Import LLVM, at r72732.

23 files changed, 2601 insertions, 0 deletions

diff --git a/examples/BrainF/BrainF.cpp b/examples/BrainF/BrainF.cpp
new file mode 100644
index 0000000..32a14c4
--- /dev/null
+++ b/examples/BrainF/BrainF.cpp
@@ -0,0 +1,458 @@
+//===-- BrainF.cpp - BrainF compiler example ----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===--------------------------------------------------------------------===//
+//
+// This class compiles the BrainF language into LLVM assembly.
+//
+// The BrainF language has 8 commands:
+// Command   Equivalent C    Action
+// -------   ------------    ------
+// ,         *h=getchar();   Read a character from stdin, 255 on EOF
+// .         putchar(*h);    Write a character to stdout
+// -         --*h;           Decrement tape
+// +         ++*h;           Increment tape
+// <         --h;            Move head left
+// >         ++h;            Move head right
+// [         while(*h) {     Start loop
+// ]         }               End loop
+//
+//===--------------------------------------------------------------------===//
+
+#include "BrainF.h"
+#include "llvm/Constants.h"
+#include "llvm/Intrinsics.h"
+#include "llvm/ADT/STLExtras.h"
+#include <iostream>
+using namespace llvm;
+
+//Set the constants for naming
+const char *BrainF::tapereg = "tape";
+const char *BrainF::headreg = "head";
+const char *BrainF::label   = "brainf";
+const char *BrainF::testreg = "test";
+
+Module *BrainF::parse(std::istream *in1, int mem, CompileFlags cf) {
+  in       = in1;
+  memtotal = mem;
+  comflag  = cf;
+
+  header();
+  readloop(0, 0, 0);
+  delete builder;
+  return module;
+}
+
+void BrainF::header() {
+  module = new Module("BrainF");
+
+  //Function prototypes
+
+  //declare void @llvm.memset.i32(i8 *, i8, i32, i32)
+  const Type *Tys[] = { Type::Int32Ty };
+  Function *memset_func = Intrinsic::getDeclaration(module, Intrinsic::memset,
+                                                    Tys, 1);
+
+  //declare i32 @getchar()
+  getchar_func = cast<Function>(module->
+    getOrInsertFunction("getchar", IntegerType::Int32Ty, NULL));
+
+  //declare i32 @putchar(i32)
+  putchar_func = cast<Function>(module->
+    getOrInsertFunction("putchar", IntegerType::Int32Ty,
+                        IntegerType::Int32Ty, NULL));
+
+
+  //Function header
+
+  //define void @brainf()
+  brainf_func = cast<Function>(module->
+    getOrInsertFunction("brainf", Type::VoidTy, NULL));
+
+  builder = new IRBuilder<>(BasicBlock::Create(label, brainf_func));
+
+  //%arr = malloc i8, i32 %d
+  ConstantInt *val_mem = ConstantInt::get(APInt(32, memtotal));
+  ptr_arr = builder->CreateMalloc(IntegerType::Int8Ty, val_mem, "arr");
+
+  //call void @llvm.memset.i32(i8 *%arr, i8 0, i32 %d, i32 1)
+  {
+    Value *memset_params[] = {
+      ptr_arr,
+      ConstantInt::get(APInt(8, 0)),
+      val_mem,
+      ConstantInt::get(APInt(32, 1))
+    };
+
+    CallInst *memset_call = builder->
+      CreateCall(memset_func, memset_params, array_endof(memset_params));
+    memset_call->setTailCall(false);
+  }
+
+  //%arrmax = getelementptr i8 *%arr, i32 %d
+  if (comflag & flag_arraybounds) {
+    ptr_arrmax = builder->
+      CreateGEP(ptr_arr, ConstantInt::get(APInt(32, memtotal)), "arrmax");
+  }
+
+  //%head.%d = getelementptr i8 *%arr, i32 %d
+  curhead = builder->CreateGEP(ptr_arr,
+                               ConstantInt::get(APInt(32, memtotal/2)),
+                               headreg);
+
+
+
+  //Function footer
+
+  //brainf.end:
+  endbb = BasicBlock::Create(label, brainf_func);
+
+  //free i8 *%arr
+  new FreeInst(ptr_arr, endbb);
+
+  //ret void
+  ReturnInst::Create(endbb);
+
+
+
+  //Error block for array out of bounds
