2 files changed, 86 insertions, 0 deletions
diff --git a/Tests/AK/CMakeLists.txt b/Tests/AK/CMakeLists.txt
index 38b066fcbe..ec48588c6f 100644
--- a/Tests/AK/CMakeLists.txt
+++ b/Tests/AK/CMakeLists.txt
@@ -26,6 +26,7 @@ set(AK_TEST_SOURCES
     TestEnumBits.cpp
     TestFind.cpp
     TestFixedArray.cpp
+    TestFloatingPoint.cpp
     TestFormat.cpp
     TestGenericLexer.cpp
     TestHashFunctions.cpp
diff --git a/Tests/AK/TestFloatingPoint.cpp b/Tests/AK/TestFloatingPoint.cpp
new file mode 100644
index 0000000000..da6a2fe4cc
--- /dev/null
+++ b/Tests/AK/TestFloatingPoint.cpp
@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2022, Jelle Raaijmakers <jelle@gmta.nl>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/FloatingPoint.h>
+#include <LibTest/TestCase.h>
+#include <math.h>
+
+TEST_CASE(f16_1_5_10_to_native_float)
+{
+    auto within_approximate = [](u16 lhs, float rhs) -> bool {
+        auto f32_lhs = convert_to_native_float(FloatingPointBits<1, 5, 10>(lhs));
+        return fabsf(f32_lhs - rhs) <= 0.00001f;
+    };
+
+    EXPECT(within_approximate(0x0000, 0.f));
+    EXPECT(within_approximate(0x03FF, 0.000061f));
+    EXPECT(within_approximate(0x3CEF, 1.23339f));
+    EXPECT(within_approximate(0xBC00, -1.f));
+    EXPECT(within_approximate(0xA266, -0.0125f));
+
+    float result;
+    result = convert_to_native_float(FloatingPointBits<1, 5, 10>(0xFC01u));
+    EXPECT(isnan(result));
+
+    result = convert_to_native_float(FloatingPointBits<1, 5, 10>(0x7C00u));
+    EXPECT(isinf(result));
+}
+
+TEST_CASE(float_to_double_roundtrips)
+{
+    auto roundtrip = [](float floatvalue1) {
+        auto doublevalue = convert_from_native_float<DoubleFloatingPointBits>(floatvalue1).as_double();
+        auto floatbits = convert_from_native_double<SingleFloatingPointBits>(doublevalue);
+        auto floatvalue2 = convert_to_native_float(floatbits);
+
+        EXPECT_APPROXIMATE(floatvalue1, floatvalue2);
+    };
+
+    roundtrip(-1.0f);
+    roundtrip(-0.1f);
+    roundtrip(0.0f);
+    roundtrip(0.000001f);
+    roundtrip(0.1f);
+    roundtrip(1.0f);
+    roundtrip(3.141592f);
+    roundtrip(16777216.0f);
+    roundtrip(33554432.0f);
+
+    roundtrip(1 / 0.0f);
+    roundtrip(1 / -0.0f);
+    roundtrip(0 / 0.0f);
+}
+
+TEST_CASE(normalize_denormalize)
+{
+    // Go from denormalized float to normalized double
+    auto denormalized_float = 6.709679e-39f;
+    auto denormalized_float_bits = SingleFloatingPointBits(denormalized_float);
+    auto normalized_double = convert_to_native_double(denormalized_float_bits);
+    EXPECT_APPROXIMATE(denormalized_float, normalized_double);
+
+    // Go back from normalized double to denormalized float
+    auto normalized_double_bits = DoubleFloatingPointBits(normalized_double);
+    auto reconstructed_denormalized_float = convert_to_native_float(normalized_double_bits);
+    EXPECT_APPROXIMATE(denormalized_float, reconstructed_denormalized_float);
+}
+
+TEST_CASE(large_exponent)
+{
+    // Make sure we support at least 62 bits of exponent
+    auto large_exponent_float = convert_from_native_double<FloatingPointBits<1, 62, 1>>(1.0);
+    auto converted_double = convert_to_native_double(large_exponent_float);
+    EXPECT_APPROXIMATE(converted_double, 1.0);
+}
+
+TEST_CASE(large_mantissa)
+{
+    // Make sure we support at least 62 bits of mantissa
+    auto large_exponent_float = convert_from_native_double<FloatingPointBits<1, 1, 62>>(1.0);
+    auto converted_double = convert_to_native_double(large_exponent_float);
+    EXPECT_APPROXIMATE(converted_double, 1.0);
+}