Import LLVM, at r72732.

10 files changed, 4462 insertions, 0 deletions

diff --git a/lib/ExecutionEngine/JIT/CMakeLists.txt b/lib/ExecutionEngine/JIT/CMakeLists.txt
new file mode 100644
index 0000000..d7980d0
--- /dev/null
+++ b/lib/ExecutionEngine/JIT/CMakeLists.txt
@@ -0,0 +1,11 @@
+# TODO: Support other architectures. See Makefile.
+add_definitions(-DENABLE_X86_JIT)
+
+add_partially_linked_object(LLVMJIT
+  Intercept.cpp
+  JIT.cpp
+  JITDwarfEmitter.cpp
+  JITEmitter.cpp
+  JITMemoryManager.cpp
+  TargetSelect.cpp
+  )
diff --git a/lib/ExecutionEngine/JIT/Intercept.cpp b/lib/ExecutionEngine/JIT/Intercept.cpp
new file mode 100644
index 0000000..3dcc462
--- /dev/null
+++ b/lib/ExecutionEngine/JIT/Intercept.cpp
@@ -0,0 +1,148 @@
+//===-- Intercept.cpp - System function interception routines -------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// If a function call occurs to an external function, the JIT is designed to use
+// the dynamic loader interface to find a function to call.  This is useful for
+// calling system calls and library functions that are not available in LLVM.
+// Some system calls, however, need to be handled specially.  For this reason,
+// we intercept some of them here and use our own stubs to handle them.
+//
+//===----------------------------------------------------------------------===//
+
+#include "JIT.h"
+#include "llvm/Support/Streams.h"
+#include "llvm/System/DynamicLibrary.h"
+#include "llvm/Config/config.h"
+using namespace llvm;
+
+// AtExitHandlers - List of functions to call when the program exits,
+// registered with the atexit() library function.
+static std::vector<void (*)()> AtExitHandlers;
+
+/// runAtExitHandlers - Run any functions registered by the program's
+/// calls to atexit(3), which we intercept and store in
+/// AtExitHandlers.
+///
+static void runAtExitHandlers() {
+  while (!AtExitHandlers.empty()) {
+    void (*Fn)() = AtExitHandlers.back();
+    AtExitHandlers.pop_back();
+    Fn();
+  }
+}
+
+//===----------------------------------------------------------------------===//
+// Function stubs that are invoked instead of certain library calls
+//===----------------------------------------------------------------------===//
+
+// Force the following functions to be linked in to anything that uses the
+// JIT. This is a hack designed to work around the all-too-clever Glibc
+// strategy of making these functions work differently when inlined vs. when
+// not inlined, and hiding their real definitions in a separate archive file
+// that the dynamic linker can't see. For more info, search for
+// 'libc_nonshared.a' on Google, or read http://llvm.org/PR274.
+#if defined(__linux__)
+#if defined(HAVE_SYS_STAT_H)
+#include <sys/stat.h>
+#endif
+#include <fcntl.h>
+/* stat functions are redirecting to __xstat with a version number.  On x86-64 
+ * linking with libc_nonshared.a and -Wl,--export-dynamic doesn't make 'stat' 
+ * available as an exported symbol, so we have to add it explicitly.
+ */
+class StatSymbols {
+public:
+  StatSymbols() {
+    sys::DynamicLibrary::AddSymbol("stat", (void*)(intptr_t)stat);
+    sys::DynamicLibrary::AddSymbol("fstat", (void*)(intptr_t)fstat);
+    sys::DynamicLibrary::AddSymbol("lstat", (void*)(intptr_t)lstat);
+    sys::DynamicLibrary::AddSymbol("stat64", (void*)(intptr_t)stat64);
+    sys::DynamicLibrary::AddSymbol("\x1stat64", (void*)(intptr_t)stat64);
+    sys::DynamicLibrary::AddSymbol("\x1open64", (void*)(intptr_t)open64);
+    sys::DynamicLibrary::AddSymbol("\x1lseek64", (void*)(intptr_t)lseek64);
+    sys::DynamicLibrary::AddSymbol("fstat64", (void*)(intptr_t)fstat64);
+    sys::DynamicLibrary::AddSymbol("lstat64", (void*)(intptr_t)lstat64);
+    sys::DynamicLibrary::AddSymbol("atexit", (void*)(intptr_t)atexit);
+    sys::DynamicLibrary::AddSymbol("mknod", (void*)(intptr_t)mknod);
+  }
+};
+static StatSymbols initStatSymbols;
+#endif // __linux__
+
+// jit_exit - Used to intercept the "exit" library call.
+static void jit_exit(int Status) {
+  runAtExitHandlers();   // Run atexit handlers...
+  exit(Status);
+}
+
+// jit_atexit - Used to intercept the "atexit" library call.
+static int jit_atexit(void (*Fn)(void)) {
+  AtExitHandlers.push_back(Fn);    // Take note of atexit handler...
+  return 0;  // Always successful
+}
+
+//===----------------------------------------------------------------------===//
+//
+/// getPointerToNamedFunction - This method returns the address of the specified
+/// function by using the dynamic loader interface.  As such it is only useful
+/// for resolving library symbols, not code generated symbols.
+///
+void *JIT::getPointerToNamedFunction(const std::string &Name,
+                                     bool AbortOnFailure) {
+  if (!isSymbolSearchingDisabled()) {
+    // Check to see if this is one of the functions we want to intercept.  Note,
+    // we cast to intptr_t here to silence a -pedantic warning that complains
+    // about casting a function pointer to a normal pointer.
+    if (Name == "exit") return (void*)(intptr_t)&jit_exit;
+    if (Name == "atexit") return (void*)(intptr_t)&jit_atexit;
+
+    const char *NameStr = Name.c_str();
+    // If this is an asm specifier, skip the sentinal.
+    if (NameStr[0] == 1) ++NameStr;
+    
+    // If it's an external function, look it up in the process image...
+    void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr);
+    if (Ptr) return Ptr;
+    
+    // If it wasn't found and if it starts with an underscore ('_') character,
+    // and has an asm specifier, try again without the underscore.
+    if (Name[0] == 1 && NameStr[0] == '_') {
+      Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr+1);
+      if (Ptr) return Ptr;
+    }
+    
+    // Darwin/PPC adds $LDBLStub suffixes to various symbols like printf.  These
+    // are references to hidden visibility symbols that dlsym cannot resolve.
+    // If we have one of these, strip off $LDBLStub and try again.
+#if defined(__APPLE__) && defined(__ppc__)
+    if (Name.size() > 9 && Name[Name.size()-9] == '$' &&
+        memcmp(&Name[Name.size()-8], "LDBLStub", 8) == 0) {
+      // First try turning $LDBLStub into $LDBL128. If that fails, strip it off.
+      // This mirrors logic in libSystemStubs.a.
+      std::string Prefix = std::string(Name.begin(), Name.end()-9);
+      if (void *Ptr = getPointerToNamedFunction(Prefix+"$LDBL128", false))
+        return Ptr;
+      if (void *Ptr = getPointerToNamedFunction(Prefix, false))
+        return Ptr;
+    }
+#endif
+  }
+  
+  /// If a LazyFunctionCreator is installed, use it to get/create the function.
+  if (LazyFunctionCreator)
+    if (void *RP = LazyFunctionCreator(Name))
+      return RP;
+
+  if (AbortOnFailure) {
+    cerr << "ERROR: Program used external function '" << Name
+         << "' which could not be resolved!\n";
+    abort();
+  }
+  return 0;
+}
diff --git a/lib/ExecutionEngine/JIT/JIT.cpp b/lib/ExecutionEngine/JIT/JIT.cpp
new file mode 100644
index 0000000..f8ae884
--- /dev/null
+++ b/lib/ExecutionEngine/JIT/JIT.cpp
@@ -0,0 +1,708 @@
+//===-- JIT.cpp - LLVM Just in Time Compiler ------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This tool implements a just-in-time compiler for LLVM, allowing direct
+// execution of LLVM bitcode in an efficient manner.
+//
+//===----------------------------------------------------------------------===//
+
+#include "JIT.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Function.h"
+#include "llvm/GlobalVariable.h"
+#include "llvm/Instructions.h"
+#include "llvm/ModuleProvider.h"
+#include "llvm/CodeGen/JITCodeEmitter.h"
+#include "llvm/ExecutionEngine/GenericValue.h"
+#include "llvm/CodeGen/MachineCodeInfo.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetJITInfo.h"
+#include "llvm/Support/Dwarf.h"
+#include "llvm/Support/MutexGuard.h"
+#include "llvm/System/DynamicLibrary.h"
+#include "llvm/Config/config.h"
+
+using namespace llvm;
+
+#ifdef __APPLE__ 
+// Apple gcc defaults to -fuse-cxa-atexit (i.e. calls __cxa_atexit instead
+// of atexit). It passes the address of linker generated symbol __dso_handle
+// to the function.
+// This configuration change happened at version 5330.
+# include <AvailabilityMacros.h>
+# if defined(MAC_OS_X_VERSION_10_4) && \
+     ((MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_4) || \
+      (MAC_OS_X_VERSION_MIN_REQUIRED == MAC_OS_X_VERSION_10_4 && \
+       __APPLE_CC__ >= 5330))
+#  ifndef HAVE___DSO_HANDLE
+#   define HAVE___DSO_HANDLE 1
+#  endif
+# endif
+#endif
+
+#if HAVE___DSO_HANDLE
+extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
+#endif
+
+namespace {
+
+static struct RegisterJIT {
+  RegisterJIT() { JIT::Register(); }
+} JITRegistrator;
+
+}
+
+namespace llvm {
+  void LinkInJIT() {
+  }
+}
+
+
+#if defined(__GNUC__) && !defined(__ARM__EABI__)
+ 
+// libgcc defines the __register_frame function to dynamically register new
+// dwarf frames for exception handling. This functionality is not portable
+// across compilers and is only provided by GCC. We use the __register_frame
+// function here so that code generated by the JIT cooperates with the unwinding
+// runtime of libgcc. When JITting with exception handling enable, LLVM
+// generates dwarf frames and registers it to libgcc with __register_frame.
+//
+// The __register_frame function works with Linux.
+//
+// Unfortunately, this functionality seems to be in libgcc after the unwinding
+// library of libgcc for darwin was written. The code for darwin overwrites the
+// value updated by __register_frame with a value fetched with "keymgr".
+// "keymgr" is an obsolete functionality, which should be rewritten some day.
+// In the meantime, since "keymgr" is on all libgccs shipped with apple-gcc, we
+// need a workaround in LLVM which uses the "keymgr" to dynamically modify the
+// values of an opaque key, used by libgcc to find dwarf tables.
+
+extern "C" void __register_frame(void*);
+
+#if defined(__APPLE__) && MAC_OS_X_VERSION_MAX_ALLOWED <= 1050
+# define USE_KEYMGR 1
+#else
+# define USE_KEYMGR 0
+#endif
+
+#if USE_KEYMGR
+
+namespace {
+
+// LibgccObject - This is the structure defined in libgcc. There is no #include
+// provided for this structure, so we also define it here. libgcc calls it
+// "struct object". The structure is undocumented in libgcc.
+struct LibgccObject {
+  void *unused1;
+  void *unused2;
+  void *unused3;
+  
+  /// frame - Pointer to the exception table.
+  void *frame;
+  
+  /// encoding -  The encoding of the object?
+  union {
+    struct {
+      unsigned long sorted : 1;
+      unsigned long from_array : 1;
+      unsigned long mixed_encoding : 1;
+      unsigned long encoding : 8;
+      unsigned long count : 21; 
+    } b;
+    size_t i;
+  } encoding;
+  
+  /// fde_end - libgcc defines this field only if some macro is defined. We
+  /// include this field even if it may not there, to make libgcc happy.
+  char *fde_end;
+  
+  /// next - At least we know it's a chained list!
+  struct LibgccObject *next;
+};
+
+// "kemgr" stuff. Apparently, all frame tables are stored there.
+extern "C" void _keymgr_set_and_unlock_processwide_ptr(int, void *);
+extern "C" void *_keymgr_get_and_lock_processwide_ptr(int);
+#define KEYMGR_GCC3_DW2_OBJ_LIST        302     /* Dwarf2 object list  */
+
+/// LibgccObjectInfo - libgcc defines this struct as km_object_info. It
+/// probably contains all dwarf tables that are loaded.
+struct LibgccObjectInfo {
+
+  /// seenObjects - LibgccObjects already parsed by the unwinding runtime.
+  ///
+  struct LibgccObject* seenObjects;
+
+  /// unseenObjects - LibgccObjects not parsed yet by the unwinding runtime.
+  ///
+  struct LibgccObject* unseenObjects;
+  
+  unsigned unused[2];
+};
+
+/// darwin_register_frame - Since __register_frame does not work with darwin's
+/// libgcc,we provide our own function, which "tricks" libgcc by modifying the
+/// "Dwarf2 object list" key.
+void DarwinRegisterFrame(void* FrameBegin) {
+  // Get the key.
+  LibgccObjectInfo* LOI = (struct LibgccObjectInfo*)
+    _keymgr_get_and_lock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST);
+  assert(LOI && "This should be preallocated by the runtime");
+  
+  // Allocate a new LibgccObject to represent this frame. Deallocation of this
+  // object may be impossible: since darwin code in libgcc was written after
+  // the ability to dynamically register frames, things may crash if we
+  // deallocate it.
+  struct LibgccObject* ob = (struct LibgccObject*)
+    malloc(sizeof(struct LibgccObject));
+  
+  // Do like libgcc for the values of the field.
+  ob->unused1 = (void *)-1;
+  ob->unused2 = 0;
+  ob->unused3 = 0;
+  ob->frame = FrameBegin;
+  ob->encoding.i = 0; 
+  ob->encoding.b.encoding = llvm::dwarf::DW_EH_PE_omit;
+  
+  // Put the info on both places, as libgcc uses the first or the the second
+  // field. Note that we rely on having two pointers here. If fde_end was a
+  // char, things would get complicated.
+  ob->fde_end = (char*)LOI->unseenObjects;
+  ob->next = LOI->unseenObjects;
+  
+  // Update the key's unseenObjects list.
+  LOI->unseenObjects = ob;
+  
+  // Finally update the "key". Apparently, libgcc requires it. 
+  _keymgr_set_and_unlock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST,
+                                         LOI);
+
+}
+
+}
+#endif // __APPLE__
+#endif // __GNUC__
+
+/// createJIT - This is the factory method for creating a JIT for the current
+/// machine, it does not fall back to the interpreter.  This takes ownership
+/// of the module provider.
+ExecutionEngine *ExecutionEngine::createJIT(ModuleProvider *MP,
+                                            std::string *ErrorStr,
+                                            JITMemoryManager *JMM,
+                                            CodeGenOpt::Level OptLevel) {
+  ExecutionEngine *EE = JIT::createJIT(MP, ErrorStr, JMM, OptLevel);
+  if (!EE) return 0;
+  
+  // Make sure we can resolve symbols in the program as well. The zero arg
+  // to the function tells DynamicLibrary to load the program, not a library.
+  sys::DynamicLibrary::LoadLibraryPermanently(0, ErrorStr);
+  return EE;
+}
+
+JIT::JIT(ModuleProvider *MP, TargetMachine &tm, TargetJITInfo &tji,
+         JITMemoryManager *JMM, CodeGenOpt::Level OptLevel)
+  : ExecutionEngine(MP), TM(tm), TJI(tji) {
+  setTargetData(TM.getTargetData());
+
+  jitstate = new JITState(MP);
+
+  // Initialize JCE
+  JCE = createEmitter(*this, JMM);
+
+  // Add target data
+  MutexGuard locked(lock);
+  FunctionPassManager &PM = jitstate->getPM(locked);
+  PM.add(new TargetData(*TM.getTargetData()));
+
+  // Turn the machine code intermediate representation into bytes in memory that
+  // may be executed.
+  if (TM.addPassesToEmitMachineCode(PM, *JCE, OptLevel)) {
+    cerr << "Target does not support machine code emission!\n";
+    abort();
+  }
+  
+  // Register routine for informing unwinding runtime about new EH frames
+#if defined(__GNUC__) && !defined(__ARM_EABI__)
+#if USE_KEYMGR
+  struct LibgccObjectInfo* LOI = (struct LibgccObjectInfo*)
+    _keymgr_get_and_lock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST);
+  
+  // The key is created on demand, and libgcc creates it the first time an
+  // exception occurs. Since we need the key to register frames, we create
+  // it now.
+  if (!LOI)
+    LOI = (LibgccObjectInfo*)calloc(sizeof(struct LibgccObjectInfo), 1); 
+  _keymgr_set_and_unlock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST, LOI);
+  InstallExceptionTableRegister(DarwinRegisterFrame);
+#else
+  InstallExceptionTableRegister(__register_frame);
+#endif // __APPLE__
+#endif // __GNUC__
+  
+  // Initialize passes.
+  PM.doInitialization();
+}
+
+JIT::~JIT() {
+  delete jitstate;
+  delete JCE;
+  delete &TM;
+}
+
+/// addModuleProvider - Add a new ModuleProvider to the JIT.  If we previously
+/// removed the last ModuleProvider, we need re-initialize jitstate with a valid
+/// ModuleProvider.
+void JIT::addModuleProvider(ModuleProvider *MP) {
+  MutexGuard locked(lock);
+
+  if (Modules.empty()) {
+    assert(!jitstate && "jitstate should be NULL if Modules vector is empty!");
+
+    jitstate = new JITState(MP);
+
+    FunctionPassManager &PM = jitstate->getPM(locked);
+    PM.add(new TargetData(*TM.getTargetData()));
+
+    // Turn the machine code intermediate representation into bytes in memory
+    // that may be executed.
+    if (TM.addPassesToEmitMachineCode(PM, *JCE, CodeGenOpt::Default)) {
+      cerr << "Target does not support machine code emission!\n";
+      abort();
+    }
+    
+    // Initialize passes.
+    PM.doInitialization();
+  }
+  
+  ExecutionEngine::addModuleProvider(MP);
+}
+
+/// removeModuleProvider - If we are removing the last ModuleProvider, 
+/// invalidate the jitstate since the PassManager it contains references a
+/// released ModuleProvider.
+Module *JIT::removeModuleProvider(ModuleProvider *MP, std::string *E) {
+  Module *result = ExecutionEngine::removeModuleProvider(MP, E);
+  
+  MutexGuard locked(lock);
+  
+  if (jitstate->getMP() == MP) {
+    delete jitstate;
+    jitstate = 0;
+  }
+  
+  if (!jitstate && !Modules.empty()) {
+    jitstate = new JITState(Modules[0]);
+
+    FunctionPassManager &PM = jitstate->getPM(locked);
+    PM.add(new TargetData(*TM.getTargetData()));
+    
+    // Turn the machine code intermediate representation into bytes in memory
+    // that may be executed.
+    if (TM.addPassesToEmitMachineCode(PM, *JCE, CodeGenOpt::Default)) {
+      cerr << "Target does not support machine code emission!\n";
+      abort();
+    }
+    
+    // Initialize passes.
+    PM.doInitialization();
+  }    
+  return result;
+}
+
+/// deleteModuleProvider - Remove a ModuleProvider from the list of modules,
+/// and deletes the ModuleProvider and owned Module.  Avoids materializing 
+/// the underlying module.
+void JIT::deleteModuleProvider(ModuleProvider *MP, std::string *E) {
+  ExecutionEngine::deleteModuleProvider(MP, E);
+  
+  MutexGuard locked(lock);
+  
+  if (jitstate->getMP() == MP) {
+    delete jitstate;
+    jitstate = 0;
+  }
+
+  if (!jitstate && !Modules.empty()) {
+    jitstate = new JITState(Modules[0]);
+    
+    FunctionPassManager &PM = jitstate->getPM(locked);
+    PM.add(new TargetData(*TM.getTargetData()));
+    
+    // Turn the machine code intermediate representation into bytes in memory
+    // that may be executed.
+    if (TM.addPassesToEmitMachineCode(PM, *JCE, CodeGenOpt::Default)) {
+      cerr << "Target does not support machine code emission!\n";
+      abort();
+    }
+    
+    // Initialize passes.
+    PM.doInitialization();
+  }    
+}
+
+/// run - Start execution with the specified function and arguments.
+///
+GenericValue JIT::runFunction(Function *F,
+                              const std::vector<GenericValue> &ArgValues) {
+  assert(F && "Function *F was null at entry to run()");
+
+  void *FPtr = getPointerToFunction(F);
+  assert(FPtr && "Pointer to fn's code was null after getPointerToFunction");
+  const FunctionType *FTy = F->getFunctionType();
+  const Type *RetTy = FTy->getReturnType();
+
+  assert((FTy->getNumParams() == ArgValues.size() ||
+          (FTy->isVarArg() && FTy->getNumParams() <= ArgValues.size())) &&
+         "Wrong number of arguments passed into function!");
+  assert(FTy->getNumParams() == ArgValues.size() &&
+         "This doesn't support passing arguments through varargs (yet)!");
+
+  // Handle some common cases first.  These cases correspond to common `main'
+  // prototypes.
+  if (RetTy == Type::Int32Ty || RetTy == Type::VoidTy) {
+    switch (ArgValues.size()) {
+    case 3:
+      if (FTy->getParamType(0) == Type::Int32Ty &&
+          isa<PointerType>(FTy->getParamType(1)) &&
+          isa<PointerType>(FTy->getParamType(2))) {
+        int (*PF)(int, char **, const char **) =
+          (int(*)(int, char **, const char **))(intptr_t)FPtr;
+
+        // Call the function.
+        GenericValue rv;
+        rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(), 
+                                 (char **)GVTOP(ArgValues[1]),
+                                 (const char **)GVTOP(ArgValues[2])));
+        return rv;
+      }
+      break;
+    case 2:
+      if (FTy->getParamType(0) == Type::Int32Ty &&
+          isa<PointerType>(FTy->getParamType(1))) {
+        int (*PF)(int, char **) = (int(*)(int, char **))(intptr_t)FPtr;
+
+        // Call the function.
+        GenericValue rv;
+        rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(), 
+                                 (char **)GVTOP(ArgValues[1])));
+        return rv;
+      }
+      break;
+    case 1:
+      if (FTy->getNumParams() == 1 &&
+          FTy->getParamType(0) == Type::Int32Ty) {
+        GenericValue rv;
+        int (*PF)(int) = (int(*)(int))(intptr_t)FPtr;
+        rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue()));
+        return rv;
+      }
+      break;
+    }
+  }
+
+  // Handle cases where no arguments are passed first.
