These -m options are defined for the H8/300 implementations:
Shorten some address references at link time, when possible; uses the linker option -relax. See
ld and the H8/300 in Using ld, for a fuller description.
Generate code for the H8/300H.
Generate code for the H8S.
Generate code for the H8S and H8/300H in the normal mode. This switch must be used either with -mh or -ms.
Generate code for the H8S/2600. This switch must be used with -ms.
Extended registers are stored on stack before execution of function with monitor attribute. Default option is -mexr. This option is valid only for H8S targets.
Extended registers are not stored on stack before execution of function with monitor attribute. Default option is -mno-exr. This option is valid only for H8S targets.
int data 32 bits by default.
On the H8/300H and H8S, use the same alignment rules as for the H8/300. The default for the H8/300H and H8S is to align longs and floats on 4-byte boundaries. -malign-300 causes them to be aligned on 2-byte boundaries. This option has no effect on the H8/300.