[llvm-commits] [llvm] r122791 - /llvm/trunk/lib/Transforms/Scalar/LoopInstSimplify.cpp

Duncan Sands baldrick at free.fr
Tue Jan 4 00:20:19 PST 2011


Hi Cameron,

> Address most of Duncan's review comments. Also, make LoopInstSimplify a simple
> FunctionPass. It probably doesn't have a reason to be a LoopPass, as it will
> probably drop the simple fixed point and either use RPO iteration or Duncan's
> approach in instsimplify of only revisiting instructions that have changed.
>
> The next step is to preserve LoopSimplify. This looks like it won't be too hard,
> although the pass manager doesn't actually seem to respect when non-loop passes
> claim to preserve LCSSA or LoopSimplify. This will have to be fixed.

as far as I can see the pass is now identical to instsimplify, only it preserves
LCSSA form.  In that case, why not delete the pass and teach instsimplify to
preserve LCSSA form if it detects the presence of the LCSSA analysis?  However
I think Chris is right and you should go back to having this be a loop pass.

Ciao, Duncan.




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