+  if (ArgValues.empty()) {
+    GenericValue rv;
+    switch (RetTy->getTypeID()) {
+    default: assert(0 && "Unknown return type for function call!");
+    case Type::IntegerTyID: {
+      unsigned BitWidth = cast<IntegerType>(RetTy)->getBitWidth();
+      if (BitWidth == 1)
+        rv.IntVal = APInt(BitWidth, ((bool(*)())(intptr_t)FPtr)());
+      else if (BitWidth <= 8)
+        rv.IntVal = APInt(BitWidth, ((char(*)())(intptr_t)FPtr)());
+      else if (BitWidth <= 16)
+        rv.IntVal = APInt(BitWidth, ((short(*)())(intptr_t)FPtr)());
+      else if (BitWidth <= 32)
+        rv.IntVal = APInt(BitWidth, ((int(*)())(intptr_t)FPtr)());
+      else if (BitWidth <= 64)
+        rv.IntVal = APInt(BitWidth, ((int64_t(*)())(intptr_t)FPtr)());
+      else 
+        assert(0 && "Integer types > 64 bits not supported");
+      return rv;
+    }
+    case Type::VoidTyID:
+      rv.IntVal = APInt(32, ((int(*)())(intptr_t)FPtr)());
+      return rv;
+    case Type::FloatTyID:
+      rv.FloatVal = ((float(*)())(intptr_t)FPtr)();
+      return rv;
+    case Type::DoubleTyID:
+      rv.DoubleVal = ((double(*)())(intptr_t)FPtr)();
+      return rv;
+    case Type::X86_FP80TyID:
+    case Type::FP128TyID:
+    case Type::PPC_FP128TyID:
+      assert(0 && "long double not supported yet");
+      return rv;
+    case Type::PointerTyID:
+      return PTOGV(((void*(*)())(intptr_t)FPtr)());
+    }
+  }
+
+  // Okay, this is not one of our quick and easy cases.  Because we don't have a
+  // full FFI, we have to codegen a nullary stub function that just calls the
+  // function we are interested in, passing in constants for all of the
+  // arguments.  Make this function and return.
+
+  // First, create the function.
+  FunctionType *STy=FunctionType::get(RetTy, std::vector<const Type*>(), false);
+  Function *Stub = Function::Create(STy, Function::InternalLinkage, "",
+                                    F->getParent());
+
+  // Insert a basic block.
+  BasicBlock *StubBB = BasicBlock::Create("", Stub);
+
+  // Convert all of the GenericValue arguments over to constants.  Note that we
+  // currently don't support varargs.
+  SmallVector<Value*, 8> Args;
+  for (unsigned i = 0, e = ArgValues.size(); i != e; ++i) {
+    Constant *C = 0;
+    const Type *ArgTy = FTy->getParamType(i);
+    const GenericValue &AV = ArgValues[i];
+    switch (ArgTy->getTypeID()) {
+    default: assert(0 && "Unknown argument type for function call!");
+    case Type::IntegerTyID:
+        C = ConstantInt::get(AV.IntVal);
+        break;
+    case Type::FloatTyID:
+        C = ConstantFP::get(APFloat(AV.FloatVal));
+        break;
+    case Type::DoubleTyID:
+        C = ConstantFP::get(APFloat(AV.DoubleVal));
+        break;
+    case Type::PPC_FP128TyID:
+    case Type::X86_FP80TyID:
+    case Type::FP128TyID:
+        C = ConstantFP::get(APFloat(AV.IntVal));
+        break;
+    case Type::PointerTyID:
+      void *ArgPtr = GVTOP(AV);
+      if (sizeof(void*) == 4)
+        C = ConstantInt::get(Type::Int32Ty, (int)(intptr_t)ArgPtr);
+      else
+        C = ConstantInt::get(Type::Int64Ty, (intptr_t)ArgPtr);
+      C = ConstantExpr::getIntToPtr(C, ArgTy);  // Cast the integer to pointer
+      break;
+    }
+    Args.push_back(C);
+  }
+
+  CallInst *TheCall = CallInst::Create(F, Args.begin(), Args.end(),
+                                       "", StubBB);
+  TheCall->setCallingConv(F->getCallingConv());
+  TheCall->setTailCall();
+  if (TheCall->getType() != Type::VoidTy)
+    ReturnInst::Create(TheCall, StubBB);    // Return result of the call.
+  else
+    ReturnInst::Create(StubBB);             // Just return void.
+
+  // Finally, return the value returned by our nullary stub function.
+  return runFunction(Stub, std::vector<GenericValue>());
+}
+
+/// runJITOnFunction - Run the FunctionPassManager full of
+/// just-in-time compilation passes on F, hopefully filling in
+/// GlobalAddress[F] with the address of F's machine code.
+///
+void JIT::runJITOnFunction(Function *F, MachineCodeInfo *MCI) {
+  MutexGuard locked(lock);
+
+  registerMachineCodeInfo(MCI);
+
+  runJITOnFunctionUnlocked(F, locked);
+
+  registerMachineCodeInfo(0);
+}
+
+void JIT::runJITOnFunctionUnlocked(Function *F, const MutexGuard &locked) {
+  static bool isAlreadyCodeGenerating = false;
+  assert(!isAlreadyCodeGenerating && "Error: Recursive compilation detected!");
+
+  // JIT the function
+  isAlreadyCodeGenerating = true;
+  jitstate->getPM(locked).run(*F);
+  isAlreadyCodeGenerating = false;
+
+  // If the function referred to another function that had not yet been
+  // read from bitcode, but we are jitting non-lazily, emit it now.
+  while (!jitstate->getPendingFunctions(locked).empty()) {
+    Function *PF = jitstate->getPendingFunctions(locked).back();
+    jitstate->getPendingFunctions(locked).pop_back();
+
+    // JIT the function
+    isAlreadyCodeGenerating = true;
+    jitstate->getPM(locked).run(*PF);
+    isAlreadyCodeGenerating = false;
+    
+    // Now that the function has been jitted, ask the JITEmitter to rewrite
+    // the stub with real address of the function.
+    updateFunctionStub(PF);
+  }
+  
+  // If the JIT is configured to emit info so that dlsym can be used to
+  // rewrite stubs to external globals, do so now.
+  if (areDlsymStubsEnabled() && isLazyCompilationDisabled())
+    updateDlsymStubTable();
+}
+
+/// getPointerToFunction - This method is used to get the address of the
+/// specified function, compiling it if neccesary.
+///
+void *JIT::getPointerToFunction(Function *F) {
+
+  if (void *Addr = getPointerToGlobalIfAvailable(F))
+    return Addr;   // Check if function already code gen'd
+
+  MutexGuard locked(lock);
+
+  // Make sure we read in the function if it exists in this Module.
+  if (F->hasNotBeenReadFromBitcode()) {
+    // Determine the module provider this function is provided by.
+    Module *M = F->getParent();
+    ModuleProvider *MP = 0;
+    for (unsigned i = 0, e = Modules.size(); i != e; ++i) {
+      if (Modules[i]->getModule() == M) {
+        MP = Modules[i];
+        break;
+      }
+    }
+    assert(MP && "Function isn't in a module we know about!");
+    
+    std::string ErrorMsg;
+    if (MP->materializeFunction(F, &ErrorMsg)) {
+      cerr << "Error reading function '" << F->getName()
+           << "' from bitcode file: " << ErrorMsg << "\n";
+      abort();
+    }
+
+    // Now retry to get the address.
+    if (void *Addr = getPointerToGlobalIfAvailable(F))
+      return Addr;
+  }
+
+  if (F->isDeclaration()) {
+    bool AbortOnFailure =
+      !areDlsymStubsEnabled() && !F->hasExternalWeakLinkage();
+    void *Addr = getPointerToNamedFunction(F->getName(), AbortOnFailure);
+    addGlobalMapping(F, Addr);
+    return Addr;
+  }
+
+  runJITOnFunctionUnlocked(F, locked);
+
+  void *Addr = getPointerToGlobalIfAvailable(F);
+  assert(Addr && "Code generation didn't add function to GlobalAddress table!");
+  return Addr;
+}
+
+/// getOrEmitGlobalVariable - Return the address of the specified global
+/// variable, possibly emitting it to memory if needed.  This is used by the
+/// Emitter.
+void *JIT::getOrEmitGlobalVariable(const GlobalVariable *GV) {
+  MutexGuard locked(lock);
+
+  void *Ptr = getPointerToGlobalIfAvailable(GV);
+  if (Ptr) return Ptr;
+
+  // If the global is external, just remember the address.
+  if (GV->isDeclaration()) {
+#if HAVE___DSO_HANDLE
+    if (GV->getName() == "__dso_handle")
+      return (void*)&__dso_handle;
+#endif
+    Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(GV->getName().c_str());
+    if (Ptr == 0 && !areDlsymStubsEnabled()) {
+      cerr << "Could not resolve external global address: "
+           << GV->getName() << "\n";
+      abort();
+    }
+    addGlobalMapping(GV, Ptr);
+  } else {
+    // GlobalVariable's which are not "constant" will cause trouble in a server
+    // situation. It's returned in the same block of memory as code which may
+    // not be writable.
+    if (isGVCompilationDisabled() && !GV->isConstant()) {
+      cerr << "Compilation of non-internal GlobalValue is disabled!\n";
+      abort();
+    }
+    // If the global hasn't been emitted to memory yet, allocate space and
+    // emit it into memory.  It goes in the same array as the generated
+    // code, jump tables, etc.
+    const Type *GlobalType = GV->getType()->getElementType();
+    size_t S = getTargetData()->getTypeAllocSize(GlobalType);
+    size_t A = getTargetData()->getPreferredAlignment(GV);
+    if (GV->isThreadLocal()) {
+      MutexGuard locked(lock);
+      Ptr = TJI.allocateThreadLocalMemory(S);
+    } else if (TJI.allocateSeparateGVMemory()) {
+      if (A <= 8) {
+        Ptr = malloc(S);
+      } else {
+        // Allocate S+A bytes of memory, then use an aligned pointer within that
+        // space.
+        Ptr = malloc(S+A);
+        unsigned MisAligned = ((intptr_t)Ptr & (A-1));
+        Ptr = (char*)Ptr + (MisAligned ? (A-MisAligned) : 0);
+      }
+    } else {
+      Ptr = JCE->allocateSpace(S, A);
+    }
+    addGlobalMapping(GV, Ptr);
+    EmitGlobalVariable(GV);
+  }
+  return Ptr;
+}
+
+/// recompileAndRelinkFunction - This method is used to force a function
+/// which has already been compiled, to be compiled again, possibly
+/// after it has been modified. Then the entry to the old copy is overwritten
+/// with a branch to the new copy. If there was no old copy, this acts
+/// just like JIT::getPointerToFunction().
+///
+void *JIT::recompileAndRelinkFunction(Function *F) {
+  void *OldAddr = getPointerToGlobalIfAvailable(F);
+
+  // If it's not already compiled there is no reason to patch it up.
+  if (OldAddr == 0) { return getPointerToFunction(F); }
+
+  // Delete the old function mapping.
+  addGlobalMapping(F, 0);
+
+  // Recodegen the function
+  runJITOnFunction(F);
+
+  // Update state, forward the old function to the new function.
+  void *Addr = getPointerToGlobalIfAvailable(F);
+  assert(Addr && "Code generation didn't add function to GlobalAddress table!");
+  TJI.replaceMachineCodeForFunction(OldAddr, Addr);
+  return Addr;
+}
+
+/// getMemoryForGV - This method abstracts memory allocation of global
+/// variable so that the JIT can allocate thread local variables depending
+/// on the target.
+///
+char* JIT::getMemoryForGV(const GlobalVariable* GV) {
+  const Type *ElTy = GV->getType()->getElementType();
+  size_t GVSize = (size_t)getTargetData()->getTypeAllocSize(ElTy);
+  if (GV->isThreadLocal()) {
+    MutexGuard locked(lock);
+    return TJI.allocateThreadLocalMemory(GVSize);
+  } else {
+    return new char[GVSize];
+  }
+}
+
+void JIT::addPendingFunction(Function *F) {
+  MutexGuard locked(lock);
+  jitstate->getPendingFunctions(locked).push_back(F);
+}
diff --git a/lib/ExecutionEngine/JIT/JIT.h b/lib/ExecutionEngine/JIT/JIT.h
new file mode 100644
index 0000000..3ccb2dd
--- /dev/null
+++ b/lib/ExecutionEngine/JIT/JIT.h
@@ -0,0 +1,176 @@
+//===-- JIT.h - Class definition for the JIT --------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the top-level JIT data structure.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef JIT_H
+#define JIT_H
+
+#include "llvm/ExecutionEngine/ExecutionEngine.h"
+#include "llvm/PassManager.h"
+
+namespace llvm {
+
+class Function;
+class TargetMachine;
+class TargetJITInfo;
+class MachineCodeEmitter;
+class MachineCodeInfo;
+
+class JITState {
+private:
+  FunctionPassManager PM;  // Passes to compile a function
+  ModuleProvider *MP;      // ModuleProvider used to create the PM
+
+  /// PendingFunctions - Functions which have not been code generated yet, but
+  /// were called from a function being code generated.
+  std::vector<Function*> PendingFunctions;
+
+public:
+  explicit JITState(ModuleProvider *MP) : PM(MP), MP(MP) {}
+
+  FunctionPassManager &getPM(const MutexGuard &L) {
+    return PM;
+  }
+  
+  ModuleProvider *getMP() const { return MP; }
+  std::vector<Function*> &getPendingFunctions(const MutexGuard &L) {
+    return PendingFunctions;
+  }
+};
+
+
+class JIT : public ExecutionEngine {
+  TargetMachine &TM;       // The current target we are compiling to
+  TargetJITInfo &TJI;      // The JITInfo for the target we are compiling to
+  JITCodeEmitter *JCE;     // JCE object
+
+  JITState *jitstate;
+
+  JIT(ModuleProvider *MP, TargetMachine &tm, TargetJITInfo &tji, 
+      JITMemoryManager *JMM, CodeGenOpt::Level OptLevel);
+public:
+  ~JIT();
+
+  static void Register() {
+    JITCtor = create;
+  }
+  
+  /// getJITInfo - Return the target JIT information structure.
+  ///
+  TargetJITInfo &getJITInfo() const { return TJI; }
+
+  /// create - Create an return a new JIT compiler if there is one available
+  /// for the current target.  Otherwise, return null.
+  ///
+  static ExecutionEngine *create(ModuleProvider *MP, std::string *Err,
+                                 CodeGenOpt::Level OptLevel =
+                                   CodeGenOpt::Default) {
+    return createJIT(MP, Err, 0, OptLevel);
+  }
+
+  virtual void addModuleProvider(ModuleProvider *MP);
+  
+  /// removeModuleProvider - Remove a ModuleProvider from the list of modules.
+  /// Relases the Module from the ModuleProvider, materializing it in the
+  /// process, and returns the materialized Module.
+  virtual Module *removeModuleProvider(ModuleProvider *MP,
+                                       std::string *ErrInfo = 0);
+
+  /// deleteModuleProvider - Remove a ModuleProvider from the list of modules,
+  /// and deletes the ModuleProvider and owned Module.  Avoids materializing 
+  /// the underlying module.
+  virtual void deleteModuleProvider(ModuleProvider *P,std::string *ErrInfo = 0);
+
+  /// runFunction - Start execution with the specified function and arguments.
+  ///
+  virtual GenericValue runFunction(Function *F,
+                                   const std::vector<GenericValue> &ArgValues);
+
+  /// getPointerToNamedFunction - This method returns the address of the
+  /// specified function by using the dlsym function call.  As such it is only
+  /// useful for resolving library symbols, not code generated symbols.
+  ///
+  /// If AbortOnFailure is false and no function with the given name is
+  /// found, this function silently returns a null pointer. Otherwise,
+  /// it prints a message to stderr and aborts.
+  ///
+  void *getPointerToNamedFunction(const std::string &Name,
+                                  bool AbortOnFailure = true);
+
+  // CompilationCallback - Invoked the first time that a call site is found,
+  // which causes lazy compilation of the target function.
+  //
+  static void CompilationCallback();
+
+  /// getPointerToFunction - This returns the address of the specified function,
+  /// compiling it if necessary.
+  ///
+  void *getPointerToFunction(Function *F);
+
+  /// getOrEmitGlobalVariable - Return the address of the specified global
+  /// variable, possibly emitting it to memory if needed.  This is used by the
+  /// Emitter.
+  void *getOrEmitGlobalVariable(const GlobalVariable *GV);
+
+  /// getPointerToFunctionOrStub - If the specified function has been
+  /// code-gen'd, return a pointer to the function.  If not, compile it, or use
+  /// a stub to implement lazy compilation if available.
+  ///
+  void *getPointerToFunctionOrStub(Function *F);
+
+  /// recompileAndRelinkFunction - This method is used to force a function
+  /// which has already been compiled, to be compiled again, possibly
+  /// after it has been modified. Then the entry to the old copy is overwritten
+  /// with a branch to the new copy. If there was no old copy, this acts
+  /// just like JIT::getPointerToFunction().
+  ///
+  void *recompileAndRelinkFunction(Function *F);
+
+  /// freeMachineCodeForFunction - deallocate memory used to code-generate this
+  /// Function.
+  ///
+  void freeMachineCodeForFunction(Function *F);
+
+  /// addPendingFunction - while jitting non-lazily, a called but non-codegen'd
+  /// function was encountered.  Add it to a pending list to be processed after 
+  /// the current function.
+  /// 
+  void addPendingFunction(Function *F);
+  
+  /// getCodeEmitter - Return the code emitter this JIT is emitting into.
+  JITCodeEmitter *getCodeEmitter() const { return JCE; }
+  
+  static ExecutionEngine *createJIT(ModuleProvider *MP, std::string *Err,
+                                    JITMemoryManager *JMM,
+                                    CodeGenOpt::Level OptLevel);
+
+
+  // Run the JIT on F and return information about the generated code
+  void runJITOnFunction(Function *F, MachineCodeInfo *MCI = 0);
+
+private:
+  static JITCodeEmitter *createEmitter(JIT &J, JITMemoryManager *JMM);
+  void registerMachineCodeInfo(MachineCodeInfo *MCI);
+  void runJITOnFunctionUnlocked(Function *F, const MutexGuard &locked);
+  void updateFunctionStub(Function *F);
+  void updateDlsymStubTable();
+
+protected:
+
+  /// getMemoryforGV - Allocate memory for a global variable.
+  virtual char* getMemoryForGV(const GlobalVariable* GV);
+
+};
+
+} // End llvm namespace
+
+#endif
diff --git a/lib/ExecutionEngine/JIT/JITDwarfEmitter.cpp b/lib/ExecutionEngine/JIT/JITDwarfEmitter.cpp
new file mode 100644
index 0000000..e101ef3
--- /dev/null
+++ b/lib/ExecutionEngine/JIT/JITDwarfEmitter.cpp
@@ -0,0 +1,1056 @@
+//===----- JITDwarfEmitter.cpp - Write dwarf tables into memory -----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines a JITDwarfEmitter object that is used by the JIT to
+// write dwarf tables to memory.
+//
+//===----------------------------------------------------------------------===//
+
+#include "JIT.h"
+#include "JITDwarfEmitter.h"
+#include "llvm/Function.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/CodeGen/JITCodeEmitter.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineLocation.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/ExecutionEngine/JITMemoryManager.h"
+#include "llvm/Target/TargetAsmInfo.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetFrameInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+
+using namespace llvm;
+
+JITDwarfEmitter::JITDwarfEmitter(JIT& theJit) : Jit(theJit) {}
+
+
+unsigned char* JITDwarfEmitter::EmitDwarfTable(MachineFunction& F, 
+                                               JITCodeEmitter& jce,
+                                               unsigned char* StartFunction,
+                                               unsigned char* EndFunction) {
+  const TargetMachine& TM = F.getTarget();
+  TD = TM.getTargetData();
+  needsIndirectEncoding = TM.getTargetAsmInfo()->getNeedsIndirectEncoding();
+  stackGrowthDirection = TM.getFrameInfo()->getStackGrowthDirection();
+  RI = TM.getRegisterInfo();
+  JCE = &jce;
+  
+  unsigned char* ExceptionTable = EmitExceptionTable(&F, StartFunction,
+                                                     EndFunction);
+      
+  unsigned char* Result = 0;
+  unsigned char* EHFramePtr = 0;
+
+  const std::vector<Function *> Personalities = MMI->getPersonalities();
+  EHFramePtr = EmitCommonEHFrame(Personalities[MMI->getPersonalityIndex()]);
+
+  Result = EmitEHFrame(Personalities[MMI->getPersonalityIndex()], EHFramePtr,
+                       StartFunction, EndFunction, ExceptionTable);
+  
+  return Result;
+}
+
+
+void 
+JITDwarfEmitter::EmitFrameMoves(intptr_t BaseLabelPtr,
+                                const std::vector<MachineMove> &Moves) const {
+  unsigned PointerSize = TD->getPointerSize();
+  int stackGrowth = stackGrowthDirection == TargetFrameInfo::StackGrowsUp ?
+          PointerSize : -PointerSize;
+  bool IsLocal = false;
+  unsigned BaseLabelID = 0;
+
+  for (unsigned i = 0, N = Moves.size(); i < N; ++i) {
+    const MachineMove &Move = Moves[i];
+    unsigned LabelID = Move.getLabelID();
+    
+    if (LabelID) {
+      LabelID = MMI->MappedLabel(LabelID);
+    
+      // Throw out move if the label is invalid.
+      if (!LabelID) continue;
+    }
+    
+    intptr_t LabelPtr = 0;
+    if (LabelID) LabelPtr = JCE->getLabelAddress(LabelID);
+
+    const MachineLocation &Dst = Move.getDestination();
+    const MachineLocation &Src = Move.getSource();
+    
+    // Advance row if new location.
+    if (BaseLabelPtr && LabelID && (BaseLabelID != LabelID || !IsLocal)) {
+      JCE->emitByte(dwarf::DW_CFA_advance_loc4);
+      JCE->emitInt32(LabelPtr - BaseLabelPtr);
+      
+      BaseLabelID = LabelID; 
+      BaseLabelPtr = LabelPtr;
+      IsLocal = true;
+    }
+    
+    // If advancing cfa.
