Add test_minmax that checks different comparisons when nans and infs are related.

1 files changed, 89 insertions, 0 deletions

diff --git a/tests/test_minmax.c b/tests/test_minmax.c
new file mode 100644
index 00000000..998c60d4
--- /dev/null
+++ b/tests/test_minmax.c
@@ -0,0 +1,89 @@
+#include <math.h>
+#include <assert.h>
+#include <float.h>
+#include <stdio.h>
+
+union fi
+{
+	float f;
+	unsigned int i;
+};
+
+unsigned int Float2Int(float f)
+{
+	union fi a;
+	a.f = f;
+	return a.i;
+}
+
+float Fminf(float x, float y)
+{
+	if (x < y || !(y == y))
+		return x;
+	else if (y < x || !(x == x))
+		return y;
+	else if (x != 0.f)
+		return x;
+	else
+		return Float2Int(x) == 0 ? y : x;
+}
+
+float Fmaxf(float x, float y)
+{
+	if (x > y || !(y == y))
+		return x;
+	else if (y > x || !(x == x))
+		return y;
+	else if (x != 0.f)
+		return x;
+	else
+		return Float2Int(x) == 0 ? x : y;
+}
+
+void TestMin(float a, float b, float ret)
+{
+	float x = Fminf(a, b);
+	if (x != ret)
+		printf("min(%f, %f) returned %f, should return ret: %f\n", a, b, x, ret);
+	assert(Float2Int(x) == Float2Int(ret));
+	float y = Fminf(b, a);
+	if (y != ret)
+		printf("min(%f, %f) returned %f, should return ret: %f\n", b, a, y, ret);
+	assert(Float2Int(y) == Float2Int(ret));
+}
+
+void TestMax(float a, float b, float ret)
+{
+	float x = Fmaxf(a, b);
+	if (x != ret)
+		printf("max(%f, %f) returned %f, should return ret: %f\n", a, b, x, ret);
+	assert(Float2Int(x) == Float2Int(ret));
+	float y = Fmaxf(b, a);
+	if (y != ret)
+		printf("max(%f, %f) returned %f, should return ret: %f\n", b, a, x, ret);
+	assert(Float2Int(y) == Float2Int(ret));
+}
+
+int main()
+{
+	TestMin(-INFINITY, INFINITY, -INFINITY);
+	TestMax(-INFINITY, INFINITY, INFINITY);
+
+	TestMin(-INFINITY, 1.f, -INFINITY);
+	TestMax(-INFINITY, 1.f, 1.f);
+
+	TestMin(INFINITY, 1.f, 1.f);
+	TestMax(INFINITY, 1.f, INFINITY);
+
+	TestMin(-INFINITY, NAN, -INFINITY);
+	TestMax(-INFINITY, NAN, -INFINITY);
+	assert(Float2Int(0.0f) != Float2Int(-0.0f));
+
+	if (NAN == NAN)
+		printf("NAN == NAN\n");
+	if (NAN != NAN)
+		printf("NAN != NAN\n");
+	TestMin(-0.0f, 0.0f, -0.0f);
+	TestMax(-0.0f, 0.0f, 0.0f);
+	printf("Success!\n");
+}