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Re: local data flow


Kenneth Zadeck wrote:



The right way to do this is not to build chains but to define your own
dataflow problem to do this.


But wouldn't I need to update the problem solution every time a change a bit of the
program - which would be much more costly then doing a local update of some
local def-firstuse or use-nextuse chains?


I think that what you want is something like the reaching uses problem
but you want a forwards version of this rather than a backwards version
as is defined in df-problems.c.


It is reaching uses, but the starting point is not necessarily a definition, but is more
often a use. I want to know about uses that are forward of the current site in the
control flow, but I suppose this is best computed with a backward propagation of
lifeness data. AFAICT that's the same direction that the current reaching use problem
has.




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