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Re: VTA merge - cmdline


On Jun  5, 2009, Richard Guenther <richard.guenther@gmail.com> wrote:

> On Fri, Jun 5, 2009 at 6:48 PM, Richard Henderson<rth@redhat.com> wrote:
>> Alexandre Oliva wrote:
>>> 
>>> cmdline (7K) - new command line flags to turn VTA on or off, as well as
>>> a few debugging options that helped me debug it
>> 
>> Ok.

> -fmin-insn-uid should be a --param.

Whatever.  I still can't see the difference, but I have no reason to not
change it along these lines.  It's mostly just mechanical work for no
purpose I can grasp.

Where's documentation that explains when a flag should be good old -f
and when it should be the new (and IMHO redundant) --param?

If there isn't any, perhaps someone who actually understands the
difference and can justify the rationale behind it should write it, and
mark old flags that deviate from the new order to avoid giving people
like myself ideas ;-)

> -fverbose-cselib should be split out completely I guess.

You mean out of this patchset?  That would be quite a pain, it's quite
intertwined with the changes in var-tracking and cselib.  I was hoping
to avoid the pain of separating it.

> And why does it not use -fdump-rtl-var-tracking-details and the
> dump_flags machinery?

One of the (poor) reasons is that var-tracking dumps are not in the
vartrack rtl dump on IA64.  (sched2 and var-tracking run as part of
mach-reorg or some such there)

Another more important reason is that the idea of using such details
flags never occurred to me.  I just got the idea of a verbose flag like
this from -fsched-verbose, and it seemed just fine to me.

I'm not even sure the -fverbose-cselib dumps are useful any more,
although they were useful in a distant past.  I guess dropping it might
be easier than figuring out how to get to the -details flag of specific
compilation passes within cselib, that is used by several passes.  I'm
clueless as to how to do that, but I'd look into it if it makes sense to
keep the dumps.

-- 
Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist      Red Hat Brazil Compiler Engineer


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