PCH merge breakage on PA

Geoff Keating geoffk@geoffk.org
Wed Jun 5 19:31:00 GMT 2002


> Date: Wed, 5 Jun 2002 12:47:40 -0700
> From: Janis Johnson <janis187@us.ibm.com>
> Cc: Geoff Keating <geoffk@redhat.com>, dave@hiauly1.hia.nrc.ca,
>    gcc-patches@gcc.gnu.org
> Content-Disposition: inline
> User-Agent: Mutt/1.2.5i
> 
> On Wed, Jun 05, 2002 at 01:06:55PM -0600, law@redhat.com wrote:
> > Seems to be working.  I got a clean 3-stage of the PA port.
> > 
> > Note it seems like the compiler just got a hell of a lot slower.  I don't
> > know if it's the PCH code, the tracer code or something else, but things
> > sure feel like they went to hell recently.
> > 
> > jeff
> > 
> 
> I just started looking into why the compiler I built today on ia64-linux
> takes 3-4 times as long to compile as the compiler I built yesterday.
> The information from -ftime-report shows the same distribution across
> passes.  In both cases I did a simple make of C only starting with
> GCC 3.0.4.
> 
> Is it possible that additional checking got turned on by default?

I did add some additional checking to the C++ compiler.  It really
shouldn't have cost that much, though.  Could you try running a
profile and seeing where the time is going?

I am a bit worried about what's going on with performance.  Even on
x86, reports indicate a 10% slowdown.  Since all of the GC marking
takes less than 20% of the total time, that means that either the GC
code got 50% slower, which didn't happen when I was testing (I was
expecting less than 10% slowdown of the 10%, so about a 1% performance
impact)---or something else was changed.

-- 
- Geoffrey Keating <geoffk@geoffk.org> <geoffk@redhat.com>



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