+  if (comflag & flag_arraybounds)
+  {
+    //@aberrormsg = internal constant [%d x i8] c"\00"
+    Constant *msg_0 = ConstantArray::
+      get("Error: The head has left the tape.", true);
+
+    GlobalVariable *aberrormsg = new GlobalVariable(
+      msg_0->getType(),
+      true,
+      GlobalValue::InternalLinkage,
+      msg_0,
+      "aberrormsg",
+      module);
+
+    //declare i32 @puts(i8 *)
+    Function *puts_func = cast<Function>(module->
+      getOrInsertFunction("puts", IntegerType::Int32Ty,
+                          PointerType::getUnqual(IntegerType::Int8Ty), NULL));
+
+    //brainf.aberror:
+    aberrorbb = BasicBlock::Create(label, brainf_func);
+
+    //call i32 @puts(i8 *getelementptr([%d x i8] *@aberrormsg, i32 0, i32 0))
+    {
+      Constant *zero_32 = Constant::getNullValue(IntegerType::Int32Ty);
+
+      Constant *gep_params[] = {
+        zero_32,
+        zero_32
+      };
+
+      Constant *msgptr = ConstantExpr::
+        getGetElementPtr(aberrormsg, gep_params,
+                         array_lengthof(gep_params));
+
+      Value *puts_params[] = {
+        msgptr
+      };
+
+      CallInst *puts_call =
+        CallInst::Create(puts_func,
+                         puts_params, array_endof(puts_params),
+                         "", aberrorbb);
+      puts_call->setTailCall(false);
+    }
+
+    //br label %brainf.end
+    BranchInst::Create(endbb, aberrorbb);
+  }
+}
+
+void BrainF::readloop(PHINode *phi, BasicBlock *oldbb, BasicBlock *testbb) {
+  Symbol cursym = SYM_NONE;
+  int curvalue = 0;
+  Symbol nextsym = SYM_NONE;
+  int nextvalue = 0;
+  char c;
+  int loop;
+  int direction;
+
+  while(cursym != SYM_EOF && cursym != SYM_ENDLOOP) {
+    // Write out commands
+    switch(cursym) {
+      case SYM_NONE:
+        // Do nothing
+        break;
+
+      case SYM_READ:
+        {
+          //%tape.%d = call i32 @getchar()
+          CallInst *getchar_call = builder->CreateCall(getchar_func, tapereg);
+          getchar_call->setTailCall(false);
+          Value *tape_0 = getchar_call;
+
+          //%tape.%d = trunc i32 %tape.%d to i8
+          Value *tape_1 = builder->
+            CreateTrunc(tape_0, IntegerType::Int8Ty, tapereg);
+
+          //store i8 %tape.%d, i8 *%head.%d
+          builder->CreateStore(tape_1, curhead);
+        }
+        break;
+
+      case SYM_WRITE:
+        {
+          //%tape.%d = load i8 *%head.%d
+          LoadInst *tape_0 = builder->CreateLoad(curhead, tapereg);
+
+          //%tape.%d = sext i8 %tape.%d to i32
+          Value *tape_1 = builder->
+            CreateSExt(tape_0, IntegerType::Int32Ty, tapereg);
+
+          //call i32 @putchar(i32 %tape.%d)
+          Value *putchar_params[] = {
+            tape_1
+          };
+          CallInst *putchar_call = builder->
+            CreateCall(putchar_func,
+                       putchar_params, array_endof(putchar_params));
+          putchar_call->setTailCall(false);
+        }
+        break;
+
+      case SYM_MOVE:
+        {
+          //%head.%d = getelementptr i8 *%head.%d, i32 %d
+          curhead = builder->
+            CreateGEP(curhead, ConstantInt::get(APInt(32, curvalue)),
+                      headreg);
+
+          //Error block for array out of bounds
+          if (comflag & flag_arraybounds)
+          {
+            //%test.%d = icmp uge i8 *%head.%d, %arrmax
+            Value *test_0 = builder->
+              CreateICmpUGE(curhead, ptr_arrmax, testreg);
+
+            //%test.%d = icmp ult i8 *%head.%d, %arr
+            Value *test_1 = builder->
+              CreateICmpULT(curhead, ptr_arr, testreg);
+
+            //%test.%d = or i1 %test.%d, %test.%d
