diff --git a/llvm/utils/TableGen/CompressInstEmitter.cpp b/llvm/utils/TableGen/CompressInstEmitter.cpp
--- a/llvm/utils/TableGen/CompressInstEmitter.cpp
+++ b/llvm/utils/TableGen/CompressInstEmitter.cpp
@@ -72,7 +72,6 @@
 #include "CodeGenTarget.h"
 #include "llvm/ADT/IndexedMap.h"
 #include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
diff --git a/llvm/utils/TableGen/GICombinerEmitter.cpp b/llvm/utils/TableGen/GICombinerEmitter.cpp
--- a/llvm/utils/TableGen/GICombinerEmitter.cpp
+++ b/llvm/utils/TableGen/GICombinerEmitter.cpp
@@ -23,7 +23,6 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ScopedPrinter.h"
-#include "llvm/Support/Timer.h"
 #include "llvm/TableGen/Error.h"
 #include "llvm/TableGen/StringMatcher.h"
 #include "llvm/TableGen/TableGenBackend.h"
diff --git a/llvm/utils/TableGen/GlobalISelEmitter.cpp b/llvm/utils/TableGen/GlobalISelEmitter.cpp
--- a/llvm/utils/TableGen/GlobalISelEmitter.cpp
+++ b/llvm/utils/TableGen/GlobalISelEmitter.cpp
@@ -32,7 +32,6 @@
 #include "CodeGenDAGPatterns.h"
 #include "SubtargetFeatureInfo.h"
 #include "llvm/ADT/Optional.h"
-#include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Support/CodeGenCoverage.h"
 #include "llvm/Support/CommandLine.h"
@@ -668,7 +667,6 @@
 class OperandMatcher;
 class MatchAction;
 class PredicateMatcher;
-class RuleMatcher;
 
 class Matcher {
 public:
diff --git a/llvm/utils/TableGen/InfoByHwMode.h b/llvm/utils/TableGen/InfoByHwMode.h
--- a/llvm/utils/TableGen/InfoByHwMode.h
+++ b/llvm/utils/TableGen/InfoByHwMode.h
@@ -20,11 +20,9 @@
 
 #include <map>
 #include <string>
-#include <vector>
 
 namespace llvm {
 
-struct CodeGenHwModes;
 class Record;
 class raw_ostream;
 
diff --git a/llvm/utils/TableGen/InfoByHwMode.cpp b/llvm/utils/TableGen/InfoByHwMode.cpp
--- a/llvm/utils/TableGen/InfoByHwMode.cpp
+++ b/llvm/utils/TableGen/InfoByHwMode.cpp
@@ -18,7 +18,6 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 
-#include <set>
 #include <string>
 
 using namespace llvm;
diff --git a/llvm/utils/TableGen/IntrinsicEmitter.cpp b/llvm/utils/TableGen/IntrinsicEmitter.cpp
--- a/llvm/utils/TableGen/IntrinsicEmitter.cpp
+++ b/llvm/utils/TableGen/IntrinsicEmitter.cpp
@@ -18,7 +18,6 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/TableGen/Error.h"
 #include "llvm/TableGen/Record.h"
-#include "llvm/TableGen/StringMatcher.h"
 #include "llvm/TableGen/StringToOffsetTable.h"
 #include "llvm/TableGen/TableGenBackend.h"
 #include <algorithm>
diff --git a/llvm/utils/TableGen/OptParserEmitter.cpp b/llvm/utils/TableGen/OptParserEmitter.cpp
--- a/llvm/utils/TableGen/OptParserEmitter.cpp
+++ b/llvm/utils/TableGen/OptParserEmitter.cpp
@@ -13,7 +13,6 @@
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/TableGen/Record.h"
 #include "llvm/TableGen/TableGenBackend.h"
-#include <cctype>
 #include <cstring>
 #include <map>
 #include <memory>
diff --git a/llvm/utils/TableGen/OptRSTEmitter.cpp b/llvm/utils/TableGen/OptRSTEmitter.cpp
--- a/llvm/utils/TableGen/OptRSTEmitter.cpp
+++ b/llvm/utils/TableGen/OptRSTEmitter.cpp
@@ -8,15 +8,8 @@
 
