These ‘-m’ options are defined for the VAX:
-munix
¶Do not output certain jump instructions (aobleq
and so on)
that the Unix assembler for the VAX cannot handle across long
ranges.
-mgnu
¶Do output those jump instructions, on the assumption that the GNU assembler is being used.
-md
¶-md-float
Use the D_floating data format for double-precision floating-point numbers instead of G_floating.
-mg
¶-mg-float
Use the G_floating data format for double-precision floating-point numbers instead of D_floating.
-mlra
¶-mno-lra
Enable Local Register Allocation. This is still experimental for the VAX, so by default the compiler uses standard reload.