diff --git a/include/llvm/MC/MCContext.h b/include/llvm/MC/MCContext.h
index 1251c5f..0db3dee 100644
--- a/include/llvm/MC/MCContext.h
+++ b/include/llvm/MC/MCContext.h
@@ -11,6 +11,7 @@
 #define LLVM_MC_MCCONTEXT_H
 
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/MC/MCDwarf.h"
 #include "llvm/MC/SectionKind.h"
@@ -105,9 +106,9 @@
     /// We now emit a line table for each compile unit. To reduce the prologue
     /// size of each line table, the files and directories used by each compile
     /// unit are separated.
-    typedef std::map<unsigned, std::vector<MCDwarfFile *> > MCDwarfFilesMap;
+    typedef std::map<unsigned, SmallVector<MCDwarfFile *, 4> > MCDwarfFilesMap;
     MCDwarfFilesMap MCDwarfFilesCUMap;
-    std::map<unsigned, std::vector<StringRef> > MCDwarfDirsCUMap;
+    std::map<unsigned, SmallVector<StringRef, 4> > MCDwarfDirsCUMap;
 
     /// The current dwarf line information from the last dwarf .loc directive.
     MCDwarfLoc CurrentDwarfLoc;
@@ -301,10 +302,10 @@
       return false;
     }
 
-    const std::vector<MCDwarfFile *> &getMCDwarfFiles(unsigned CUID = 0) {
+    const SmallVectorImpl<MCDwarfFile *> &getMCDwarfFiles(unsigned CUID = 0) {
       return MCDwarfFilesCUMap[CUID];
     }
-    const std::vector<StringRef> &getMCDwarfDirs(unsigned CUID = 0) {
+    const SmallVectorImpl<StringRef> &getMCDwarfDirs(unsigned CUID = 0) {
       return MCDwarfDirsCUMap[CUID];
     }
 
diff --git a/lib/MC/MCContext.cpp b/lib/MC/MCContext.cpp
index 26d378e..9adcc02 100644
--- a/lib/MC/MCContext.cpp
+++ b/lib/MC/MCContext.cpp
@@ -304,8 +304,8 @@
   // Note: in GenericAsmParser::ParseDirectiveFile() FileNumber was checked
   // to not be less than one.  This needs to be change to be not less than zero.
 
-  std::vector<MCDwarfFile *>& MCDwarfFiles = MCDwarfFilesCUMap[CUID];
-  std::vector<StringRef>& MCDwarfDirs = MCDwarfDirsCUMap[CUID];
+  SmallVectorImpl<MCDwarfFile *>& MCDwarfFiles = MCDwarfFilesCUMap[CUID];
+  SmallVectorImpl<StringRef>& MCDwarfDirs = MCDwarfDirsCUMap[CUID];
   // Make space for this FileNumber in the MCDwarfFiles vector if needed.
   if (FileNumber >= MCDwarfFiles.size()) {
     MCDwarfFiles.resize(FileNumber + 1);
@@ -366,7 +366,7 @@
 /// isValidDwarfFileNumber - takes a dwarf file number and returns true if it
 /// currently is assigned and false otherwise.
 bool MCContext::isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID) {
-  std::vector<MCDwarfFile *>& MCDwarfFiles = MCDwarfFilesCUMap[CUID];
+  SmallVectorImpl<MCDwarfFile *>& MCDwarfFiles = MCDwarfFilesCUMap[CUID];
   if(FileNumber == 0 || FileNumber >= MCDwarfFiles.size())
     return false;
 
diff --git a/lib/MC/MCDwarf.cpp b/lib/MC/MCDwarf.cpp
index c81abe9..0f8f074 100644
--- a/lib/MC/MCDwarf.cpp
+++ b/lib/MC/MCDwarf.cpp
@@ -298,7 +298,7 @@
   // Put out the directory and file tables.
 
   // First the directory table.
-  const std::vector<StringRef> &MCDwarfDirs =
+  const SmallVectorImpl<StringRef> &MCDwarfDirs =
     context.getMCDwarfDirs(CUID);
   for (unsigned i = 0; i < MCDwarfDirs.size(); i++) {
     MCOS->EmitBytes(MCDwarfDirs[i]); // the DirectoryName
@@ -307,7 +307,7 @@
   MCOS->EmitIntValue(0, 1); // Terminate the directory list
 
   // Second the file table.
-  const std::vector<MCDwarfFile *> &MCDwarfFiles =
+  const SmallVectorImpl<MCDwarfFile *> &MCDwarfFiles =
     MCOS->getContext().getMCDwarfFiles(CUID);
   for (unsigned i = 1; i < MCDwarfFiles.size(); i++) {
     MCOS->EmitBytes(MCDwarfFiles[i]->getName()); // FileName
@@ -643,13 +643,13 @@
 
   // AT_name, the name of the source file.  Reconstruct from the first directory
   // and file table entries.
-  const std::vector<StringRef> &MCDwarfDirs =
+  const SmallVectorImpl<StringRef> &MCDwarfDirs =
     context.getMCDwarfDirs();
   if (MCDwarfDirs.size() > 0) {
     MCOS->EmitBytes(MCDwarfDirs[0]);
     MCOS->EmitBytes("/");
   }
-  const std::vector<MCDwarfFile *> &MCDwarfFiles =
+  const SmallVectorImpl<MCDwarfFile *> &MCDwarfFiles =
     MCOS->getContext().getMCDwarfFiles();
   MCOS->EmitBytes(MCDwarfFiles[1]->getName());
   MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index 6ab49ec..9d52377 100644
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -626,7 +626,7 @@
     return TokError("unmatched .ifs or .elses");
 
   // Check to see there are no empty DwarfFile slots.
-  const std::vector<MCDwarfFile *> &MCDwarfFiles =
+  const SmallVectorImpl<MCDwarfFile *> &MCDwarfFiles =
     getContext().getMCDwarfFiles();
   for (unsigned i = 1; i < MCDwarfFiles.size(); i++) {
     if (!MCDwarfFiles[i])
@@ -1495,7 +1495,7 @@
     // If we previously parsed a cpp hash file line comment then make sure the
     // current Dwarf File is for the CppHashFilename if not then emit the
     // Dwarf File table for it and adjust the line number for the .loc.
-    const std::vector<MCDwarfFile *> &MCDwarfFiles = 
+    const SmallVectorImpl<MCDwarfFile *> &MCDwarfFiles = 
       getContext().getMCDwarfFiles();
     if (CppHashFilename.size() != 0) {
       if (MCDwarfFiles[getContext().getGenDwarfFileNumber()]->getName() !=