+    if (Dst.isReg() && Dst.getReg() == MachineLocation::VirtualFP) {
+      if (!Src.isReg()) {
+        if (Src.getReg() == MachineLocation::VirtualFP) {
+          JCE->emitByte(dwarf::DW_CFA_def_cfa_offset);
+        } else {
+          JCE->emitByte(dwarf::DW_CFA_def_cfa);
+          JCE->emitULEB128Bytes(RI->getDwarfRegNum(Src.getReg(), true));
+        }
+        
+        int Offset = -Src.getOffset();
+        
+        JCE->emitULEB128Bytes(Offset);
+      } else {
+        assert(0 && "Machine move no supported yet.");
+      }
+    } else if (Src.isReg() &&
+      Src.getReg() == MachineLocation::VirtualFP) {
+      if (Dst.isReg()) {
+        JCE->emitByte(dwarf::DW_CFA_def_cfa_register);
+        JCE->emitULEB128Bytes(RI->getDwarfRegNum(Dst.getReg(), true));
+      } else {
+        assert(0 && "Machine move no supported yet.");
+      }
+    } else {
+      unsigned Reg = RI->getDwarfRegNum(Src.getReg(), true);
+      int Offset = Dst.getOffset() / stackGrowth;
+      
+      if (Offset < 0) {
+        JCE->emitByte(dwarf::DW_CFA_offset_extended_sf);
+        JCE->emitULEB128Bytes(Reg);
+        JCE->emitSLEB128Bytes(Offset);
+      } else if (Reg < 64) {
+        JCE->emitByte(dwarf::DW_CFA_offset + Reg);
+        JCE->emitULEB128Bytes(Offset);
+      } else {
+        JCE->emitByte(dwarf::DW_CFA_offset_extended);
+        JCE->emitULEB128Bytes(Reg);
+        JCE->emitULEB128Bytes(Offset);
+      }
+    }
+  }
+}
+
+/// SharedTypeIds - How many leading type ids two landing pads have in common.
+static unsigned SharedTypeIds(const LandingPadInfo *L,
+                              const LandingPadInfo *R) {
+  const std::vector<int> &LIds = L->TypeIds, &RIds = R->TypeIds;
+  unsigned LSize = LIds.size(), RSize = RIds.size();
+  unsigned MinSize = LSize < RSize ? LSize : RSize;
+  unsigned Count = 0;
+
+  for (; Count != MinSize; ++Count)
+    if (LIds[Count] != RIds[Count])
+      return Count;
+
+  return Count;
+}
+
+
+/// PadLT - Order landing pads lexicographically by type id.
+static bool PadLT(const LandingPadInfo *L, const LandingPadInfo *R) {
+  const std::vector<int> &LIds = L->TypeIds, &RIds = R->TypeIds;
+  unsigned LSize = LIds.size(), RSize = RIds.size();
+  unsigned MinSize = LSize < RSize ? LSize : RSize;
+
+  for (unsigned i = 0; i != MinSize; ++i)
+    if (LIds[i] != RIds[i])
+      return LIds[i] < RIds[i];
+
+  return LSize < RSize;
+}
+
+namespace {
+
+struct KeyInfo {
+  static inline unsigned getEmptyKey() { return -1U; }
+  static inline unsigned getTombstoneKey() { return -2U; }
+  static unsigned getHashValue(const unsigned &Key) { return Key; }
+  static bool isEqual(unsigned LHS, unsigned RHS) { return LHS == RHS; }
+  static bool isPod() { return true; }
+};
+
+/// ActionEntry - Structure describing an entry in the actions table.
+struct ActionEntry {
+  int ValueForTypeID; // The value to write - may not be equal to the type id.
+  int NextAction;
+  struct ActionEntry *Previous;
+};
+
+/// PadRange - Structure holding a try-range and the associated landing pad.
+struct PadRange {
+  // The index of the landing pad.
+  unsigned PadIndex;
+  // The index of the begin and end labels in the landing pad's label lists.
+  unsigned RangeIndex;
+};
+
+typedef DenseMap<unsigned, PadRange, KeyInfo> RangeMapType;
+
+/// CallSiteEntry - Structure describing an entry in the call-site table.
+struct CallSiteEntry {
+  unsigned BeginLabel; // zero indicates the start of the function.
+  unsigned EndLabel;   // zero indicates the end of the function.
+  unsigned PadLabel;   // zero indicates that there is no landing pad.
+  unsigned Action;
+};
+
+}
+
+unsigned char* JITDwarfEmitter::EmitExceptionTable(MachineFunction* MF,
+                                         unsigned char* StartFunction,
+                                         unsigned char* EndFunction) const {
+  // Map all labels and get rid of any dead landing pads.
+  MMI->TidyLandingPads();
+
+  const std::vector<GlobalVariable *> &TypeInfos = MMI->getTypeInfos();
+  const std::vector<unsigned> &FilterIds = MMI->getFilterIds();
+  const std::vector<LandingPadInfo> &PadInfos = MMI->getLandingPads();
+  if (PadInfos.empty()) return 0;
+
+  // Sort the landing pads in order of their type ids.  This is used to fold
+  // duplicate actions.
+  SmallVector<const LandingPadInfo *, 64> LandingPads;
+  LandingPads.reserve(PadInfos.size());
+  for (unsigned i = 0, N = PadInfos.size(); i != N; ++i)
+    LandingPads.push_back(&PadInfos[i]);
+  std::sort(LandingPads.begin(), LandingPads.end(), PadLT);
+
+  // Negative type ids index into FilterIds, positive type ids index into
+  // TypeInfos.  The value written for a positive type id is just the type
+  // id itself.  For a negative type id, however, the value written is the
+  // (negative) byte offset of the corresponding FilterIds entry.  The byte
+  // offset is usually equal to the type id, because the FilterIds entries
+  // are written using a variable width encoding which outputs one byte per
+  // entry as long as the value written is not too large, but can differ.
+  // This kind of complication does not occur for positive type ids because
+  // type infos are output using a fixed width encoding.
+  // FilterOffsets[i] holds the byte offset corresponding to FilterIds[i].
+  SmallVector<int, 16> FilterOffsets;
+  FilterOffsets.reserve(FilterIds.size());
+  int Offset = -1;
+  for(std::vector<unsigned>::const_iterator I = FilterIds.begin(),
+    E = FilterIds.end(); I != E; ++I) {
+    FilterOffsets.push_back(Offset);
+    Offset -= TargetAsmInfo::getULEB128Size(*I);
+  }
+
+  // Compute the actions table and gather the first action index for each
+  // landing pad site.
+  SmallVector<ActionEntry, 32> Actions;
+  SmallVector<unsigned, 64> FirstActions;
+  FirstActions.reserve(LandingPads.size());
+
+  int FirstAction = 0;
+  unsigned SizeActions = 0;
+  for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
+    const LandingPadInfo *LP = LandingPads[i];
+    const std::vector<int> &TypeIds = LP->TypeIds;
+    const unsigned NumShared = i ? SharedTypeIds(LP, LandingPads[i-1]) : 0;
+    unsigned SizeSiteActions = 0;
+
+    if (NumShared < TypeIds.size()) {
+      unsigned SizeAction = 0;
+      ActionEntry *PrevAction = 0;
+
+      if (NumShared) {
+        const unsigned SizePrevIds = LandingPads[i-1]->TypeIds.size();
+        assert(Actions.size());
+        PrevAction = &Actions.back();
+        SizeAction = TargetAsmInfo::getSLEB128Size(PrevAction->NextAction) +
+          TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID);
+        for (unsigned j = NumShared; j != SizePrevIds; ++j) {
+          SizeAction -= TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID);
+          SizeAction += -PrevAction->NextAction;
+          PrevAction = PrevAction->Previous;
+        }
+      }
+
+      // Compute the actions.
+      for (unsigned I = NumShared, M = TypeIds.size(); I != M; ++I) {
+        int TypeID = TypeIds[I];
+        assert(-1-TypeID < (int)FilterOffsets.size() && "Unknown filter id!");
+        int ValueForTypeID = TypeID < 0 ? FilterOffsets[-1 - TypeID] : TypeID;
+        unsigned SizeTypeID = TargetAsmInfo::getSLEB128Size(ValueForTypeID);
+
+        int NextAction = SizeAction ? -(SizeAction + SizeTypeID) : 0;
+        SizeAction = SizeTypeID + TargetAsmInfo::getSLEB128Size(NextAction);
+        SizeSiteActions += SizeAction;
+
+        ActionEntry Action = {ValueForTypeID, NextAction, PrevAction};
+        Actions.push_back(Action);
+
+        PrevAction = &Actions.back();
+      }
+
+      // Record the first action of the landing pad site.
+      FirstAction = SizeActions + SizeSiteActions - SizeAction + 1;
+    } // else identical - re-use previous FirstAction
+
+    FirstActions.push_back(FirstAction);
+
+    // Compute this sites contribution to size.
+    SizeActions += SizeSiteActions;
+  }
+
+  // Compute the call-site table.  Entries must be ordered by address.
+  SmallVector<CallSiteEntry, 64> CallSites;
+
+  RangeMapType PadMap;
+  for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
+    const LandingPadInfo *LandingPad = LandingPads[i];
+    for (unsigned j=0, E = LandingPad->BeginLabels.size(); j != E; ++j) {
+      unsigned BeginLabel = LandingPad->BeginLabels[j];
+      assert(!PadMap.count(BeginLabel) && "Duplicate landing pad labels!");
+      PadRange P = { i, j };
+      PadMap[BeginLabel] = P;
+    }
+  }
+
+  bool MayThrow = false;
+  unsigned LastLabel = 0;
+  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
+        I != E; ++I) {
+    for (MachineBasicBlock::const_iterator MI = I->begin(), E = I->end();
+          MI != E; ++MI) {
+      if (!MI->isLabel()) {
+        MayThrow |= MI->getDesc().isCall();
+        continue;
+      }
+
+      unsigned BeginLabel = MI->getOperand(0).getImm();
+      assert(BeginLabel && "Invalid label!");
+
+      if (BeginLabel == LastLabel)
+        MayThrow = false;
+
+      RangeMapType::iterator L = PadMap.find(BeginLabel);
+
+      if (L == PadMap.end())
+        continue;
+
+      PadRange P = L->second;
+      const LandingPadInfo *LandingPad = LandingPads[P.PadIndex];
+
+      assert(BeginLabel == LandingPad->BeginLabels[P.RangeIndex] &&
+              "Inconsistent landing pad map!");
+
+      // If some instruction between the previous try-range and this one may
+      // throw, create a call-site entry with no landing pad for the region
+      // between the try-ranges.
+      if (MayThrow) {
+        CallSiteEntry Site = {LastLabel, BeginLabel, 0, 0};
+        CallSites.push_back(Site);
+      }
+
+      LastLabel = LandingPad->EndLabels[P.RangeIndex];
+      CallSiteEntry Site = {BeginLabel, LastLabel,
+        LandingPad->LandingPadLabel, FirstActions[P.PadIndex]};
+
+      assert(Site.BeginLabel && Site.EndLabel && Site.PadLabel &&
+              "Invalid landing pad!");
+
+      // Try to merge with the previous call-site.
+      if (CallSites.size()) {
+        CallSiteEntry &Prev = CallSites.back();
+        if (Site.PadLabel == Prev.PadLabel && Site.Action == Prev.Action) {
+          // Extend the range of the previous entry.
+          Prev.EndLabel = Site.EndLabel;
+          continue;
+        }
+      }
+
+      // Otherwise, create a new call-site.
+      CallSites.push_back(Site);
+    }
+  }
+  // If some instruction between the previous try-range and the end of the
+  // function may throw, create a call-site entry with no landing pad for the
+  // region following the try-range.
+  if (MayThrow) {
+    CallSiteEntry Site = {LastLabel, 0, 0, 0};
+    CallSites.push_back(Site);
+  }
+
+  // Final tallies.
+  unsigned SizeSites = CallSites.size() * (sizeof(int32_t) + // Site start.
+                                            sizeof(int32_t) + // Site length.
+                                            sizeof(int32_t)); // Landing pad.
+  for (unsigned i = 0, e = CallSites.size(); i < e; ++i)
+    SizeSites += TargetAsmInfo::getULEB128Size(CallSites[i].Action);
+
+  unsigned SizeTypes = TypeInfos.size() * TD->getPointerSize();
+
+  unsigned TypeOffset = sizeof(int8_t) + // Call site format
+                        // Call-site table length
+                        TargetAsmInfo::getULEB128Size(SizeSites) + 
+                        SizeSites + SizeActions + SizeTypes;
+
+  unsigned TotalSize = sizeof(int8_t) + // LPStart format
+                       sizeof(int8_t) + // TType format
+                       TargetAsmInfo::getULEB128Size(TypeOffset) + // TType base offset
+                       TypeOffset;
+
+  unsigned SizeAlign = (4 - TotalSize) & 3;
+
+  // Begin the exception table.
+  JCE->emitAlignment(4);
+  for (unsigned i = 0; i != SizeAlign; ++i) {
+    JCE->emitByte(0);
+    // Asm->EOL("Padding");
+  }
+  
+  unsigned char* DwarfExceptionTable = (unsigned char*)JCE->getCurrentPCValue();
+
+  // Emit the header.
+  JCE->emitByte(dwarf::DW_EH_PE_omit);
+  // Asm->EOL("LPStart format (DW_EH_PE_omit)");
+  JCE->emitByte(dwarf::DW_EH_PE_absptr);
+  // Asm->EOL("TType format (DW_EH_PE_absptr)");
+  JCE->emitULEB128Bytes(TypeOffset);
+  // Asm->EOL("TType base offset");
+  JCE->emitByte(dwarf::DW_EH_PE_udata4);
+  // Asm->EOL("Call site format (DW_EH_PE_udata4)");
+  JCE->emitULEB128Bytes(SizeSites);
+  // Asm->EOL("Call-site table length");
+
+  // Emit the landing pad site information.
+  for (unsigned i = 0; i < CallSites.size(); ++i) {
+    CallSiteEntry &S = CallSites[i];
+    intptr_t BeginLabelPtr = 0;
+    intptr_t EndLabelPtr = 0;
+
+    if (!S.BeginLabel) {
+      BeginLabelPtr = (intptr_t)StartFunction;
+      JCE->emitInt32(0);
+    } else {
+      BeginLabelPtr = JCE->getLabelAddress(S.BeginLabel);
+      JCE->emitInt32(BeginLabelPtr - (intptr_t)StartFunction);
+    }
+
+    // Asm->EOL("Region start");
+
+    if (!S.EndLabel) {
+      EndLabelPtr = (intptr_t)EndFunction;
+      JCE->emitInt32((intptr_t)EndFunction - BeginLabelPtr);
+    } else {
+      EndLabelPtr = JCE->getLabelAddress(S.EndLabel);
+      JCE->emitInt32(EndLabelPtr - BeginLabelPtr);
+    }
+    //Asm->EOL("Region length");
+
+    if (!S.PadLabel) {
+      JCE->emitInt32(0);
+    } else {
+      unsigned PadLabelPtr = JCE->getLabelAddress(S.PadLabel);
+      JCE->emitInt32(PadLabelPtr - (intptr_t)StartFunction);
+    }
+    // Asm->EOL("Landing pad");
+
+    JCE->emitULEB128Bytes(S.Action);
+    // Asm->EOL("Action");
+  }
+
+  // Emit the actions.
+  for (unsigned I = 0, N = Actions.size(); I != N; ++I) {
+    ActionEntry &Action = Actions[I];
+
+    JCE->emitSLEB128Bytes(Action.ValueForTypeID);
+    //Asm->EOL("TypeInfo index");
+    JCE->emitSLEB128Bytes(Action.NextAction);
+    //Asm->EOL("Next action");
+  }
+
+  // Emit the type ids.
+  for (unsigned M = TypeInfos.size(); M; --M) {
+    GlobalVariable *GV = TypeInfos[M - 1];
+    
+    if (GV) {
+      if (TD->getPointerSize() == sizeof(int32_t)) {
+        JCE->emitInt32((intptr_t)Jit.getOrEmitGlobalVariable(GV));
+      } else {
+        JCE->emitInt64((intptr_t)Jit.getOrEmitGlobalVariable(GV));
+      }
+    } else {
+      if (TD->getPointerSize() == sizeof(int32_t))
+        JCE->emitInt32(0);
+      else
+        JCE->emitInt64(0);
+    }
+    // Asm->EOL("TypeInfo");
+  }
+
+  // Emit the filter typeids.
+  for (unsigned j = 0, M = FilterIds.size(); j < M; ++j) {
+    unsigned TypeID = FilterIds[j];
+    JCE->emitULEB128Bytes(TypeID);
+    //Asm->EOL("Filter TypeInfo index");
+  }
+  
+  JCE->emitAlignment(4);
+
+  return DwarfExceptionTable;
+}
+
+unsigned char*
+JITDwarfEmitter::EmitCommonEHFrame(const Function* Personality) const {
+  unsigned PointerSize = TD->getPointerSize();
+  int stackGrowth = stackGrowthDirection == TargetFrameInfo::StackGrowsUp ?
+          PointerSize : -PointerSize;
+  
+  unsigned char* StartCommonPtr = (unsigned char*)JCE->getCurrentPCValue();
+  // EH Common Frame header
+  JCE->allocateSpace(4, 0);
+  unsigned char* FrameCommonBeginPtr = (unsigned char*)JCE->getCurrentPCValue();
+  JCE->emitInt32((int)0);
+  JCE->emitByte(dwarf::DW_CIE_VERSION);
+  JCE->emitString(Personality ? "zPLR" : "zR");
+  JCE->emitULEB128Bytes(1);
+  JCE->emitSLEB128Bytes(stackGrowth);
+  JCE->emitByte(RI->getDwarfRegNum(RI->getRARegister(), true));
+  
+  if (Personality) {
+    // Augmentation Size: 3 small ULEBs of one byte each, and the personality
+    // function which size is PointerSize.
+    JCE->emitULEB128Bytes(3 + PointerSize); 
+    
+    // We set the encoding of the personality as direct encoding because we use
+    // the function pointer. The encoding is not relative because the current
+    // PC value may be bigger than the personality function pointer.
+    if (PointerSize == 4) {
+      JCE->emitByte(dwarf::DW_EH_PE_sdata4); 
+      JCE->emitInt32(((intptr_t)Jit.getPointerToGlobal(Personality)));
+    } else {
+      JCE->emitByte(dwarf::DW_EH_PE_sdata8);
+      JCE->emitInt64(((intptr_t)Jit.getPointerToGlobal(Personality)));
+    }
+    
+    JCE->emitULEB128Bytes(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
+    JCE->emitULEB128Bytes(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
+      
+  } else {
+    JCE->emitULEB128Bytes(1);
+    JCE->emitULEB128Bytes(dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4);
+  }
+
+  std::vector<MachineMove> Moves;
+  RI->getInitialFrameState(Moves);
+  EmitFrameMoves(0, Moves);
+  JCE->emitAlignment(PointerSize);
+  
+  JCE->emitInt32At((uintptr_t*)StartCommonPtr, 
+              (uintptr_t)((unsigned char*)JCE->getCurrentPCValue() - 
+                          FrameCommonBeginPtr));
+
+  return StartCommonPtr;
+}
+
+
+unsigned char*
+JITDwarfEmitter::EmitEHFrame(const Function* Personality,
+                             unsigned char* StartCommonPtr,
+                             unsigned char* StartFunction, 
+                             unsigned char* EndFunction,
+                             unsigned char* ExceptionTable) const {
+  unsigned PointerSize = TD->getPointerSize();
+  
+  // EH frame header.
+  unsigned char* StartEHPtr = (unsigned char*)JCE->getCurrentPCValue();
+  JCE->allocateSpace(4, 0);
+  unsigned char* FrameBeginPtr = (unsigned char*)JCE->getCurrentPCValue();
+  // FDE CIE Offset
+  JCE->emitInt32(FrameBeginPtr - StartCommonPtr);
+  JCE->emitInt32(StartFunction - (unsigned char*)JCE->getCurrentPCValue());
+  JCE->emitInt32(EndFunction - StartFunction);
+
+  // If there is a personality and landing pads then point to the language
+  // specific data area in the exception table.
+  if (MMI->getPersonalityIndex()) {
+    JCE->emitULEB128Bytes(4);
+        
+    if (!MMI->getLandingPads().empty()) {
+      JCE->emitInt32(ExceptionTable - (unsigned char*)JCE->getCurrentPCValue());
+    } else {
+      JCE->emitInt32((int)0);
+    }
+  } else {
+    JCE->emitULEB128Bytes(0);
+  }
+      
+  // Indicate locations of function specific  callee saved registers in
+  // frame.
+  EmitFrameMoves((intptr_t)StartFunction, MMI->getFrameMoves());
+      
+  JCE->emitAlignment(PointerSize);
+  
+  // Indicate the size of the table
+  JCE->emitInt32At((uintptr_t*)StartEHPtr, 
+              (uintptr_t)((unsigned char*)JCE->getCurrentPCValue() - 
+                          StartEHPtr));
+  
+  // Double zeroes for the unwind runtime
+  if (PointerSize == 8) {
+    JCE->emitInt64(0);
+    JCE->emitInt64(0);
+  } else {
+    JCE->emitInt32(0);
+    JCE->emitInt32(0);
+  }
+
+  
+  return StartEHPtr;
+}
+
+unsigned JITDwarfEmitter::GetDwarfTableSizeInBytes(MachineFunction& F,
+                                         JITCodeEmitter& jce,
+                                         unsigned char* StartFunction,
+                                         unsigned char* EndFunction) {
+  const TargetMachine& TM = F.getTarget();
+  TD = TM.getTargetData();
+  needsIndirectEncoding = TM.getTargetAsmInfo()->getNeedsIndirectEncoding();
+  stackGrowthDirection = TM.getFrameInfo()->getStackGrowthDirection();
+  RI = TM.getRegisterInfo();
+  JCE = &jce;
+  unsigned FinalSize = 0;
+  
+  FinalSize += GetExceptionTableSizeInBytes(&F);
+      
+  const std::vector<Function *> Personalities = MMI->getPersonalities();
+  FinalSize += 
+    GetCommonEHFrameSizeInBytes(Personalities[MMI->getPersonalityIndex()]);
+
+  FinalSize += GetEHFrameSizeInBytes(Personalities[MMI->getPersonalityIndex()],
+                                     StartFunction);
+  
+  return FinalSize;
+}
+
+/// RoundUpToAlign - Add the specified alignment to FinalSize and returns
+/// the new value.
+static unsigned RoundUpToAlign(unsigned FinalSize, unsigned Alignment) {
+  if (Alignment == 0) Alignment = 1;
+  // Since we do not know where the buffer will be allocated, be pessimistic.
