[PATCH] D75044: [AArch64] __builtin_return_address for PAuth.

[Daniel Kiss via Phabricator via llvm-commits]

danielkiss updated this revision to Diff 266595.
danielkiss marked an inline comment as done.
danielkiss retitled this revision from "[AArch64] __builtin_extract_return_addr  for PAuth." to "[AArch64] __builtin_return_address for PAuth.".
danielkiss edited the summary of this revision.
danielkiss added a comment.

Changing the implementation from __builtin_extract_return_addr to __builtin_return_address.
Stripping PAC in __builtin_return_address is a better solution,  because:

- we should not expose PAC bits to the user because it could be passed around and that would be an ABI break.
- __builtin_extract_return_addr has a pair, the __builtin_frob_return_addr which won't be supported with PAC.

I'm thinking of adding a warning if __builtin_frob_return_addr is used with PAC on.
Same change will be proposed from gcc too.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D75044/new/

https://reviews.llvm.org/D75044

Files:
  llvm/include/llvm/CodeGen/ISDOpcodes.h
  llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
  llvm/test/CodeGen/AArch64/aarch64-signedreturnaddress.ll

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