From: Gerd Stolpmann <info@gerd-stolpmann.de>
To: Benedikt Meurer <benedikt.meurer@googlemail.com>
Cc: caml-list@inria.fr, Fischbach Marcell <marcellfischbach@googlemail.com>
Subject: Re: [Caml-list] Linear Scan Register Allocator for ocamlopt/ocamlnat
Date: Thu, 25 Aug 2011 12:21:08 +0200 [thread overview]
Message-ID: <1314267668.3496.62.camel@thinkpad> (raw)
In-Reply-To: <CD4A0DAD-15D3-4A74-92E8-87F7C9772C2D@googlemail.com>
Am Donnerstag, den 25.08.2011, 11:34 +0200 schrieb Benedikt Meurer:
> On Aug 25, 2011, at 10:02 , Benedikt Meurer wrote:
>
> >>> - http://ps.informatik.uni-siegen.de/~meurer/tmp/compiletime_timings.pdf contains a comparison of the ocamlopt invocations.
> >>> - http://ps.informatik.uni-siegen.de/~meurer/tmp/runtime_timings.pdf contains comparison of the generated code.
> >>>
> >>> As can be seen from the results, amd64 is more sensitive to register allocator changes than i386.
> >>
> >> Well, this particular i386 CPU model is a strange guy - Northwoods have
> >> this extremely long pipeline, which is very sensitive to unforeseen
> >> jumps. It would be more interesting to see this test on a modern CPU in
> >> i386 mode. My guess is that it behaves then more like amd64.
> >
> > Modern CPUs most probably don't run ocaml in 32bit mode, but more likely in long mode. That's why we choose to run the i386 on "real 32bit hardware", where the ocaml i386 port is actually used.
Right. However, if you look at new 32-bit-only CPUs like older Atoms
these base on modern cores where only some of the circuits were omitted
that are needed for 64-bit execution.
> >
> > I'll rerun the benchmark in 32bit mode on a modern cpu to see how things change.
>
> Reran the benchmark with 32bit ocaml on the MBP (Early 2011), results are available at:
>
> http://ps.informatik.uni-siegen.de/~meurer/tmp/linscan-i7-i386-timings.pdf
Hard to interpret. I have the impression that the compile times for
graph coloring on i386 are lower than on amd64 - has maybe to do with
the number of registers - but those for linear scanning are about the
same. (I'm comparing here with the amd64 numbers taken on the same
machine.)
The graphs for the runtimes are on a logarithmic scale. Do you also have
raw numbers?
Gerd
>
> Benedikt
>
>
>
--
------------------------------------------------------------
Gerd Stolpmann, Darmstadt, Germany gerd@gerd-stolpmann.de
Creator of GODI and camlcity.org.
Contact details: http://www.camlcity.org/contact.html
Company homepage: http://www.gerd-stolpmann.de
*** Searching for new projects! Need consulting for system
*** programming in Ocaml? Gerd Stolpmann can help you.
------------------------------------------------------------
next prev parent reply other threads:[~2011-08-25 10:21 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-01 14:53 Benedikt Meurer
2011-08-01 15:03 ` [Caml-list] " Benedikt Meurer
2011-08-01 15:04 ` [Caml-list] " Gabriel Scherer
2011-08-01 16:57 ` Benedikt Meurer
2011-08-24 19:35 ` Benedikt Meurer
2011-08-24 20:40 ` Gerd Stolpmann
2011-08-25 8:02 ` Benedikt Meurer
2011-08-25 9:34 ` Benedikt Meurer
2011-08-25 10:21 ` Gerd Stolpmann [this message]
2011-08-25 10:25 ` Pierre-Alexandre Voye
2011-08-26 10:58 ` Guillaume Yziquel
2011-08-26 12:29 ` Erik de Castro Lopo
[not found] ` <CANnJ5GfmnOhk8mJor8PfrGoC1-5vZWOgUKNZMT9k69iu0TBCeA@mail.gmail.com>
[not found] ` <CANnJ5Gf4AnKPDvrKiYx0joiPbQVOCdFWgPR24Y1ZYYL1Qv5=fg@mail.gmail.com>
2011-08-26 18:33 ` Pierre-Alexandre Voye
2011-08-30 21:07 ` Fermin Reig
2011-08-30 21:21 ` Pierre-Alexandre Voye
2011-08-25 10:43 ` Benedikt Meurer
2011-08-24 20:47 ` malc
2011-08-26 12:40 ` Roberto Di Cosmo
2011-08-01 15:29 ` Wojciech Meyer
2011-08-01 17:03 ` Benedikt Meurer
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1314267668.3496.62.camel@thinkpad \
--to=info@gerd-stolpmann.de \
--cc=benedikt.meurer@googlemail.com \
--cc=caml-list@inria.fr \
--cc=marcellfischbach@googlemail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).