[GISel] Make create.*InstructionSelector arguments const (#98243)

The InstructionSelector objects all take these arguments in as `const`.
This function does not modify the object. Therefore we can mark them as
`const` here.

Author: michaelmaitland

llvm/lib/Target/AArch64/AArch64.h

@@ -62,7 +62,8 @@ FunctionPass *createSMEABIPass();
 ModulePass *createSVEIntrinsicOptsPass();
 InstructionSelector *
 createAArch64InstructionSelector(const AArch64TargetMachine &,
-                                 AArch64Subtarget &, AArch64RegisterBankInfo &);
+                                 const AArch64Subtarget &,
+                                 const AArch64RegisterBankInfo &);
 FunctionPass *createAArch64O0PreLegalizerCombiner();
 FunctionPass *createAArch64PreLegalizerCombiner();
 FunctionPass *createAArch64PostLegalizerCombiner(bool IsOptNone);

llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp

@@ -7790,8 +7790,8 @@ void AArch64InstructionSelector::processPHIs(MachineFunction &MF) {
 namespace llvm {
 InstructionSelector *
 createAArch64InstructionSelector(const AArch64TargetMachine &TM,
-                                 AArch64Subtarget &Subtarget,
-                                 AArch64RegisterBankInfo &RBI) {
+                                 const AArch64Subtarget &Subtarget,
+                                 const AArch64RegisterBankInfo &RBI) {
   return new AArch64InstructionSelector(TM, Subtarget, RBI);
 }
 }

llvm/lib/Target/Mips/Mips.h

@@ -41,9 +41,9 @@ FunctionPass *createMipsPreLegalizeCombiner();
 FunctionPass *createMipsPostLegalizeCombiner(bool IsOptNone);
 FunctionPass *createMipsMulMulBugPass();
 
-InstructionSelector *createMipsInstructionSelector(const MipsTargetMachine &,
-                                                   MipsSubtarget &,
-                                                   MipsRegisterBankInfo &);
+InstructionSelector *
+createMipsInstructionSelector(const MipsTargetMachine &, const MipsSubtarget &,
+                              const MipsRegisterBankInfo &);
 
 void initializeMicroMipsSizeReducePass(PassRegistry &);
 void initializeMipsBranchExpansionPass(PassRegistry &);

llvm/lib/Target/Mips/MipsInstructionSelector.cpp

@@ -927,9 +927,10 @@ bool MipsInstructionSelector::select(MachineInstr &I) {
 }
 
 namespace llvm {
-InstructionSelector *createMipsInstructionSelector(const MipsTargetMachine &TM,
-                                                   MipsSubtarget &Subtarget,
-                                                   MipsRegisterBankInfo &RBI) {
+InstructionSelector *
+createMipsInstructionSelector(const MipsTargetMachine &TM,
+                              const MipsSubtarget &Subtarget,
+                              const MipsRegisterBankInfo &RBI) {
   return new MipsInstructionSelector(TM, Subtarget, RBI);
 }
 } // end namespace llvm

llvm/lib/Target/RISCV/GISel/RISCVInstructionSelector.cpp

@@ -1330,8 +1330,8 @@ void RISCVInstructionSelector::emitFence(AtomicOrdering FenceOrdering,
 namespace llvm {
 InstructionSelector *
 createRISCVInstructionSelector(const RISCVTargetMachine &TM,
-                               RISCVSubtarget &Subtarget,
-                               RISCVRegisterBankInfo &RBI) {
+                               const RISCVSubtarget &Subtarget,
+                               const RISCVRegisterBankInfo &RBI) {
   return new RISCVInstructionSelector(TM, Subtarget, RBI);
 }
 } // end namespace llvm

llvm/lib/Target/RISCV/RISCV.h

@@ -79,9 +79,10 @@ void initializeRISCVMoveMergePass(PassRegistry &);
 FunctionPass *createRISCVPushPopOptimizationPass();
 void initializeRISCVPushPopOptPass(PassRegistry &);
 
-InstructionSelector *createRISCVInstructionSelector(const RISCVTargetMachine &,
-                                                    RISCVSubtarget &,
-                                                    RISCVRegisterBankInfo &);
+InstructionSelector *
+createRISCVInstructionSelector(const RISCVTargetMachine &,
+                               const RISCVSubtarget &,
+                               const RISCVRegisterBankInfo &);
 void initializeRISCVDAGToDAGISelLegacyPass(PassRegistry &);
 
 FunctionPass *createRISCVPostLegalizerCombiner();

llvm/lib/Target/X86/GISel/X86InstructionSelector.cpp

@@ -1871,7 +1871,7 @@ bool X86InstructionSelector::selectSelect(MachineInstr &I,
 
 InstructionSelector *
 llvm::createX86InstructionSelector(const X86TargetMachine &TM,
-                                   X86Subtarget &Subtarget,
-                                   X86RegisterBankInfo &RBI) {
+                                   const X86Subtarget &Subtarget,
+                                   const X86RegisterBankInfo &RBI) {
   return new X86InstructionSelector(TM, Subtarget, RBI);
 }

llvm/lib/Target/X86/X86.h

@@ -161,8 +161,8 @@ FunctionPass *createX86InsertX87waitPass();
 FunctionPass *createX86PartialReductionPass();
 
 InstructionSelector *createX86InstructionSelector(const X86TargetMachine &TM,
-                                                  X86Subtarget &,
-                                                  X86RegisterBankInfo &);
+                                                  const X86Subtarget &,
+                                                  const X86RegisterBankInfo &);
 
 FunctionPass *createX86LoadValueInjectionLoadHardeningPass();
 FunctionPass *createX86LoadValueInjectionRetHardeningPass();