From: Tom de Vries <Tom_deVries@mentor.com>
To: Jakub Jelinek <jakub@redhat.com>, Richard Biener <rguenther@suse.de>
Cc: "gcc-patches@gnu.org" <gcc-patches@gnu.org>
Subject: Re: [PATCH, 4/16] Implement -foffload-alias
Date: Thu, 12 Nov 2015 16:04:00 -0000 [thread overview]
Message-ID: <5644B84D.6050504@mentor.com> (raw)
In-Reply-To: <20151111110034.GF5675@tucnak.redhat.com>
On 11/11/15 12:00, Jakub Jelinek wrote:
> On Wed, Nov 11, 2015 at 11:51:02AM +0100, Richard Biener wrote:
>>> The option -foffload-alias=pointer instructs the compiler to assume that
>>> objects references in an offload region do not alias.
>>>
>>> The option -foffload-alias=all instructs the compiler to make no
>>> assumptions about aliasing in offload regions.
>>>
>>> The default value is -foffload-alias=none.
>>
>> I think global options for this is nonsense. Please follow what
>> we do for #pragma GCC ivdep for example, thus allow the alias
>> behavior to be specified per "region" (whatever makes sense here
>> in the context of offloading).
So, IIUC, instead of a global option foffload-alias, you're saying
something like the following would be acceptable:
...
#pragma GCC offload-alias=<none|pointer|all>
#pragma acc kernels copyin (a[0:N], b[0:N]) copyout (c[0:N])
{
#pragma acc loop
for (COUNTERTYPE ii = 0; ii < N; ii++)
c[ii] = a[ii] + b[ii];
}
...
?
I suppose that would work (though a global option would allow us to
easily switch between none/pointer/all values in a large number of
files, something that might be useful when f.i. running an openacc test
suite).
> Yeah, completely agreed. I don't see why the offloaded region would be in
> any way special, they are C/C++/Fortran code as any other.
> What we can and should improve is teach IPA aliasing/points to analysis
> about the way we lower the host vs. offloading region boundary, so that
> if alias analysis on the caller of GOMP_target_ext/GOACC_parallel_keyed
> determines something it can be used on the offloaded function side and vice
> versa,
I agree this would be a nice way to solve the aliasing info problem, but
considering the remark of Richard at
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46032#c19 :
...
Not that I think IPA PTA is anywhere near production ready
...
I haven't considered proceeding in that direction.
Thanks,
- Tom
> but a switch like the above is just wrong.
next prev parent reply other threads:[~2015-11-12 16:04 UTC|newest]
Thread overview: 133+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-09 15:35 [PATCH series, 16] Use parloops to parallelize oacc kernels regions Tom de Vries
2015-11-09 15:44 ` [PATCH, 1/16] Insert new exit block only when needed in transform_to_exit_first_loop_alt Tom de Vries
2015-11-11 10:50 ` Richard Biener
2015-11-09 15:45 ` [PATCH, 2/16] Make create_parallel_loop return void Tom de Vries
2015-11-11 10:50 ` Richard Biener
2015-11-09 15:51 ` [PATCH, 3/16] Ignore reduction clause on kernels directive Tom de Vries
2015-11-24 12:25 ` [PING][PATCH, " Tom de Vries
2016-01-18 14:24 ` [PING^2][PATCH, " Tom de Vries
2016-01-18 14:26 ` Jakub Jelinek
