check_memcmp
check_memcmp(data1, data2, i, -0x55);
check_memcmp(data1 + i, data2 + i, 256 - i, i - (i ^ 0x55));
check_memcmp(data1 + 128, data2 + 128, i, 255);
check_memcmp(data2 + 128, data1 + 128, i, -255);
check_memcmp(data1 + 129 - i, data2 + 129 - i, i, 255);
check_memcmp(data2 + 129 - i, data1 + 129 - i, i, -255);
check_memcmp(data1 + 129 - i, data2 + 129 - i, i * 2, 255);
check_memcmp(data2 + 129 - i, data1 + 129 - i, i * 2, -255);
check_memcmp(data1 + 128, data2 + 128, i, -2);
check_memcmp(data2 + 128, data1 + 128, i, 2);
check_memcmp(data1 + 129 - i, data2 + 129 - i, i, -2);
check_memcmp(data2 + 129 - i, data1 + 129 - i, i, 2);
check_memcmp(data1 + 129 - i, data2 + 129 - i, i * 2, -2);
check_memcmp(data2 + 129 - i, data1 + 129 - i, i * 2, 2);
check_memcmp(data1 + 128, data2 + 128, i, -2);
check_memcmp(data2 + 128, data1 + 128, i, 2);
check_memcmp(data1 + 129 - i, data2 + 129 - i, i, -2);
check_memcmp(data2 + 129 - i, data1 + 129 - i, i, 2);
check_memcmp(data1 + 129 - i, data2 + 129 - i, i * 2, -2);
check_memcmp(data2 + 129 - i, data1 + 129 - i, i * 2, 2);
check_memcmp("a", "b", 0, 0);
check_memcmp("", "", 0, 0);
check_memcmp(data1, data2, i, 0);
check_memcmp(data1 + i, data2 + i, 256 - i, 0);