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From: Jan Hubicka <hubicka@kam.mff.cuni.cz>
To: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
Cc: gcc-bugs@gcc.gnu.org
Subject: Re: [Bug rtl-optimization/102178] [12 Regression] SPECFP 2006 470.lbm regressions on AMD Zen CPUs after r12-897-gde56f95afaaa22
Date: Thu, 27 Jan 2022 10:55:33 +0100	[thread overview]
Message-ID: <YfJsFfy+FShDuNAD@kam.mff.cuni.cz> (raw)
In-Reply-To: <bug-102178-4-MLD47DAAJ7@http.gcc.gnu.org/bugzilla/>

> > According to znver2_cost
> > 
> > Cost of sse_to_integer is a little bit less than fp_store, maybe increase
> > sse_to_integer cost(more than fp_store) can helps RA to choose memory
> > instead of GPR.
> 
> That sounds reasonable - GPR<->xmm is cheaper than GPR -> stack -> xmm
> but GPR<->xmm should be more expensive than GPR/xmm<->stack.  As said above
> Zen2 can do reg -> mem, mem -> reg via renaming if 'mem' is somewhat special,
> but modeling that doesn't seem to be necessary.
> 
> We seem to have store costs of 8 and load costs of 6, I'll try bumping the
> gpr<->xmm move cost to 8.

I was simply following latencies here, so indeed reg<->mem bypass is not
really modelled.  I recall doing few experiments which was kind of
inconclusive.


  reply	other threads:[~2022-01-27  9:55 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-02 15:38 [Bug tree-optimization/102178] New: " jamborm at gcc dot gnu.org
2021-09-03  7:07 ` [Bug tree-optimization/102178] " marxin at gcc dot gnu.org
2021-09-06  6:40 ` rguenth at gcc dot gnu.org
2021-09-06  6:41 ` [Bug tree-optimization/102178] [12 Regression] " rguenth at gcc dot gnu.org
2021-09-07  2:46 ` luoxhu at gcc dot gnu.org
2021-09-08 14:06 ` jamborm at gcc dot gnu.org
2021-09-16 16:17 ` jamborm at gcc dot gnu.org
2022-01-20 10:20 ` rguenth at gcc dot gnu.org
2022-01-26 15:57 ` marxin at gcc dot gnu.org
2022-01-27  7:42 ` [Bug rtl-optimization/102178] " rguenth at gcc dot gnu.org
2022-01-27  7:55 ` rguenth at gcc dot gnu.org
2022-01-27  8:13 ` crazylht at gmail dot com
2022-01-27  8:18 ` crazylht at gmail dot com
2022-01-27  8:20 ` rguenth at gcc dot gnu.org
2022-01-27  9:34 ` rguenth at gcc dot gnu.org
2022-01-27  9:55   ` Jan Hubicka [this message]
2022-01-27  9:55 ` hubicka at kam dot mff.cuni.cz
2022-01-27 10:13 ` rguenth at gcc dot gnu.org
2022-01-27 10:14 ` rguenth at gcc dot gnu.org
2022-01-27 10:23 ` hubicka at kam dot mff.cuni.cz
2022-01-27 10:32 ` rguenth at gcc dot gnu.org
2022-01-27 11:18 ` rguenth at gcc dot gnu.org
2022-01-27 11:30 ` rguenther at suse dot de
2022-01-27 11:33 ` rguenther at suse dot de
2022-01-27 12:04   ` Jan Hubicka
2022-01-27 12:04 ` hubicka at kam dot mff.cuni.cz
2022-01-27 13:42 ` hjl.tools at gmail dot com
2022-01-27 14:24 ` rguenth at gcc dot gnu.org
2022-01-27 16:28 ` crazylht at gmail dot com
2022-01-27 16:36 ` crazylht at gmail dot com
2022-01-28 15:48 ` vmakarov at gcc dot gnu.org
2022-01-28 16:02 ` vmakarov at gcc dot gnu.org
2022-02-09 15:51 ` vmakarov at gcc dot gnu.org
2022-02-10  7:45 ` rguenth at gcc dot gnu.org
2022-02-10 15:17 ` vmakarov at gcc dot gnu.org
2022-04-11 13:04 ` rguenth at gcc dot gnu.org
2022-04-25  9:45 ` rguenth at gcc dot gnu.org
2022-04-25 12:52 ` rguenth at gcc dot gnu.org
2022-04-25 13:02 ` rguenth at gcc dot gnu.org
2022-04-25 13:09 ` rguenth at gcc dot gnu.org
2023-04-26  6:55 ` [Bug rtl-optimization/102178] [12/13/14 " rguenth at gcc dot gnu.org
2023-07-27  9:22 ` rguenth at gcc dot gnu.org
2024-05-21  9:10 ` [Bug rtl-optimization/102178] [12/13/14/15 " jakub at gcc dot gnu.org

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