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From: Segher Boessenkool <segher@kernel.crashing.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Akinobu Mita <mita@fixstars.com>,
	Paul Mackerras <paulus@samba.org>,
	linuxppc-dev list <linuxppc-dev@ozlabs.org>
Subject: Re: [RFC/PATCH] powerpc: Always use -mno-string & -mno-multiple
Date: Thu, 22 Mar 2007 13:02:42 +0100	[thread overview]
Message-ID: <5fd8e208c5e6c87f852d6a528589dce3@kernel.crashing.org> (raw)
In-Reply-To: <1174543838.10836.21.camel@localhost.localdomain>

> powerpc: Always use -mno-string and -mno-multiple
>
> The string and multiple load/store instructions are causing more
> damage than help on a lot of processors where they are microcoded
> and are generally no good for the kernel to use. Let's make sure
> we don't emit them on any powerpc variant.

And they help a lot on many 32-bit CPUs.  NAK.

If you tell your GCC to compile for a certain CPU where
these insns would be very slow, GCC will automagically
not generate them, already.


Segher

  reply	other threads:[~2007-03-22 12:03 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-03-22  6:10 [RFC/PATCH] powerpc: Always use -mno-string & -mno-multiple Benjamin Herrenschmidt
2007-03-22 12:02 ` Segher Boessenkool [this message]
2007-03-22 12:06   ` Benjamin Herrenschmidt

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