests fixed point multiplication where the intermediate result
+	// (x.raw * y.raw) overflows int32 max still works. (IE. int64 multiplication
+	// is used internally)
+	struct {
+		NOINLINE fixed operator()(fixed x, fixed y) {
+			return x * y;
+		}
+	} f;
+
+	return f(1048575, 8) == fixed(8388600);
+}
+
+bool fixed_suite::division() {
+	struct {
+		NOINLINE fixed operator()(fixed x, fixed y) {
+			return x / y;
+		}
+	} f;
+
+	return f(73, 13) == fixed(73.0 / 13.0);
+}
+
+
+}
+}
+
+TARGET_END_MODE
+