Enables 8 byte alignment for the data types longlong and double.
-align8
This option changes the default alignment of the data types longlong and double to 8 bytes. The default alignment for these data types is to 4 bytes. When used with the V5TE architectures and above, 8 byte alignment on long long and double types enables the LDRD and STRD instructions to be generated at the optimization level 1 and above.