Index: include/llvm/Bitcode/BitCodes.h
===================================================================
--- include/llvm/Bitcode/BitCodes.h
+++ include/llvm/Bitcode/BitCodes.h
@@ -25,6 +25,14 @@
 #include <cassert>
 
 namespace llvm {
+/// Offsets of the 32-bit fields of bitcode wrapper header.
+static const unsigned BWH_MagicField = 0 * 4;
+static const unsigned BWH_VersionField = 1 * 4;
+static const unsigned BWH_OffsetField = 2 * 4;
+static const unsigned BWH_SizeField = 3 * 4;
+static const unsigned BWH_CPUTypeField = 4 * 4;
+static const unsigned BWH_HeaderSize = 5 * 4;
+
 namespace bitc {
   enum StandardWidths {
     BlockIDWidth   = 8,  // We use VBR-8 for block IDs.
Index: include/llvm/Bitcode/BitcodeReader.h
===================================================================
--- include/llvm/Bitcode/BitcodeReader.h
+++ include/llvm/Bitcode/BitcodeReader.h
@@ -1,4 +1,4 @@
-//===-- llvm/Bitcode/ReaderWriter.h - Bitcode reader/writers ----*- C++ -*-===//
+//===-- llvm/Bitcode/BitcodeReader.h - Bitcode reader ----*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -7,36 +7,25 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// This header defines interfaces to read and write LLVM bitcode files/streams.
+// This header defines interfaces to read LLVM bitcode files/streams.
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_BITCODE_READERWRITER_H
-#define LLVM_BITCODE_READERWRITER_H
+#ifndef LLVM_BITCODE_BITCODEREADER_H
+#define LLVM_BITCODE_BITCODEREADER_H
 
+#include "llvm/Bitcode/BitCodes.h"
 #include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/ModuleSummaryIndex.h"
 #include "llvm/Support/Endian.h"
 #include "llvm/Support/ErrorOr.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include <memory>
-#include <string>
 
 namespace llvm {
-  class BitstreamWriter;
   class DataStreamer;
   class LLVMContext;
   class Module;
-  class ModulePass;
-  class raw_ostream;
-
-  /// Offsets of the 32-bit fields of bitcode wrapper header.
-  static const unsigned BWH_MagicField = 0*4;
-  static const unsigned BWH_VersionField = 1*4;
-  static const unsigned BWH_OffsetField = 2*4;
-  static const unsigned BWH_SizeField = 3*4;
-  static const unsigned BWH_CPUTypeField = 4*4;
-  static const unsigned BWH_HeaderSize = 5*4;
 
   /// Read the header of the specified bitcode buffer and prepare for lazy
   /// deserialization of function bodies. If ShouldLazyLoadMetadata is true,
@@ -85,34 +74,6 @@
   getModuleSummaryIndex(MemoryBufferRef Buffer,
                         const DiagnosticHandlerFunction &DiagnosticHandler);
 
-  /// \brief Write the specified module to the specified raw output stream.
-  ///
-  /// For streams where it matters, the given stream should be in "binary"
-  /// mode.
-  ///
-  /// If \c ShouldPreserveUseListOrder, encode the use-list order for each \a
-  /// Value in \c M.  These will be reconstructed exactly when \a M is
-  /// deserialized.
-  ///
-  /// If \c Index is supplied, the bitcode will contain the summary index
-  /// (currently for use in ThinLTO optimization).
-  ///
-  /// \p GenerateHash enables hashing the Module and including the hash in the
-  /// bitcode (currently for use in ThinLTO incremental build).
-  void WriteBitcodeToFile(const Module *M, raw_ostream &Out,
-                          bool ShouldPreserveUseListOrder = false,
-                          const ModuleSummaryIndex *Index = nullptr,
-                          bool GenerateHash = false);
-
-  /// Write the specified module summary index to the given raw output stream,
-  /// where it will be written in a new bitcode block. This is used when
-  /// writing the combined index file for ThinLTO. When writing a subset of the
-  /// index for a distributed backend, provide the \p ModuleToSummariesForIndex
-  /// map.
-  void WriteIndexToFile(const ModuleSummaryIndex &Index, raw_ostream &Out,
-                        const std::map<std::string, GVSummaryMapTy>
-                            *ModuleToSummariesForIndex = nullptr);
-
   /// isBitcodeWrapper - Return true if the given bytes are the magic bytes
   /// for an LLVM IR bitcode wrapper.
   ///
Index: lib/Bitcode/Reader/BitReader.cpp
===================================================================
--- lib/Bitcode/Reader/BitReader.cpp
+++ lib/Bitcode/Reader/BitReader.cpp
@@ -9,7 +9,7 @@
 