 #include "OptEmitter.h"
 #include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringMap.h"
-#include "llvm/ADT/Twine.h"
-#include "llvm/TableGen/Error.h"
 #include "llvm/TableGen/Record.h"
-#include "llvm/TableGen/TableGenBackend.h"
-#include <cctype>
-#include <cstring>
-#include <map>
 
 using namespace llvm;
 
diff --git a/llvm/utils/TableGen/PredicateExpander.h b/llvm/utils/TableGen/PredicateExpander.h
--- a/llvm/utils/TableGen/PredicateExpander.h
+++ b/llvm/utils/TableGen/PredicateExpander.h
@@ -17,12 +17,12 @@
 #define LLVM_UTILS_TABLEGEN_PREDICATEEXPANDER_H
 
 #include "llvm/ADT/StringRef.h"
-#include "llvm/Support/raw_ostream.h"
-#include "llvm/TableGen/Record.h"
+#include <vector>
 
 namespace llvm {
 
 class raw_ostream;
+class Record;
 
 class PredicateExpander {
   bool EmitCallsByRef;
diff --git a/llvm/utils/TableGen/RegisterBankEmitter.cpp b/llvm/utils/TableGen/RegisterBankEmitter.cpp
--- a/llvm/utils/TableGen/RegisterBankEmitter.cpp
+++ b/llvm/utils/TableGen/RegisterBankEmitter.cpp
@@ -17,7 +17,6 @@
 #include "llvm/TableGen/Record.h"
 #include "llvm/TableGen/TableGenBackend.h"
 
-#include "CodeGenHwModes.h"
 #include "CodeGenRegisters.h"
 #include "CodeGenTarget.h"
 
diff --git a/llvm/utils/TableGen/SearchableTableEmitter.cpp b/llvm/utils/TableGen/SearchableTableEmitter.cpp
--- a/llvm/utils/TableGen/SearchableTableEmitter.cpp
+++ b/llvm/utils/TableGen/SearchableTableEmitter.cpp
@@ -16,9 +16,6 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/StringExtras.h"
-#include "llvm/Support/Format.h"
-#include "llvm/Support/MemoryBuffer.h"
-#include "llvm/Support/SourceMgr.h"
 #include "llvm/TableGen/Error.h"
 #include "llvm/TableGen/Record.h"
 #include <algorithm>
@@ -32,8 +29,6 @@
 
 namespace {
 
-struct GenericTable;
-
 int getAsInt(Init *B) {
   return cast<IntInit>(B->convertInitializerTo(IntRecTy::get()))->getValue();
 }
diff --git a/llvm/utils/TableGen/WebAssemblyDisassemblerEmitter.h b/llvm/utils/TableGen/WebAssemblyDisassemblerEmitter.h
--- a/llvm/utils/TableGen/WebAssemblyDisassemblerEmitter.h
+++ b/llvm/utils/TableGen/WebAssemblyDisassemblerEmitter.h
@@ -14,12 +14,13 @@
 #ifndef LLVM_UTILS_TABLEGEN_WEBASSEMBLYDISASSEMBLEREMITTER_H
 #define LLVM_UTILS_TABLEGEN_WEBASSEMBLYDISASSEMBLEREMITTER_H
 
-#include "CodeGenInstruction.h"
 #include "llvm/ADT/ArrayRef.h"
-#include "llvm/Support/raw_ostream.h"
 
 namespace llvm {
 
+class CodeGenInstruction;
+class raw_ostream;
+
 void emitWebAssemblyDisassemblerTables(
     raw_ostream &OS,
     const ArrayRef<const CodeGenInstruction *> &NumberedInstructions);
diff --git a/llvm/utils/TableGen/WebAssemblyDisassemblerEmitter.cpp b/llvm/utils/TableGen/WebAssemblyDisassemblerEmitter.cpp
--- a/llvm/utils/TableGen/WebAssemblyDisassemblerEmitter.cpp
+++ b/llvm/utils/TableGen/WebAssemblyDisassemblerEmitter.cpp
@@ -14,6 +14,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "WebAssemblyDisassemblerEmitter.h"
+#include "CodeGenInstruction.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Support/raw_ostream.h"
 #include "llvm/TableGen/Record.h"
 
 namespace llvm {
diff --git a/llvm/utils/TableGen/X86DisassemblerTables.h b/llvm/utils/TableGen/X86DisassemblerTables.h
--- a/llvm/utils/TableGen/X86DisassemblerTables.h
+++ b/llvm/utils/TableGen/X86DisassemblerTables.h
@@ -17,15 +17,18 @@
 #define LLVM_UTILS_TABLEGEN_X86DISASSEMBLERTABLES_H
 
