[GlobalISel] Delete unused TargetPassConfig::addPreRegBankSelect

[MaskRay]

Summary

If there is a need in the future, addRegBankSelect() can be used instead.

[MaskRay]

Ping:)

[MaskRay]

@qcolombet 😊

[qcolombet]

Hi @MaskRay,

I would rather we keep it. Although like you said we could piggyback on addRegBankSelect, it is clearer to have a separate method and that's consistent with the other GISel passes.

Cheers,
-Quentin

llvm/include/llvm/CodeGen/TargetPassConfig.h

public:
   /// This method may be implemented by targets that want to run passes
   /// immediately before legalization.
   virtual void addPreLegalizeMachineIR() {}
 
   /// This method should install a legalize pass, which converts the instruction
   /// sequence into one that can be selected by the target.
   virtual bool addLegalizeMachineIR() { return true; }
 
-  /// This method may be implemented by targets that want to run passes
-  /// immediately before the register bank selection.
-  virtual void addPreRegBankSelect() {}
-
   /// This method should install a register bank selector pass, which
   /// assigns register banks to virtual registers without a register
   /// class or register banks.
   virtual bool addRegBankSelect() { return true; }
 
   /// This method may be implemented by targets that want to run passes
   /// immediately before the (global) instruction selection.
   virtual void addPreGlobalInstructionSelect() {}

llvm/lib/CodeGen/TargetPassConfig.cpp

if (Selector == SelectorType::GlobalISel) {
     if (addIRTranslator())
       return true;
 
     addPreLegalizeMachineIR();
 
     if (addLegalizeMachineIR())
       return true;
 
-    // Before running the register bank selector, ask the target if it
-    // wants to run some passes.
-    addPreRegBankSelect();
-
     if (addRegBankSelect())
       return true;
 
     addPreGlobalInstructionSelect();
 
     if (addGlobalInstructionSelect())
       return true;