2015-11-09 16:10 ` [PATCH, 4/16] Implement -foffload-alias Tom de Vries
2015-11-11 10:53 ` Richard Biener
2015-11-11 11:01 ` Jakub Jelinek
2015-11-12 16:04 ` Tom de Vries [this message]
2015-11-13 8:46 ` Richard Biener
2015-11-13 11:03 ` Tom de Vries
2015-11-13 11:30 ` Richard Biener
2015-11-13 11:39 ` Jakub Jelinek
2015-11-21 12:24 ` Tom de Vries
2015-11-23 11:46 ` Richard Biener
2015-11-27 11:44 ` Tom de Vries
2015-11-27 12:14 ` Tom de Vries
2015-12-02 9:59 ` Jakub Jelinek
2016-03-14 13:16 ` Tom de Vries
2016-03-14 23:18 ` Tom de Vries
2015-12-02 9:46 ` Jakub Jelinek
2015-12-02 13:11 ` Tom de Vries
2015-12-11 12:45 ` Tom de Vries
2015-12-11 13:00 ` Richard Biener
2015-12-13 16:38 ` Tom de Vries
2015-12-14 13:26 ` Richard Biener
2015-12-14 15:44 ` Tom de Vries
2015-12-16 13:16 ` Richard Biener
2015-12-16 14:43 ` Tom de Vries
2015-12-17 12:03 ` [gomp4] " Thomas Schwinge
2015-12-03 11:53 ` Tom de Vries
2015-11-09 16:31 ` [PATCH, 5/16] Add in_oacc_kernels_region in struct loop Tom de Vries
2015-11-11 10:57 ` Richard Biener
2015-11-16 11:39 ` Tom de Vries
2015-11-16 12:41 ` Richard Biener
2015-11-16 11:39 ` Tom de Vries
2015-11-09 17:39 ` [PATCH, 6/16] Add pass_oacc_kernels Tom de Vries
2015-11-11 10:59 ` Richard Biener
2015-11-19 13:51 ` Tom de Vries
2015-11-24 12:17 ` Tom de Vries
2015-11-25 10:42 ` Richard Biener
2016-02-05 12:06 ` Use plain -fopenacc to enable OpenACC kernels processing (was: [PATCH, 6/16] Add pass_oacc_kernels) Thomas Schwinge
2016-02-10 14:40 ` Use plain -fopenacc to enable OpenACC kernels processing Thomas Schwinge
2016-02-15 16:54 ` Tom de Vries
2016-02-23 15:19 ` Thomas Schwinge
2015-11-09 18:14 ` [PATCH, 7/16] Add pass_dominator_oacc_kernels Tom de Vries
2015-11-11 11:05 ` Richard Biener
2015-11-16 12:04 ` Tom de Vries
2015-11-09 18:34 ` [PATCH, 8/16] Add pass_ch_oacc_kernels Tom de Vries
2015-11-11 20:29 ` Tom de Vries
2015-11-30 12:12 ` [gomp4] Use pass_ch instead of pass_ch_oacc_kernels (was: [PATCH, 8/16] Add pass_ch_oacc_kernels) Thomas Schwinge
2015-11-09 19:53 ` [PATCH, 9/16] Add pass_parallelize_loops_oacc_kernels Tom de Vries
2015-11-16 11:59 ` Tom de Vries
2015-11-24 12:27 ` Tom de Vries
2015-12-13 16:58 ` [PIING][PATCH, " Tom de Vries
2015-12-14 15:23 ` Richard Biener
2016-01-16 22:41 ` [Committed] Move pass_expand_omp_ssa out of pass_parallelize_loops Tom de Vries
2016-01-18 12:59 ` [Committed] Allow pass_parallelize_loops to be run outside the loop pipeline Tom de Vries
2016-01-18 13:07 ` [committed] Add oacc_kernels_p argument to pass_parallelize_loops Tom de Vries
2016-01-18 13:30 ` [committed] Add pass_parallelize_loops to pass_oacc_kernels Tom de Vries
2016-01-20 8:54 ` [committed] Add oacc_kernels_p argument to pass_parallelize_loops Thomas Schwinge
2016-01-20 10:31 ` Tom de Vries
2015-11-09 19:59 ` [PATCH, 10/16] Add pass_oacc_kernels pass group in passes.def Tom de Vries
2015-11-11 11:03 ` Richard Biener
2015-11-16 11:55 ` Tom de Vries
2015-11-16 12:45 ` Richard Biener
2015-11-16 23:21 ` Tom de Vries
2015-11-17 10:05 ` Richard Biener
2015-11-17 14:54 ` Tom de Vries
2015-11-17 15:18 ` Richard Biener
2015-11-17 15:39 ` Tom de Vries
