Options for /lib/optim on System V/386

[Piercarlo Grandi]

I have been asked to post a list of options for the /lib/optim component
of the System V/386 3.2 SDS. Here they are, with some information
derived by trial and error:

	-a	?
	-b	trace block analysis
	-c	?
	-d	trace live register analysis
	-e	trace start of optimizer phases
	-h	disable peephole optimizations
	-i PATH	read from PATH
	-l	trace label removal
	-m	trace block merging
	-n	disable reordering
	-o PATH	write to PATH
	-l	statistics on cases
	-r	?
	-s	print optimizer statistics
	-u	trace unreachability analysis
	-w	trace window analysis
	-x	?
	-y N	inline only if smaller than N
	-z	disable inlining
	-K OPT	enable OPT suboption (?)
	-V	print optimizer version

In practice most of the options are informational only, and it is quite
fascinating to see what the optimizer is up to. The really useful ones
are '-yN', to enable/disable or expand/restrict inlining, '-s' for
curiosity, and '-h' to disable peephole simplication in certain rare
cases.

It would be nice if somebody from AT&T could give a more authoritative
and complete summary, but do not count on it; after all they are the
guys that would not give you the as(1) manual by default...
--
Piercarlo "Peter" Grandi           | ARPA: pcg%cs.aber.ac.uk at nsfnet-relay.ac.uk
Dept of CS, UCW Aberystwyth        | UUCP: ...!mcsun!ukc!aber-cs!pcg
Penglais, Aberystwyth SY23 3BZ, UK | INET: pcg at cs.aber.ac.uk