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Re: 3.2 vs 3.1 speed
- From: "Vladimir N. Makarov" <vmakarov at redhat dot com>
- To: Dan Nicolaescu <dann at godzilla dot ICS dot UCI dot EDU>
- Cc: gcc at gcc dot gnu dot org
- Date: Wed, 05 Jun 2002 09:49:40 -0400
- Subject: Re: 3.2 vs 3.1 speed
- References: <200206041838.aa10762@gremlin-relay.ics.uci.edu>
Dan Nicolaescu wrote:
> I did a little test on the speed of 3.2 and 3.1 using the example
> posted earlier today on a Sparc machine with 1GB RAM.
> 3.2 was last updated on May 25.
>
> 3.2 is _slower_ than 3.1 at compiling the same preprocessed file.
>
> It looks like the main reasons for the speed decrease are: garbage
> collection, expand and scheduling.
> The times are the ones reported by -ftime-report
>
> The source code used is at: http://www.ics.uci.edu/~dann/orb.i.bz2
>
> Hope somebody can figure out what is going on...
Hi, Dan. I'll look at the 1st insn scheduling (the 2nd insn scheduling is
actually faster) today. As David, I suspect the code is slower because
scheduling lookahead. I think that the specific features of code is in long
ready queues. I have some ideas how to improve such behavior.
Vlad