[PATCH] D61665: [TailCall] Disable tail call if the callee function contain __builtin_frame_address or __builtin_return_address

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

I have a few concerns here:

1. Looping over every instruction in a function is expensive, and makes any pass which checks this for every call in a function take quadratic time overall.
2. You can't inspect the body of a function pointer, or a function in a different translation unit, so we can't make this work consistently.
3. Even in the same translation unit, how do we "preserve" the behavior for values greater than 1?

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I'd prefer to just leave the current behavior if it isn't causing any practical problems.  The user can always use -fno-optimize-sibling-calls if their codebase needs it for some reason.


Repository:
  rL LLVM

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  https://reviews.llvm.org/D61665/new/

https://reviews.llvm.org/D61665