A question about bytecodes + unsigned load performance ./. add performace

Christian Thalinger Christian.Thalinger at Sun.COM
Fri Jan 16 06:29:04 PST 2009

On Thu, 2009-01-15 at 12:51 -0800, John Rose wrote:
> The problem of delaying optimizations until the matcher is the  
> optimizer (esp. loop opts) can push the graph into an unrecognizable  
> shape.  If control inputs are preventing the matcher's merge-up,  
> perhaps they are fallout from loop opts or some other CFG change.
> Maybe we should bite the bullet and introduce an ideal node LoadUB  
> for read-unsigned-8 (and maybe LoadUI for read-unsigned-32? -- we  
> have LoadC for LoadUS; it could be renamed to LoadUS).
> If we rewrite LoadB/AndI pairs early to LoadUB, in Node::Ideal(), the  
> optimization will be "in the bank" and later transformations cannot  
> interfere with it.

Should I try to make that changes?

-- Christian

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