 #include "llvm-c/BitReader.h"
 #include "llvm-c/Core.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeReader.h"
 #include "llvm/IR/DiagnosticPrinter.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
Index: lib/Bitcode/Reader/BitcodeReader.cpp
===================================================================
--- lib/Bitcode/Reader/BitcodeReader.cpp
+++ lib/Bitcode/Reader/BitcodeReader.cpp
@@ -7,6 +7,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/Bitcode/BitcodeReader.h"
 #include "llvm/ADT/APFloat.h"
 #include "llvm/ADT/APInt.h"
 #include "llvm/ADT/ArrayRef.h"
@@ -20,7 +21,6 @@
 #include "llvm/ADT/Twine.h"
 #include "llvm/Bitcode/BitstreamReader.h"
 #include "llvm/Bitcode/LLVMBitCodes.h"
-#include "llvm/Bitcode/ReaderWriter.h"
 #include "llvm/IR/Argument.h"
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/AutoUpgrade.h"
Index: lib/Bitcode/Writer/BitWriter.cpp
===================================================================
--- lib/Bitcode/Writer/BitWriter.cpp
+++ lib/Bitcode/Writer/BitWriter.cpp
@@ -8,9 +8,10 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm-c/BitWriter.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
Index: lib/Bitcode/Writer/BitcodeWriter.cpp
===================================================================
--- lib/Bitcode/Writer/BitcodeWriter.cpp
+++ lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -11,12 +11,12 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/Bitcode/BitcodeWriter.h"
 #include "ValueEnumerator.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/Bitcode/BitstreamWriter.h"
 #include "llvm/Bitcode/LLVMBitCodes.h"
-#include "llvm/Bitcode/ReaderWriter.h"
 #include "llvm/IR/CallSite.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DebugInfoMetadata.h"
Index: lib/Bitcode/Writer/BitcodeWriterPass.cpp
===================================================================
--- lib/Bitcode/Writer/BitcodeWriterPass.cpp
+++ lib/Bitcode/Writer/BitcodeWriterPass.cpp
@@ -13,7 +13,7 @@
 
 #include "llvm/Bitcode/BitcodeWriterPass.h"
 #include "llvm/Analysis/ModuleSummaryAnalysis.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/PassManager.h"
 #include "llvm/Pass.h"
Index: lib/CodeGen/ParallelCG.cpp
===================================================================
--- lib/CodeGen/ParallelCG.cpp
+++ lib/CodeGen/ParallelCG.cpp
@@ -12,7 +12,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/CodeGen/ParallelCG.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeReader.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
Index: lib/IR/Core.cpp
===================================================================
--- lib/IR/Core.cpp
+++ lib/IR/Core.cpp
@@ -14,7 +14,7 @@
 
