[all-commits] [llvm/llvm-project] fae3f9: [ARM] Fix prologue/epilogue for pacbti-m leaf func...

[john-brawn-arm via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: fae3f9ec4febd3140df297bcd05e969fd43dc231
      https://github.com/llvm/llvm-project/commit/fae3f9ec4febd3140df297bcd05e969fd43dc231
  Author: John Brawn <john.brawn at arm.com>
  Date:   2023-09-04 (Mon, 04 Sep 2023)

  Changed paths:
    M llvm/lib/Target/ARM/ARMFrameLowering.cpp
    A llvm/test/CodeGen/Thumb2/pacbti-m-stack-arg.ll

  Log Message:
  -----------
  [ARM] Fix prologue/epilogue for pacbti-m leaf functions

R12 is callee-saved in functions with pacbti-m enabled, but this is
done in assignCalleeSavedSpillSlots, meaning that in
determineCalleeSaves we have to manually set CanEliminateFrame.

This fixes a bug where in leaf functions with no other callee-saved
registers the aut instruction wouldn't be emitted and stack offsets
of arguments passed on the stack would be incorrect.

Differential Revision: https://reviews.llvm.org/D157865