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Re: [tcb] Incremental SSA updates


Zdenek Dvorak wrote:

because we do not do many of them (usually one or two per optimization
pass, at most).  I definitely can come up with examples where ignoring
this during incremental ssa updates would cause quadratic behavior.

OK, that would be interesting to have, if you can produce them. Thanks.

How do you know the block does not contain uses of affected names,
without scanning it?

Oh, we do a pre-pass scan in prepare_blocks_for_update. Your approach uses DU chains, which saves you from doing this. That's what I'm mostly interested in testing. I'll let you know as soon as I have something useful to report.


Diego.



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