 #include "llvm-c/Core.h"
 #include "llvm/ADT/StringSwitch.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeReader.h"
 #include "llvm/IR/Attributes.h"
 #include "AttributeSetNode.h"
 #include "llvm/IR/CallSite.h"
Index: lib/IRReader/IRReader.cpp
===================================================================
--- lib/IRReader/IRReader.cpp
+++ lib/IRReader/IRReader.cpp
@@ -11,7 +11,7 @@
 #include "llvm-c/Core.h"
 #include "llvm-c/IRReader.h"
 #include "llvm/AsmParser/Parser.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeReader.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Support/MemoryBuffer.h"
Index: lib/LTO/LTO.cpp
===================================================================
--- lib/LTO/LTO.cpp
+++ lib/LTO/LTO.cpp
@@ -14,7 +14,8 @@
 #include "llvm/LTO/LTO.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeReader.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/CodeGen/Analysis.h"
 #include "llvm/IR/AutoUpgrade.h"
 #include "llvm/IR/DiagnosticPrinter.h"
Index: lib/LTO/LTOBackend.cpp
===================================================================
--- lib/LTO/LTOBackend.cpp
+++ lib/LTO/LTOBackend.cpp
@@ -20,7 +20,8 @@
 #include "llvm/Analysis/LoopPassManager.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeReader.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/PassManager.h"
 #include "llvm/IR/Verifier.h"
Index: lib/LTO/LTOCodeGenerator.cpp
===================================================================
--- lib/LTO/LTOCodeGenerator.cpp
+++ lib/LTO/LTOCodeGenerator.cpp
@@ -19,7 +19,7 @@
 #include "llvm/Analysis/Passes.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/CodeGen/ParallelCG.h"
 #include "llvm/CodeGen/RuntimeLibcalls.h"
 #include "llvm/Config/config.h"
Index: lib/LTO/LTOModule.cpp
===================================================================
--- lib/LTO/LTOModule.cpp
+++ lib/LTO/LTOModule.cpp
@@ -14,7 +14,7 @@
 
 #include "llvm/LTO/legacy/LTOModule.h"
 #include "llvm/ADT/Triple.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeReader.h"
 #include "llvm/CodeGen/Analysis.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DiagnosticPrinter.h"
Index: lib/LTO/ThinLTOCodeGenerator.cpp
===================================================================
--- lib/LTO/ThinLTOCodeGenerator.cpp
+++ lib/LTO/ThinLTOCodeGenerator.cpp
@@ -24,8 +24,9 @@
 #include "llvm/Analysis/ProfileSummaryInfo.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/Bitcode/BitcodeReader.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/Bitcode/BitcodeWriterPass.h"
-#include "llvm/Bitcode/ReaderWriter.h"
 #include "llvm/ExecutionEngine/ObjectMemoryBuffer.h"
 #include "llvm/IR/DiagnosticPrinter.h"
 #include "llvm/IR/LLVMContext.h"
Index: lib/Object/IRObjectFile.cpp
===================================================================
--- lib/Object/IRObjectFile.cpp
+++ lib/Object/IRObjectFile.cpp
@@ -14,7 +14,7 @@
 #include "llvm/Object/IRObjectFile.h"
 #include "RecordStreamer.h"
 #include "llvm/ADT/STLExtras.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeReader.h"
 #include "llvm/IR/GVMaterializer.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Mangler.h"
Index: lib/Object/ModuleSummaryIndexObjectFile.cpp
===================================================================
--- lib/Object/ModuleSummaryIndexObjectFile.cpp
+++ lib/Object/ModuleSummaryIndexObjectFile.cpp
@@ -13,7 +13,7 @@
 
