[PATCH] D77632: [TLI] Per-function fveclib for math library used for vectorization

[Mehdi AMINI via Phabricator via cfe-commits]

mehdi_amini added a comment.

The existing TLI provides a very convenient way to define a VecLib without LLVM knowing about it ahead of time. This feature is important for any embedded use of LLVM as a library out-of-tree (I'll add a unit-test in-tree).
I don't think it is a big change to this patch to preserve the current ability but I wanted to check first (and in the meantime I reverted in temporarily in https://reviews.llvm.org/D77925 to avoid the feature regression).

At the moment the place where you seem to use this knowledge is with the `enum VectorLibrary`  in the `TargetLibraryInfoImpl` class, and the `VecLibDescs` array which statically contains the known VecLib.
It seems to me that if we replace this enum with a string instead to identify the VecLib everything should still hold together and this would fit with minor changes to this path. The `VecLibDescs` could just be a `StringMap<VectorLibraryDescriptors>` in this case.

That was a third-party (in my case the XLA compiler) can still register its own "XLA" VecLib and add all the descriptors.

How does it sound?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D77632/new/

https://reviews.llvm.org/D77632