From: Michael Matz <matz@suse.de>
To: Dominique Dhumieres <dominiq@lps.ens.fr>
Cc: paul.richard.thomas@gmail.com, gcc-patches@gcc.gnu.org,
fortran@gcc.gnu.org
Subject: Re: Implement stack arrays even for unknown sizes
Date: Fri, 15 Apr 2011 12:38:00 -0000 [thread overview]
Message-ID: <Pine.LNX.4.64.1104151428390.1989@wotan.suse.de> (raw)
In-Reply-To: <20110414210403.F14F23BE18@mailhost.lps.ens.fr>
Hi,
On Thu, 14 Apr 2011, Dominique Dhumieres wrote:
> I have forgotten to mentionned that I have a variant of fatigue
> in which I have done the inlining manually along with few other
> optimizations and the timing for it is
>
> [macbook] lin/test% gfc -Ofast fatigue_v8.f90
> [macbook] lin/test% time a.out > /dev/null
> 2.793u 0.002s 0:02.79 100.0% 0+0k 0+1io 0pf+0w
> [macbook] lin/test% gfc -Ofast -fwhole-program fatigue_v8.f90
> [macbook] lin/test% time a.out > /dev/null
> 2.680u 0.003s 0:02.68 100.0% 0+0k 0+2io 0pf+0w
> [macbook] lin/test% gfc -Ofast -fwhole-program -flto fatigue_v8.f90
> [macbook] lin/test% time a.out > /dev/null
> 2.671u 0.002s 0:02.67 100.0% 0+0k 0+2io 0pf+0w
> [macbook] lin/test% gfc -Ofast -fwhole-program -fstack-arrays fatigue_v8.f90
> [macbook] lin/test% time a.out > /dev/null
> 2.680u 0.003s 0:02.68 100.0% 0+0k 0+2io 0pf+0w
> [macbook] lin/test% gfc -Ofast -fwhole-program -flto -fstack-arrays fatigue_v8.f90
> [macbook] lin/test% time a.out > /dev/null
> 2.677u 0.003s 0:02.68 99.6% 0+0k 0+0io 0pf+0w
>
> So the timing of the original code with
> -Ofast -finline-limit=600 -fwhole-program -flto -fstack-arrays
> is quite close to this lower bound.
>
> I have also looked at the failure for gfortran.dg/elemental_dependency_1.f90
> and it seems due to a spurious integer(kind=4) A.37[4]; (and friends) in
Yes, this is due to the DECL_EXPR statement which is rendered by the
dumper just the same as a normal decl. The testcase looks for exactly one
such decl, but with -fstack-arrays there are exactly two for each such
array.
> integer(kind=4) A.37[4];
So, this is the normal decl.
> atmp.36.dim[0].ubound = 3;
> integer(kind=4) A.37[4];
And this is the DECL_EXPR statement, which then actually is transformed
into the stack_save/alloca/stack_restore sequence.
Ciao,
Michael.
next prev parent reply other threads:[~2011-04-15 12:31 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-09 10:08 Dominique Dhumieres
2011-04-09 12:17 ` Paul Richard Thomas
2011-04-10 13:29 ` Dominique Dhumieres
2011-04-11 11:49 ` Michael Matz
2011-04-11 11:58 ` Axel Freyn
2011-04-11 13:35 ` Eric Botcazou
2011-04-11 14:06 ` Dominique Dhumieres
2011-04-11 14:59 ` Michael Matz
2011-04-11 16:04 ` Michael Matz
2011-04-11 16:45 ` Steven Bosscher
2011-04-12 11:54 ` Michael Matz
2011-04-12 12:42 ` N.M. Maclaren
2011-04-11 16:46 ` Dominique Dhumieres
2011-04-11 16:59 ` H.J. Lu
2011-04-11 17:06 ` N.M. Maclaren
2011-04-11 18:28 ` Tobias Burnus
2011-04-11 21:18 ` Dominique Dhumieres
2011-04-12 6:23 ` Paul Richard Thomas
2011-04-12 6:35 ` Dominique Dhumieres
2011-04-13 9:42 ` Paul Richard Thomas
2011-04-13 10:38 ` Richard Guenther
2011-04-13 11:13 ` Richard Guenther
2011-04-14 13:32 ` Dominique Dhumieres
2011-04-13 13:46 ` Paul Richard Thomas
2011-04-14 13:59 ` Michael Matz
2011-04-14 15:28 ` Michael Matz
2011-04-14 19:29 ` Dominique Dhumieres
2011-04-15 2:01 ` Dominique Dhumieres
2011-04-15 12:38 ` Michael Matz [this message]
2011-04-15 14:06 ` Dominique Dhumieres
2011-04-15 15:19 ` Michael Matz
2011-04-15 15:26 ` Jerry DeLisle
2011-04-15 22:41 ` Michael Matz
2011-04-14 20:23 ` Tobias Burnus
2011-04-14 20:30 ` Tobias Burnus
-- strict thread matches above, loose matches on Subject: below --
2011-04-08 21:29 Michael Matz
2011-04-09 8:21 ` N.M. Maclaren
2011-04-09 8:51 ` Magnus Fromreide
2011-04-09 9:02 ` Eric Botcazou
2011-04-09 9:49 ` N.M. Maclaren
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