[PATCH] D20206: GlobalsAA: Don't assume that intrinsics can't access global variables

[Tom Stellard via llvm-commits]

tstellarAMD added a comment.

In http://reviews.llvm.org/D20206#428381, @dberlin wrote:

> So this is an interesting question.
>  Outside of very specific intrinsics (barriers), or intrinsics passed global
>  variables, which intrinsics do you believe can affect global variables and
>  why?


There probably aren't many besides barriers and maybe some of the cache flushing intrinsics.

> :)

> 

> (Because if the answer is "none", we should probably make the ability to

>  read/write non-passed-in globals an intrinsic property that folks have to

>  opt-in to)


My thinking is that is would be easier to treat intrinsics and functions the same rather than having to add an attribute that makes intrinsics behave like functions.  There are already attributes like: readnone, readonly, argmemonly that can be used to specify that an intrinsic won't access globals.  It doesn't seem like it is too much trouble to ask people to use those for intrinsics, and it looks like most intrinsics already are using these.


http://reviews.llvm.org/D20206