Test case for historical reasons

[r22410]

ir/be/test/invsqrt.c

+/**
+ * magical invsqrt function from Quake III code
+ * see: http://www.codemaestro.com/reviews/9
+ */
+
+float InvSqrt(float x)
+{
+	float xhalf = 0.5f*x;
+	int i = *(int*)&x;
+	i = 0x5f3759df - (i>>1);
+	x = *(float*)&i;
+	x = x*(1.5f-xhalf*x*x);
+	return x;
+}
+
+int main(void) {
+	int result = InvSqrt(0.00056);
+	printf("Result: %d (should be 42)", result);
+	return result != 42;
+}