[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Gcl-devel] Re: 10%, for what it's worth

From: Camm Maguire
Subject: [Gcl-devel] Re: 10%, for what it's worth
Date: 26 Aug 2005 17:44:10 -0400
User-agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2

Greetings! Please excuse my silence of late as I've tried to catch up
on work that had accumulated during my vacation.

Robert Boyer <address@hidden> writes:

> It looks like an icc-9 version of GCL is about 9% faster than a gcc version
> on the Nqthm tests under GCL 2.7.0.
>    ICC
>    run-gbc time    :   2362.520 secs
>    child run time  :    115.530 secs
>    gbc time        :     97.970 secs
>    GCC
>    run-gbc time    :   2447.650 secs
>    child run time  :    156.270 secs
>    gbc time        :    215.780 secs
>    (/ (+ 2447.6 156.2 215.8) (+ 2362.5 115.5 98)) =   1.094

Thank you for these very interesting results!

1) I'd very much be interested in the icc compiler warning output that
   bounced in the mail -- perhaps you can tell me where to retrieve!

2) Of course the lion's chare of the improvement is in gc time, and I
   bet I know exactly where -- sweeping the relocatable area.  I'd
   wager icc uses sse and prefetch instructions to do the copy much
   faster.  Thankfully, we can get the same using pure open source
   tools.  gcc-4.0 now spits out sse, and even without it we can make
   use of atlas tuned blas copy routines.  You can confirm/refute in
   part by doing objjdump -d gbc.o | grep xmm

3) I'd love to see a breakdown preferably by routine of the run-gbc
   time improvements.  I don't suppose icc speaks gprof?

Take care,

> Bob

Camm Maguire                                            address@hidden
"The earth is but one country, and mankind its citizens."  --  Baha'u'llah

reply via email to

[Prev in Thread] Current Thread [Next in Thread]