From: Cesar Philippidis <cesar_philippidis@mentor.com>
To: Nathan Sidwell <nathan@acm.org>, GCC Patches <gcc-patches@gcc.gnu.org>
Cc: Jakub Jelinek <jakub@redhat.com>,
Thomas Schwinge <THOMAS_SCHWINGE@mentor.com>
Subject: Re: [gomp4] Redesign oacc_parallel launch API
Date: Thu, 06 Aug 2015 16:33:00 -0000 [thread overview]
Message-ID: <55C38C5D.6040602@mentor.com> (raw)
In-Reply-To: <55B7B332.1010603@acm.org>
[-- Attachment #1: Type: text/plain, Size: 1891 bytes --]
On 07/28/2015 09:52 AM, Nathan Sidwell wrote:
> I've committed this patch to the gomp4 branch to redo the launch API.
> I'll post a version for trunk once the versioning patch gets approved &
> committed.
>
> This changes the API in a number of ways, allowing device-specific
> knowledge to be moved into the device compiler and out of the host
> compiler.
>
> Firstly, we attach a tuple of launch dimensions as an attribute to the
> offloaded function's 'oacc function' attribute. These are the constant
> launch dimensions. Dynamic dimensions get a zero for their slot in this
> list. Further this list can be extended in the future to an alist keyed
> by device_type.
>
> Dynamic dimensions are computed on the host. however they are passed
> via varadic args to the GOACC_parallel function (which is renamed). The
> varadic args are passed using key/value representation, and 3 keys are
> currently defined:
> END -- end of the varadic list
> DIM - set of runtime-computed dimensions. Only the dynamic ones are
> passed.
> ASYNC_WAIT - an async and a set of waits (possibly zero).
>
> I have arranged for the key to have a slot that can later be filled by
> device_type, and hence support multiple device types.
>
> The constant dimensions can be used in expansion of the GOACC_nid
> function in the device compiler. The device compiler could also process
> that list to select the device_type slot that is appropriate.
>
> For PTX the backend is augmented to emit the launch dimensions into the
> target data, from whence the ptx plugin can pick them up and overwrite
> with any dynamic ones passed in from the launch function.
Looking at set_oacc_fn_attrib, it appears that const values are also
considered dynamic. See the attached test case more more info. Is that
the expected behavior? If not, I could take a look at this after I
finished my reduction patch.
Cesar
[-- Attachment #2: vlength.c --]
[-- Type: text/x-csrc, Size: 250 bytes --]
#include <stdio.h>
const int vl = 32;
int
main ()
{
unsigned int red = 0;
#pragma acc parallel loop vector_length (vl) vector reduction (+:red) copy (red)
for (int i = 0; i < 100; i++)
red ++;
printf ("red = %d\n", red);
return 0;
}
next prev parent reply other threads:[~2015-08-06 16:33 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-28 17:11 Nathan Sidwell
2015-07-28 17:46 ` Nathan Sidwell
2015-07-29 9:57 ` Thomas Schwinge
2015-07-29 12:43 ` Nathan Sidwell
2015-07-29 22:14 ` Nathan Sidwell
2015-07-30 14:46 ` Nathan Sidwell
2015-07-30 15:05 ` Thomas Schwinge
2015-08-06 16:33 ` Cesar Philippidis [this message]
2015-08-06 19:51 ` Nathan Sidwell
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=55C38C5D.6040602@mentor.com \
--to=cesar_philippidis@mentor.com \
--cc=THOMAS_SCHWINGE@mentor.com \
--cc=gcc-patches@gcc.gnu.org \
--cc=jakub@redhat.com \
--cc=nathan@acm.org \
/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 read-only IMAP folder(s) and NNTP newsgroup(s).