+            Value *test_2 = builder->
+              CreateOr(test_0, test_1, testreg);
+
+            //br i1 %test.%d, label %main.%d, label %main.%d
+            BasicBlock *nextbb = BasicBlock::Create(label, brainf_func);
+            builder->CreateCondBr(test_2, aberrorbb, nextbb);
+
+            //main.%d:
+            builder->SetInsertPoint(nextbb);
+          }
+        }
+        break;
+
+      case SYM_CHANGE:
+        {
+          //%tape.%d = load i8 *%head.%d
+          LoadInst *tape_0 = builder->CreateLoad(curhead, tapereg);
+
+          //%tape.%d = add i8 %tape.%d, %d
+          Value *tape_1 = builder->
+            CreateAdd(tape_0, ConstantInt::get(APInt(8, curvalue)), tapereg);
+
+          //store i8 %tape.%d, i8 *%head.%d\n"
+          builder->CreateStore(tape_1, curhead);
+        }
+        break;
+
+      case SYM_LOOP:
+        {
+          //br label %main.%d
+          BasicBlock *testbb = BasicBlock::Create(label, brainf_func);
+          builder->CreateBr(testbb);
+
+          //main.%d:
+          BasicBlock *bb_0 = builder->GetInsertBlock();
+          BasicBlock *bb_1 = BasicBlock::Create(label, brainf_func);
+          builder->SetInsertPoint(bb_1);
+
+          // Make part of PHI instruction now, wait until end of loop to finish
+          PHINode *phi_0 =
+            PHINode::Create(PointerType::getUnqual(IntegerType::Int8Ty),
+                            headreg, testbb);
+          phi_0->reserveOperandSpace(2);
+          phi_0->addIncoming(curhead, bb_0);
+          curhead = phi_0;
+
+          readloop(phi_0, bb_1, testbb);
+        }
+        break;
+
+      default:
+        std::cerr << "Error: Unknown symbol.\n";
+        abort();
+        break;
+    }
+
+    cursym = nextsym;
+    curvalue = nextvalue;
+    nextsym = SYM_NONE;
+
+    // Reading stdin loop
+    loop = (cursym == SYM_NONE)
+        || (cursym == SYM_MOVE)
+        || (cursym == SYM_CHANGE);
+    while(loop) {
+      *in>>c;
+      if (in->eof()) {
+        if (cursym == SYM_NONE) {
+          cursym = SYM_EOF;
+        } else {
+          nextsym = SYM_EOF;
+        }
+        loop = 0;
+      } else {
+        direction = 1;
+        switch(c) {
+          case '-':
+            direction = -1;
+            // Fall through
+
+          case '+':
+            if (cursym == SYM_CHANGE) {
+              curvalue += direction;
+              // loop = 1
+            } else {
+              if (cursym == SYM_NONE) {
+                cursym = SYM_CHANGE;
+                curvalue = direction;
+                // loop = 1
+              } else {
+                nextsym = SYM_CHANGE;
+                nextvalue = direction;
+                loop = 0;
+              }
+            }
+            break;
+
+          case '<':
+            direction = -1;
+            // Fall through
+
+          case '>':
+            if (cursym == SYM_MOVE) {
+              curvalue += direction;
+              // loop = 1
+            } else {
+              if (cursym == SYM_NONE) {
+                cursym = SYM_MOVE;
+                curvalue = direction;
+                // loop = 1
+              } else {
+                nextsym = SYM_MOVE;
+                nextvalue = direction;
+                loop = 0;
+              }
+            }
+            break;
+
+          case ',':
+            if (cursym == SYM_NONE) {
+              cursym = SYM_READ;
+            } else {
+              nextsym = SYM_READ;
+            }
+            loop = 0;
+            break;
+
+          case '.':
+            if (cursym == SYM_NONE) {
+              cursym = SYM_WRITE;
+            } else {
+              nextsym = SYM_WRITE;
+            }
+            loop = 0;