 #include "llvm/Object/ModuleSummaryIndexObjectFile.h"
 #include "llvm/ADT/STLExtras.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeReader.h"
 #include "llvm/IR/ModuleSummaryIndex.h"
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/Object/ObjectFile.h"
Index: tools/bugpoint/OptimizerDriver.cpp
===================================================================
--- tools/bugpoint/OptimizerDriver.cpp
+++ tools/bugpoint/OptimizerDriver.cpp
@@ -16,7 +16,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "BugDriver.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Module.h"
Index: tools/gold/gold-plugin.cpp
===================================================================
--- tools/gold/gold-plugin.cpp
+++ tools/gold/gold-plugin.cpp
@@ -12,7 +12,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeReader.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/CodeGen/CommandFlags.h"
 #include "llvm/Config/config.h" // plugin-api.h requires HAVE_STDINT_H
 #include "llvm/IR/Constants.h"
Index: tools/lli/lli.cpp
===================================================================
--- tools/lli/lli.cpp
+++ tools/lli/lli.cpp
@@ -18,7 +18,7 @@
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/Triple.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeReader.h"
 #include "llvm/CodeGen/LinkAllCodegenComponents.h"
 #include "llvm/ExecutionEngine/GenericValue.h"
 #include "llvm/ExecutionEngine/Interpreter.h"
Index: tools/llvm-as/llvm-as.cpp
===================================================================
--- tools/llvm-as/llvm-as.cpp
+++ tools/llvm-as/llvm-as.cpp
@@ -16,7 +16,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/AsmParser/Parser.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Verifier.h"
Index: tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp
===================================================================
--- tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp
+++ tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp
@@ -28,9 +28,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/Bitcode/BitcodeReader.h"
 #include "llvm/Bitcode/BitstreamReader.h"
 #include "llvm/Bitcode/LLVMBitCodes.h"
-#include "llvm/Bitcode/ReaderWriter.h"
 #include "llvm/IR/Verifier.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Format.h"
Index: tools/llvm-dis/llvm-dis.cpp
===================================================================
--- tools/llvm-dis/llvm-dis.cpp
+++ tools/llvm-dis/llvm-dis.cpp
@@ -17,7 +17,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/IR/LLVMContext.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeReader.h"
 #include "llvm/IR/AssemblyAnnotationWriter.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/DiagnosticInfo.h"
Index: tools/llvm-link/llvm-link.cpp
===================================================================
--- tools/llvm-link/llvm-link.cpp
+++ tools/llvm-link/llvm-link.cpp
@@ -13,7 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/STLExtras.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/IR/AutoUpgrade.h"
 #include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/DiagnosticPrinter.h"
Index: tools/llvm-lto/llvm-lto.cpp
===================================================================
--- tools/llvm-lto/llvm-lto.cpp
+++ tools/llvm-lto/llvm-lto.cpp
@@ -13,7 +13,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/StringSet.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeReader.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/CodeGen/CommandFlags.h"
 #include "llvm/IR/DiagnosticPrinter.h"
 #include "llvm/IR/LLVMContext.h"
Index: tools/llvm-split/llvm-split.cpp
===================================================================
--- tools/llvm-split/llvm-split.cpp
+++ tools/llvm-split/llvm-split.cpp
@@ -12,7 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/StringExtras.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Verifier.h"
 #include "llvm/IRReader/IRReader.h"
Index: tools/lto/lto.cpp
===================================================================
--- tools/lto/lto.cpp
+++ tools/lto/lto.cpp
@@ -14,7 +14,7 @@
 
 #include "llvm-c/lto.h"
 #include "llvm/ADT/STLExtras.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeReader.h"
 #include "llvm/CodeGen/CommandFlags.h"
 #include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/DiagnosticPrinter.h"
Index: tools/verify-uselistorder/verify-uselistorder.cpp
===================================================================
--- tools/verify-uselistorder/verify-uselistorder.cpp
+++ tools/verify-uselistorder/verify-uselistorder.cpp
@@ -30,7 +30,8 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/AsmParser/Parser.h"
-#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/Bitcode/BitcodeReader.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/UseListOrder.h"
Index: unittests/Bitcode/BitReaderTest.cpp
===================================================================
--- unittests/Bitcode/BitReaderTest.cpp
+++ unittests/Bitcode/BitReaderTest.cpp
@@ -7,12 +7,13 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallString.h"
 #include "llvm/AsmParser/Parser.h"
+#include "llvm/Bitcode/BitcodeReader.h"
+#include "llvm/Bitcode/BitcodeWriter.h"
 #include "llvm/Bitcode/BitstreamReader.h"
 #include "llvm/Bitcode/BitstreamWriter.h"
-#include "llvm/Bitcode/ReaderWriter.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/LLVMContext.h"