[llvm-commits] [llvm] r53085 - /llvm/trunk/lib/Transforms/Scalar/LoopUnswitch.cpp

[Devang Patel]

On Jul 2, 2008, at 11:00 PM, Chris Lattner wrote:

> Devang,
>
> In the short term, a horrible but "better than nothing" solution is
> for Unswitch to declare that it preserves domtree info... and have it
> call "recalculate" on the domtree analysis any time it actually
> unswitches a loop in a function.
>
> The advantage of this approach is that recalculation of domtree only
> happens if an unswitch happens.  If you have:
>
> pass_a
> loopunswitch
> pass_b
>
> and all of them need dominfo, you will get:
>
> dominfo
> pass_a
> loopunswitch  <sometimes recomputes dominfo from scratch>
> pass_b
>
> instead of:
>
> dominfo
> pass_a
> loopunswitch
> dominfo  <always computed>
> pass_b
>
> What do you think?

good idea.

Thanks!
-
Devang