+            break;
+
+          case '[':
+            if (cursym == SYM_NONE) {
+              cursym = SYM_LOOP;
+            } else {
+              nextsym = SYM_LOOP;
+            }
+            loop = 0;
+            break;
+
+          case ']':
+            if (cursym == SYM_NONE) {
+              cursym = SYM_ENDLOOP;
+            } else {
+              nextsym = SYM_ENDLOOP;
+            }
+            loop = 0;
+            break;
+
+          // Ignore other characters
+          default:
+            break;
+        }
+      }
+    }
+  }
+
+  if (cursym == SYM_ENDLOOP) {
+    if (!phi) {
+      std::cerr << "Error: Extra ']'\n";
+      abort();
+    }
+
+    // Write loop test
+    {
+      //br label %main.%d
+      builder->CreateBr(testbb);
+
+      //main.%d:
+
+      //%head.%d = phi i8 *[%head.%d, %main.%d], [%head.%d, %main.%d]
+      //Finish phi made at beginning of loop
+      phi->addIncoming(curhead, builder->GetInsertBlock());
+      Value *head_0 = phi;
+
+      //%tape.%d = load i8 *%head.%d
+      LoadInst *tape_0 = new LoadInst(head_0, tapereg, testbb);
+
+      //%test.%d = icmp eq i8 %tape.%d, 0
+      ICmpInst *test_0 = new ICmpInst(ICmpInst::ICMP_EQ, tape_0,
+                                      ConstantInt::get(APInt(8, 0)), testreg,
+                                      testbb);
+
+      //br i1 %test.%d, label %main.%d, label %main.%d
+      BasicBlock *bb_0 = BasicBlock::Create(label, brainf_func);
+      BranchInst::Create(bb_0, oldbb, test_0, testbb);
+
+      //main.%d:
+      builder->SetInsertPoint(bb_0);
+
+      //%head.%d = phi i8 *[%head.%d, %main.%d]
+      PHINode *phi_1 = builder->
+        CreatePHI(PointerType::getUnqual(IntegerType::Int8Ty), headreg);
+      phi_1->reserveOperandSpace(1);
+      phi_1->addIncoming(head_0, testbb);
+      curhead = phi_1;
+    }
+
+    return;
+  }
+
+  //End of the program, so go to return block
+  builder->CreateBr(endbb);
+
+  if (phi) {
+    std::cerr << "Error: Missing ']'\n";
+    abort();
+  }
+}
diff --git a/examples/BrainF/BrainF.h b/examples/BrainF/BrainF.h
new file mode 100644
index 0000000..06c00ae
--- /dev/null
+++ b/examples/BrainF/BrainF.h
@@ -0,0 +1,91 @@
+//===-- BrainF.h - BrainF compiler class ----------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===--------------------------------------------------------------------===//
+//
+// This class stores the data for the BrainF compiler so it doesn't have
+// to pass all of it around.  The main method is parse.
+//
+//===--------------------------------------------------------------------===//
+
+#ifndef BRAINF_H
+#define BRAINF_H
+
+#include "llvm/Module.h"
+#include "llvm/Support/IRBuilder.h"
+
+using namespace llvm;
+
+/// This class provides a parser for the BrainF language.
+/// The class itself is made to store values during
+/// parsing so they don't have to be passed around
+/// as much.
+class BrainF {
+  public:
+    /// Options for how BrainF should compile
+    enum CompileFlags {
+      flag_off         = 0,
+      flag_arraybounds = 1
+    };
+
+    /// This is the main method.  It parses BrainF from in1
+    /// and returns the module with a function
+    /// void brainf()
+    /// containing the resulting code.
+    /// On error, it calls abort.
+    /// The caller must delete the returned module.
+    Module *parse(std::istream *in1, int mem, CompileFlags cf);
+
+  protected:
+    /// The different symbols in the BrainF language
+    enum Symbol {
+      SYM_NONE,
+      SYM_READ,
+      SYM_WRITE,
+      SYM_MOVE,
+      SYM_CHANGE,
+      SYM_LOOP,
+      SYM_ENDLOOP,
+      SYM_EOF
+    };
+
+    /// Names of the different parts of the language.