+  return FinalSize + Alignment;
+}
+  
+unsigned
+JITDwarfEmitter::GetEHFrameSizeInBytes(const Function* Personality,
+                                       unsigned char* StartFunction) const { 
+  unsigned PointerSize = TD->getPointerSize();
+  unsigned FinalSize = 0;
+  // EH frame header.
+  FinalSize += PointerSize;
+  // FDE CIE Offset
+  FinalSize += 3 * PointerSize;
+  // If there is a personality and landing pads then point to the language
+  // specific data area in the exception table.
+  if (MMI->getPersonalityIndex()) {
+    FinalSize += TargetAsmInfo::getULEB128Size(4); 
+    FinalSize += PointerSize;
+  } else {
+    FinalSize += TargetAsmInfo::getULEB128Size(0);
+  }
+      
+  // Indicate locations of function specific  callee saved registers in
+  // frame.
+  FinalSize += GetFrameMovesSizeInBytes((intptr_t)StartFunction,
+                                        MMI->getFrameMoves());
+      
+  FinalSize = RoundUpToAlign(FinalSize, 4);
+  
+  // Double zeroes for the unwind runtime
+  FinalSize += 2 * PointerSize;
+
+  return FinalSize;
+}
+
+unsigned JITDwarfEmitter::GetCommonEHFrameSizeInBytes(const Function* Personality) 
+  const {
+
+  unsigned PointerSize = TD->getPointerSize();
+  int stackGrowth = stackGrowthDirection == TargetFrameInfo::StackGrowsUp ?
+          PointerSize : -PointerSize;
+  unsigned FinalSize = 0; 
+  // EH Common Frame header
+  FinalSize += PointerSize;
+  FinalSize += 4;
+  FinalSize += 1;
+  FinalSize += Personality ? 5 : 3; // "zPLR" or "zR"
+  FinalSize += TargetAsmInfo::getULEB128Size(1);
+  FinalSize += TargetAsmInfo::getSLEB128Size(stackGrowth);
+  FinalSize += 1;
+  
+  if (Personality) {
+    FinalSize += TargetAsmInfo::getULEB128Size(7);
+    
+    // Encoding
+    FinalSize+= 1;
+    //Personality
+    FinalSize += PointerSize;
+    
+    FinalSize += TargetAsmInfo::getULEB128Size(dwarf::DW_EH_PE_pcrel);
+    FinalSize += TargetAsmInfo::getULEB128Size(dwarf::DW_EH_PE_pcrel);
+      
+  } else {
+    FinalSize += TargetAsmInfo::getULEB128Size(1);
+    FinalSize += TargetAsmInfo::getULEB128Size(dwarf::DW_EH_PE_pcrel);
+  }
+
+  std::vector<MachineMove> Moves;
+  RI->getInitialFrameState(Moves);
+  FinalSize += GetFrameMovesSizeInBytes(0, Moves);
+  FinalSize = RoundUpToAlign(FinalSize, 4);
+  return FinalSize;
+}
+
+unsigned
+JITDwarfEmitter::GetFrameMovesSizeInBytes(intptr_t BaseLabelPtr,
+                                  const std::vector<MachineMove> &Moves) const {
+  unsigned PointerSize = TD->getPointerSize();
+  int stackGrowth = stackGrowthDirection == TargetFrameInfo::StackGrowsUp ?
+          PointerSize : -PointerSize;
+  bool IsLocal = BaseLabelPtr;
+  unsigned FinalSize = 0; 
+
+  for (unsigned i = 0, N = Moves.size(); i < N; ++i) {
+    const MachineMove &Move = Moves[i];
+    unsigned LabelID = Move.getLabelID();
+    
+    if (LabelID) {
+      LabelID = MMI->MappedLabel(LabelID);
+    
+      // Throw out move if the label is invalid.
+      if (!LabelID) continue;
+    }
+    
+    intptr_t LabelPtr = 0;
+    if (LabelID) LabelPtr = JCE->getLabelAddress(LabelID);
+
+    const MachineLocation &Dst = Move.getDestination();
+    const MachineLocation &Src = Move.getSource();
+    
+    // Advance row if new location.
+    if (BaseLabelPtr && LabelID && (BaseLabelPtr != LabelPtr || !IsLocal)) {
+      FinalSize++;
+      FinalSize += PointerSize;
+      BaseLabelPtr = LabelPtr;
+      IsLocal = true;
+    }
+    
+    // If advancing cfa.
+    if (Dst.isReg() && Dst.getReg() == MachineLocation::VirtualFP) {
+      if (!Src.isReg()) {
+        if (Src.getReg() == MachineLocation::VirtualFP) {
+          ++FinalSize;
+        } else {
+          ++FinalSize;
+          unsigned RegNum = RI->getDwarfRegNum(Src.getReg(), true);
+          FinalSize += TargetAsmInfo::getULEB128Size(RegNum);
+        }
+        
+        int Offset = -Src.getOffset();
+        
+        FinalSize += TargetAsmInfo::getULEB128Size(Offset);
+      } else {
+        assert(0 && "Machine move no supported yet.");
+      }
+    } else if (Src.isReg() &&
+      Src.getReg() == MachineLocation::VirtualFP) {
+      if (Dst.isReg()) {
+        ++FinalSize;
+        unsigned RegNum = RI->getDwarfRegNum(Dst.getReg(), true);
+        FinalSize += TargetAsmInfo::getULEB128Size(RegNum);
+      } else {
+        assert(0 && "Machine move no supported yet.");
+      }
+    } else {
+      unsigned Reg = RI->getDwarfRegNum(Src.getReg(), true);
+      int Offset = Dst.getOffset() / stackGrowth;
+      
+      if (Offset < 0) {
+        ++FinalSize;
+        FinalSize += TargetAsmInfo::getULEB128Size(Reg);
+        FinalSize += TargetAsmInfo::getSLEB128Size(Offset);
+      } else if (Reg < 64) {
+        ++FinalSize;
+        FinalSize += TargetAsmInfo::getULEB128Size(Offset);
+      } else {
+        ++FinalSize;
+        FinalSize += TargetAsmInfo::getULEB128Size(Reg);
+        FinalSize += TargetAsmInfo::getULEB128Size(Offset);
+      }
+    }
+  }
+  return FinalSize;
+}
+
+unsigned 
+JITDwarfEmitter::GetExceptionTableSizeInBytes(MachineFunction* MF) const {
+  unsigned FinalSize = 0;
+
+  // Map all labels and get rid of any dead landing pads.
+  MMI->TidyLandingPads();
+
+  const std::vector<GlobalVariable *> &TypeInfos = MMI->getTypeInfos();
+  const std::vector<unsigned> &FilterIds = MMI->getFilterIds();
+  const std::vector<LandingPadInfo> &PadInfos = MMI->getLandingPads();
+  if (PadInfos.empty()) return 0;
+
+  // Sort the landing pads in order of their type ids.  This is used to fold
+  // duplicate actions.
+  SmallVector<const LandingPadInfo *, 64> LandingPads;
+  LandingPads.reserve(PadInfos.size());
+  for (unsigned i = 0, N = PadInfos.size(); i != N; ++i)
+    LandingPads.push_back(&PadInfos[i]);
+  std::sort(LandingPads.begin(), LandingPads.end(), PadLT);
+
+  // Negative type ids index into FilterIds, positive type ids index into
+  // TypeInfos.  The value written for a positive type id is just the type
+  // id itself.  For a negative type id, however, the value written is the
+  // (negative) byte offset of the corresponding FilterIds entry.  The byte
+  // offset is usually equal to the type id, because the FilterIds entries
+  // are written using a variable width encoding which outputs one byte per
+  // entry as long as the value written is not too large, but can differ.
+  // This kind of complication does not occur for positive type ids because
+  // type infos are output using a fixed width encoding.
+  // FilterOffsets[i] holds the byte offset corresponding to FilterIds[i].
+  SmallVector<int, 16> FilterOffsets;
+  FilterOffsets.reserve(FilterIds.size());
+  int Offset = -1;
+  for(std::vector<unsigned>::const_iterator I = FilterIds.begin(),
+    E = FilterIds.end(); I != E; ++I) {
+    FilterOffsets.push_back(Offset);
+    Offset -= TargetAsmInfo::getULEB128Size(*I);
+  }
+
+  // Compute the actions table and gather the first action index for each
+  // landing pad site.
+  SmallVector<ActionEntry, 32> Actions;
+  SmallVector<unsigned, 64> FirstActions;
+  FirstActions.reserve(LandingPads.size());
+
+  int FirstAction = 0;
+  unsigned SizeActions = 0;
+  for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
+    const LandingPadInfo *LP = LandingPads[i];
+    const std::vector<int> &TypeIds = LP->TypeIds;
+    const unsigned NumShared = i ? SharedTypeIds(LP, LandingPads[i-1]) : 0;
+    unsigned SizeSiteActions = 0;
+
+    if (NumShared < TypeIds.size()) {
+      unsigned SizeAction = 0;
+      ActionEntry *PrevAction = 0;
+
+      if (NumShared) {
+        const unsigned SizePrevIds = LandingPads[i-1]->TypeIds.size();
+        assert(Actions.size());
+        PrevAction = &Actions.back();
+        SizeAction = TargetAsmInfo::getSLEB128Size(PrevAction->NextAction) +
+          TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID);
+        for (unsigned j = NumShared; j != SizePrevIds; ++j) {
+          SizeAction -= TargetAsmInfo::getSLEB128Size(PrevAction->ValueForTypeID);
+          SizeAction += -PrevAction->NextAction;
+          PrevAction = PrevAction->Previous;
+        }
+      }
+
+      // Compute the actions.
+      for (unsigned I = NumShared, M = TypeIds.size(); I != M; ++I) {
+        int TypeID = TypeIds[I];
+        assert(-1-TypeID < (int)FilterOffsets.size() && "Unknown filter id!");
+        int ValueForTypeID = TypeID < 0 ? FilterOffsets[-1 - TypeID] : TypeID;
+        unsigned SizeTypeID = TargetAsmInfo::getSLEB128Size(ValueForTypeID);
+
+        int NextAction = SizeAction ? -(SizeAction + SizeTypeID) : 0;
+        SizeAction = SizeTypeID + TargetAsmInfo::getSLEB128Size(NextAction);
+        SizeSiteActions += SizeAction;
+
+        ActionEntry Action = {ValueForTypeID, NextAction, PrevAction};
+        Actions.push_back(Action);
+
+        PrevAction = &Actions.back();
+      }
+
+      // Record the first action of the landing pad site.
+      FirstAction = SizeActions + SizeSiteActions - SizeAction + 1;
+    } // else identical - re-use previous FirstAction
+
+    FirstActions.push_back(FirstAction);
+
+    // Compute this sites contribution to size.
+    SizeActions += SizeSiteActions;
+  }
+
+  // Compute the call-site table.  Entries must be ordered by address.
+  SmallVector<CallSiteEntry, 64> CallSites;
+
+  RangeMapType PadMap;
+  for (unsigned i = 0, N = LandingPads.size(); i != N; ++i) {
+    const LandingPadInfo *LandingPad = LandingPads[i];
+    for (unsigned j=0, E = LandingPad->BeginLabels.size(); j != E; ++j) {
+      unsigned BeginLabel = LandingPad->BeginLabels[j];
+      assert(!PadMap.count(BeginLabel) && "Duplicate landing pad labels!");
+      PadRange P = { i, j };
+      PadMap[BeginLabel] = P;
+    }
+  }
+
+  bool MayThrow = false;
+  unsigned LastLabel = 0;
+  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
+        I != E; ++I) {
+    for (MachineBasicBlock::const_iterator MI = I->begin(), E = I->end();
+          MI != E; ++MI) {
+      if (!MI->isLabel()) {
+        MayThrow |= MI->getDesc().isCall();
+        continue;
+      }
+
+      unsigned BeginLabel = MI->getOperand(0).getImm();
+      assert(BeginLabel && "Invalid label!");
+
+      if (BeginLabel == LastLabel)
+        MayThrow = false;
+
+      RangeMapType::iterator L = PadMap.find(BeginLabel);
+
+      if (L == PadMap.end())
+        continue;
+
+      PadRange P = L->second;
+      const LandingPadInfo *LandingPad = LandingPads[P.PadIndex];
+
+      assert(BeginLabel == LandingPad->BeginLabels[P.RangeIndex] &&
+              "Inconsistent landing pad map!");
+
+      // If some instruction between the previous try-range and this one may
+      // throw, create a call-site entry with no landing pad for the region
+      // between the try-ranges.
+      if (MayThrow) {
+        CallSiteEntry Site = {LastLabel, BeginLabel, 0, 0};
+        CallSites.push_back(Site);
+      }
+
+      LastLabel = LandingPad->EndLabels[P.RangeIndex];
+      CallSiteEntry Site = {BeginLabel, LastLabel,
+        LandingPad->LandingPadLabel, FirstActions[P.PadIndex]};
+
+      assert(Site.BeginLabel && Site.EndLabel && Site.PadLabel &&
+              "Invalid landing pad!");
+
+      // Try to merge with the previous call-site.
+      if (CallSites.size()) {
+        CallSiteEntry &Prev = CallSites.back();
+        if (Site.PadLabel == Prev.PadLabel && Site.Action == Prev.Action) {
+          // Extend the range of the previous entry.
+          Prev.EndLabel = Site.EndLabel;
+          continue;
+        }
+      }
+
+      // Otherwise, create a new call-site.
+      CallSites.push_back(Site);
+    }
+  }
+  // If some instruction between the previous try-range and the end of the
+  // function may throw, create a call-site entry with no landing pad for the
+  // region following the try-range.
+  if (MayThrow) {
+    CallSiteEntry Site = {LastLabel, 0, 0, 0};
+    CallSites.push_back(Site);
+  }
+
+  // Final tallies.
+  unsigned SizeSites = CallSites.size() * (sizeof(int32_t) + // Site start.
+                                            sizeof(int32_t) + // Site length.
+                                            sizeof(int32_t)); // Landing pad.
+  for (unsigned i = 0, e = CallSites.size(); i < e; ++i)
+    SizeSites += TargetAsmInfo::getULEB128Size(CallSites[i].Action);
+
+  unsigned SizeTypes = TypeInfos.size() * TD->getPointerSize();
+
+  unsigned TypeOffset = sizeof(int8_t) + // Call site format
+                        // Call-site table length
+                        TargetAsmInfo::getULEB128Size(SizeSites) + 
+                        SizeSites + SizeActions + SizeTypes;
+
+  unsigned TotalSize = sizeof(int8_t) + // LPStart format
+                       sizeof(int8_t) + // TType format
+                       TargetAsmInfo::getULEB128Size(TypeOffset) + // TType base offset
+                       TypeOffset;
+
+  unsigned SizeAlign = (4 - TotalSize) & 3;
+
+  // Begin the exception table.
+  FinalSize = RoundUpToAlign(FinalSize, 4);
+  for (unsigned i = 0; i != SizeAlign; ++i) {
+    ++FinalSize;
+  }
+  
+  unsigned PointerSize = TD->getPointerSize();
+
+  // Emit the header.
+  ++FinalSize;
+  // Asm->EOL("LPStart format (DW_EH_PE_omit)");
+  ++FinalSize;
+  // Asm->EOL("TType format (DW_EH_PE_absptr)");
+  ++FinalSize;
+  // Asm->EOL("TType base offset");
+  ++FinalSize;
+  // Asm->EOL("Call site format (DW_EH_PE_udata4)");
+  ++FinalSize;
+  // Asm->EOL("Call-site table length");
+
+  // Emit the landing pad site information.
+  for (unsigned i = 0; i < CallSites.size(); ++i) {
+    CallSiteEntry &S = CallSites[i];
+
+    // Asm->EOL("Region start");
+    FinalSize += PointerSize;
+    
+    //Asm->EOL("Region length");
+    FinalSize += PointerSize;
+
+    // Asm->EOL("Landing pad");
+    FinalSize += PointerSize;
+
+    FinalSize += TargetAsmInfo::getULEB128Size(S.Action);
+    // Asm->EOL("Action");
+  }
+
+  // Emit the actions.
+  for (unsigned I = 0, N = Actions.size(); I != N; ++I) {
+    ActionEntry &Action = Actions[I];
+
+    //Asm->EOL("TypeInfo index");
+    FinalSize += TargetAsmInfo::getSLEB128Size(Action.ValueForTypeID);
+    //Asm->EOL("Next action");
+    FinalSize += TargetAsmInfo::getSLEB128Size(Action.NextAction);
+  }
+
+  // Emit the type ids.
+  for (unsigned M = TypeInfos.size(); M; --M) {
+    // Asm->EOL("TypeInfo");
+    FinalSize += PointerSize;
+  }
+
+  // Emit the filter typeids.
+  for (unsigned j = 0, M = FilterIds.size(); j < M; ++j) {
+    unsigned TypeID = FilterIds[j];
+    FinalSize += TargetAsmInfo::getULEB128Size(TypeID);
+    //Asm->EOL("Filter TypeInfo index");
+  }
+  
+  FinalSize = RoundUpToAlign(FinalSize, 4);
+
+  return FinalSize;
+}
diff --git a/lib/ExecutionEngine/JIT/JITDwarfEmitter.h b/lib/ExecutionEngine/JIT/JITDwarfEmitter.h
new file mode 100644
index 0000000..9120ed4
--- /dev/null
+++ b/lib/ExecutionEngine/JIT/JITDwarfEmitter.h
@@ -0,0 +1,87 @@
+//===------ JITDwarfEmitter.h - Write dwarf tables into memory ------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines a JITDwarfEmitter object that is used by the JIT to
+// write dwarf tables to memory.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTION_ENGINE_JIT_DWARFEMITTER_H
+#define LLVM_EXECUTION_ENGINE_JIT_DWARFEMITTER_H
+
+namespace llvm {
+
+class Function;
+class JITCodeEmitter;
+class MachineFunction;
+class MachineModuleInfo;
+class MachineMove;
+class TargetData;
+class TargetMachine;
+class TargetRegisterInfo;
+
+class JITDwarfEmitter {
+  const TargetData* TD;
+  JITCodeEmitter* JCE;
+  const TargetRegisterInfo* RI;
+  MachineModuleInfo* MMI;
+  JIT& Jit;
+  bool needsIndirectEncoding;
+  bool stackGrowthDirection;
+  
+  unsigned char* EmitExceptionTable(MachineFunction* MF,
+                                    unsigned char* StartFunction, 
+                                    unsigned char* EndFunction) const;
+
+  void EmitFrameMoves(intptr_t BaseLabelPtr, 
+                      const std::vector<MachineMove> &Moves) const;
+    
+  unsigned char* EmitCommonEHFrame(const Function* Personality) const;
+
+  unsigned char* EmitEHFrame(const Function* Personality, 
+                             unsigned char* StartBufferPtr,
+                             unsigned char* StartFunction, 
+                             unsigned char* EndFunction,
+                             unsigned char* ExceptionTable) const;
+    
+  unsigned GetExceptionTableSizeInBytes(MachineFunction* MF) const;
+  
+  unsigned
+    GetFrameMovesSizeInBytes(intptr_t BaseLabelPtr, 
+                             const std::vector<MachineMove> &Moves) const;
+    
+  unsigned GetCommonEHFrameSizeInBytes(const Function* Personality) const;
+
+  unsigned GetEHFrameSizeInBytes(const Function* Personality, 
+                                 unsigned char* StartFunction) const; 
+    
+public:
+  
+  JITDwarfEmitter(JIT& jit);
+  
+  unsigned char* EmitDwarfTable(MachineFunction& F, 
+                                JITCodeEmitter& JCE,
+                                unsigned char* StartFunction,
+                                unsigned char* EndFunction);
+  
+  
+  unsigned GetDwarfTableSizeInBytes(MachineFunction& F, 
+                                    JITCodeEmitter& JCE,
+                                    unsigned char* StartFunction,
+                                    unsigned char* EndFunction);
+
+  void setModuleInfo(MachineModuleInfo* Info) {
+    MMI = Info;
+  }
+};
+
+
+} // end namespace llvm
+
+#endif // LLVM_EXECUTION_ENGINE_JIT_DWARFEMITTER_H
diff --git a/lib/ExecutionEngine/JIT/JITEmitter.cpp b/lib/ExecutionEngine/JIT/JITEmitter.cpp
new file mode 100644
index 0000000..d3b0820
--- /dev/null
+++ b/lib/ExecutionEngine/JIT/JITEmitter.cpp
@@ -0,0 +1,1615 @@
+//===-- JITEmitter.cpp - Write machine code to executable memory ----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines a MachineCodeEmitter object that is used by the JIT to
+// write machine code to memory and remember where relocatable values are.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "jit"
+#include "JIT.h"
+#include "JITDwarfEmitter.h"
+#include "llvm/Constants.h"
+#include "llvm/Module.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/CodeGen/JITCodeEmitter.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineConstantPool.h"
+#include "llvm/CodeGen/MachineJumpTableInfo.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachineRelocation.h"
+#include "llvm/ExecutionEngine/JITMemoryManager.h"
+#include "llvm/ExecutionEngine/GenericValue.h"
+#include "llvm/CodeGen/MachineCodeInfo.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetJITInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/MutexGuard.h"
+#include "llvm/Support/ValueHandle.h"
+#include "llvm/System/Disassembler.h"
+#include "llvm/System/Memory.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Statistic.h"
+#include <algorithm>
+#ifndef NDEBUG
+#include <iomanip>
+#endif
+using namespace llvm;
+
+STATISTIC(NumBytes, "Number of bytes of machine code compiled");
+STATISTIC(NumRelos, "Number of relocations applied");
+static JIT *TheJIT = 0;
+
+
+//===----------------------------------------------------------------------===//
+// JIT lazy compilation code.
+//
+namespace {
+  class JITResolverState {
+  public:
+    typedef std::map<AssertingVH<Function>, void*> FunctionToStubMapTy;
+    typedef std::map<void*, Function*> StubToFunctionMapTy;
+    typedef std::map<AssertingVH<GlobalValue>, void*> GlobalToIndirectSymMapTy;
+  private:
+    /// FunctionToStubMap - Keep track of the stub created for a particular
+    /// function so that we can reuse them if necessary.
+    FunctionToStubMapTy FunctionToStubMap;
+
+    /// StubToFunctionMap - Keep track of the function that each stub
+    /// corresponds to.
+    StubToFunctionMapTy StubToFunctionMap;
+
+    /// GlobalToIndirectSymMap - Keep track of the indirect symbol created for a
+    /// particular GlobalVariable so that we can reuse them if necessary.
