[PATCH] D80249: CodeGen: Don't lazily construct MachineFunctionInfo

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added a comment.
Herald added a subscriber: wuzish.

In D80249#2107516 <https://reviews.llvm.org/D80249#2107516>, @kparzysz wrote:

> A "create" function shouldn't return a null pointer.  I think there should be a default MFI that has nothing in it, and it would be what the `createMachineFunctionInfo` returns a pointer to in the absence of overrides.  It could even be statically allocated since is has no members:
>
>   virtual MachineFunctionInfo *
>   createMachineFunctionInfo(BumpPtrAllocator &Allocator, const Function &F,
>                             const TargetSubtargetInfo *STI) const {
>     static MachineFunctionInfo default;
>     return &default;
>   }
>
>
> Edit: fix indentation in the code


I did try to do this, but it didn't work out. It introduces a dependence on CodeGen from Target. I don't think anywhere else uses this pattern to avoid overrides, and just returns null. I don't think this is really an issue in practice, since this is only ever called from target code


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  https://reviews.llvm.org/D80249/new/

https://reviews.llvm.org/D80249