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Date: Thu, 23 Jul 2009 11:25:34 +0200
Message-ID: <761ea48b0907230225g77d7d0e6q6e1fd8af302ed795@mail.gmail.com>
Subject: Re: [Qemu-devel] [PATCH] RFC: TCG constant propagation.
From: Laurent Desnogues <laurent.desnogues@gmail.com>
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To: Filip Navara <filip.navara@gmail.com>
Cc: qemu-devel@nongnu.org, Paul Brook <paul@codesourcery.com>

On Thu, Jul 23, 2009 at 11:08 AM, Filip Navara<filip.navara@gmail.com> wrote:
> Also it looks that the actual code size is worse for TCG ARM target
> with this optimization. To mitigate it I propose the other attached
> patch which uses the barrel shifter for more optimal generation of the
> "movi" operation. I can't test it, so any help is welcome.

This is wrong for two reasons:
   - this is a rotation, you only check for shifts
   - the rotation amount is multiplied by 2 before being applied to the
     8-bit immediate field.


Laurent