From mboxrd@z Thu Jan  1 00:00:00 1970
From: Antriksh Pany <antriksh.pany@gmail.com>
Subject: Re: [PATCH 4/5] tree-walk: unroll get_mode since loop boundaries are well-known
Date: Tue, 5 Apr 2011 16:55:24 -0700
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Cc: Junio C Hamano <gitster@pobox.com>, git@vger.kernel.org,
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To: Dan McGee <dpmcgee@gmail.com>
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On Mon, Apr 4, 2011 at 10:33 PM, Dan McGee <dpmcgee@gmail.com> wrote:
> ....
> Totally agree; I should have tried to do it this way in the first
> place. However, compiling the fixed-length 0 to 5 loop does not
> produce fully-unrolled assembly for me with CFLAGS="-march=native
> -mtune=native -O2 -pipe -g" on x86_64. I see two copies of the loop
> only, and even worse is the (lack of) performance (each is the mode of
> 3 runs). Compilers are stupid apparently.
> ....

Can you try -O3? Or an explicit '-funroll-loops'?
gcc I think does not do aggressive speed optimizations at the cost of
space when at O2.

Cheers
Antriksh