diff --git a/llvm/include/llvm/CodeGen/GlobalISel/CallLowering.h b/llvm/include/llvm/CodeGen/GlobalISel/CallLowering.h
--- a/llvm/include/llvm/CodeGen/GlobalISel/CallLowering.h
+++ b/llvm/include/llvm/CodeGen/GlobalISel/CallLowering.h
@@ -17,10 +17,8 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/CodeGen/CallingConvLower.h"
-#include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineOperand.h"
 #include "llvm/CodeGen/TargetCallingConv.h"
-#include "llvm/IR/Attributes.h"
 #include "llvm/IR/CallingConv.h"
 #include "llvm/IR/Type.h"
 #include "llvm/IR/Value.h"
@@ -31,11 +29,13 @@
 
 namespace llvm {
 
+class AttributeList;
 class CallBase;
 class DataLayout;
 class Function;
 class FunctionLoweringInfo;
 class MachineIRBuilder;
+class MachineFunction;
 struct MachinePointerInfo;
 class MachineRegisterInfo;
 class TargetLowering;
diff --git a/llvm/include/llvm/CodeGen/GlobalISel/Legalizer.h b/llvm/include/llvm/CodeGen/GlobalISel/Legalizer.h
--- a/llvm/include/llvm/CodeGen/GlobalISel/Legalizer.h
+++ b/llvm/include/llvm/CodeGen/GlobalISel/Legalizer.h
@@ -22,13 +22,15 @@
 
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/StringRef.h"
-#include "llvm/CodeGen/GlobalISel/LegalizerInfo.h"
-#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 
 namespace llvm {
 
+class LegalizerInfo;
+class MachineIRBuilder;
+class MachineInstr;
+class GISelChangeObserver;
 class LostDebugLocObserver;
 
 class Legalizer : public MachineFunctionPass {
diff --git a/llvm/include/llvm/CodeGen/GlobalISel/LegalizerHelper.h b/llvm/include/llvm/CodeGen/GlobalISel/LegalizerHelper.h
--- a/llvm/include/llvm/CodeGen/GlobalISel/LegalizerHelper.h
+++ b/llvm/include/llvm/CodeGen/GlobalISel/LegalizerHelper.h
@@ -22,6 +22,7 @@
 
 #include "llvm/CodeGen/GlobalISel/CallLowering.h"
 #include "llvm/CodeGen/RuntimeLibcalls.h"
+#include "llvm/CodeGen/TargetOpcodes.h"
 
 namespace llvm {
 // Forward declarations.
diff --git a/llvm/include/llvm/CodeGen/RegisterUsageInfo.h b/llvm/include/llvm/CodeGen/RegisterUsageInfo.h
--- a/llvm/include/llvm/CodeGen/RegisterUsageInfo.h
+++ b/llvm/include/llvm/CodeGen/RegisterUsageInfo.h
@@ -20,7 +20,6 @@
 
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseMap.h"
-#include "llvm/CodeGen/RegisterUsageInfo.h"
 #include "llvm/InitializePasses.h"
 #include "llvm/Pass.h"
 #include "llvm/PassRegistry.h"
diff --git a/llvm/lib/CodeGen/GlobalISel/Legalizer.cpp b/llvm/lib/CodeGen/GlobalISel/Legalizer.cpp
--- a/llvm/lib/CodeGen/GlobalISel/Legalizer.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/Legalizer.cpp
@@ -14,7 +14,6 @@
 
 #include "llvm/CodeGen/GlobalISel/Legalizer.h"
 #include "llvm/ADT/PostOrderIterator.h"
-#include "llvm/ADT/SetVector.h"
 #include "llvm/Analysis/OptimizationRemarkEmitter.h"
 #include "llvm/CodeGen/GlobalISel/CSEInfo.h"
 #include "llvm/CodeGen/GlobalISel/CSEMIRBuilder.h"
diff --git a/llvm/lib/CodeGen/GlobalISel/Utils.cpp b/llvm/lib/CodeGen/GlobalISel/Utils.cpp
--- a/llvm/lib/CodeGen/GlobalISel/Utils.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/Utils.cpp
@@ -23,7 +23,6 @@
 #include "llvm/CodeGen/MachineInstrBuilder.h"
 #include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/CodeGen/MachineSizeOpts.h"
 #include "llvm/CodeGen/RegisterBankInfo.h"
 #include "llvm/CodeGen/StackProtector.h"
 #include "llvm/CodeGen/TargetInstrInfo.h"
diff --git a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
--- a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
@@ -43,9 +43,6 @@
 using namespace llvm;
 
 namespace llvm {
-class DIExpression;
-class DILocalVariable;
-class DILocation;
 class MDNode;
 class RegisterBank;
 
diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp
@@ -39,7 +39,6 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MachineValueType.h"
-#include "llvm/Support/MathExtras.h"
 #include <cassert>
 #include <cstdint>
 #include <iterator>
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -36,8 +36,8 @@
 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineInstr.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineInstrBundleIterator.h"
 #include "llvm/CodeGen/MachineMemOperand.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/MachineOperand.h"