testing: addition read precision of a floating number

test/test_addition.c

@@ -6,6 +6,11 @@
 
 num carry[1];
 
+union {
+    float f;
+    unsigned int i;
+} a[5];
+
 void setUp(void)
 {
 }
@@ -151,6 +156,24 @@ void test_addition_signnumber(void) {
     TEST_ASSERT_EQUAL_UINT(expected[1], result[1]);
 }
 
+void test_addition_precisionfloatingnumber(void) {
+    unsigned int result[5];
+    a[0].f = 0, a[1].f = -34753168, a[2].f = 75613594, a[3].f = -0.00000044568721, a[4].f = 0.0000004796123;
+    unsigned int expected[5] = { ( a[0].i << 9) >> 9 , ( a[1].i << 9) >> 9, ( a[2].i << 9) >> 9, ( a[3].i << 9) >> 9, ( a[4].i << 9) >> 9};
+
+    result[0] = m( a[0].i );
+    result[1] = m( a[1].i );
+    result[2] = m( a[2].i );
+    result[3] = m( a[3].i );
+    result[4] = m( a[4].i );
+
+    TEST_ASSERT_EQUAL_UINT(expected[0], result[0]);
+    TEST_ASSERT_EQUAL_UINT(expected[1], result[1]);
+    TEST_ASSERT_EQUAL_UINT(expected[2], result[2]);
+    TEST_ASSERT_EQUAL_UINT(expected[3], result[3]);
+    TEST_ASSERT_EQUAL_UINT(expected[4], result[4]);
+}
+
 void test_addition_addition_float_0plus0gleich0(void) {
     float result;
     float expected = 0.0;