[PATCH] D68028: [clang] Add no_builtin attribute

Fri Sep 27 06:50:56 PDT 2019

tejohnson added a comment.

In D68028#1685912 <https://reviews.llvm.org/D68028#1685912>, @gchatelet wrote:

> @tejohnson I believe this is the missing part for D67923 <https://reviews.llvm.org/D67923>.

Thanks, yep I will take a closer look at the patch today.

> I'm unsure if we still need the `BitVector` at all in the `TLI` since it could be a simple attribute lookup on the function.

If we didn't save the info on the TLI we would instead need to save the Function object in the TLI and query the attribute info off the Function on every lookup, which seems heavier weight. I think caching the info in that object for fast lookup is going to be better. And as noted in the comments there, we can replace it with the existing AvailableArray moved from the base Impl object into the TLI and remove the override bitvector once this goes in, we use these attributes to set the TLI info on construction, and we remove the clang code that sets the unavailability from the CodeGenOpts which will no longer be needed. If this patch goes in first I can just modify my TLI patch to do that all in one go. Maybe that is best...

> Do you see any problematic interactions with the inlining phase?

The inliner will need to be modified to respect the function attributes.

Repository:
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https://reviews.llvm.org/D68028