[all-commits] [llvm/llvm-project] bd3ee3: Revert "[AArch64][v8.3A] Avoid inserting implicit ...

[Evgenii Stepanov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: bd3ee371e9f0b09d2315701399e48be27844feec
      https://github.com/llvm/llvm-project/commit/bd3ee371e9f0b09d2315701399e48be27844feec
  Author: Evgenii Stepanov <eugenis at google.com>
  Date:   2023-01-19 (Thu, 19 Jan 2023)

  Changed paths:
    M llvm/lib/Target/AArch64/AArch64FrameLowering.cpp
    M llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
    M llvm/test/CodeGen/AArch64/aarch64-signedreturnaddress.ll
    M llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-sp-mod.ll
    M llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-subtarget.ll
    M llvm/test/CodeGen/AArch64/machine-outliner-retaddr-sign-v8-3.ll
    M llvm/test/CodeGen/AArch64/pacbti-llvm-generated-funcs-2.ll
    M llvm/test/CodeGen/AArch64/pacbti-module-attrs.ll
    M llvm/test/CodeGen/AArch64/sign-return-address-cfi-negate-ra-state.ll
    M llvm/test/CodeGen/AArch64/sign-return-address.ll
    M llvm/test/CodeGen/AArch64/wineh-pac.ll

  Log Message:
  -----------
  Revert "[AArch64][v8.3A] Avoid inserting implicit landing pads (PACI*SP)"

Linux kernel sets SCTRL_EL1.BT0 and BT1 to 1 unconditionally, which
makes PACIASP equivalent to BTI C + PACIA LR,SP.

Use the shorter instruction sequence by default.

I'm not aware of anyone who needs the opposite. They are welcome to
revert to the current behavior under a subtarget feature or an
environment check.

This reverts commit 571c8c5263a79293aaadae07b11feb36726eaf53.

Differential Revision: https://reviews.llvm.org/D141978