The Vax version of as accepts any of the following options,
gives a warning message that the option was ignored and proceeds.
These options are for compatibility with scripts designed for other
people's assemblers.
-D (Debug)
-S (Symbol Table)
-T (Token Trace)
These are obsolete options used to debug old assemblers.
-d (Displacement size for JUMPs)
This option expects a number following the `-d'. Like options
that expect filenames, the number may immediately follow the
`-d' (old standard) or constitute the whole of the command line
argument that follows `-d' (GNU standard).
-V (Virtualize Interpass Temporary File)
Some other assemblers use a temporary file. This option
commanded them to keep the information in active memory rather
than in a disk file. as always does this, so this
option is redundant.
-J (JUMPify Longer Branches)
Many 32-bit computers permit a variety of branch instructions
to do the same job. Some of these instructions are short (and
fast) but have a limited range; others are long (and slow) but
can branch anywhere in virtual memory. Often there are 3
flavors of branch: short, medium and long. Some other
assemblers would emit short and medium branches, unless told by
this option to emit short and long branches.
-t (Temporary File Directory)
Some other assemblers may use a temporary file, and this option
takes a filename being the directory to site the temporary
file. Since as does not use a temporary disk file, this
option makes no difference. `-t' needs exactly one
filename.
The Vax version of the assembler accepts two options when
compiled for VMS. They are `-h', and `-+'. The
`-h' option prevents as from modifying the
symbol-table entries for symbols that contain lowercase
characters (I think). The `-+' option causes as to
print warning messages if the FILENAME part of the object file,
or any symbol name is larger than 31 characters. The `-+'
option also inserts some code following the `_main'
symbol so that the object file is compatible with Vax-11
"C".