+    /// Tape is used for reading and writing the tape.
+    /// headreg is used for the position of the head.
+    /// label is used for the labels for the BasicBlocks.
+    /// testreg is used for testing the loop exit condition.
+    static const char *tapereg;
+    static const char *headreg;
+    static const char *label;
+    static const char *testreg;
+
+    /// Put the brainf function preamble and other fixed pieces of code
+    void header();
+
+    /// The main loop for parsing.  It calls itself recursively
+    /// to handle the depth of nesting of "[]".
+    void readloop(PHINode *phi, BasicBlock *oldbb, BasicBlock *testbb);
+
+    /// Constants during parsing
+    int memtotal;
+    CompileFlags comflag;
+    std::istream *in;
+    Module *module;
+    Function *brainf_func;
+    Function *getchar_func;
+    Function *putchar_func;
+    Value *ptr_arr;
+    Value *ptr_arrmax;
+    BasicBlock *endbb;
+    BasicBlock *aberrorbb;
+
+    /// Variables
+    IRBuilder<> *builder;
+    Value *curhead;
+};
+
+#endif
diff --git a/examples/BrainF/BrainFDriver.cpp b/examples/BrainF/BrainFDriver.cpp
new file mode 100644
index 0000000..34fb806
--- /dev/null
+++ b/examples/BrainF/BrainFDriver.cpp
@@ -0,0 +1,155 @@
+//===-- BrainFDriver.cpp - BrainF compiler driver -----------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===--------------------------------------------------------------------===//
+//
+// This program converts the BrainF language into LLVM assembly,
+// which it can then run using the JIT or output as BitCode.
+//
+// This implementation has a tape of 65536 bytes,
+// with the head starting in the middle.
+// Range checking is off by default, so be careful.
+// It can be enabled with -abc.
+//
+// Use:
+// ./BrainF -jit      prog.bf          #Run program now
+// ./BrainF -jit -abc prog.bf          #Run program now safely
+// ./BrainF           prog.bf          #Write as BitCode
+//
+// lli prog.bf.bc                      #Run generated BitCode
+// llvm-ld -native -o=prog prog.bf.bc  #Compile BitCode into native executable
+//
+//===--------------------------------------------------------------------===//
+
+#include "BrainF.h"
+#include "llvm/Constants.h"
+#include "llvm/ModuleProvider.h"
+#include "llvm/Analysis/Verifier.h"
+#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/ExecutionEngine/GenericValue.h"
+#include "llvm/ExecutionEngine/JIT.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/ManagedStatic.h"
+#include <fstream>
+#include <iostream>
+using namespace llvm;
+
+//Command line options
+
+static cl::opt<std::string>
+InputFilename(cl::Positional, cl::desc("<input brainf>"));
+
+static cl::opt<std::string>
+OutputFilename("o", cl::desc("Output filename"), cl::value_desc("filename"));
+
+static cl::opt<bool>
+ArrayBoundsChecking("abc", cl::desc("Enable array bounds checking"));
+
+static cl::opt<bool>
+JIT("jit", cl::desc("Run program Just-In-Time"));
+
+
+//Add main function so can be fully compiled
+void addMainFunction(Module *mod) {
+  //define i32 @main(i32 %argc, i8 **%argv)
+  Function *main_func = cast<Function>(mod->
+    getOrInsertFunction("main", IntegerType::Int32Ty, IntegerType::Int32Ty,
+                        PointerType::getUnqual(PointerType::getUnqual(
+                          IntegerType::Int8Ty)), NULL));
+  {
+    Function::arg_iterator args = main_func->arg_begin();
+    Value *arg_0 = args++;
+    arg_0->setName("argc");
+    Value *arg_1 = args++;
+    arg_1->setName("argv");
+  }
+
+  //main.0:
