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From: Paul Brook <paul@codesourcery.com>
Subject: Re: [Qemu-devel] [PATCH][ppc] convert SPE logical instructions to TCG
Date: Wed, 15 Oct 2008 10:32:27 +0100
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To: qemu-devel@nongnu.org
Cc: Nathan Froyd <froydnj@codesourcery.com>

On Wednesday 15 October 2008 03:09:16 Nathan Froyd wrote:
> + =A0 =A0TCGv t0 =3D tcg_temp_local_new(TCG_TYPE_I64); =A0 =A0 =A0 =A0 =
=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0
> =A0+ =A0 =A0TCGv t1 =3D tcg_temp_local_new(TCG_TYPE_I64); =A0 =A0 =A0 =A0=
 =A0 =A0 =A0 =A0 =A0 =A0

These should be tcg_temp_new.

Local variables (tcg_temp_local_new) introduce a lot of additional overhead=
,=20
should only be used when absolutely necessary. A local variable is required=
=20
if the value is required to live over multiple basic blocks. i.e. accross a=
=20
branch op or a dyngen op. In the latter case it's probably best to eliminat=
e=20
the dyngen op.

Paul