[PATCH] D18046: [X86] Providing correct unwind info in function epilogue

[Violeta Vukobrat via llvm-commits]

violetav added a comment.

Hi Keno,

Thanks for the explanation. Just to check if I am following you, my understanding of your idea is to:

- insert CFI instructions in epilogue during frame lowering (I suppose to use cfi_adjust_cfa_offset)
- surround epilogue with remember state/restore state CFI instructions (also in frame lowering)
- teach TailDuplication to recognize and allow this pattern (a pair of remember/restore state instructions + adjust instructions in between). By "allowing" I mean to duplicate that block even though it contains CFI instructions.
- have the late pass remove duplicate remember/restore state instructions

Is this what you had in mind?


Repository:
  rL LLVM

http://reviews.llvm.org/D18046