[PATCH] D80249: WIP: CodeGen: Don't lazily construct MachineFunctionInfo

[Matt Arsenault via Phabricator via llvm-commits]

arsenm created this revision.
arsenm added reviewers: thegameg, craig.topper, qcolombet, paquette, rampitec, scott.linder, kparzysz, hfinkel, aemerson, aditya_nandakumar, dsanders, ahatanak, asb, bruno, sunfish.
Herald added subscribers: kerbowa, dexonsmith, hiraditya, tpr, nhaehnle, wdng, jvesely.
Herald added a project: LLVM.

This fixes what I consider to be an API flaw I've tripped over
multiple times. The point this is constructed isn't well defined, so
depending on where this is first called, you can conclude different
information based on the MachineFunction. For example, the AMDGPU
implementation inspected the MachineFrameInfo on construction for the
stack objects and if the frame has calls. This kind of worked in
SelectionDAG which visited all allocas up front, but broke in
GlobalISel which hasn't visited any of the IR when arguments are
lowered.

      

I've run into similar problems before with the MIR parser and trying
to make use of other MachineFunction fields, so I think it's best to
just categorically disallow dependency on the MachineFunction state in
the constructor and to always construct this at the same time as the
MachineFunction itself.

      

A missing feature I still could use is a way to access an custom
analysis pass on the IR here.

I'll update the rest of the targets after initial comments


https://reviews.llvm.org/D80249

Files:
  llvm/include/llvm/CodeGen/MachineFunction.h
  llvm/include/llvm/Target/TargetMachine.h
  llvm/lib/CodeGen/MachineFunction.cpp
  llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp
  llvm/lib/Target/AMDGPU/AMDGPUMachineFunction.cpp
  llvm/lib/Target/AMDGPU/AMDGPUMachineFunction.h
  llvm/lib/Target/AMDGPU/AMDGPUSubtarget.cpp
  llvm/lib/Target/AMDGPU/AMDGPUSubtarget.h
  llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
  llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.h
  llvm/lib/Target/AMDGPU/R600MachineFunctionInfo.cpp
  llvm/lib/Target/AMDGPU/R600MachineFunctionInfo.h
  llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.cpp
  llvm/lib/Target/AMDGPU/SIMachineFunctionInfo.h
  llvm/lib/Target/X86/X86MachineFunctionInfo.h
  llvm/lib/Target/X86/X86TargetMachine.cpp
  llvm/lib/Target/X86/X86TargetMachine.h

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