+    GlobalToIndirectSymMapTy GlobalToIndirectSymMap;
+
+  public:
+    FunctionToStubMapTy& getFunctionToStubMap(const MutexGuard& locked) {
+      assert(locked.holds(TheJIT->lock));
+      return FunctionToStubMap;
+    }
+
+    StubToFunctionMapTy& getStubToFunctionMap(const MutexGuard& locked) {
+      assert(locked.holds(TheJIT->lock));
+      return StubToFunctionMap;
+    }
+
+    GlobalToIndirectSymMapTy& getGlobalToIndirectSymMap(const MutexGuard& locked) {
+      assert(locked.holds(TheJIT->lock));
+      return GlobalToIndirectSymMap;
+    }
+  };
+
+  /// JITResolver - Keep track of, and resolve, call sites for functions that
+  /// have not yet been compiled.
+  class JITResolver {
+    typedef JITResolverState::FunctionToStubMapTy FunctionToStubMapTy;
+    typedef JITResolverState::StubToFunctionMapTy StubToFunctionMapTy;
+    typedef JITResolverState::GlobalToIndirectSymMapTy GlobalToIndirectSymMapTy;
+
+    /// LazyResolverFn - The target lazy resolver function that we actually
+    /// rewrite instructions to use.
+    TargetJITInfo::LazyResolverFn LazyResolverFn;
+
+    JITResolverState state;
+
+    /// ExternalFnToStubMap - This is the equivalent of FunctionToStubMap for
+    /// external functions.
+    std::map<void*, void*> ExternalFnToStubMap;
+
+    /// revGOTMap - map addresses to indexes in the GOT
+    std::map<void*, unsigned> revGOTMap;
+    unsigned nextGOTIndex;
+
+    static JITResolver *TheJITResolver;
+  public:
+    explicit JITResolver(JIT &jit) : nextGOTIndex(0) {
+      TheJIT = &jit;
+
+      LazyResolverFn = jit.getJITInfo().getLazyResolverFunction(JITCompilerFn);
+      assert(TheJITResolver == 0 && "Multiple JIT resolvers?");
+      TheJITResolver = this;
+    }
+    
+    ~JITResolver() {
+      TheJITResolver = 0;
+    }
+
+    /// getFunctionStubIfAvailable - This returns a pointer to a function stub
+    /// if it has already been created.
+    void *getFunctionStubIfAvailable(Function *F);
+
+    /// getFunctionStub - This returns a pointer to a function stub, creating
+    /// one on demand as needed.  If empty is true, create a function stub
+    /// pointing at address 0, to be filled in later.
+    void *getFunctionStub(Function *F);
+
+    /// getExternalFunctionStub - Return a stub for the function at the
+    /// specified address, created lazily on demand.
+    void *getExternalFunctionStub(void *FnAddr);
+
+    /// getGlobalValueIndirectSym - Return an indirect symbol containing the
+    /// specified GV address.
+    void *getGlobalValueIndirectSym(GlobalValue *V, void *GVAddress);
+
+    /// AddCallbackAtLocation - If the target is capable of rewriting an
+    /// instruction without the use of a stub, record the location of the use so
+    /// we know which function is being used at the location.
+    void *AddCallbackAtLocation(Function *F, void *Location) {
+      MutexGuard locked(TheJIT->lock);
+      /// Get the target-specific JIT resolver function.
+      state.getStubToFunctionMap(locked)[Location] = F;
+      return (void*)(intptr_t)LazyResolverFn;
+    }
+    
+    void getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
+                           SmallVectorImpl<void*> &Ptrs);
+    
+    GlobalValue *invalidateStub(void *Stub);
+
+    /// getGOTIndexForAddress - Return a new or existing index in the GOT for
+    /// an address.  This function only manages slots, it does not manage the
+    /// contents of the slots or the memory associated with the GOT.
+    unsigned getGOTIndexForAddr(void *addr);
+
+    /// JITCompilerFn - This function is called to resolve a stub to a compiled
+    /// address.  If the LLVM Function corresponding to the stub has not yet
+    /// been compiled, this function compiles it first.
+    static void *JITCompilerFn(void *Stub);
+  };
+}
+
+JITResolver *JITResolver::TheJITResolver = 0;
+
+/// getFunctionStubIfAvailable - This returns a pointer to a function stub
+/// if it has already been created.
+void *JITResolver::getFunctionStubIfAvailable(Function *F) {
+  MutexGuard locked(TheJIT->lock);
+
+  // If we already have a stub for this function, recycle it.
+  void *&Stub = state.getFunctionToStubMap(locked)[F];
+  return Stub;
+}
+
+/// getFunctionStub - This returns a pointer to a function stub, creating
+/// one on demand as needed.
+void *JITResolver::getFunctionStub(Function *F) {
+  MutexGuard locked(TheJIT->lock);
+
+  // If we already have a stub for this function, recycle it.
+  void *&Stub = state.getFunctionToStubMap(locked)[F];
+  if (Stub) return Stub;
+
+  // Call the lazy resolver function unless we are JIT'ing non-lazily, in which
+  // case we must resolve the symbol now.
+  void *Actual =  TheJIT->isLazyCompilationDisabled() 
+    ? (void *)0 : (void *)(intptr_t)LazyResolverFn;
+   
+  // If this is an external declaration, attempt to resolve the address now
+  // to place in the stub.
+  if (F->isDeclaration() && !F->hasNotBeenReadFromBitcode()) {
+    Actual = TheJIT->getPointerToFunction(F);
+
+    // If we resolved the symbol to a null address (eg. a weak external)
+    // don't emit a stub. Return a null pointer to the application.  If dlsym
+    // stubs are enabled, not being able to resolve the address is not
+    // meaningful.
+    if (!Actual && !TheJIT->areDlsymStubsEnabled()) return 0;
+  }
+
+  // Codegen a new stub, calling the lazy resolver or the actual address of the
+  // external function, if it was resolved.
+  Stub = TheJIT->getJITInfo().emitFunctionStub(F, Actual,
+                                               *TheJIT->getCodeEmitter());
+
+  if (Actual != (void*)(intptr_t)LazyResolverFn) {
+    // If we are getting the stub for an external function, we really want the
+    // address of the stub in the GlobalAddressMap for the JIT, not the address
+    // of the external function.
+    TheJIT->updateGlobalMapping(F, Stub);
+  }
+
+  DOUT << "JIT: Stub emitted at [" << Stub << "] for function '"
+       << F->getName() << "'\n";
+
+  // Finally, keep track of the stub-to-Function mapping so that the
+  // JITCompilerFn knows which function to compile!
+  state.getStubToFunctionMap(locked)[Stub] = F;
+  
+  // If we are JIT'ing non-lazily but need to call a function that does not
+  // exist yet, add it to the JIT's work list so that we can fill in the stub
+  // address later.
+  if (!Actual && TheJIT->isLazyCompilationDisabled())
+    if (!F->isDeclaration() || F->hasNotBeenReadFromBitcode())
+      TheJIT->addPendingFunction(F);
+  
+  return Stub;
+}
+
+/// getGlobalValueIndirectSym - Return a lazy pointer containing the specified
+/// GV address.
+void *JITResolver::getGlobalValueIndirectSym(GlobalValue *GV, void *GVAddress) {
+  MutexGuard locked(TheJIT->lock);
+
+  // If we already have a stub for this global variable, recycle it.
+  void *&IndirectSym = state.getGlobalToIndirectSymMap(locked)[GV];
+  if (IndirectSym) return IndirectSym;
+
+  // Otherwise, codegen a new indirect symbol.
+  IndirectSym = TheJIT->getJITInfo().emitGlobalValueIndirectSym(GV, GVAddress,
+                                                     *TheJIT->getCodeEmitter());
+
+  DOUT << "JIT: Indirect symbol emitted at [" << IndirectSym << "] for GV '"
+       << GV->getName() << "'\n";
+
+  return IndirectSym;
+}
+
+/// getExternalFunctionStub - Return a stub for the function at the
+/// specified address, created lazily on demand.
+void *JITResolver::getExternalFunctionStub(void *FnAddr) {
+  // If we already have a stub for this function, recycle it.
+  void *&Stub = ExternalFnToStubMap[FnAddr];
+  if (Stub) return Stub;
+
+  Stub = TheJIT->getJITInfo().emitFunctionStub(0, FnAddr,
+                                               *TheJIT->getCodeEmitter());
+
+  DOUT << "JIT: Stub emitted at [" << Stub
+       << "] for external function at '" << FnAddr << "'\n";
+  return Stub;
+}
+
+unsigned JITResolver::getGOTIndexForAddr(void* addr) {
+  unsigned idx = revGOTMap[addr];
+  if (!idx) {
+    idx = ++nextGOTIndex;
+    revGOTMap[addr] = idx;
+    DOUT << "JIT: Adding GOT entry " << idx << " for addr [" << addr << "]\n";
+  }
+  return idx;
+}
+
+void JITResolver::getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
+                                    SmallVectorImpl<void*> &Ptrs) {
+  MutexGuard locked(TheJIT->lock);
+  
+  FunctionToStubMapTy &FM = state.getFunctionToStubMap(locked);
+  GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked);
+  
+  for (FunctionToStubMapTy::iterator i = FM.begin(), e = FM.end(); i != e; ++i){
+    Function *F = i->first;
+    if (F->isDeclaration() && F->hasExternalLinkage()) {
+      GVs.push_back(i->first);
+      Ptrs.push_back(i->second);
+    }
+  }
+  for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end();
+       i != e; ++i) {
+    GVs.push_back(i->first);
+    Ptrs.push_back(i->second);
+  }
+}
+
+GlobalValue *JITResolver::invalidateStub(void *Stub) {
+  MutexGuard locked(TheJIT->lock);
+  
+  FunctionToStubMapTy &FM = state.getFunctionToStubMap(locked);
+  StubToFunctionMapTy &SM = state.getStubToFunctionMap(locked);
+  GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked);
+  
+  // Look up the cheap way first, to see if it's a function stub we are
+  // invalidating.  If so, remove it from both the forward and reverse maps.
+  if (SM.find(Stub) != SM.end()) {
+    Function *F = SM[Stub];
+    SM.erase(Stub);
+    FM.erase(F);
+    return F;
+  }
+  
+  // Otherwise, it might be an indirect symbol stub.  Find it and remove it.
+  for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end();
+       i != e; ++i) {
+    if (i->second != Stub)
+      continue;
+    GlobalValue *GV = i->first;
+    GM.erase(i);
+    return GV;
+  }
+  
+  // Lastly, check to see if it's in the ExternalFnToStubMap.
+  for (std::map<void *, void *>::iterator i = ExternalFnToStubMap.begin(),
+       e = ExternalFnToStubMap.end(); i != e; ++i) {
+    if (i->second != Stub)
+      continue;
+    ExternalFnToStubMap.erase(i);
+    break;
+  }
+  
+  return 0;
+}
+
+/// JITCompilerFn - This function is called when a lazy compilation stub has
+/// been entered.  It looks up which function this stub corresponds to, compiles
+/// it if necessary, then returns the resultant function pointer.
+void *JITResolver::JITCompilerFn(void *Stub) {
+  JITResolver &JR = *TheJITResolver;
+  
+  Function* F = 0;
+  void* ActualPtr = 0;
+
+  {
+    // Only lock for getting the Function. The call getPointerToFunction made
+    // in this function might trigger function materializing, which requires
+    // JIT lock to be unlocked.
+    MutexGuard locked(TheJIT->lock);
+
+    // The address given to us for the stub may not be exactly right, it might be
+    // a little bit after the stub.  As such, use upper_bound to find it.
+    StubToFunctionMapTy::iterator I =
+      JR.state.getStubToFunctionMap(locked).upper_bound(Stub);
+    assert(I != JR.state.getStubToFunctionMap(locked).begin() &&
+           "This is not a known stub!");
+    F = (--I)->second;
+    ActualPtr = I->first;
+  }
+
+  // If we have already code generated the function, just return the address.
+  void *Result = TheJIT->getPointerToGlobalIfAvailable(F);
+  
+  if (!Result) {
+    // Otherwise we don't have it, do lazy compilation now.
+    
+    // If lazy compilation is disabled, emit a useful error message and abort.
+    if (TheJIT->isLazyCompilationDisabled()) {
+      cerr << "LLVM JIT requested to do lazy compilation of function '"
+      << F->getName() << "' when lazy compiles are disabled!\n";
+      abort();
+    }
+  
+    // We might like to remove the stub from the StubToFunction map.
+    // We can't do that! Multiple threads could be stuck, waiting to acquire the
+    // lock above. As soon as the 1st function finishes compiling the function,
+    // the next one will be released, and needs to be able to find the function
+    // it needs to call.
+    //JR.state.getStubToFunctionMap(locked).erase(I);
+
+    DOUT << "JIT: Lazily resolving function '" << F->getName()
+         << "' In stub ptr = " << Stub << " actual ptr = "
+         << ActualPtr << "\n";
+
+    Result = TheJIT->getPointerToFunction(F);
+  }
+  
+  // Reacquire the lock to erase the stub in the map.
+  MutexGuard locked(TheJIT->lock);
+
+  // We don't need to reuse this stub in the future, as F is now compiled.
+  JR.state.getFunctionToStubMap(locked).erase(F);
+
+  // FIXME: We could rewrite all references to this stub if we knew them.
+
+  // What we will do is set the compiled function address to map to the
+  // same GOT entry as the stub so that later clients may update the GOT
+  // if they see it still using the stub address.
+  // Note: this is done so the Resolver doesn't have to manage GOT memory
+  // Do this without allocating map space if the target isn't using a GOT
+  if(JR.revGOTMap.find(Stub) != JR.revGOTMap.end())
+    JR.revGOTMap[Result] = JR.revGOTMap[Stub];
+
+  return Result;
+}
+
+//===----------------------------------------------------------------------===//
+// Function Index Support
+
+// On MacOS we generate an index of currently JIT'd functions so that
+// performance tools can determine a symbol name and accurate code range for a
+// PC value.  Because performance tools are generally asynchronous, the code
+// below is written with the hope that it could be interrupted at any time and
+// have useful answers.  However, we don't go crazy with atomic operations, we
+// just do a "reasonable effort".
+#ifdef __APPLE__ 
+#define ENABLE_JIT_SYMBOL_TABLE 0
+#endif
+
+/// JitSymbolEntry - Each function that is JIT compiled results in one of these
+/// being added to an array of symbols.  This indicates the name of the function
+/// as well as the address range it occupies.  This allows the client to map
+/// from a PC value to the name of the function.
+struct JitSymbolEntry {
+  const char *FnName;   // FnName - a strdup'd string.
+  void *FnStart;
+  intptr_t FnSize;
+};
+
+
+struct JitSymbolTable {
+  /// NextPtr - This forms a linked list of JitSymbolTable entries.  This
+  /// pointer is not used right now, but might be used in the future.  Consider
+  /// it reserved for future use.
+  JitSymbolTable *NextPtr;
+  
+  /// Symbols - This is an array of JitSymbolEntry entries.  Only the first
+  /// 'NumSymbols' symbols are valid.
+  JitSymbolEntry *Symbols;
+  
+  /// NumSymbols - This indicates the number entries in the Symbols array that
+  /// are valid.
+  unsigned NumSymbols;
+  
+  /// NumAllocated - This indicates the amount of space we have in the Symbols
+  /// array.  This is a private field that should not be read by external tools.
+  unsigned NumAllocated;
+};
+
+#if ENABLE_JIT_SYMBOL_TABLE 
+JitSymbolTable *__jitSymbolTable;
+#endif
+
+static void AddFunctionToSymbolTable(const char *FnName, 
+                                     void *FnStart, intptr_t FnSize) {
+  assert(FnName != 0 && FnStart != 0 && "Bad symbol to add");
+  JitSymbolTable **SymTabPtrPtr = 0;
+#if !ENABLE_JIT_SYMBOL_TABLE
+  return;
+#else
+  SymTabPtrPtr = &__jitSymbolTable;
+#endif
+  
+  // If this is the first entry in the symbol table, add the JitSymbolTable
+  // index.
+  if (*SymTabPtrPtr == 0) {
+    JitSymbolTable *New = new JitSymbolTable();
+    New->NextPtr = 0;
+    New->Symbols = 0;
+    New->NumSymbols = 0;
+    New->NumAllocated = 0;
+    *SymTabPtrPtr = New;
+  }
+  
+  JitSymbolTable *SymTabPtr = *SymTabPtrPtr;
+  
+  // If we have space in the table, reallocate the table.
+  if (SymTabPtr->NumSymbols >= SymTabPtr->NumAllocated) {
+    // If we don't have space, reallocate the table.
+    unsigned NewSize = std::max(64U, SymTabPtr->NumAllocated*2);
+    JitSymbolEntry *NewSymbols = new JitSymbolEntry[NewSize];
+    JitSymbolEntry *OldSymbols = SymTabPtr->Symbols;
+    
+    // Copy the old entries over.
+    memcpy(NewSymbols, OldSymbols, SymTabPtr->NumSymbols*sizeof(OldSymbols[0]));
+    
+    // Swap the new symbols in, delete the old ones.
+    SymTabPtr->Symbols = NewSymbols;
+    SymTabPtr->NumAllocated = NewSize;
+    delete [] OldSymbols;
+  }
+  
+  // Otherwise, we have enough space, just tack it onto the end of the array.
+  JitSymbolEntry &Entry = SymTabPtr->Symbols[SymTabPtr->NumSymbols];
+  Entry.FnName = strdup(FnName);
+  Entry.FnStart = FnStart;
+  Entry.FnSize = FnSize;
+  ++SymTabPtr->NumSymbols;
+}
+
+static void RemoveFunctionFromSymbolTable(void *FnStart) {
+  assert(FnStart && "Invalid function pointer");
+  JitSymbolTable **SymTabPtrPtr = 0;
+#if !ENABLE_JIT_SYMBOL_TABLE
+  return;
+#else
+  SymTabPtrPtr = &__jitSymbolTable;
+#endif
+  
+  JitSymbolTable *SymTabPtr = *SymTabPtrPtr;
+  JitSymbolEntry *Symbols = SymTabPtr->Symbols;
+  
+  // Scan the table to find its index.  The table is not sorted, so do a linear
+  // scan.
+  unsigned Index;
+  for (Index = 0; Symbols[Index].FnStart != FnStart; ++Index)
+    assert(Index != SymTabPtr->NumSymbols && "Didn't find function!");
+  
+  // Once we have an index, we know to nuke this entry, overwrite it with the
+  // entry at the end of the array, making the last entry redundant.
+  const char *OldName = Symbols[Index].FnName;
+  Symbols[Index] = Symbols[SymTabPtr->NumSymbols-1];
+  free((void*)OldName);
+  
+  // Drop the number of symbols in the table.
+  --SymTabPtr->NumSymbols;
+
+  // Finally, if we deleted the final symbol, deallocate the table itself.
+  if (SymTabPtr->NumSymbols != 0) 
+    return;
+  
+  *SymTabPtrPtr = 0;
+  delete [] Symbols;
+  delete SymTabPtr;
+}
+
+//===----------------------------------------------------------------------===//
+// JITEmitter code.
+//
+namespace {
+  /// JITEmitter - The JIT implementation of the MachineCodeEmitter, which is
+  /// used to output functions to memory for execution.
+  class JITEmitter : public JITCodeEmitter {
+    JITMemoryManager *MemMgr;
+
+    // When outputting a function stub in the context of some other function, we
+    // save BufferBegin/BufferEnd/CurBufferPtr here.
+    uint8_t *SavedBufferBegin, *SavedBufferEnd, *SavedCurBufferPtr;
+
+    /// Relocations - These are the relocations that the function needs, as
+    /// emitted.
+    std::vector<MachineRelocation> Relocations;
+    
+    /// MBBLocations - This vector is a mapping from MBB ID's to their address.
+    /// It is filled in by the StartMachineBasicBlock callback and queried by
+    /// the getMachineBasicBlockAddress callback.
+    std::vector<uintptr_t> MBBLocations;
+
+    /// ConstantPool - The constant pool for the current function.
+    ///
+    MachineConstantPool *ConstantPool;
+
+    /// ConstantPoolBase - A pointer to the first entry in the constant pool.
+    ///
+    void *ConstantPoolBase;
+
+    /// ConstPoolAddresses - Addresses of individual constant pool entries.
+    ///
+    SmallVector<uintptr_t, 8> ConstPoolAddresses;
+
+    /// JumpTable - The jump tables for the current function.
+    ///
+    MachineJumpTableInfo *JumpTable;
+    
+    /// JumpTableBase - A pointer to the first entry in the jump table.
+    ///
+    void *JumpTableBase;
+
+    /// Resolver - This contains info about the currently resolved functions.
+    JITResolver Resolver;
+    
+    /// DE - The dwarf emitter for the jit.
+    JITDwarfEmitter *DE;
+
+    /// LabelLocations - This vector is a mapping from Label ID's to their 
+    /// address.
+    std::vector<uintptr_t> LabelLocations;
+
+    /// MMI - Machine module info for exception informations
+    MachineModuleInfo* MMI;
+
+    // GVSet - a set to keep track of which globals have been seen
+    SmallPtrSet<const GlobalVariable*, 8> GVSet;
+
+    // CurFn - The llvm function being emitted.  Only valid during 
+    // finishFunction().
+    const Function *CurFn;
+    
+    // CurFnStubUses - For a given Function, a vector of stubs that it
+    // references.  This facilitates the JIT detecting that a stub is no
+    // longer used, so that it may be deallocated.
+    DenseMap<const Function *, SmallVector<void*, 1> > CurFnStubUses;
+    
+    // StubFnRefs - For a given pointer to a stub, a set of Functions which
+    // reference the stub.  When the count of a stub's references drops to zero,
+    // the stub is unused.
+    DenseMap<void *, SmallPtrSet<const Function*, 1> > StubFnRefs;
+    
+    // ExtFnStubs - A map of external function names to stubs which have entries
+    // in the JITResolver's ExternalFnToStubMap.
+    StringMap<void *> ExtFnStubs;
+
+    // MCI - A pointer to a MachineCodeInfo object to update with information.