2015-11-17 22:21 ` [PATCH, PR68373 ] Call scev_const_prop in pass_parallelize_loops::execute Tom de Vries
2015-11-19 9:36 ` Tom de Vries
2015-11-20 10:15 ` Richard Biener
2015-11-18 8:30 ` [PATCH, 10/16] Add pass_oacc_kernels pass group in passes.def Richard Biener
2015-11-18 16:22 ` Bernhard Reutner-Fischer
2015-11-20 12:53 ` [committed, trivial] Fix typo and trailing whitespace in dump-file strings in parloops Tom de Vries
2015-11-19 0:35 ` [PATCH, 10/16] Add pass_oacc_kernels pass group in passes.def Tom de Vries
2015-11-20 10:28 ` Richard Biener
2015-11-21 8:42 ` Tom de Vries
2015-11-23 11:31 ` Richard Biener
2015-11-23 15:53 ` Tom de Vries
2015-11-23 16:38 ` Richard Biener
2015-11-19 10:31 ` Tom de Vries
2015-11-20 10:37 ` Richard Biener
2015-11-20 13:27 ` Tom de Vries
2015-11-20 13:29 ` Richard Biener
2015-11-20 16:34 ` Tom de Vries
2015-11-23 10:11 ` Richard Biener
2015-11-24 12:22 ` Tom de Vries
2015-11-24 13:19 ` Richard Biener
2015-11-24 14:33 ` Tom de Vries
2015-11-24 14:36 ` Richard Biener
2015-11-24 15:05 ` Tom de Vries
2015-11-25 10:43 ` Richard Biener
2015-11-25 10:44 ` Richard Biener
2015-11-30 17:48 ` [gomp4] " Thomas Schwinge
2015-11-22 23:37 ` [PATCH] Don't reapply loops flags if unnecessary in loop_optimizer_init Tom de Vries
2015-11-23 10:33 ` Richard Biener
2015-11-23 11:27 ` Tom de Vries
2015-11-09 20:02 ` [PATCH, 11/16] Update testcases after adding kernels pass group Tom de Vries
2015-11-11 11:03 ` Richard Biener
2015-11-12 14:32 ` Tom de Vries
2015-11-12 14:43 ` Richard Biener
2015-11-12 15:42 ` David Malcolm
2015-11-13 9:44 ` Richard Biener
2015-11-09 20:06 ` [PATCH, 12/16] Handle acc loop directive Tom de Vries
2015-11-24 12:30 ` [PING][PATCH, " Tom de Vries
2016-01-18 14:27 ` [PING^2][PATCH, " Tom de Vries
2016-01-26 12:38 ` [PING^3][PATCH, " Tom de Vries
2016-01-26 12:50 ` Jakub Jelinek
2016-02-12 11:11 ` Tom de Vries
2016-02-22 10:55 ` Tom de Vries
2016-02-22 10:58 ` Jakub Jelinek
2016-02-29 3:27 ` Tom de Vries
2016-03-07 8:22 ` [PING][PATCH, " Tom de Vries
2016-03-14 6:21 ` [PING^2][PATCH, " Tom de Vries
2015-11-09 20:08 ` [PATCH, 13/16] Add c-c++-common/goacc/kernels-*.c Tom de Vries
2016-01-18 13:33 ` [committed] Add oacc kernels tests in goacc Tom de Vries
2015-11-09 20:09 ` [PATCH, 14/16] Add gfortran.dg/goacc/kernels-*.f95 Tom de Vries
2015-11-09 20:11 ` [PATCH, 15/16] Add libgomp.oacc-c-c++-common/kernels-*.c Tom de Vries
2016-01-18 13:39 ` [comitted] Add oacc kernels test in libgomp Tom de Vries
2016-03-09 9:18 ` [PATCH, 15/16] Add libgomp.oacc-c-c++-common/kernels-*.c Tom de Vries
2016-03-18 12:46 ` Scan for parallelization of the oacc kernels test-cases in gfortran.dg/goacc (was: [PATCH, 15/16] Add libgomp.oacc-c-c++-common/kernels-*.c) Thomas Schwinge
2016-04-05 9:13 ` Scan for parallelization of the oacc kernels test-cases in gfortran.dg/goacc Tom de Vries
2016-04-07 15:26 ` Thomas Schwinge
2015-11-09 20:12 ` [PATCH, 16/16] Add libgomp.oacc-fortran/kernels-*.f95 Tom de Vries
2016-03-09 9:19 ` Tom de Vries
2016-03-16 13:12 ` Thomas Schwinge
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