 #include "X86DisassemblerShared.h"
-#include "X86ModRMFilters.h"
-#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/X86DisassemblerDecoderCommon.h"
 #include <map>
+#include <memory>
 #include <vector>
 
 namespace llvm {
+class raw_ostream;
 
 namespace X86Disassembler {
 
+class ModRMFilter;
+
 /// DisassemblerTables - Encapsulates all the decode tables being generated by
 ///   the table emitter.  Contains functions to populate the tables as well as
 ///   to emit them as hierarchical C structures suitable for consumption by the
diff --git a/llvm/utils/TableGen/X86DisassemblerTables.cpp b/llvm/utils/TableGen/X86DisassemblerTables.cpp
--- a/llvm/utils/TableGen/X86DisassemblerTables.cpp
+++ b/llvm/utils/TableGen/X86DisassemblerTables.cpp
@@ -15,9 +15,12 @@
 
 #include "X86DisassemblerTables.h"
 #include "X86DisassemblerShared.h"
-#include "llvm/ADT/STLExtras.h"
+#include "X86ModRMFilters.h"
+#include "llvm/ADT/STLArrayExtras.h"
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Format.h"
+#include "llvm/Support/raw_ostream.h"
 #include <map>
 
 using namespace llvm;
diff --git a/llvm/utils/TableGen/X86FoldTablesEmitter.cpp b/llvm/utils/TableGen/X86FoldTablesEmitter.cpp
--- a/llvm/utils/TableGen/X86FoldTablesEmitter.cpp
+++ b/llvm/utils/TableGen/X86FoldTablesEmitter.cpp
@@ -40,8 +40,6 @@
       : RegInstStr(RegInstStr), MemInstStr(MemInstStr), Strategy(Strategy) {}
 };
 
-class IsMatch;
-
 // List of instructions requiring explicitly aligned memory.
 const char *ExplicitAlign[] = {"MOVDQA",  "MOVAPS",  "MOVAPD",  "MOVNTPS",
                                "MOVNTPD", "MOVNTDQ", "MOVNTDQA"};
diff --git a/llvm/utils/TableGen/X86RecognizableInstr.h b/llvm/utils/TableGen/X86RecognizableInstr.h
--- a/llvm/utils/TableGen/X86RecognizableInstr.h
+++ b/llvm/utils/TableGen/X86RecognizableInstr.h
@@ -16,13 +16,16 @@
 #ifndef LLVM_UTILS_TABLEGEN_X86RECOGNIZABLEINSTR_H
 #define LLVM_UTILS_TABLEGEN_X86RECOGNIZABLEINSTR_H
 
-#include "CodeGenTarget.h"
-#include "X86DisassemblerTables.h"
+#include "CodeGenInstruction.h"
 #include "llvm/Support/DataTypes.h"
-#include "llvm/TableGen/Record.h"
+#include "llvm/Support/X86DisassemblerDecoderCommon.h"
+
+struct InstructionSpecifier;
 
 namespace llvm {
 
+class Record;
+
 #define X86_INSTR_MRM_MAPPING     \
   MAP(C0, 64)                     \
   MAP(C1, 65)                     \
@@ -153,6 +156,8 @@
 
 namespace X86Disassembler {
 
+class DisassemblerTables;
+
 /// RecognizableInstr - Encapsulates all information required to decode a single
 ///   instruction, as extracted from the LLVM instruction tables.  Has methods
 ///   to interpret the information available in the LLVM tables, and to emit the
diff --git a/llvm/utils/TableGen/X86RecognizableInstr.cpp b/llvm/utils/TableGen/X86RecognizableInstr.cpp
--- a/llvm/utils/TableGen/X86RecognizableInstr.cpp
+++ b/llvm/utils/TableGen/X86RecognizableInstr.cpp
@@ -15,8 +15,10 @@
 
 #include "X86RecognizableInstr.h"
 #include "X86DisassemblerShared.h"
+#include "X86DisassemblerTables.h"
 #include "X86ModRMFilters.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/TableGen/Record.h"
 #include <string>
 
 using namespace llvm;