The presence of a # on a line indicates the start of a comment that extends to the end of the current line.
If a # appears as the first character of a line then the whole line is treated as a comment, but in this case the line could also be a logical line number directive (see Comments) or a preprocessor control command (see Preprocessing).
If the assembler has been configured for the ppc-*-solaris* target then the ! character also acts as a line comment character. This can be disabled via the -mno-solaris command-line option.
The ; character can be used to separate statements on the same line.