[PATCH] D158084: [AArch64] Stack probing for function prologues

[Momchil Velikov via Phabricator via llvm-commits]

chill added a comment.

Continuation of https://reviews.llvm.org/D96004

I've added emission of asynchronous unwind directives and some other tweaks here and there.

There're is a known  issue with the CFI fixup pass - that pass assumes a function prologue is contained in a single basic block. With stack probes this is no longer true
as we may create loop(s) while still setting up the frame and issuing CFI directives. I'll think about solving it.

@tnfchris I've read your comments in the original review and I think nevertheless this patch is compatible with GCC even though it does not
behave exactly the same. Main point is that since we store `x29` for frames > 240 bytes, we can assume and maintain for the duration of the function
prologue that the stack has been probed at `[sp]`.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D158084/new/

https://reviews.llvm.org/D158084