[llvm-branch-commits] [llvm] AMDGPU/GlobalISel: RBSelect (PR #112863)

[Diana Picus via llvm-branch-commits]

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@@ -63,4 +70,189 @@ char &llvm::AMDGPURBSelectID = AMDGPURBSelect::ID;
 
 FunctionPass *llvm::createAMDGPURBSelectPass() { return new AMDGPURBSelect(); }
 
-bool AMDGPURBSelect::runOnMachineFunction(MachineFunction &MF) { return true; }
+bool shouldRBSelect(MachineInstr &MI) {
+  if (isTargetSpecificOpcode(MI.getOpcode()) && !MI.isPreISelOpcode())
+    return false;
+
+  if (MI.getOpcode() == AMDGPU::PHI || MI.getOpcode() == AMDGPU::IMPLICIT_DEF)
+    return false;
+
+  if (MI.isInlineAsm())
+    return false;
+
+  return true;
+}
+
+void setRB(MachineInstr &MI, MachineOperand &DefOP, MachineIRBuilder B,
+           MachineRegisterInfo &MRI, const RegisterBank &RB) {
+  Register Reg = DefOP.getReg();
+  // Register that already has Register class got it during pre-inst selection
+  // of another instruction. Maybe cross bank copy was required so we insert a
+  // copy trat can be removed later. This simplifies post-rb-legalize artifact
----------------
rovka wrote:

```suggestion
  // copy that can be removed later. This simplifies post-rb-legalize artifact
```

https://github.com/llvm/llvm-project/pull/112863