> -----Original Message-----
> From: rguent...@c653.arch.suse.de <rguent...@c653.arch.suse.de> On
> Behalf Of Richard Biener
> Sent: Thursday, November 5, 2020 10:17 AM
> To: Tamar Christina <tamar.christ...@arm.com>
> Cc: gcc-patches@gcc.gnu.org; nd <n...@arm.com>; o...@ucw.cz
> Subject: RE: [PATCH] SLP: Move load/store-lanes check till late
>
> On Wed, 4 Nov 2020, Tamar Christina wrote:
>
> > Hi Richi,
> >
> > > -----Original Message-----
> > > From: rguent...@c653.arch.suse.de <rguent...@c653.arch.suse.de> On
> > > Behalf Of Richard Biener
> > > Sent: Wednesday, November 4, 2020 8:07 AM
> > > To: Tamar Christina <tamar.christ...@arm.com>
> > > Cc: gcc-patches@gcc.gnu.org; nd <n...@arm.com>; o...@ucw.cz
> > > Subject: RE: [PATCH] SLP: Move load/store-lanes check till late
> > >
> > > On Tue, 3 Nov 2020, Tamar Christina wrote:
> > >
> > > > Hi Richi,
> > > >
> > > > We decided to take the regression in any code-gen this could give
> > > > and fix it properly next stage-1. As such here's a new patch
> > > > based on your previous feedback.
> > > >
> > > > Ok for master?
> > >
> > > Looks good sofar but be aware that you elide the
> > >
> > > - && vect_store_lanes_supported
> > > - (STMT_VINFO_VECTYPE (scalar_stmts[0]), group_size,
> > > false))
> > >
> > > part of the check - that is, you don't verify the store part of the
> > > instance can use store-lanes. Btw, this means the original code
> > > cancelled an instance only when the SLP graph entry is a store-lane
> > > capable store but your variant would also cancel in case there's a load-
> lane capable reduction.
> > >
> >
> > I do still have it,
> >
> > if (loads_permuted
> > && vect_store_lanes_supported (vectype, group_size, false))
> >
> > I just grab the type from the SLP_TREE_VECTYPE (slp_root); which
> > should be the store if one exists.
> >
> > > I think that you eventually want to re-instantiate the store-lane
> > > check but treat it the same as any of the load checks (thus not
> > > require all instances to be stores for the cancellation).
> > > But at least when a store cannot use store-lanes we probably
> > > shouldn't cancel the SLP.
> >
> > I did however elide the kind check, that was added as part of the
> > rebase, it looked like kind wasn't Being stored inside the SLP instance and
> I'd have to redo the analysis to find it.
> >
> > Does it does reasonable to include kind as a field in the SLP instance?
> >
> > >
> > > Anyway, the patch is OK for master. The store-lane check part can
> > > be re- added as followup.
> > >
> >
> > Thanks! Will do.
>
> Btw, the patch regressed
>
> FAIL: gcc.dg/vect/slp-11b.c -flto -ffat-lto-objects scan-tree-dump-times vect
> "vectorizing stmts using SLP" 1
> FAIL: gcc.dg/vect/slp-11b.c scan-tree-dump-times vect "vectorizing stmts
> using SLP" 1
> FAIL: gcc.dg/vect/slp-perm-6.c -flto -ffat-lto-objects scan-tree-dump vect
> "Built SLP cancelled: can use load/store-lanes"
> FAIL: gcc.dg/vect/slp-perm-6.c -flto -ffat-lto-objects scan-tree-dump vect
> "LOAD_LANES"
> FAIL: gcc.dg/vect/slp-perm-6.c -flto -ffat-lto-objects scan-tree-dump vect
> "STORE_LANES"
> FAIL: gcc.dg/vect/slp-perm-6.c scan-tree-dump vect "Built SLP cancelled:
> can use load/store-lanes"
> FAIL: gcc.dg/vect/slp-perm-6.c scan-tree-dump vect "LOAD_LANES"
> FAIL: gcc.dg/vect/slp-perm-6.c scan-tree-dump vect "STORE_LANES"
>
> on x86_64. The slp-11b.c testcase is interesting since there extract_muldiv
> folding makes the group of four stores not matching so we split into a size of
> 3 and one remaining store.
> This causes us to arrive at
>
> note: node 0x441a940 (max_nunits=4, refcnt=2)
> note: stmt 0 _2 = in[_1];
> note: stmt 1 _6 = in[_5];
> note: stmt 2 _10 = in[_8];
> note: load permutation { 0 2 1 }
>
> which on x86_64 we in the end cannot handle (without SSE4 I think) so it fails
> to SLP there. Guess arm can do the permute but not the load-lane here.
