llvm dev - Jan 2020 - Alignment parameter attributes

"Doerfert, Johannes via llvm-dev" <llvm-dev at lists.llvm.org>
writes:
> We could use a custom tag on `llvm.assume`, as an extension of
> https://reviews.llvm.org/D72475, but that is not yet implemented.
I had thought about using llvm.assume but was wondering if there is a
better way.  Tagging the loads with metadata really seems about the same
amount of effort.  Both require major surgery to code generation.

Thanks for your help Johannes!

                  -David

It might be interesting to add "pointee" attributes on pointers, that
is attributes that are attached to the pointee, however that requires a larger
discussion.

________________________________________
From: Greene, David <david.greene at hpe.com>
Sent: Tuesday, January 14, 2020 16:23
To: Doerfert, Johannes
Cc: llvm-dev at lists.llvm.org
Subject: Re: [llvm-dev] Alignment parameter attributes

"Doerfert, Johannes via llvm-dev" <llvm-dev at lists.llvm.org>
writes:
> We could use a custom tag on `llvm.assume`, as an extension of
> https://reviews.llvm.org/D72475, but that is not yet implemented.
I had thought about using llvm.assume but was wondering if there is a
better way.  Tagging the loads with metadata really seems about the same
amount of effort.  Both require major surgery to code generation.

Thanks for your help Johannes!

                  -David

"Doerfert, Johannes via llvm-dev" <llvm-dev at lists.llvm.org>
writes:
> It might be interesting to add "pointee" attributes on pointers,
that
> is attributes that are attached to the pointee, however that requires
> a larger discussion.
For sure.  I think it could be useful but we would need more use-cases
to justify it.  I'm not sure my situation rises to the level of being a
really compelling case since there are other ways to fix this issue,
they just aren't very pleasant to implement.  :)

                        -David

Haven't followed the discussion in detail - but just in case: pointee types
aren't something you should build further reliance on as the long term plan
is to remove them. (to have opaque pointer types that don't carry any
information about what they point to) - in part because LLVM doesn't
provide any guarantees about the type safety of pointers, etc.

On Tue, Jan 14, 2020 at 2:27 PM Doerfert, Johannes via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> It might be interesting to add "pointee" attributes on pointers,
that is
> attributes that are attached to the pointee, however that requires a larger
> discussion.
>
> ________________________________________
> From: Greene, David <david.greene at hpe.com>
> Sent: Tuesday, January 14, 2020 16:23
> To: Doerfert, Johannes
> Cc: llvm-dev at lists.llvm.org
> Subject: Re: [llvm-dev] Alignment parameter attributes
>
> "Doerfert, Johannes via llvm-dev" <llvm-dev at
lists.llvm.org> writes:
>
> > We could use a custom tag on `llvm.assume`, as an extension of
> > https://reviews.llvm.org/D72475, but that is not yet implemented.
>
> I had thought about using llvm.assume but was wondering if there is a
> better way.  Tagging the loads with metadata really seems about the same
> amount of effort.  Both require major surgery to code generation.
>
> Thanks for your help Johannes!
>
>                   -David
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
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