Re: [Qemu-devel] [PATCH 1/3] tcg: add ext{8,16,32}u_i{32,64} TCG ops

[Nathan Froyd]

On Wed, Sep 30, 2009 at 11:09:35PM +0200, Aurelien Jarno wrote:
> Currently zero extensions ops are implemented by a and op with a
> constant. This is then catched in some backend, and replaced by
> a zero extension instruction. While this works well on RISC
> machines, this adds a useless register move on non-RISC machines.
> 
> This patch adds ext{8,16,32}u_i{32,64} TCG ops that can be
> implemented in the backends to avoid emitting useless register
> moves.

I have to ask--does this make things go faster?

-Nathan