[NFC] Use forward decl of MachineCombinerPattern enum to reduce dependencies

[dmgreen]

Sounds good to me.

[asi-sc]

Thanks for the review.
@dmgreen, could you please submit the patch on my behalf? Author: Anton Sidorenko <[e-mail]>

[dmgreen]

Sure thing. Can do.

llvm/include/llvm/CodeGen/TargetInstrInfo.h

 #define LLVM_CODEGEN_TARGETINSTRINFO_H
 
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DenseMapInfo.h"
 #include "llvm/ADT/None.h"
 #include "llvm/CodeGen/MIRFormatter.h"
 #include "llvm/CodeGen/MachineBasicBlock.h"
-#include "llvm/CodeGen/MachineCombinerPattern.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineOperand.h"
 #include "llvm/CodeGen/MachineOutliner.h"
 #include "llvm/CodeGen/RegisterClassInfo.h"
 #include "llvm/CodeGen/VirtRegMap.h"
 #include "llvm/MC/MCInstrInfo.h"

 class SelectionDAG;
 class SMSchedule;
 class SwingSchedulerDAG;
 class RegScavenger;
 class TargetRegisterClass;
 class TargetRegisterInfo;
 class TargetSchedModel;
 class TargetSubtargetInfo;
+enum class MachineCombinerPattern;
 
 template <class T> class SmallVectorImpl;
 
 using ParamLoadedValue = std::pair<MachineOperand, DIExpression*>;
 
 struct DestSourcePair {
   const MachineOperand *Destination;
   const MachineOperand *Source;

llvm/lib/CodeGen/MachineCombiner.cpp

 //===---- MachineCombiner.cpp - Instcombining on SSA form machine code ----===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // The machine combiner pass uses machine trace metrics to ensure the combined
 // instructions do not lengthen the critical path or the resource depth.
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/ProfileSummaryInfo.h"
 #include "llvm/CodeGen/LazyMachineBlockFrequencyInfo.h"
+#include "llvm/CodeGen/MachineCombinerPattern.h"
 #include "llvm/CodeGen/MachineDominators.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineLoopInfo.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/MachineSizeOpts.h"
 #include "llvm/CodeGen/MachineTraceMetrics.h"
 #include "llvm/CodeGen/RegisterClassInfo.h"

llvm/lib/CodeGen/TargetInstrInfo.cpp

 //===-- TargetInstrInfo.cpp - Target Instruction Information --------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the TargetInstrInfo class.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/CodeGen/TargetInstrInfo.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/BinaryFormat/Dwarf.h"
+#include "llvm/CodeGen/MachineCombinerPattern.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineMemOperand.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/MachineScheduler.h"
 #include "llvm/CodeGen/PseudoSourceValue.h"
 #include "llvm/CodeGen/ScoreboardHazardRecognizer.h"
 #include "llvm/CodeGen/StackMaps.h"

llvm/lib/Target/AArch64/AArch64InstrInfo.h

 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_LIB_TARGET_AARCH64_AARCH64INSTRINFO_H
 #define LLVM_LIB_TARGET_AARCH64_AARCH64INSTRINFO_H
 
 #include "AArch64.h"
 #include "AArch64RegisterInfo.h"
 #include "llvm/ADT/Optional.h"
-#include "llvm/CodeGen/MachineCombinerPattern.h"
 #include "llvm/CodeGen/TargetInstrInfo.h"
 #include "llvm/Support/TypeSize.h"
 
 #define GET_INSTRINFO_HEADER
 #include "AArch64GenInstrInfo.inc"
 
 namespace llvm {
 

llvm/lib/Target/AArch64/AArch64InstrInfo.cpp

 #include "AArch64MachineFunctionInfo.h"
 #include "AArch64Subtarget.h"
 #include "MCTargetDesc/AArch64AddressingModes.h"
 #include "Utils/AArch64BaseInfo.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/CodeGen/MachineCombinerPattern.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineMemOperand.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/MachineOperand.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"

llvm/lib/Target/PowerPC/PPCInstrInfo.cpp

 #include "PPCInstrBuilder.h"
 #include "PPCMachineFunctionInfo.h"
 #include "PPCTargetMachine.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/CodeGen/LiveIntervals.h"
+#include "llvm/CodeGen/MachineCombinerPattern.h"
 #include "llvm/CodeGen/MachineConstantPool.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineMemOperand.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/PseudoSourceValue.h"
 #include "llvm/CodeGen/RegisterClassInfo.h"