[all-commits] [llvm/llvm-project] 2dcf05: [CodeGen] Store call frame size in MachineBasicBlock

[Jay Foad via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 2dcf0512599280ba68a5028f24ea96dfdb37b7b7
      https://github.com/llvm/llvm-project/commit/2dcf0512599280ba68a5028f24ea96dfdb37b7b7
  Author: Jay Foad <jay.foad at amd.com>
  Date:   2023-07-27 (Thu, 27 Jul 2023)

  Changed paths:
    M llvm/include/llvm/CodeGen/MachineBasicBlock.h
    M llvm/include/llvm/CodeGen/TargetInstrInfo.h
    M llvm/lib/CodeGen/MIRParser/MILexer.cpp
    M llvm/lib/CodeGen/MIRParser/MILexer.h
    M llvm/lib/CodeGen/MIRParser/MIParser.cpp
    M llvm/lib/CodeGen/MachineBasicBlock.cpp
    M llvm/lib/CodeGen/MachineVerifier.cpp
    M llvm/lib/CodeGen/PrologEpilogInserter.cpp
    M llvm/lib/CodeGen/TargetInstrInfo.cpp
    M llvm/lib/Target/ARM/ARMISelLowering.cpp
    M llvm/lib/Target/AVR/AVRISelLowering.cpp
    M llvm/lib/Target/M68k/M68kISelLowering.cpp
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/ARM/2013-06-03-ByVal-2Kbytes.ll
    M llvm/test/CodeGen/ARM/no-register-coalescing-in-returnsTwice.mir
    A llvm/test/CodeGen/MIR/ARM/call-frame-size.mir
    M llvm/tools/llvm-reduce/ReducerWorkItem.cpp

  Log Message:
  -----------
  [CodeGen] Store call frame size in MachineBasicBlock

Record the call frame size on entry to each basic block. This is usually
zero except when a basic block has been split in the middle of a call
sequence.

This simplifies PEI::replaceFrameIndices which previously had to visit
basic blocks in a specific order and had special handling for
unreachable blocks. More importantly it paves the way for an equally
simple implementation of a backwards version of replaceFrameIndices,
which is required to fully convert PrologEpilogInserter to backwards
register scavenging, which is preferred because it does not rely on
accurate kill flags.

Differential Revision: https://reviews.llvm.org/D156113