diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 78739bb..82c1765 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -43,7 +43,6 @@
 #include "llvm/Target/TargetRegisterInfo.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallString.h"
-#include "llvm/ADT/StringExtras.h"
 #include <cerrno>
 using namespace llvm;
 
@@ -523,12 +522,11 @@
 /// PrintULEB128 - Print a series of hexadecimal values (separated by commas)
 /// representing an unsigned leb128 value.
 void AsmPrinter::PrintULEB128(unsigned Value) const {
-  char Buffer[20];
   do {
     unsigned char Byte = static_cast<unsigned char>(Value & 0x7f);
     Value >>= 7;
     if (Value) Byte |= 0x80;
-    O << "0x" << utohex_buffer(Byte, Buffer+20);
+    PrintHex(Byte);
     if (Value) O << ", ";
   } while (Value);
 }
@@ -538,14 +536,13 @@
 void AsmPrinter::PrintSLEB128(int Value) const {
   int Sign = Value >> (8 * sizeof(Value) - 1);
   bool IsMore;
-  char Buffer[20];
 
   do {
     unsigned char Byte = static_cast<unsigned char>(Value & 0x7f);
     Value >>= 7;
     IsMore = Value != Sign || ((Byte ^ Sign) & 0x40) != 0;
     if (IsMore) Byte |= 0x80;
-    O << "0x" << utohex_buffer(Byte, Buffer+20);
+    PrintHex(Byte);
     if (IsMore) O << ", ";
   } while (IsMore);
 }
@@ -556,9 +553,9 @@
 
 /// PrintHex - Print a value as a hexadecimal value.
 ///
-void AsmPrinter::PrintHex(int Value) const { 
-  char Buffer[20];
-  O << "0x" << utohex_buffer(static_cast<unsigned>(Value), Buffer+20);
+void AsmPrinter::PrintHex(uint64_t Value) const {
+  O << "0x";
+  O.write_hex(Value);
 }
 
 /// EOL - Print a newline character to asm stream.  If a comment is present
@@ -567,18 +564,8 @@
   O << '\n';
 }
 
-void AsmPrinter::EOL(const std::string &Comment) const {
-  if (VerboseAsm && !Comment.empty()) {
-    O.PadToColumn(MAI->getCommentColumn());
-    O << MAI->getCommentString()
-      << ' '
-      << Comment;
-  }
-  O << '\n';
-}
-
-void AsmPrinter::EOL(const char* Comment) const {
-  if (VerboseAsm && *Comment) {
+void AsmPrinter::EOL(const Twine &Comment) const {
+  if (VerboseAsm && !Comment.isTriviallyEmpty()) {
     O.PadToColumn(MAI->getCommentColumn());
     O << MAI->getCommentString()
       << ' '
@@ -624,8 +611,8 @@
   return 0;
 }
 
-void AsmPrinter::EOL(const char *Comment, unsigned Encoding) const {
-  if (VerboseAsm && *Comment) {
+void AsmPrinter::EOL(const Twine &Comment, unsigned Encoding) const {
+  if (VerboseAsm && !Comment.isTriviallyEmpty()) {
     O.PadToColumn(MAI->getCommentColumn());
     O << MAI->getCommentString()
       << ' '
@@ -755,7 +742,7 @@
 
 
 /// EmitFile - Emit a .file directive.
-void AsmPrinter::EmitFile(unsigned Number, const std::string &Name) const {
+void AsmPrinter::EmitFile(unsigned Number, StringRef Name) const {
   O << "\t.file\t" << Number << " \"";
   for (unsigned i = 0, N = Name.size(); i < N; ++i)
     printStringChar(O, Name[i]);
diff --git a/lib/CodeGen/AsmPrinter/DIE.cpp b/lib/CodeGen/AsmPrinter/DIE.cpp
index e740a56..ff7994a 100644
--- a/lib/CodeGen/AsmPrinter/DIE.cpp
+++ b/lib/CodeGen/AsmPrinter/DIE.cpp
@@ -13,6 +13,7 @@
 
 #include "DIE.h"
 #include "DwarfPrinter.h"
+#include "llvm/ADT/Twine.h"
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCSymbol.h"
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 3b08e53..33a6273 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -2343,14 +2343,10 @@
   // Emit the code (index) for the abbreviation.
   Asm->EmitULEB128Bytes(AbbrevNumber);
 
-  if (Asm->isVerbose())
-    Asm->EOL(std::string("Abbrev [" +
-                         utostr(AbbrevNumber) +
-                         "] 0x" + utohexstr(Die->getOffset()) +
-                         ":0x" + utohexstr(Die->getSize()) + " " +
-                         dwarf::TagString(Abbrev->getTag())));
-  else
-    Asm->EOL();
+  Asm->EOL("Abbrev [" + Twine(AbbrevNumber) + "] 0x" +
+           Twine::utohexstr(Die->getOffset()) + ":0x" +
+           Twine::utohexstr(Die->getSize()) + " " +
+           dwarf::TagString(Abbrev->getTag()));
 
   SmallVector<DIEValue*, 32> &Values = Die->getValues();
   const SmallVector<DIEAbbrevData, 8> &AbbrevData = Abbrev->getData();
diff --git a/lib/CodeGen/AsmPrinter/DwarfPrinter.cpp b/lib/CodeGen/AsmPrinter/DwarfPrinter.cpp
index 73e8331..7aca41e 100644
--- a/lib/CodeGen/AsmPrinter/DwarfPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfPrinter.cpp
@@ -24,7 +24,6 @@
 #include "llvm/Target/TargetRegisterInfo.h"
 #include "llvm/Support/Dwarf.h"
 #include "llvm/Support/ErrorHandling.h"
-#include "llvm/ADT/StringExtras.h"
 using namespace llvm;
 
 Dwarf::Dwarf(raw_ostream &OS, AsmPrinter *A, const MCAsmInfo *T,
@@ -225,10 +224,7 @@
         Asm->EOL("Offset");
       } else if (Reg < 64) {
         Asm->EmitInt8(dwarf::DW_CFA_offset + Reg);
-        if (Asm->isVerbose())
-          Asm->EOL("DW_CFA_offset + Reg (" + utostr(Reg) + ")");
-        else
-          Asm->EOL();
+        Asm->EOL("DW_CFA_offset + Reg (" + Twine(Reg) + ")");
         Asm->EmitULEB128Bytes(Offset);
         Asm->EOL("Offset");
       } else {