From: "Andre Vieira (lists)" <andre.simoesdiasvieira@arm.com>
To: Richard Biener <rguenther@suse.de>
Cc: "gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>,
richard.sandiford@arm.com
Subject: Re: [PATCH 1v2/3][vect] Add main vectorized loop unrolling
Date: Tue, 30 Nov 2021 11:36:54 +0000 [thread overview]
Message-ID: <5477e0cb-6dc9-e828-7c20-a99de3c6840c@arm.com> (raw)
In-Reply-To: <r8r6pnqr-nn92-pqpo-p0s4-n6no777ppn6q@fhfr.qr>
On 25/11/2021 12:46, Richard Biener wrote:
> Oops, my fault, yes, it does. I would suggest to refactor things so
> that the mode_i = first_loop_i case is there only once. I also wonder
> if all the argument about starting at 0 doesn't apply to the
> not unrolled LOOP_VINFO_EPIL_USING_PARTIAL_VECTORS_P as well? So
> what's the reason to differ here? So in the end I'd just change
> the existing
>
> if (LOOP_VINFO_EPIL_USING_PARTIAL_VECTORS_P (first_loop_vinfo))
> {
>
> to
>
> if (LOOP_VINFO_EPIL_USING_PARTIAL_VECTORS_P (first_loop_vinfo)
> || first_loop_vinfo->suggested_unroll_factor > 1)
> {
>
> and maybe revisit this when we have an actual testcase showing that
> doing sth else has a positive effect?
>
> Thanks,
> Richard.
So I had a quick chat with Richard Sandiford and he is suggesting
resetting mode_i to 0 for all cases.
He pointed out that for some tunings the SVE mode might come after the
NEON mode, which means that even for not-unrolled loop_vinfos we could
end up with a suboptimal choice of mode for the epilogue. I.e. it could
be that we pick V16QI for main vectorization, but that's VNx16QI + 1 in
the array, so we'd not try VNx16QI for the epilogue.
This would simplify the mode selecting cases, by just simply restarting
at mode_i in all epilogue cases. Is that something you'd be OK?
Regards,
Andre
next prev parent reply other threads:[~2021-11-30 11:36 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-17 15:27 [PATCH 0/3][vect] Enable vector unrolling of main loop Andre Vieira (lists)
2021-09-17 15:31 ` [PATCH 1/3][vect] Add main vectorized loop unrolling Andre Vieira (lists)
2021-09-21 12:30 ` Richard Biener
2021-09-21 16:34 ` Andre Vieira (lists)
2021-09-22 6:14 ` Richard Biener
2021-09-30 8:52 ` [PATCH 1v2/3][vect] " Andre Vieira (lists)
2021-10-01 8:19 ` Richard Biener
2021-10-04 16:30 ` Richard Sandiford
2021-10-12 10:35 ` Andre Vieira (lists)
2021-10-15 8:48 ` Richard Biener
2021-10-20 13:29 ` Andre Vieira (lists)
2021-10-21 12:14 ` Richard Biener
2021-10-22 10:18 ` Richard Sandiford
2021-11-11 16:02 ` Andre Vieira (lists)
2021-11-12 13:12 ` Richard Biener
2021-11-22 11:41 ` Andre Vieira (lists)
2021-11-22 12:39 ` Richard Biener
2021-11-24 9:46 ` Andre Vieira (lists)
2021-11-24 11:00 ` Richard Biener
2021-11-25 10:40 ` Andre Vieira (lists)
2021-11-25 12:46 ` Richard Biener
2021-11-30 11:36 ` Andre Vieira (lists) [this message]
2021-11-30 13:56 ` Richard Biener
2021-12-07 11:27 ` [vect] Re-analyze all modes for epilogues Andre Vieira (lists)
2021-12-07 11:31 ` Andre Vieira (lists)
2021-12-07 11:48 ` Richard Biener
2021-12-07 13:31 ` Richard Sandiford
2021-12-07 13:33 ` Richard Biener
2021-12-07 11:45 ` Richard Biener
2021-12-07 15:17 ` Andre Vieira (lists)
2021-12-13 16:41 ` Andre Vieira (lists)
2021-12-14 11:39 ` Richard Sandiford
2021-12-17 16:33 ` Andre Vieira (lists)
2022-01-07 12:39 ` Richard Sandiford
2022-01-10 18:31 ` [PATCH 1v2/3][vect] Add main vectorized loop unrolling Andre Vieira (lists)
2022-01-11 7:14 ` Richard Biener
2021-10-22 10:12 ` Richard Sandiford
2021-09-17 15:32 ` [PATCH 2/3][vect] Consider outside costs earlier for epilogue loops Andre Vieira (lists)
2021-10-14 13:44 ` Andre Vieira (lists)
2021-10-22 15:33 ` Richard Sandiford
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