From: Segher Boessenkool <segher@kernel.crashing.org>
To: David Woodhouse <dwmw2@infradead.org>
Cc: linuxppc-dev@ozlabs.org, Michael Neuling <mikey@neuling.org>,
viro@zeniv.linux.org.uk
Subject: Re: [PATCH] powerpc: provide __bswapdi2
Date: Mon, 13 May 2013 18:55:27 +0200 [thread overview]
Message-ID: <1A549319-FA61-4FB2-97D1-2D9273331019@kernel.crashing.org> (raw)
In-Reply-To: <1368441187.24723.38.camel@i7.infradead.org>
> rlwinm 10,4,8,0xffffffff
> rlwinm 11,3,8,0xffffffff
> rlwimi 10,4,24,0,7
> rlwimi 11,3,24,0,7
> rlwimi 10,4,24,16,23
> rlwimi 11,3,24,16,23
> mr 4,11
> mr 3,10
>> Actually, I'd swap the two mr instructions to never
>> have an instruction that uses the result from the
>> previous one.
>
> Bad GCC. No biscuit.
>
> Should we file a PR?
This is scheduled just fine. Every pair of instructions here can
execute together (on most CPUs, if not all); all instructions after
it are dependent on previous instructions. There also is no issue
(group) restriction that makes this scheduling suboptimal afaics.
Segher
next prev parent reply other threads:[~2013-05-13 16:56 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-10 21:18 [PATCH] powerpc: provide __bswapdi2 David Woodhouse
2013-05-13 6:48 ` Anton Blanchard
2013-05-13 7:20 ` Alan Modra
2013-05-13 10:27 ` David Woodhouse
2013-05-13 16:47 ` Segher Boessenkool
2013-05-13 7:09 ` Michael Neuling
2013-05-13 7:20 ` [PATCH v2] " Michael Neuling
2013-05-13 7:33 ` [PATCH] " Gabriel Paubert
2013-05-13 10:23 ` [PATCH v3] " Michael Neuling
2013-05-13 10:33 ` [PATCH] " David Woodhouse
2013-05-13 10:38 ` David Woodhouse
2013-05-13 10:51 ` Joakim Tjernlund
2013-05-13 11:12 ` Joakim Tjernlund
2013-05-13 13:12 ` Gabriel Paubert
2013-05-13 16:55 ` Segher Boessenkool [this message]
2013-05-14 1:09 ` Stephen Rothwell
2013-05-14 1:25 ` Michael Neuling
2013-05-14 6:59 ` David Woodhouse
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