+    MachineCodeInfo *MCI;
+
+  public:
+    JITEmitter(JIT &jit, JITMemoryManager *JMM) : Resolver(jit), CurFn(0), MCI(0) {
+      MemMgr = JMM ? JMM : JITMemoryManager::CreateDefaultMemManager();
+      if (jit.getJITInfo().needsGOT()) {
+        MemMgr->AllocateGOT();
+        DOUT << "JIT is managing a GOT\n";
+      }
+
+      if (ExceptionHandling) DE = new JITDwarfEmitter(jit);
+    }
+    ~JITEmitter() { 
+      delete MemMgr;
+      if (ExceptionHandling) delete DE;
+    }
+
+    /// classof - Methods for support type inquiry through isa, cast, and
+    /// dyn_cast:
+    ///
+    static inline bool classof(const JITEmitter*) { return true; }
+    static inline bool classof(const MachineCodeEmitter*) { return true; }
+    
+    JITResolver &getJITResolver() { return Resolver; }
+
+    virtual void startFunction(MachineFunction &F);
+    virtual bool finishFunction(MachineFunction &F);
+    
+    void emitConstantPool(MachineConstantPool *MCP);
+    void initJumpTableInfo(MachineJumpTableInfo *MJTI);
+    void emitJumpTableInfo(MachineJumpTableInfo *MJTI);
+    
+    virtual void startGVStub(const GlobalValue* GV, unsigned StubSize,
+                                   unsigned Alignment = 1);
+    virtual void startGVStub(const GlobalValue* GV, void *Buffer,
+                             unsigned StubSize);
+    virtual void* finishGVStub(const GlobalValue *GV);
+
+    /// allocateSpace - Reserves space in the current block if any, or
+    /// allocate a new one of the given size.
+    virtual void *allocateSpace(uintptr_t Size, unsigned Alignment);
+
+    virtual void addRelocation(const MachineRelocation &MR) {
+      Relocations.push_back(MR);
+    }
+    
+    virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {
+      if (MBBLocations.size() <= (unsigned)MBB->getNumber())
+        MBBLocations.resize((MBB->getNumber()+1)*2);
+      MBBLocations[MBB->getNumber()] = getCurrentPCValue();
+      DOUT << "JIT: Emitting BB" << MBB->getNumber() << " at ["
+           << (void*) getCurrentPCValue() << "]\n";
+    }
+
+    virtual uintptr_t getConstantPoolEntryAddress(unsigned Entry) const;
+    virtual uintptr_t getJumpTableEntryAddress(unsigned Entry) const;
+
+    virtual uintptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const {
+      assert(MBBLocations.size() > (unsigned)MBB->getNumber() && 
+             MBBLocations[MBB->getNumber()] && "MBB not emitted!");
+      return MBBLocations[MBB->getNumber()];
+    }
+
+    /// deallocateMemForFunction - Deallocate all memory for the specified
+    /// function body.
+    void deallocateMemForFunction(Function *F);
+
+    /// AddStubToCurrentFunction - Mark the current function being JIT'd as
+    /// using the stub at the specified address. Allows
+    /// deallocateMemForFunction to also remove stubs no longer referenced.
+    void AddStubToCurrentFunction(void *Stub);
+    
+    /// getExternalFnStubs - Accessor for the JIT to find stubs emitted for
+    /// MachineRelocations that reference external functions by name.
+    const StringMap<void*> &getExternalFnStubs() const { return ExtFnStubs; }
+    
+    virtual void emitLabel(uint64_t LabelID) {
+      if (LabelLocations.size() <= LabelID)
+        LabelLocations.resize((LabelID+1)*2);
+      LabelLocations[LabelID] = getCurrentPCValue();
+    }
+
+    virtual uintptr_t getLabelAddress(uint64_t LabelID) const {
+      assert(LabelLocations.size() > (unsigned)LabelID && 
+             LabelLocations[LabelID] && "Label not emitted!");
+      return LabelLocations[LabelID];
+    }
+ 
+    virtual void setModuleInfo(MachineModuleInfo* Info) {
+      MMI = Info;
+      if (ExceptionHandling) DE->setModuleInfo(Info);
+    }
+
+    void setMemoryExecutable(void) {
+      MemMgr->setMemoryExecutable();
+    }
+    
+    JITMemoryManager *getMemMgr(void) const { return MemMgr; }
+
+    void setMachineCodeInfo(MachineCodeInfo *mci) {
+      MCI = mci;
+    }
+
+  private:
+    void *getPointerToGlobal(GlobalValue *GV, void *Reference, bool NoNeedStub);
+    void *getPointerToGVIndirectSym(GlobalValue *V, void *Reference,
+                                    bool NoNeedStub);
+    unsigned addSizeOfGlobal(const GlobalVariable *GV, unsigned Size);
+    unsigned addSizeOfGlobalsInConstantVal(const Constant *C, unsigned Size);
+    unsigned addSizeOfGlobalsInInitializer(const Constant *Init, unsigned Size);
+    unsigned GetSizeOfGlobalsInBytes(MachineFunction &MF);
+  };
+}
+
+void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
+                                     bool DoesntNeedStub) {
+  if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
+    return TheJIT->getOrEmitGlobalVariable(GV);
+
+  if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V))
+    return TheJIT->getPointerToGlobal(GA->resolveAliasedGlobal(false));
+
+  // If we have already compiled the function, return a pointer to its body.
+  Function *F = cast<Function>(V);
+  void *ResultPtr;
+  if (!DoesntNeedStub && !TheJIT->isLazyCompilationDisabled()) {
+    // Return the function stub if it's already created.
+    ResultPtr = Resolver.getFunctionStubIfAvailable(F);
+    if (ResultPtr)
+      AddStubToCurrentFunction(ResultPtr);
+  } else {
+    ResultPtr = TheJIT->getPointerToGlobalIfAvailable(F);
+  }
+  if (ResultPtr) return ResultPtr;
+
+  // If this is an external function pointer, we can force the JIT to
+  // 'compile' it, which really just adds it to the map.  In dlsym mode, 
+  // external functions are forced through a stub, regardless of reloc type.
+  if (F->isDeclaration() && !F->hasNotBeenReadFromBitcode() &&
+      DoesntNeedStub && !TheJIT->areDlsymStubsEnabled())
+    return TheJIT->getPointerToFunction(F);
+
+  // Okay, the function has not been compiled yet, if the target callback
+  // mechanism is capable of rewriting the instruction directly, prefer to do
+  // that instead of emitting a stub.  This uses the lazy resolver, so is not
+  // legal if lazy compilation is disabled.
+  if (DoesntNeedStub && !TheJIT->isLazyCompilationDisabled())
+    return Resolver.AddCallbackAtLocation(F, Reference);
+
+  // Otherwise, we have to emit a stub.
+  void *StubAddr = Resolver.getFunctionStub(F);
+
+  // Add the stub to the current function's list of referenced stubs, so we can
+  // deallocate them if the current function is ever freed.  It's possible to
+  // return null from getFunctionStub in the case of a weak extern that fails
+  // to resolve.
+  if (StubAddr)
+    AddStubToCurrentFunction(StubAddr);
+
+  return StubAddr;
+}
+
+void *JITEmitter::getPointerToGVIndirectSym(GlobalValue *V, void *Reference,
+                                            bool NoNeedStub) {
+  // Make sure GV is emitted first, and create a stub containing the fully
+  // resolved address.
+  void *GVAddress = getPointerToGlobal(V, Reference, true);
+  void *StubAddr = Resolver.getGlobalValueIndirectSym(V, GVAddress);
+  
+  // Add the stub to the current function's list of referenced stubs, so we can
+  // deallocate them if the current function is ever freed.
+  AddStubToCurrentFunction(StubAddr);
+  
+  return StubAddr;
+}
+
+void JITEmitter::AddStubToCurrentFunction(void *StubAddr) {
+  if (!TheJIT->areDlsymStubsEnabled())
+    return;
+  
+  assert(CurFn && "Stub added to current function, but current function is 0!");
+  
+  SmallVectorImpl<void*> &StubsUsed = CurFnStubUses[CurFn];
+  StubsUsed.push_back(StubAddr);
+
+  SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[StubAddr];
+  FnRefs.insert(CurFn);
+}
+
+static unsigned GetConstantPoolSizeInBytes(MachineConstantPool *MCP,
+                                           const TargetData *TD) {
+  const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
+  if (Constants.empty()) return 0;
+
+  unsigned Size = 0;
+  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
+    MachineConstantPoolEntry CPE = Constants[i];
+    unsigned AlignMask = CPE.getAlignment() - 1;
+    Size = (Size + AlignMask) & ~AlignMask;
+    const Type *Ty = CPE.getType();
+    Size += TD->getTypeAllocSize(Ty);
+  }
+  return Size;
+}
+
+static unsigned GetJumpTableSizeInBytes(MachineJumpTableInfo *MJTI) {
+  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
+  if (JT.empty()) return 0;
+  
+  unsigned NumEntries = 0;
+  for (unsigned i = 0, e = JT.size(); i != e; ++i)
+    NumEntries += JT[i].MBBs.size();
+
+  unsigned EntrySize = MJTI->getEntrySize();
+
+  return NumEntries * EntrySize;
+}
+
+static uintptr_t RoundUpToAlign(uintptr_t Size, unsigned Alignment) {
+  if (Alignment == 0) Alignment = 1;
+  // Since we do not know where the buffer will be allocated, be pessimistic. 
+  return Size + Alignment;
+}
+
+/// addSizeOfGlobal - add the size of the global (plus any alignment padding)
+/// into the running total Size.
+
+unsigned JITEmitter::addSizeOfGlobal(const GlobalVariable *GV, unsigned Size) {
+  const Type *ElTy = GV->getType()->getElementType();
+  size_t GVSize = (size_t)TheJIT->getTargetData()->getTypeAllocSize(ElTy);
+  size_t GVAlign = 
+      (size_t)TheJIT->getTargetData()->getPreferredAlignment(GV);
+  DOUT << "JIT: Adding in size " << GVSize << " alignment " << GVAlign;
+  DEBUG(GV->dump());
+  // Assume code section ends with worst possible alignment, so first
+  // variable needs maximal padding.
+  if (Size==0)
+    Size = 1;
+  Size = ((Size+GVAlign-1)/GVAlign)*GVAlign;
+  Size += GVSize;
+  return Size;
+}
+
+/// addSizeOfGlobalsInConstantVal - find any globals that we haven't seen yet
+/// but are referenced from the constant; put them in GVSet and add their
+/// size into the running total Size.
+
+unsigned JITEmitter::addSizeOfGlobalsInConstantVal(const Constant *C, 
+                                              unsigned Size) {
+  // If its undefined, return the garbage.
+  if (isa<UndefValue>(C))
+    return Size;
+
+  // If the value is a ConstantExpr
+  if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
+    Constant *Op0 = CE->getOperand(0);
+    switch (CE->getOpcode()) {
+    case Instruction::GetElementPtr:
+    case Instruction::Trunc:
+    case Instruction::ZExt:
+    case Instruction::SExt:
+    case Instruction::FPTrunc:
+    case Instruction::FPExt:
+    case Instruction::UIToFP:
+    case Instruction::SIToFP:
+    case Instruction::FPToUI:
+    case Instruction::FPToSI:
+    case Instruction::PtrToInt:
+    case Instruction::IntToPtr:
+    case Instruction::BitCast: {
+      Size = addSizeOfGlobalsInConstantVal(Op0, Size);
+      break;
+    }
+    case Instruction::Add:
+    case Instruction::Sub:
+    case Instruction::Mul:
+    case Instruction::UDiv:
+    case Instruction::SDiv:
+    case Instruction::URem:
+    case Instruction::SRem:
+    case Instruction::And:
+    case Instruction::Or:
+    case Instruction::Xor: {
+      Size = addSizeOfGlobalsInConstantVal(Op0, Size);
+      Size = addSizeOfGlobalsInConstantVal(CE->getOperand(1), Size);
+      break;
+    }
+    default: {
+       cerr << "ConstantExpr not handled: " << *CE << "\n";
+      abort();
+    }
+    }
+  }
+
+  if (C->getType()->getTypeID() == Type::PointerTyID)
+    if (const GlobalVariable* GV = dyn_cast<GlobalVariable>(C))
+      if (GVSet.insert(GV))
+        Size = addSizeOfGlobal(GV, Size);
+
+  return Size;
+}
+
+/// addSizeOfGLobalsInInitializer - handle any globals that we haven't seen yet
+/// but are referenced from the given initializer.
+
+unsigned JITEmitter::addSizeOfGlobalsInInitializer(const Constant *Init, 
+                                              unsigned Size) {
+  if (!isa<UndefValue>(Init) &&
+      !isa<ConstantVector>(Init) &&
+      !isa<ConstantAggregateZero>(Init) &&
+      !isa<ConstantArray>(Init) &&
+      !isa<ConstantStruct>(Init) &&
+      Init->getType()->isFirstClassType())
+    Size = addSizeOfGlobalsInConstantVal(Init, Size);
+  return Size;
+}
+
+/// GetSizeOfGlobalsInBytes - walk the code for the function, looking for
+/// globals; then walk the initializers of those globals looking for more.
+/// If their size has not been considered yet, add it into the running total
+/// Size.
+
+unsigned JITEmitter::GetSizeOfGlobalsInBytes(MachineFunction &MF) {
+  unsigned Size = 0;
+  GVSet.clear();
+
+  for (MachineFunction::iterator MBB = MF.begin(), E = MF.end(); 
+       MBB != E; ++MBB) {
+    for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
+         I != E; ++I) {
+      const TargetInstrDesc &Desc = I->getDesc();
+      const MachineInstr &MI = *I;
+      unsigned NumOps = Desc.getNumOperands();
+      for (unsigned CurOp = 0; CurOp < NumOps; CurOp++) {
+        const MachineOperand &MO = MI.getOperand(CurOp);
+        if (MO.isGlobal()) {
+          GlobalValue* V = MO.getGlobal();
+          const GlobalVariable *GV = dyn_cast<const GlobalVariable>(V);
+          if (!GV)
+            continue;
+          // If seen in previous function, it will have an entry here.
+          if (TheJIT->getPointerToGlobalIfAvailable(GV))
+            continue;
+          // If seen earlier in this function, it will have an entry here.
+          // FIXME: it should be possible to combine these tables, by
+          // assuming the addresses of the new globals in this module
+          // start at 0 (or something) and adjusting them after codegen
+          // complete.  Another possibility is to grab a marker bit in GV.
+          if (GVSet.insert(GV))
+            // A variable as yet unseen.  Add in its size.
+            Size = addSizeOfGlobal(GV, Size);
+        }
+      }
+    }
+  }
+  DOUT << "JIT: About to look through initializers\n";
+  // Look for more globals that are referenced only from initializers.
+  // GVSet.end is computed each time because the set can grow as we go.
+  for (SmallPtrSet<const GlobalVariable *, 8>::iterator I = GVSet.begin(); 
+       I != GVSet.end(); I++) {
+    const GlobalVariable* GV = *I;
+    if (GV->hasInitializer())
+      Size = addSizeOfGlobalsInInitializer(GV->getInitializer(), Size);
+  }
+
+  return Size;
+}
+
+void JITEmitter::startFunction(MachineFunction &F) {
+  DOUT << "JIT: Starting CodeGen of Function "
+       << F.getFunction()->getName() << "\n";
+
+  uintptr_t ActualSize = 0;
+  // Set the memory writable, if it's not already
+  MemMgr->setMemoryWritable();
+  if (MemMgr->NeedsExactSize()) {
+    DOUT << "JIT: ExactSize\n";
+    const TargetInstrInfo* TII = F.getTarget().getInstrInfo();
+    MachineJumpTableInfo *MJTI = F.getJumpTableInfo();
+    MachineConstantPool *MCP = F.getConstantPool();
+    
+    // Ensure the constant pool/jump table info is at least 4-byte aligned.
+    ActualSize = RoundUpToAlign(ActualSize, 16);
+    
+    // Add the alignment of the constant pool
+    ActualSize = RoundUpToAlign(ActualSize, MCP->getConstantPoolAlignment());
+
+    // Add the constant pool size
+    ActualSize += GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
+
+    // Add the aligment of the jump table info
+    ActualSize = RoundUpToAlign(ActualSize, MJTI->getAlignment());
+
+    // Add the jump table size
+    ActualSize += GetJumpTableSizeInBytes(MJTI);
+    
+    // Add the alignment for the function
+    ActualSize = RoundUpToAlign(ActualSize,
+                                std::max(F.getFunction()->getAlignment(), 8U));
+
+    // Add the function size
+    ActualSize += TII->GetFunctionSizeInBytes(F);
+
+    DOUT << "JIT: ActualSize before globals " << ActualSize << "\n";
+    // Add the size of the globals that will be allocated after this function.
+    // These are all the ones referenced from this function that were not
+    // previously allocated.
+    ActualSize += GetSizeOfGlobalsInBytes(F);
+    DOUT << "JIT: ActualSize after globals " << ActualSize << "\n";
+  }
+
+  BufferBegin = CurBufferPtr = MemMgr->startFunctionBody(F.getFunction(),
+                                                         ActualSize);
+  BufferEnd = BufferBegin+ActualSize;
+  
+  // Ensure the constant pool/jump table info is at least 4-byte aligned.
+  emitAlignment(16);
+
+  emitConstantPool(F.getConstantPool());
+  initJumpTableInfo(F.getJumpTableInfo());
+
+  // About to start emitting the machine code for the function.
+  emitAlignment(std::max(F.getFunction()->getAlignment(), 8U));
+  TheJIT->updateGlobalMapping(F.getFunction(), CurBufferPtr);
+
+  MBBLocations.clear();
+}
+
+bool JITEmitter::finishFunction(MachineFunction &F) {
+  if (CurBufferPtr == BufferEnd) {
+    // FIXME: Allocate more space, then try again.
+    cerr << "JIT: Ran out of space for generated machine code!\n";
+    abort();
+  }
+  
+  emitJumpTableInfo(F.getJumpTableInfo());
+  
+  // FnStart is the start of the text, not the start of the constant pool and
+  // other per-function data.
+  uint8_t *FnStart =
+    (uint8_t *)TheJIT->getPointerToGlobalIfAvailable(F.getFunction());
+
+  // FnEnd is the end of the function's machine code.
+  uint8_t *FnEnd = CurBufferPtr;
+
+  if (!Relocations.empty()) {
+    CurFn = F.getFunction();
+    NumRelos += Relocations.size();
+
+    // Resolve the relocations to concrete pointers.
+    for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
+      MachineRelocation &MR = Relocations[i];
+      void *ResultPtr = 0;
+      if (!MR.letTargetResolve()) {
+        if (MR.isExternalSymbol()) {
+          ResultPtr = TheJIT->getPointerToNamedFunction(MR.getExternalSymbol(),
+                                                        false);
+          DOUT << "JIT: Map \'" << MR.getExternalSymbol() << "\' to ["
+               << ResultPtr << "]\n";  
+
+          // If the target REALLY wants a stub for this function, emit it now.
+          if (!MR.doesntNeedStub()) {
+            if (!TheJIT->areDlsymStubsEnabled()) {
+              ResultPtr = Resolver.getExternalFunctionStub(ResultPtr);
+            } else {
+              void *&Stub = ExtFnStubs[MR.getExternalSymbol()];
+              if (!Stub) {
+                Stub = Resolver.getExternalFunctionStub((void *)&Stub);
+                AddStubToCurrentFunction(Stub);
+              }
+              ResultPtr = Stub;
+            }
+          }
+        } else if (MR.isGlobalValue()) {
+          ResultPtr = getPointerToGlobal(MR.getGlobalValue(),
+                                         BufferBegin+MR.getMachineCodeOffset(),
+                                         MR.doesntNeedStub());
+        } else if (MR.isIndirectSymbol()) {
+          ResultPtr = getPointerToGVIndirectSym(MR.getGlobalValue(),
+                                          BufferBegin+MR.getMachineCodeOffset(),
+                                          MR.doesntNeedStub());
+        } else if (MR.isBasicBlock()) {
+          ResultPtr = (void*)getMachineBasicBlockAddress(MR.getBasicBlock());
+        } else if (MR.isConstantPoolIndex()) {
+          ResultPtr = (void*)getConstantPoolEntryAddress(MR.getConstantPoolIndex());
+        } else {
+          assert(MR.isJumpTableIndex());
+          ResultPtr=(void*)getJumpTableEntryAddress(MR.getJumpTableIndex());
+        }
+
+        MR.setResultPointer(ResultPtr);
+      }
+
+      // if we are managing the GOT and the relocation wants an index,
+      // give it one
+      if (MR.isGOTRelative() && MemMgr->isManagingGOT()) {
+        unsigned idx = Resolver.getGOTIndexForAddr(ResultPtr);
+        MR.setGOTIndex(idx);
+        if (((void**)MemMgr->getGOTBase())[idx] != ResultPtr) {
+          DOUT << "JIT: GOT was out of date for " << ResultPtr
+               << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
+               << "\n";
+          ((void**)MemMgr->getGOTBase())[idx] = ResultPtr;
+        }
+      }
+    }
+
+    CurFn = 0;
+    TheJIT->getJITInfo().relocate(BufferBegin, &Relocations[0],
+                                  Relocations.size(), MemMgr->getGOTBase());
+  }
+
+  // Update the GOT entry for F to point to the new code.
+  if (MemMgr->isManagingGOT()) {
+    unsigned idx = Resolver.getGOTIndexForAddr((void*)BufferBegin);
+    if (((void**)MemMgr->getGOTBase())[idx] != (void*)BufferBegin) {
+      DOUT << "JIT: GOT was out of date for " << (void*)BufferBegin
+           << " pointing at " << ((void**)MemMgr->getGOTBase())[idx] << "\n";
+      ((void**)MemMgr->getGOTBase())[idx] = (void*)BufferBegin;
+    }
+  }
+
+  // CurBufferPtr may have moved beyond FnEnd, due to memory allocation for
+  // global variables that were referenced in the relocations.
+  MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
+
+  if (CurBufferPtr == BufferEnd) {
+    // FIXME: Allocate more space, then try again.
+    cerr << "JIT: Ran out of space for generated machine code!\n";
+    abort();
+  }
+
+  BufferBegin = CurBufferPtr = 0;
+  NumBytes += FnEnd-FnStart;
+
+  // Invalidate the icache if necessary.
+  sys::Memory::InvalidateInstructionCache(FnStart, FnEnd-FnStart);
+  
+  // Add it to the JIT symbol table if the host wants it.
+  AddFunctionToSymbolTable(F.getFunction()->getNameStart(),
+                           FnStart, FnEnd-FnStart);
+
+  DOUT << "JIT: Finished CodeGen of [" << (void*)FnStart
+       << "] Function: " << F.getFunction()->getName()
+       << ": " << (FnEnd-FnStart) << " bytes of text, "
+       << Relocations.size() << " relocations\n";
+
+  if (MCI) {
+    MCI->setAddress(FnStart);
+    MCI->setSize(FnEnd-FnStart);
+  }
+
+  Relocations.clear();
+  ConstPoolAddresses.clear();
+
+  // Mark code region readable and executable if it's not so already.
