[llvm] GlobalISel lane masks merging (PR #73337)

[Matt Arsenault via llvm-commits]

================
@@ -415,19 +411,19 @@ FunctionPass *llvm::createSILowerI1CopiesPass() {
   return new SILowerI1Copies();
 }
 
-static unsigned createLaneMaskReg(MachineFunction &MF) {
-  const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
-  MachineRegisterInfo &MRI = MF.getRegInfo();
-  return MRI.createVirtualRegister(ST.isWave32() ? &AMDGPU::SReg_32RegClass
-                                                 : &AMDGPU::SReg_64RegClass);
+Register llvm::createLaneMaskReg(MachineRegisterInfo *MRI,
+                                 Register *LaneMaskRegAttrs) {
----------------
arsenm wrote:

What's the point of these parameters being pointers? 

https://github.com/llvm/llvm-project/pull/73337