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Re: [tree-ssa] Removing redundant loads


On Thu, 2003-05-29 at 17:32, Daniel Berlin wrote:

> Right. So why are we spending time on implementing into-SSA 
> optimizations?
>
Because we can?

They come at essentially zero cost as they are piggy-backed to the SSA
renamer pass.  They catch easy things that help us save time on later
passes.  They give us something we still don't have (copy-prop,
redundancy elimination).

Again, once we start testing different combinations of passes we'll find
out which one we like best.  It's very easy to test, really.  But we
first need to have them implemented.

One potential scenario would be to enable the dominator-based
optimizations at -O1 (they're really blazingly fast) and have PRE run at
-O2 or higher.


Diego.


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