+  MemMgr->setMemoryExecutable();
+
+#ifndef NDEBUG
+  {
+    if (sys::hasDisassembler()) {
+      DOUT << "JIT: Disassembled code:\n";
+      DOUT << sys::disassembleBuffer(FnStart, FnEnd-FnStart, (uintptr_t)FnStart);
+    } else {
+      DOUT << "JIT: Binary code:\n";
+      DOUT << std::hex;
+      uint8_t* q = FnStart;
+      for (int i = 0; q < FnEnd; q += 4, ++i) {
+        if (i == 4)
+          i = 0;
+        if (i == 0)
+          DOUT << "JIT: " << std::setw(8) << std::setfill('0')
+               << (long)(q - FnStart) << ": ";
+        bool Done = false;
+        for (int j = 3; j >= 0; --j) {
+          if (q + j >= FnEnd)
+            Done = true;
+          else
+            DOUT << std::setw(2) << std::setfill('0') << (unsigned short)q[j];
+        }
+        if (Done)
+          break;
+        DOUT << ' ';
+        if (i == 3)
+          DOUT << '\n';
+      }
+      DOUT << std::dec;
+      DOUT<< '\n';
+    }
+  }
+#endif
+  if (ExceptionHandling) {
+    uintptr_t ActualSize = 0;
+    SavedBufferBegin = BufferBegin;
+    SavedBufferEnd = BufferEnd;
+    SavedCurBufferPtr = CurBufferPtr;
+    
+    if (MemMgr->NeedsExactSize()) {
+      ActualSize = DE->GetDwarfTableSizeInBytes(F, *this, FnStart, FnEnd);
+    }
+
+    BufferBegin = CurBufferPtr = MemMgr->startExceptionTable(F.getFunction(),
+                                                             ActualSize);
+    BufferEnd = BufferBegin+ActualSize;
+    uint8_t* FrameRegister = DE->EmitDwarfTable(F, *this, FnStart, FnEnd);
+    MemMgr->endExceptionTable(F.getFunction(), BufferBegin, CurBufferPtr,
+                              FrameRegister);
+    BufferBegin = SavedBufferBegin;
+    BufferEnd = SavedBufferEnd;
+    CurBufferPtr = SavedCurBufferPtr;
+
+    TheJIT->RegisterTable(FrameRegister);
+  }
+
+  if (MMI)
+    MMI->EndFunction();
+ 
+  return false;
+}
+
+/// deallocateMemForFunction - Deallocate all memory for the specified
+/// function body.  Also drop any references the function has to stubs.
+void JITEmitter::deallocateMemForFunction(Function *F) {
+  MemMgr->deallocateMemForFunction(F);
+
+  // If the function did not reference any stubs, return.
+  if (CurFnStubUses.find(F) == CurFnStubUses.end())
+    return;
+  
+  // For each referenced stub, erase the reference to this function, and then
+  // erase the list of referenced stubs.
+  SmallVectorImpl<void *> &StubList = CurFnStubUses[F];
+  for (unsigned i = 0, e = StubList.size(); i != e; ++i) {
+    void *Stub = StubList[i];
+    
+    // If we already invalidated this stub for this function, continue.
+    if (StubFnRefs.count(Stub) == 0)
+      continue;
+      
+    SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[Stub];
+    FnRefs.erase(F);
+    
+    // If this function was the last reference to the stub, invalidate the stub
+    // in the JITResolver.  Were there a memory manager deallocateStub routine,
+    // we could call that at this point too.
+    if (FnRefs.empty()) {
+      DOUT << "\nJIT: Invalidated Stub at [" << Stub << "]\n";
+      StubFnRefs.erase(Stub);
+
+      // Invalidate the stub.  If it is a GV stub, update the JIT's global
+      // mapping for that GV to zero, otherwise, search the string map of
+      // external function names to stubs and remove the entry for this stub.
+      GlobalValue *GV = Resolver.invalidateStub(Stub);
+      if (GV) {
+        TheJIT->updateGlobalMapping(GV, 0);
+      } else {
+        for (StringMapIterator<void*> i = ExtFnStubs.begin(),
+             e = ExtFnStubs.end(); i != e; ++i) {
+          if (i->second == Stub) {
+            ExtFnStubs.erase(i);
+            break;
+          }
+        }
+      }
+    }
+  }
+  CurFnStubUses.erase(F);
+}
+
+
+void* JITEmitter::allocateSpace(uintptr_t Size, unsigned Alignment) {
+  if (BufferBegin)
+    return JITCodeEmitter::allocateSpace(Size, Alignment);
+
+  // create a new memory block if there is no active one.
+  // care must be taken so that BufferBegin is invalidated when a
+  // block is trimmed
+  BufferBegin = CurBufferPtr = MemMgr->allocateSpace(Size, Alignment);
+  BufferEnd = BufferBegin+Size;
+  return CurBufferPtr;
+}
+
+void JITEmitter::emitConstantPool(MachineConstantPool *MCP) {
+  if (TheJIT->getJITInfo().hasCustomConstantPool())
+    return;
+
+  const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
+  if (Constants.empty()) return;
+
+  unsigned Size = GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
+  unsigned Align = MCP->getConstantPoolAlignment();
+  ConstantPoolBase = allocateSpace(Size, Align);
+  ConstantPool = MCP;
+
+  if (ConstantPoolBase == 0) return;  // Buffer overflow.
+
+  DOUT << "JIT: Emitted constant pool at [" << ConstantPoolBase
+       << "] (size: " << Size << ", alignment: " << Align << ")\n";
+
+  // Initialize the memory for all of the constant pool entries.
+  unsigned Offset = 0;
+  for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
+    MachineConstantPoolEntry CPE = Constants[i];
+    unsigned AlignMask = CPE.getAlignment() - 1;
+    Offset = (Offset + AlignMask) & ~AlignMask;
+
+    uintptr_t CAddr = (uintptr_t)ConstantPoolBase + Offset;
+    ConstPoolAddresses.push_back(CAddr);
+    if (CPE.isMachineConstantPoolEntry()) {
+      // FIXME: add support to lower machine constant pool values into bytes!
+      cerr << "Initialize memory with machine specific constant pool entry"
+           << " has not been implemented!\n";
+      abort();
+    }
+    TheJIT->InitializeMemory(CPE.Val.ConstVal, (void*)CAddr);
+    DOUT << "JIT:   CP" << i << " at [0x"
+         << std::hex << CAddr << std::dec << "]\n";
+
+    const Type *Ty = CPE.Val.ConstVal->getType();
+    Offset += TheJIT->getTargetData()->getTypeAllocSize(Ty);
+  }
+}
+
+void JITEmitter::initJumpTableInfo(MachineJumpTableInfo *MJTI) {
+  if (TheJIT->getJITInfo().hasCustomJumpTables())
+    return;
+
+  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
+  if (JT.empty()) return;
+  
+  unsigned NumEntries = 0;
+  for (unsigned i = 0, e = JT.size(); i != e; ++i)
+    NumEntries += JT[i].MBBs.size();
+
+  unsigned EntrySize = MJTI->getEntrySize();
+
+  // Just allocate space for all the jump tables now.  We will fix up the actual
+  // MBB entries in the tables after we emit the code for each block, since then
+  // we will know the final locations of the MBBs in memory.
+  JumpTable = MJTI;
+  JumpTableBase = allocateSpace(NumEntries * EntrySize, MJTI->getAlignment());
+}
+
+void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
+  if (TheJIT->getJITInfo().hasCustomJumpTables())
+    return;
+
+  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
+  if (JT.empty() || JumpTableBase == 0) return;
+  
+  if (TargetMachine::getRelocationModel() == Reloc::PIC_) {
+    assert(MJTI->getEntrySize() == 4 && "Cross JIT'ing?");
+    // For each jump table, place the offset from the beginning of the table
+    // to the target address.
+    int *SlotPtr = (int*)JumpTableBase;
+
+    for (unsigned i = 0, e = JT.size(); i != e; ++i) {
+      const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
+      // Store the offset of the basic block for this jump table slot in the
+      // memory we allocated for the jump table in 'initJumpTableInfo'
+      uintptr_t Base = (uintptr_t)SlotPtr;
+      for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi) {
+        uintptr_t MBBAddr = getMachineBasicBlockAddress(MBBs[mi]);
+        *SlotPtr++ = TheJIT->getJITInfo().getPICJumpTableEntry(MBBAddr, Base);
+      }
+    }
+  } else {
+    assert(MJTI->getEntrySize() == sizeof(void*) && "Cross JIT'ing?");
+    
+    // For each jump table, map each target in the jump table to the address of 
+    // an emitted MachineBasicBlock.
+    intptr_t *SlotPtr = (intptr_t*)JumpTableBase;
+
+    for (unsigned i = 0, e = JT.size(); i != e; ++i) {
+      const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
+      // Store the address of the basic block for this jump table slot in the
+      // memory we allocated for the jump table in 'initJumpTableInfo'
+      for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi)
+        *SlotPtr++ = getMachineBasicBlockAddress(MBBs[mi]);
+    }
+  }
+}
+
+void JITEmitter::startGVStub(const GlobalValue* GV, unsigned StubSize,
+                             unsigned Alignment) {
+  SavedBufferBegin = BufferBegin;
+  SavedBufferEnd = BufferEnd;
+  SavedCurBufferPtr = CurBufferPtr;
+  
+  BufferBegin = CurBufferPtr = MemMgr->allocateStub(GV, StubSize, Alignment);
+  BufferEnd = BufferBegin+StubSize+1;
+}
+
+void JITEmitter::startGVStub(const GlobalValue* GV, void *Buffer,
+                             unsigned StubSize) {
+  SavedBufferBegin = BufferBegin;
+  SavedBufferEnd = BufferEnd;
+  SavedCurBufferPtr = CurBufferPtr;
+  
+  BufferBegin = CurBufferPtr = (uint8_t *)Buffer;
+  BufferEnd = BufferBegin+StubSize+1;
+}
+
+void *JITEmitter::finishGVStub(const GlobalValue* GV) {
+  NumBytes += getCurrentPCOffset();
+  std::swap(SavedBufferBegin, BufferBegin);
+  BufferEnd = SavedBufferEnd;
+  CurBufferPtr = SavedCurBufferPtr;
+  return SavedBufferBegin;
+}
+
+// getConstantPoolEntryAddress - Return the address of the 'ConstantNum' entry
+// in the constant pool that was last emitted with the 'emitConstantPool'
+// method.
+//
+uintptr_t JITEmitter::getConstantPoolEntryAddress(unsigned ConstantNum) const {
+  assert(ConstantNum < ConstantPool->getConstants().size() &&
+         "Invalid ConstantPoolIndex!");
+  return ConstPoolAddresses[ConstantNum];
+}
+
+// getJumpTableEntryAddress - Return the address of the JumpTable with index
+// 'Index' in the jumpp table that was last initialized with 'initJumpTableInfo'
+//
+uintptr_t JITEmitter::getJumpTableEntryAddress(unsigned Index) const {
+  const std::vector<MachineJumpTableEntry> &JT = JumpTable->getJumpTables();
+  assert(Index < JT.size() && "Invalid jump table index!");
+  
+  unsigned Offset = 0;
+  unsigned EntrySize = JumpTable->getEntrySize();
+  
+  for (unsigned i = 0; i < Index; ++i)
+    Offset += JT[i].MBBs.size();
+  
+   Offset *= EntrySize;
+  
+  return (uintptr_t)((char *)JumpTableBase + Offset);
+}
+
+//===----------------------------------------------------------------------===//
+//  Public interface to this file
+//===----------------------------------------------------------------------===//
+
+JITCodeEmitter *JIT::createEmitter(JIT &jit, JITMemoryManager *JMM) {
+  return new JITEmitter(jit, JMM);
+}
+
+// getPointerToNamedFunction - This function is used as a global wrapper to
+// JIT::getPointerToNamedFunction for the purpose of resolving symbols when
+// bugpoint is debugging the JIT. In that scenario, we are loading an .so and
+// need to resolve function(s) that are being mis-codegenerated, so we need to
+// resolve their addresses at runtime, and this is the way to do it.
+extern "C" {
+  void *getPointerToNamedFunction(const char *Name) {
+    if (Function *F = TheJIT->FindFunctionNamed(Name))
+      return TheJIT->getPointerToFunction(F);
+    return TheJIT->getPointerToNamedFunction(Name);
+  }
+}
+
+// getPointerToFunctionOrStub - If the specified function has been
+// code-gen'd, return a pointer to the function.  If not, compile it, or use
+// a stub to implement lazy compilation if available.
+//
+void *JIT::getPointerToFunctionOrStub(Function *F) {
+  // If we have already code generated the function, just return the address.
+  if (void *Addr = getPointerToGlobalIfAvailable(F))
+    return Addr;
+  
+  // Get a stub if the target supports it.
+  assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
+  JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
+  return JE->getJITResolver().getFunctionStub(F);
+}
+
+void JIT::registerMachineCodeInfo(MachineCodeInfo *mc) {
+  assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
+  JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
+
+  JE->setMachineCodeInfo(mc);
+}
+
+void JIT::updateFunctionStub(Function *F) {
+  // Get the empty stub we generated earlier.
+  assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
+  JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
+  void *Stub = JE->getJITResolver().getFunctionStub(F);
+
+  // Tell the target jit info to rewrite the stub at the specified address,
+  // rather than creating a new one.
+  void *Addr = getPointerToGlobalIfAvailable(F);
+  getJITInfo().emitFunctionStubAtAddr(F, Addr, Stub, *getCodeEmitter());
+}
+
+/// updateDlsymStubTable - Emit the data necessary to relocate the stubs
+/// that were emitted during code generation.
+///
+void JIT::updateDlsymStubTable() {
+  assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
+  JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
+  
+  SmallVector<GlobalValue*, 8> GVs;
+  SmallVector<void*, 8> Ptrs;
+  const StringMap<void *> &ExtFns = JE->getExternalFnStubs();
+
+  JE->getJITResolver().getRelocatableGVs(GVs, Ptrs);
+
+  unsigned nStubs = GVs.size() + ExtFns.size();
+  
+  // If there are no relocatable stubs, return.
+  if (nStubs == 0)
+    return;
+
+  // If there are no new relocatable stubs, return.
+  void *CurTable = JE->getMemMgr()->getDlsymTable();
+  if (CurTable && (*(unsigned *)CurTable == nStubs))
+    return;
+  
+  // Calculate the size of the stub info
+  unsigned offset = 4 + 4 * nStubs + sizeof(intptr_t) * nStubs;
+  
+  SmallVector<unsigned, 8> Offsets;
+  for (unsigned i = 0; i != GVs.size(); ++i) {
+    Offsets.push_back(offset);
+    offset += GVs[i]->getName().length() + 1;
+  }
+  for (StringMapConstIterator<void*> i = ExtFns.begin(), e = ExtFns.end(); 
+       i != e; ++i) {
+    Offsets.push_back(offset);
+    offset += strlen(i->first()) + 1;
+  }
+  
+  // Allocate space for the new "stub", which contains the dlsym table.
+  JE->startGVStub(0, offset, 4);
+  
+  // Emit the number of records
+  JE->emitInt32(nStubs);
+  
+  // Emit the string offsets
+  for (unsigned i = 0; i != nStubs; ++i)
+    JE->emitInt32(Offsets[i]);
+  
+  // Emit the pointers.  Verify that they are at least 2-byte aligned, and set
+  // the low bit to 0 == GV, 1 == Function, so that the client code doing the
+  // relocation can write the relocated pointer at the appropriate place in
+  // the stub.
+  for (unsigned i = 0; i != GVs.size(); ++i) {
+    intptr_t Ptr = (intptr_t)Ptrs[i];
+    assert((Ptr & 1) == 0 && "Stub pointers must be at least 2-byte aligned!");
+    
+    if (isa<Function>(GVs[i]))
+      Ptr |= (intptr_t)1;
+           
+    if (sizeof(Ptr) == 8)
+      JE->emitInt64(Ptr);
+    else
+      JE->emitInt32(Ptr);
+  }
+  for (StringMapConstIterator<void*> i = ExtFns.begin(), e = ExtFns.end(); 
+       i != e; ++i) {
+    intptr_t Ptr = (intptr_t)i->second | 1;
+
+    if (sizeof(Ptr) == 8)
+      JE->emitInt64(Ptr);
+    else
+      JE->emitInt32(Ptr);
+  }
+  
+  // Emit the strings.
+  for (unsigned i = 0; i != GVs.size(); ++i)
+    JE->emitString(GVs[i]->getName());
+  for (StringMapConstIterator<void*> i = ExtFns.begin(), e = ExtFns.end(); 
+       i != e; ++i)
+    JE->emitString(i->first());
+  
+  // Tell the JIT memory manager where it is.  The JIT Memory Manager will
+  // deallocate space for the old one, if one existed.
+  JE->getMemMgr()->SetDlsymTable(JE->finishGVStub(0));
+}
+
+/// freeMachineCodeForFunction - release machine code memory for given Function.
+///
+void JIT::freeMachineCodeForFunction(Function *F) {
+
+  // Delete translation for this from the ExecutionEngine, so it will get
+  // retranslated next time it is used.
+  void *OldPtr = updateGlobalMapping(F, 0);
+
+  if (OldPtr)
+    RemoveFunctionFromSymbolTable(OldPtr);
+
+  // Free the actual memory for the function body and related stuff.
+  assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
+  cast<JITEmitter>(JCE)->deallocateMemForFunction(F);
+}
+
diff --git a/lib/ExecutionEngine/JIT/JITMemoryManager.cpp b/lib/ExecutionEngine/JIT/JITMemoryManager.cpp
new file mode 100644
index 0000000..70ccdcc
--- /dev/null
+++ b/lib/ExecutionEngine/JIT/JITMemoryManager.cpp
@@ -0,0 +1,541 @@
+//===-- JITMemoryManager.cpp - Memory Allocator for JIT'd code ------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the DefaultJITMemoryManager class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/GlobalValue.h"
+#include "llvm/ExecutionEngine/JITMemoryManager.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/System/Memory.h"
+#include <map>
+#include <vector>
+#include <cassert>
+#include <climits>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+using namespace llvm;
+
+
+JITMemoryManager::~JITMemoryManager() {}
+
+//===----------------------------------------------------------------------===//
+// Memory Block Implementation.
+//===----------------------------------------------------------------------===//
+
+namespace {
+  /// MemoryRangeHeader - For a range of memory, this is the header that we put
+  /// on the block of memory.  It is carefully crafted to be one word of memory.
+  /// Allocated blocks have just this header, free'd blocks have FreeRangeHeader
+  /// which starts with this.
+  struct FreeRangeHeader;
+  struct MemoryRangeHeader {
+    /// ThisAllocated - This is true if this block is currently allocated.  If
+    /// not, this can be converted to a FreeRangeHeader.
+    unsigned ThisAllocated : 1;
+    
+    /// PrevAllocated - Keep track of whether the block immediately before us is
+    /// allocated.  If not, the word immediately before this header is the size
+    /// of the previous block.
+    unsigned PrevAllocated : 1;
+    
+    /// BlockSize - This is the size in bytes of this memory block,
+    /// including this header.
+    uintptr_t BlockSize : (sizeof(intptr_t)*CHAR_BIT - 2);
+    
+
+    /// getBlockAfter - Return the memory block immediately after this one.
+    ///
+    MemoryRangeHeader &getBlockAfter() const {
+      return *(MemoryRangeHeader*)((char*)this+BlockSize);
+    }
+    
+    /// getFreeBlockBefore - If the block before this one is free, return it,
+    /// otherwise return null.
+    FreeRangeHeader *getFreeBlockBefore() const {
+      if (PrevAllocated) return 0;
+      intptr_t PrevSize = ((intptr_t *)this)[-1];
+      return (FreeRangeHeader*)((char*)this-PrevSize);
+    }
+    
+    /// FreeBlock - Turn an allocated block into a free block, adjusting
+    /// bits in the object headers, and adding an end of region memory block.
+    FreeRangeHeader *FreeBlock(FreeRangeHeader *FreeList);
+    
+    /// TrimAllocationToSize - If this allocated block is significantly larger
+    /// than NewSize, split it into two pieces (where the former is NewSize
+    /// bytes, including the header), and add the new block to the free list.
+    FreeRangeHeader *TrimAllocationToSize(FreeRangeHeader *FreeList, 
+                                          uint64_t NewSize);
+  };
+
+  /// FreeRangeHeader - For a memory block that isn't already allocated, this
+  /// keeps track of the current block and has a pointer to the next free block.
+  /// Free blocks are kept on a circularly linked list.
+  struct FreeRangeHeader : public MemoryRangeHeader {
+    FreeRangeHeader *Prev;
+    FreeRangeHeader *Next;
+    
+    /// getMinBlockSize - Get the minimum size for a memory block.  Blocks
+    /// smaller than this size cannot be created.
+    static unsigned getMinBlockSize() {
+      return sizeof(FreeRangeHeader)+sizeof(intptr_t);
+    }
+    
+    /// SetEndOfBlockSizeMarker - The word at the end of every free block is
+    /// known to be the size of the free block.  Set it for this block.
+    void SetEndOfBlockSizeMarker() {
+      void *EndOfBlock = (char*)this + BlockSize;
+      ((intptr_t *)EndOfBlock)[-1] = BlockSize;
+    }
+
+    FreeRangeHeader *RemoveFromFreeList() {
+      assert(Next->Prev == this && Prev->Next == this && "Freelist broken!");
+      Next->Prev = Prev;
+      return Prev->Next = Next;
+    }
+    
+    void AddToFreeList(FreeRangeHeader *FreeList) {
+      Next = FreeList;
+      Prev = FreeList->Prev;
+      Prev->Next = this;
+      Next->Prev = this;
+    }
+
+    /// GrowBlock - The block after this block just got deallocated.  Merge it
+    /// into the current block.
+    void GrowBlock(uintptr_t NewSize);
+    
+    /// AllocateBlock - Mark this entire block allocated, updating freelists
+    /// etc.  This returns a pointer to the circular free-list.
+    FreeRangeHeader *AllocateBlock();
+  };
+}
+
+
+/// AllocateBlock - Mark this entire block allocated, updating freelists
+/// etc.  This returns a pointer to the circular free-list.
+FreeRangeHeader *FreeRangeHeader::AllocateBlock() {
+  assert(!ThisAllocated && !getBlockAfter().PrevAllocated &&
+         "Cannot allocate an allocated block!");
+  // Mark this block allocated.
