From: Richard Biener <rguenther@suse.de>
To: Richard Sandiford <richard.sandiford@arm.com>
Cc: "Andre Vieira (lists)" <andre.simoesdiasvieira@arm.com>,
"gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>
Subject: Re: [vect] Re-analyze all modes for epilogues
Date: Tue, 7 Dec 2021 14:33:38 +0100 (CET) [thread overview]
Message-ID: <qn892161-sppq-qs53-96s8-r4n87nosso6@fhfr.qr> (raw)
In-Reply-To: <mpta6hcpmmh.fsf@arm.com>
On Tue, 7 Dec 2021, Richard Sandiford wrote:
> Richard Biener <rguenther@suse.de> writes:
> > On Tue, 7 Dec 2021, Andre Vieira (lists) wrote:
> >
> >> Hi,
> >>
> >> Rebased on top of the epilogue mode patch.
> >>
> >> OK for trunk?
> >
> > @@ -7242,7 +7315,8 @@ vectorizable_reduction (loop_vec_info loop_vinfo,
> > participating. */
> > if (ncopies > 1
> > && (STMT_VINFO_RELEVANT (stmt_info) <= vect_used_only_live)
> > - && reduc_chain_length == 1)
> > + && reduc_chain_length == 1
> > + && loop_vinfo->suggested_unroll_factor == 1)
> > single_defuse_cycle = true;
> >
> > if (single_defuse_cycle || lane_reduc_code_p)
> >
> > It seems to me that 'ncopies' should include
> > loop_vinfo->suggested_unroll_factor already so the check shouldn't be
> > necessary.
>
> Yeah, ncopies will be >1 for the unroll case. But the point is that
> for unrolling, we want each unrolled loop to have its own reduction
> accumulator, since reducing the aggregate loop-carried latency is one
> of the main benefits of unrolling a reduction.
Ah, I see. Please add a comment above this check then.
Richard.
next prev parent reply other threads:[~2021-12-07 13:33 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)
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 [this message]
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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