>
> For gcc.dg/vect/slp-perm-6.c the XFAILs shouldn't be done
> for !vect_load_lanes targets. Not sure if that's possible easily, like with a
> { target vect_load_lanes } { xfail vect_load_lanes } combo ...? I suggest to
> make it xfail everywhere instead and add a comment as to we're expecting
> those only for vect_load_lanes targets.
Yes just fixed these, the change in gcc.dg/vect/slp-11b.c shouldn't be there
and I updated the target selector properly :)
Cheers,
Tamar
>
> Richard.
>
> > > Thanks,
> > > Richard.
> > >
> > > > Thanks,
> > > > Tamar
> > > >
> > > > gcc/ChangeLog:
> > > >
> > > > * tree-vect-slp.c (vect_analyze_slp_instance): Moved load/store
> > > lanes
> > > > check to ...
> > > > * tree-vect-loop.c (vect_analyze_loop_2): ..Here
> > > >
> > > > gcc/testsuite/ChangeLog:
> > > >
> > > > * gcc.dg/vect/slp-11b.c: Update output scan.
> > > > * gcc.dg/vect/slp-perm-6.c: Likewise.
> > > >
> > > > > -----Original Message-----
> > > > > From: rguent...@c653.arch.suse.de <rguent...@c653.arch.suse.de>
> > > > > On Behalf Of Richard Biener
> > > > > Sent: Thursday, October 22, 2020 9:44 AM
> > > > > To: Tamar Christina <tamar.christ...@arm.com>
> > > > > Cc: gcc-patches@gcc.gnu.org; nd <n...@arm.com>; o...@ucw.cz
> > > > > Subject: Re: [PATCH] SLP: Move load/store-lanes check till late
> > > > >
> > > > > On Wed, 21 Oct 2020, Tamar Christina wrote:
> > > > >
> > > > > > Hi All,
> > > > > >
> > > > > > This moves the code that checks for load/store lanes further
> > > > > > in the pipeline and places it after slp_optimize. This would
> > > > > > allow us to perform optimizations on the SLP tree and only
> > > > > > bail out if we really have a
> > > > > permute.
> > > > > >
> > > > > > With this change it allows us to handle permutes such as
> > > > > > {1,1,1,1} which should be handled by a load and replicate.
> > > > > >
> > > > > > This change however makes it all or nothing. Either all
> > > > > > instances can be handled or none at all. This is why some of
> > > > > > the test cases have been
> > > > > adjusted.
> > > > >
> > > > > So this possibly leaves a loop unvectorized in case there's a
> > > > > ldN/stN opportunity but another SLP instance with a permutation
> > > > > not handled by interleaving is present. What I was originally
> > > > > suggesting is to only cancel the SLP build if _all_ instances
> > > > > can be handled
> > > with ldN/stN.
> > > > >
> > > > > Of course I'm also happy with completely removing this heuristics.
> > > > >
> > > > > Note some of the comments look off now, also the assignment to
> > > > > ok before the goto is pointless and you should probably turn
> > > > > this into a dump print instead.
> > > > >
> > > > > Thanks,
> > > > > Richard.
> > > > >
> > > > > > Bootstrapped Regtested on aarch64-none-linux-gnu,
> > > > > > -x86_64-pc-linux-gnu and no issues.
> > > > > >
> > > > > > Ok for master?
> > > > >
> > > > >
> > > > >
> > > > > > Thanks,
> > > > > > Tamar
> > > > > >
> > > > > > gcc/ChangeLog:
> > > > > >
> > > > > > * tree-vect-slp.c (vect_analyze_slp_instance): Moved
> > > > > > load/store
> > > > > lanes
> > > > > > check to ...
> > > > > > * tree-vect-loop.c (vect_analyze_loop_2): ..Here
> > > > > >
> > > > > > gcc/testsuite/ChangeLog:
> > > > > >
> > > > > > * gcc.dg/vect/slp-11b.c: Update output scan.
> > > > > > * gcc.dg/vect/slp-perm-6.c: Likewise.
> > > > > >
> > > > > >
> > > > >
> > > > > --
> > > > > Richard Biener <rguent...@suse.de> SUSE Software Solutions
> > > > > Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany; GF:
> > > > > Felix Imend
> > > >
> > >
> > > --
> > > Richard Biener <rguent...@suse.de>
> > > SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409
> > > Nuernberg, Germany; GF: Felix Imend
> >
>
> --
> Richard Biener <rguent...@suse.de>
> SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409
> Nuernberg, Germany; GF: Felix Imend
