[LLVMdev] AliasAnalysis Documentation Ambiguity

Dan Gohman gohman at apple.com
Fri Jun 11 09:22:03 PDT 2010


On Jun 9, 2010, at 11:35 AM, "Thomas B. Jablin" <tjablin at cs.princeton.edu 
 > wrote:
>
> Should there be a check in BasicAliasAnalysis to ensure that O1 and  
> O2 belong to the same function, or should the documentation be  
> updated to indicate the limits of the alias method? Thanks.

I think there should be such a check.

A noalias Argument should still be NoAlias with Allocas in other  
functions, but a regular Argument should be MayAlias with them -- at  
least for the level of analysis that BasicAA does.

The noalias case is interesting though.  If you're doing extensive  
interprocedural analysis, it may be necessary to add a way to tell  
AliasAnalysis passes to completely ignore noalias.

Dan

>



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