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Re: [PATCH] mm/pg-r4k.c: Dump the generated code

To: Nigel Stephens <nigel@mips.com>
Subject: Re: [PATCH] mm/pg-r4k.c: Dump the generated code
From: "Maciej W. Rozycki" <macro@linux-mips.org>
Date: Wed, 17 Oct 2007 14:31:15 +0100 (BST)
Cc: Thiemo Seufer <ths@networkno.de>, Franck Bui-Huu <vagabon.xyz@gmail.com>, Ralf Baechle <ralf@linux-mips.org>, linux-mips@linux-mips.org
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On Wed, 17 Oct 2007, Nigel Stephens wrote:

> Aha, that probably explains it. Franck is using the "SDE for Linux v6.05"
> toolchain, and in that version of GCC -march=mips32r2 implies a default of
> -mtune=24k. Tuning for 24K implies -falign-loops=8 -falign-jumps=8 and
> -falign-functions=8. This is undoubtedly why code compiled with
> "-march=mips32r2 -msmartmips" contains more nops than "-march=4ksd".nIn theory
> the extra nops should also disappear if you compile with -Os instead of -O2.

 Another argument for using "-mtune=" explicitly when tuning for a 
particular CPU implementation is desired. :-)

  Maciej

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