[llvm-dev] Alias scope and noalias metadata

[ramshankar r via llvm-dev]

Hi there!

Greetings! I am wondering how I may be able get these annotations !noalias and !alias.scope to show up- I have a function with restrict added to the arguments but I do not see these intrinsics with clang -emit-llvm. Which pass inserts them?

Best,

Ram 

[Johannes Doerfert via llvm-dev]

Hi Ram,

The inliner will translate `noalias` on an argument to those metadata annotations.

Cheers,

  Johannes

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[ramshankar r via llvm-dev]

OK, I see. So to be clear the code is in the inliner? I would like to explore if I can do it without inlining?!

[Johannes Doerfert via llvm-dev]

The logic to do the transformation from `noalias` to that is in the inliner, I think.

You can use the metadata directly as well when you generate IR, I doubt there is a user hook from clang to do so.

There is an ongoing effort to replace/augment the alias metadata though as it is not sound and not suitable to use it for other things, e.g., local restrict pointers.

Hi Ram,


The inliner will translate `noalias` on an argument to those metadata
annotations.


Cheers,

  Johannes


On 6/3/20 10:02 AM, ramshankar r via llvm-dev wrote:

Hi there!

Greetings! I am wondering how I may be able get these annotations !noalias
and !alias.scope to show up- I have a function with restrict added to the
arguments but I do not see these intrinsics with clang -emit-llvm. Which
pass inserts them?

Best,
Ram



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LLVM Developers mailing listll...@lists.llvm.orghttps://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev