JoltPhysics/UnitTests/Core/FPFlushDenormalsTest.cpp

// Jolt Physics Library (https://github.com/jrouwe/JoltPhysics)
// SPDX-FileCopyrightText: 2021 Jorrit Rouwe
// SPDX-License-Identifier: MIT

#include "UnitTestFramework.h"
#include <Jolt/Core/FPFlushDenormals.h>
#include <atomic>

// Implemented as a global atomic so the compiler can't optimize it to a constant
extern atomic<float> TestFltMin;
atomic<float> TestFltMin = FLT_MIN;

TEST_SUITE("FlushDenormalsTests")
{
	TEST_CASE("TestFlushDenormals")
	{
		// By default flush denormals should be off
		{
			float value = TestFltMin * 0.1f;
			CHECK(value > 0.0f);
		}

		// Turn flush denormal on
		{
			FPFlushDenormals flush_denormals;

			float value = TestFltMin * 0.1f;
			CHECK(value == 0.0f);
		}

		// Check if state was properly restored
		{
			float value = TestFltMin * 0.1f;
			CHECK(value > 0.0f);
		}

		// Update TestFltMin to prevent the compiler from optimizing away TestFltMin and replace all calculations above with 0
		TestFltMin = 1.0f;
	}
}