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From: Basile STARYNKEVITCH <basile@starynkevitch.net>
To: Ian Lance Taylor <iant@google.com>
Cc: GCC Mailing List <gcc@gcc.gnu.org>
Subject: Re: very different compilation times [no optimisation]
Date: Fri, 06 Nov 2009 16:37:00 -0000	[thread overview]
Message-ID: <4AF44938.3090703@starynkevitch.net> (raw)
In-Reply-To: <4AF443FB.6060206@starynkevitch.net>

Basile STARYNKEVITCH wrote:
> Ian Lance Taylor wrote:
>> Basile STARYNKEVITCH <basile@starynkevitch.net> writes:
>>
>>> Notice that gcc 4.4 is running four times slower that gcc-4.3!
>>
>> Use the -ftime-report option with both compilers to see where the time
>> is going.
> 
> I also put the figures in the PR41971

Strangely, the timing varies widely from one run to another with the same compiler.
glinka ~/tmp 16:41 % time gcc-4.4  -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.4.o
gcc-4.4 -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.4.o  32.44s user 1.75s system 99% cpu 34.472 total
glinka ~/tmp 16:56 % time gcc-4.4  -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.4.o
gcc-4.4 -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.4.o  14.43s user 0.64s system 99% cpu 15.125 total
glinka ~/tmp 16:56 % time gcc-4.4  -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.4.o
gcc-4.4 -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.4.o  39.23s user 1.95s system 99% cpu 41.298 total
glinka ~/tmp 16:57 % time gcc-4.4  -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.4.o
gcc-4.4 -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.4.o  8.69s user 0.32s system 99% cpu 9.046 total
glinka ~/tmp 16:57 % time gcc-4.4  -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.4.o
gcc-4.4 -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.4.o  20.98s user 1.18s system 99% cpu 22.282 total



glinka ~/tmp 16:58 % time gcc-4.3  -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.3.o
gcc-4.3 -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.3.o  44.04s user 2.14s system 99% cpu 46.563 total
glinka ~/tmp 16:59 % time gcc-4.3  -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.3.o
gcc-4.3 -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.3.o  7.12s user 0.27s system 99% cpu 7.402 total
glinka ~/tmp 17:00 % time gcc-4.3  -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.3.o
gcc-4.3 -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.3.o  75.16s user 3.32s system 99% cpu 1:18.97 total
glinka ~/tmp 17:01 % time gcc-4.3  -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.3.o
gcc-4.3 -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.3.o  20.78s user 0.96s system 99% cpu 21.856 total
glinka ~/tmp 17:01 % time gcc-4.3  -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.3.o
gcc-4.3 -O0 -g -fPIC warmelt-normal-1.i -c -o warmelt-normal-1-gcc-4.3.o  7.11s user 0.32s system 99% cpu 7.442 total

I have no idea of what is happenning. (Maybe randomized address & malloc???) My desktop is not loaded (and is quadricore).


Regards.


-- 
Basile STARYNKEVITCH         http://starynkevitch.net/Basile/
email: basile<at>starynkevitch<dot>net mobile: +33 6 8501 2359
8, rue de la Faiencerie, 92340 Bourg La Reine, France
*** opinions {are only mines, sont seulement les miennes} ***

      parent reply	other threads:[~2009-11-06 16:37 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-11-06 15:04 Basile STARYNKEVITCH
2009-11-06 15:16 ` Dave Korn
2009-11-06 15:36   ` Basile STARYNKEVITCH
2009-11-06 15:35 ` Ian Lance Taylor
2009-11-06 15:43   ` Basile STARYNKEVITCH
2009-11-06 15:49     ` Dave Korn
2009-11-06 16:00       ` Ian Lance Taylor
2009-11-06 16:48         ` Basile STARYNKEVITCH
2009-11-06 16:37     ` Basile STARYNKEVITCH [this message]

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