+  ThisAllocated = 1;
+  getBlockAfter().PrevAllocated = 1;
+ 
+  // Remove it from the free list.
+  return RemoveFromFreeList();
+}
+
+/// FreeBlock - Turn an allocated block into a free block, adjusting
+/// bits in the object headers, and adding an end of region memory block.
+/// If possible, coalesce this block with neighboring blocks.  Return the
+/// FreeRangeHeader to allocate from.
+FreeRangeHeader *MemoryRangeHeader::FreeBlock(FreeRangeHeader *FreeList) {
+  MemoryRangeHeader *FollowingBlock = &getBlockAfter();
+  assert(ThisAllocated && "This block is already allocated!");
+  assert(FollowingBlock->PrevAllocated && "Flags out of sync!");
+  
+  FreeRangeHeader *FreeListToReturn = FreeList;
+  
+  // If the block after this one is free, merge it into this block.
+  if (!FollowingBlock->ThisAllocated) {
+    FreeRangeHeader &FollowingFreeBlock = *(FreeRangeHeader *)FollowingBlock;
+    // "FreeList" always needs to be a valid free block.  If we're about to
+    // coalesce with it, update our notion of what the free list is.
+    if (&FollowingFreeBlock == FreeList) {
+      FreeList = FollowingFreeBlock.Next;
+      FreeListToReturn = 0;
+      assert(&FollowingFreeBlock != FreeList && "No tombstone block?");
+    }
+    FollowingFreeBlock.RemoveFromFreeList();
+    
+    // Include the following block into this one.
+    BlockSize += FollowingFreeBlock.BlockSize;
+    FollowingBlock = &FollowingFreeBlock.getBlockAfter();
+    
+    // Tell the block after the block we are coalescing that this block is
+    // allocated.
+    FollowingBlock->PrevAllocated = 1;
+  }
+  
+  assert(FollowingBlock->ThisAllocated && "Missed coalescing?");
+  
+  if (FreeRangeHeader *PrevFreeBlock = getFreeBlockBefore()) {
+    PrevFreeBlock->GrowBlock(PrevFreeBlock->BlockSize + BlockSize);
+    return FreeListToReturn ? FreeListToReturn : PrevFreeBlock;
+  }
+
+  // Otherwise, mark this block free.
+  FreeRangeHeader &FreeBlock = *(FreeRangeHeader*)this;
+  FollowingBlock->PrevAllocated = 0;
+  FreeBlock.ThisAllocated = 0;
+
+  // Link this into the linked list of free blocks.
+  FreeBlock.AddToFreeList(FreeList);
+
+  // Add a marker at the end of the block, indicating the size of this free
+  // block.
+  FreeBlock.SetEndOfBlockSizeMarker();
+  return FreeListToReturn ? FreeListToReturn : &FreeBlock;
+}
+
+/// GrowBlock - The block after this block just got deallocated.  Merge it
+/// into the current block.
+void FreeRangeHeader::GrowBlock(uintptr_t NewSize) {
+  assert(NewSize > BlockSize && "Not growing block?");
+  BlockSize = NewSize;
+  SetEndOfBlockSizeMarker();
+  getBlockAfter().PrevAllocated = 0;
+}
+
+/// TrimAllocationToSize - If this allocated block is significantly larger
+/// than NewSize, split it into two pieces (where the former is NewSize
+/// bytes, including the header), and add the new block to the free list.
+FreeRangeHeader *MemoryRangeHeader::
+TrimAllocationToSize(FreeRangeHeader *FreeList, uint64_t NewSize) {
+  assert(ThisAllocated && getBlockAfter().PrevAllocated &&
+         "Cannot deallocate part of an allocated block!");
+
+  // Don't allow blocks to be trimmed below minimum required size
+  NewSize = std::max<uint64_t>(FreeRangeHeader::getMinBlockSize(), NewSize);
+
+  // Round up size for alignment of header.
+  unsigned HeaderAlign = __alignof(FreeRangeHeader);
+  NewSize = (NewSize+ (HeaderAlign-1)) & ~(HeaderAlign-1);
+  
+  // Size is now the size of the block we will remove from the start of the
+  // current block.
+  assert(NewSize <= BlockSize &&
+         "Allocating more space from this block than exists!");
+  
+  // If splitting this block will cause the remainder to be too small, do not
+  // split the block.
+  if (BlockSize <= NewSize+FreeRangeHeader::getMinBlockSize())
+    return FreeList;
+  
+  // Otherwise, we splice the required number of bytes out of this block, form
+  // a new block immediately after it, then mark this block allocated.
+  MemoryRangeHeader &FormerNextBlock = getBlockAfter();
+  
+  // Change the size of this block.
+  BlockSize = NewSize;
+  
+  // Get the new block we just sliced out and turn it into a free block.
+  FreeRangeHeader &NewNextBlock = (FreeRangeHeader &)getBlockAfter();
+  NewNextBlock.BlockSize = (char*)&FormerNextBlock - (char*)&NewNextBlock;
+  NewNextBlock.ThisAllocated = 0;
+  NewNextBlock.PrevAllocated = 1;
+  NewNextBlock.SetEndOfBlockSizeMarker();
+  FormerNextBlock.PrevAllocated = 0;
+  NewNextBlock.AddToFreeList(FreeList);
+  return &NewNextBlock;
+}
+
+//===----------------------------------------------------------------------===//
+// Memory Block Implementation.
+//===----------------------------------------------------------------------===//
+
+namespace {  
+  /// DefaultJITMemoryManager - Manage memory for the JIT code generation.
+  /// This splits a large block of MAP_NORESERVE'd memory into two
+  /// sections, one for function stubs, one for the functions themselves.  We
+  /// have to do this because we may need to emit a function stub while in the
+  /// middle of emitting a function, and we don't know how large the function we
+  /// are emitting is.
+  class VISIBILITY_HIDDEN DefaultJITMemoryManager : public JITMemoryManager {
+    std::vector<sys::MemoryBlock> Blocks; // Memory blocks allocated by the JIT
+    FreeRangeHeader *FreeMemoryList;      // Circular list of free blocks.
+    
+    // When emitting code into a memory block, this is the block.
+    MemoryRangeHeader *CurBlock;
+    
+    uint8_t *CurStubPtr, *StubBase;
+    uint8_t *GOTBase;     // Target Specific reserved memory
+    void *DlsymTable;     // Stub external symbol information
+
+    // Centralize memory block allocation.
+    sys::MemoryBlock getNewMemoryBlock(unsigned size);
+    
+    std::map<const Function*, MemoryRangeHeader*> FunctionBlocks;
+    std::map<const Function*, MemoryRangeHeader*> TableBlocks;
+  public:
+    DefaultJITMemoryManager();
+    ~DefaultJITMemoryManager();
+
+    void AllocateGOT();
+    void SetDlsymTable(void *);
+    
+    uint8_t *allocateStub(const GlobalValue* F, unsigned StubSize,
+                          unsigned Alignment);
+    
+    /// startFunctionBody - When a function starts, allocate a block of free
+    /// executable memory, returning a pointer to it and its actual size.
+    uint8_t *startFunctionBody(const Function *F, uintptr_t &ActualSize) {
+      
+      FreeRangeHeader* candidateBlock = FreeMemoryList;
+      FreeRangeHeader* head = FreeMemoryList;
+      FreeRangeHeader* iter = head->Next;
+
+      uintptr_t largest = candidateBlock->BlockSize;
+      
+      // Search for the largest free block
+      while (iter != head) {
+          if (iter->BlockSize > largest) {
+              largest = iter->BlockSize;
+              candidateBlock = iter;
+          }
+          iter = iter->Next;
+      }
+      
+      // Select this candidate block for allocation
+      CurBlock = candidateBlock;
+
+      // Allocate the entire memory block.
+      FreeMemoryList = candidateBlock->AllocateBlock();
+      ActualSize = CurBlock->BlockSize-sizeof(MemoryRangeHeader);
+      return (uint8_t *)(CurBlock+1);
+    }
+    
+    /// endFunctionBody - The function F is now allocated, and takes the memory
+    /// in the range [FunctionStart,FunctionEnd).
+    void endFunctionBody(const Function *F, uint8_t *FunctionStart,
+                         uint8_t *FunctionEnd) {
+      assert(FunctionEnd > FunctionStart);
+      assert(FunctionStart == (uint8_t *)(CurBlock+1) &&
+             "Mismatched function start/end!");
+
+      uintptr_t BlockSize = FunctionEnd - (uint8_t *)CurBlock;
+      FunctionBlocks[F] = CurBlock;
+
+      // Release the memory at the end of this block that isn't needed.
+      FreeMemoryList =CurBlock->TrimAllocationToSize(FreeMemoryList, BlockSize);
+    }
+
+    /// allocateSpace - Allocate a memory block of the given size.
+    uint8_t *allocateSpace(intptr_t Size, unsigned Alignment) {
+      CurBlock = FreeMemoryList;
+      FreeMemoryList = FreeMemoryList->AllocateBlock();
+
+      uint8_t *result = (uint8_t *)CurBlock+1;
+
+      if (Alignment == 0) Alignment = 1;
+      result = (uint8_t*)(((intptr_t)result+Alignment-1) &
+               ~(intptr_t)(Alignment-1));
+
+      uintptr_t BlockSize = result + Size - (uint8_t *)CurBlock;
+      FreeMemoryList =CurBlock->TrimAllocationToSize(FreeMemoryList, BlockSize);
+
+      return result;
+    }
+
+    /// startExceptionTable - Use startFunctionBody to allocate memory for the 
+    /// function's exception table.
+    uint8_t* startExceptionTable(const Function* F, uintptr_t &ActualSize) {
+      return startFunctionBody(F, ActualSize);
+    }
+
+    /// endExceptionTable - The exception table of F is now allocated, 
+    /// and takes the memory in the range [TableStart,TableEnd).
+    void endExceptionTable(const Function *F, uint8_t *TableStart,
+                           uint8_t *TableEnd, uint8_t* FrameRegister) {
+      assert(TableEnd > TableStart);
+      assert(TableStart == (uint8_t *)(CurBlock+1) &&
+             "Mismatched table start/end!");
+      
+      uintptr_t BlockSize = TableEnd - (uint8_t *)CurBlock;
+      TableBlocks[F] = CurBlock;
+
+      // Release the memory at the end of this block that isn't needed.
+      FreeMemoryList =CurBlock->TrimAllocationToSize(FreeMemoryList, BlockSize);
+    }
+    
+    uint8_t *getGOTBase() const {
+      return GOTBase;
+    }
+    
+    void *getDlsymTable() const {
+      return DlsymTable;
+    }
+    
+    /// deallocateMemForFunction - Deallocate all memory for the specified
+    /// function body.
+    void deallocateMemForFunction(const Function *F) {
+      std::map<const Function*, MemoryRangeHeader*>::iterator
+        I = FunctionBlocks.find(F);
+      if (I == FunctionBlocks.end()) return;
+      
+      // Find the block that is allocated for this function.
+      MemoryRangeHeader *MemRange = I->second;
+      assert(MemRange->ThisAllocated && "Block isn't allocated!");
+      
+      // Fill the buffer with garbage!
+#ifndef NDEBUG
+      memset(MemRange+1, 0xCD, MemRange->BlockSize-sizeof(*MemRange));
+#endif
+      
+      // Free the memory.
+      FreeMemoryList = MemRange->FreeBlock(FreeMemoryList);
+      
+      // Finally, remove this entry from FunctionBlocks.
+      FunctionBlocks.erase(I);
+      
+      I = TableBlocks.find(F);
+      if (I == TableBlocks.end()) return;
+      
+      // Find the block that is allocated for this function.
+      MemRange = I->second;
+      assert(MemRange->ThisAllocated && "Block isn't allocated!");
+      
+      // Fill the buffer with garbage!
+#ifndef NDEBUG
+      memset(MemRange+1, 0xCD, MemRange->BlockSize-sizeof(*MemRange));
+#endif
+      
+      // Free the memory.
+      FreeMemoryList = MemRange->FreeBlock(FreeMemoryList);
+      
+      // Finally, remove this entry from TableBlocks.
+      TableBlocks.erase(I);
+    }
+
+    /// setMemoryWritable - When code generation is in progress,
+    /// the code pages may need permissions changed.
+    void setMemoryWritable(void)
+    {
+      for (unsigned i = 0, e = Blocks.size(); i != e; ++i)
+        sys::Memory::setWritable(Blocks[i]);
+    }
+    /// setMemoryExecutable - When code generation is done and we're ready to
+    /// start execution, the code pages may need permissions changed.
+    void setMemoryExecutable(void)
+    {
+      for (unsigned i = 0, e = Blocks.size(); i != e; ++i)
+        sys::Memory::setExecutable(Blocks[i]);
+    }
+  };
+}
+
+DefaultJITMemoryManager::DefaultJITMemoryManager() {
+  // Allocate a 16M block of memory for functions.
+#if defined(__APPLE__) && defined(__arm__)
+  sys::MemoryBlock MemBlock = getNewMemoryBlock(4 << 20);
+#else
+  sys::MemoryBlock MemBlock = getNewMemoryBlock(16 << 20);
+#endif
+
+  uint8_t *MemBase = static_cast<uint8_t*>(MemBlock.base());
+
+  // Allocate stubs backwards from the base, allocate functions forward
+  // from the base.
+  StubBase   = MemBase;
+  CurStubPtr = MemBase + 512*1024; // Use 512k for stubs, working backwards.
+  
+  // We set up the memory chunk with 4 mem regions, like this:
+  //  [ START
+  //    [ Free      #0 ] -> Large space to allocate functions from.
+  //    [ Allocated #1 ] -> Tiny space to separate regions.
+  //    [ Free      #2 ] -> Tiny space so there is always at least 1 free block.
+  //    [ Allocated #3 ] -> Tiny space to prevent looking past end of block.
+  //  END ]
+  //
+  // The last three blocks are never deallocated or touched.
+  
+  // Add MemoryRangeHeader to the end of the memory region, indicating that
+  // the space after the block of memory is allocated.  This is block #3.
+  MemoryRangeHeader *Mem3 = (MemoryRangeHeader*)(MemBase+MemBlock.size())-1;
+  Mem3->ThisAllocated = 1;
+  Mem3->PrevAllocated = 0;
+  Mem3->BlockSize     = 0;
+  
+  /// Add a tiny free region so that the free list always has one entry.
+  FreeRangeHeader *Mem2 = 
+    (FreeRangeHeader *)(((char*)Mem3)-FreeRangeHeader::getMinBlockSize());
+  Mem2->ThisAllocated = 0;
+  Mem2->PrevAllocated = 1;
+  Mem2->BlockSize     = FreeRangeHeader::getMinBlockSize();
+  Mem2->SetEndOfBlockSizeMarker();
+  Mem2->Prev = Mem2;   // Mem2 *is* the free list for now.
+  Mem2->Next = Mem2;
+
+  /// Add a tiny allocated region so that Mem2 is never coalesced away.
+  MemoryRangeHeader *Mem1 = (MemoryRangeHeader*)Mem2-1;
+  Mem1->ThisAllocated = 1;
+  Mem1->PrevAllocated = 0;
+  Mem1->BlockSize     = (char*)Mem2 - (char*)Mem1;
+  
+  // Add a FreeRangeHeader to the start of the function body region, indicating
+  // that the space is free.  Mark the previous block allocated so we never look
+  // at it.
+  FreeRangeHeader *Mem0 = (FreeRangeHeader*)CurStubPtr;
+  Mem0->ThisAllocated = 0;
+  Mem0->PrevAllocated = 1;
+  Mem0->BlockSize = (char*)Mem1-(char*)Mem0;
+  Mem0->SetEndOfBlockSizeMarker();
+  Mem0->AddToFreeList(Mem2);
+  
+  // Start out with the freelist pointing to Mem0.
+  FreeMemoryList = Mem0;
+
+  GOTBase = NULL;
+  DlsymTable = NULL;
+}
+
+void DefaultJITMemoryManager::AllocateGOT() {
+  assert(GOTBase == 0 && "Cannot allocate the got multiple times");
+  GOTBase = new uint8_t[sizeof(void*) * 8192];
+  HasGOT = true;
+}
+
+void DefaultJITMemoryManager::SetDlsymTable(void *ptr) {
+  DlsymTable = ptr;
+}
+
+DefaultJITMemoryManager::~DefaultJITMemoryManager() {
+  for (unsigned i = 0, e = Blocks.size(); i != e; ++i)
+    sys::Memory::ReleaseRWX(Blocks[i]);
+  
+  delete[] GOTBase;
+  Blocks.clear();
+}
+
+uint8_t *DefaultJITMemoryManager::allocateStub(const GlobalValue* F,
+                                                     unsigned StubSize,
+                                                     unsigned Alignment) {
+  CurStubPtr -= StubSize;
+  CurStubPtr = (uint8_t*)(((intptr_t)CurStubPtr) &
+                          ~(intptr_t)(Alignment-1));
+  if (CurStubPtr < StubBase) {
+    // FIXME: allocate a new block
+    fprintf(stderr, "JIT ran out of memory for function stubs!\n");
+    abort();
+  }
+  return CurStubPtr;
+}
+
+sys::MemoryBlock DefaultJITMemoryManager::getNewMemoryBlock(unsigned size) {
+  // Allocate a new block close to the last one.
+  const sys::MemoryBlock *BOld = Blocks.empty() ? 0 : &Blocks.front();
+  std::string ErrMsg;
+  sys::MemoryBlock B = sys::Memory::AllocateRWX(size, BOld, &ErrMsg);
+  if (B.base() == 0) {
+    fprintf(stderr,
+            "Allocation failed when allocating new memory in the JIT\n%s\n",
+            ErrMsg.c_str());
+    abort();
+  }
+  Blocks.push_back(B);
+  return B;
+}
+
+
+JITMemoryManager *JITMemoryManager::CreateDefaultMemManager() {
+  return new DefaultJITMemoryManager();
+}
diff --git a/lib/ExecutionEngine/JIT/Makefile b/lib/ExecutionEngine/JIT/Makefile
new file mode 100644
index 0000000..e2c9c61
--- /dev/null
+++ b/lib/ExecutionEngine/JIT/Makefile
@@ -0,0 +1,37 @@
+##===- lib/ExecutionEngine/JIT/Makefile --------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+LEVEL = ../../..
+LIBRARYNAME = LLVMJIT
+
+# Get the $(ARCH) setting
+include $(LEVEL)/Makefile.config
+
+# Enable the X86 JIT if compiling on X86
+ifeq ($(ARCH), x86)
+  ENABLE_X86_JIT = 1
+endif
+
+# This flag can also be used on the command line to force inclusion
+# of the X86 JIT on non-X86 hosts
+ifdef ENABLE_X86_JIT
+  CPPFLAGS += -DENABLE_X86_JIT
+endif
+
+# Enable the Sparc JIT if compiling on Sparc
+ifeq ($(ARCH), Sparc)
+  ENABLE_SPARC_JIT = 1
+endif
+
+# This flag can also be used on the command line to force inclusion
+# of the Sparc JIT on non-Sparc hosts
+ifdef ENABLE_SPARC_JIT
+  CPPFLAGS += -DENABLE_SPARC_JIT
+endif
+
+include $(LEVEL)/Makefile.common
diff --git a/lib/ExecutionEngine/JIT/TargetSelect.cpp b/lib/ExecutionEngine/JIT/TargetSelect.cpp
new file mode 100644
index 0000000..0f20819
--- /dev/null
+++ b/lib/ExecutionEngine/JIT/TargetSelect.cpp
@@ -0,0 +1,83 @@
+//===-- TargetSelect.cpp - Target Chooser Code ----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This just asks the TargetMachineRegistry for the appropriate JIT to use, and
+// allows the user to specify a specific one on the commandline with -march=x.
+//
+//===----------------------------------------------------------------------===//
+
+#include "JIT.h"
+#include "llvm/Module.h"
+#include "llvm/ModuleProvider.h"
+#include "llvm/Support/RegistryParser.h"
+#include "llvm/Support/Streams.h"
+#include "llvm/Target/SubtargetFeature.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetMachineRegistry.h"
+using namespace llvm;
+
+static cl::opt<const TargetMachineRegistry::entry*, false,
+               RegistryParser<TargetMachine> >
+MArch("march", cl::desc("Architecture to generate assembly for:"));
+
+static cl::opt<std::string>
+MCPU("mcpu",
+  cl::desc("Target a specific cpu type (-mcpu=help for details)"),
+  cl::value_desc("cpu-name"),
+  cl::init(""));
+
+static cl::list<std::string>
+MAttrs("mattr",
+  cl::CommaSeparated,
+  cl::desc("Target specific attributes (-mattr=help for details)"),
+  cl::value_desc("a1,+a2,-a3,..."));
+
+/// createInternal - Create an return a new JIT compiler if there is one
+/// available for the current target.  Otherwise, return null.
+///
+ExecutionEngine *JIT::createJIT(ModuleProvider *MP, std::string *ErrorStr,
+                                JITMemoryManager *JMM,
+                                CodeGenOpt::Level OptLevel) {
+  const TargetMachineRegistry::entry *TheArch = MArch;
+  if (TheArch == 0) {
+    std::string Error;
+    TheArch = TargetMachineRegistry::getClosestTargetForJIT(Error);
+    if (TheArch == 0) {
+      if (ErrorStr)
+        *ErrorStr = Error;
+      return 0;
+    }
+  } else if (TheArch->JITMatchQualityFn() == 0) {
+    cerr << "WARNING: This target JIT is not designed for the host you are"
+         << " running.  If bad things happen, please choose a different "
+         << "-march switch.\n";
+  }
+
+  // Package up features to be passed to target/subtarget
+  std::string FeaturesStr;
+  if (!MCPU.empty() || !MAttrs.empty()) {
+    SubtargetFeatures Features;
+    Features.setCPU(MCPU);
+    for (unsigned i = 0; i != MAttrs.size(); ++i)
+      Features.AddFeature(MAttrs[i]);
+    FeaturesStr = Features.getString();
+  }
+
+  // Allocate a target...
+  TargetMachine *Target = TheArch->CtorFn(*MP->getModule(), FeaturesStr);
+  assert(Target && "Could not allocate target machine!");
+
+  // If the target supports JIT code generation, return a new JIT now.
+  if (TargetJITInfo *TJ = Target->getJITInfo())
+    return new JIT(MP, *Target, *TJ, JMM, OptLevel);
+
+  if (ErrorStr)
+    *ErrorStr = "target does not support JIT code generation";
+  return 0;
+}