[all-commits] [llvm/llvm-project] 792853: [SystemZ] Remove the ManipulatesSP flag from backe...

[Jonas Paulsson via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 792853cb786b360fad6dedb9066b76ecd958cb93
      https://github.com/llvm/llvm-project/commit/792853cb786b360fad6dedb9066b76ecd958cb93
  Author: Jonas Paulsson <paulsson at linux.vnet.ibm.com>
  Date:   2022-01-20 (Thu, 20 Jan 2022)

  Changed paths:
    M llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp
    M llvm/lib/Target/SystemZ/SystemZISelLowering.cpp
    M llvm/lib/Target/SystemZ/SystemZMachineFunctionInfo.h

  Log Message:
  -----------
  [SystemZ] Remove the ManipulatesSP flag from backend (NFC).

This flag was set in the presence of stacksave/stackrestore in order to force
a frame pointer.

This should however not be needed per the comment in MachineFrameInfo.h
stating that a a variable sized object "...is the sole condition which
prevents frame pointer elimination", and experiments have also shown that
there seems to be no effect whatsoever on code generation with ManipulatesSP.

Review: Ulrich Weigand