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