+  BasicBlock *bb = BasicBlock::Create("main.0", main_func);
+
+  //call void @brainf()
+  {
+    CallInst *brainf_call = CallInst::Create(mod->getFunction("brainf"),
+                                             "", bb);
+    brainf_call->setTailCall(false);
+  }
+
+  //ret i32 0
+  ReturnInst::Create(ConstantInt::get(APInt(32, 0)), bb);
+}
+
+int main(int argc, char **argv) {
+  cl::ParseCommandLineOptions(argc, argv, " BrainF compiler\n");
+
+  if (InputFilename == "") {
+    std::cerr<<"Error: You must specify the filename of the program to "
+    "be compiled.  Use --help to see the options.\n";
+    abort();
+  }
+
+  //Get the output stream
+  std::ostream *out = &std::cout;
+  if (!JIT) {
+    if (OutputFilename == "") {
+      std::string base = InputFilename;
+      if (InputFilename == "-") {base = "a";}
+
+      //Use default filename
+      const char *suffix = ".bc";
+      OutputFilename = base+suffix;
+    }
+    if (OutputFilename != "-") {
+      out = new std::
+        ofstream(OutputFilename.c_str(),
+                 std::ios::out | std::ios::trunc | std::ios::binary);
+    }
+  }
+
+  //Get the input stream
+  std::istream *in = &std::cin;
+  if (InputFilename != "-") {
+    in = new std::ifstream(InputFilename.c_str());
+  }
+
+  //Gather the compile flags
+  BrainF::CompileFlags cf = BrainF::flag_off;
+  if (ArrayBoundsChecking) {
+    cf = BrainF::CompileFlags(cf | BrainF::flag_arraybounds);
+  }
+
+  //Read the BrainF program
+  BrainF bf;
+  Module *mod = bf.parse(in, 65536, cf); //64 KiB
+  if (in != &std::cin) {delete in;}
+  addMainFunction(mod);
+
+  //Verify generated code
+  if (verifyModule(*mod)) {
+    std::cerr<<"Error: module failed verification.  This shouldn't happen.\n";
+    abort();
+  }
+
+  //Write it out
+  if (JIT) {
+    std::cout << "------- Running JIT -------\n";
+    ExistingModuleProvider *mp = new ExistingModuleProvider(mod);
+    ExecutionEngine *ee = ExecutionEngine::create(mp, false);
+    std::vector<GenericValue> args;
+    Function *brainf_func = mod->getFunction("brainf");
+    GenericValue gv = ee->runFunction(brainf_func, args);
+  } else {
+    WriteBitcodeToFile(mod, *out);
+  }
+
+  //Clean up
+  if (out != &std::cout) {delete out;}
+  delete mod;
+
+  llvm_shutdown();
+
+  return 0;
+}
diff --git a/examples/BrainF/CMakeLists.txt b/examples/BrainF/CMakeLists.txt
new file mode 100644
index 0000000..7bec105
--- /dev/null
+++ b/examples/BrainF/CMakeLists.txt
@@ -0,0 +1,6 @@
+set(LLVM_LINK_COMPONENTS jit bitwriter nativecodegen interpreter)
+
+add_llvm_example(BrainF
+  BrainF.cpp
+  BrainFDriver.cpp
+  )
diff --git a/examples/BrainF/Makefile b/examples/BrainF/Makefile
new file mode 100644
index 0000000..2c3e066
--- /dev/null
+++ b/examples/BrainF/Makefile
@@ -0,0 +1,15 @@
+##===- examples/BrainF/Makefile ----------------------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+LEVEL = ../..
+TOOLNAME = BrainF
+EXAMPLE_TOOL = 1
+
+LINK_COMPONENTS := jit bitwriter nativecodegen interpreter
+
+include $(LEVEL)/Makefile.common
diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
new file mode 100644
index 0000000..c5b8079
--- /dev/null
+++ b/examples/CMakeLists.txt
@@ -0,0 +1,12 @@
+add_subdirectory(BrainF)
+add_subdirectory(Fibonacci)
+add_subdirectory(HowToUseJIT)
+add_subdirectory(Kaleidoscope)
+add_subdirectory(ModuleMaker)
+
+include(CheckIncludeFile)
+check_include_file(pthread.h HAVE_PTHREAD_H)
+
+if( HAVE_PTHREAD_H )
+  add_subdirectory(ParallelJIT)
+endif( HAVE_PTHREAD_H )
diff --git a/examples/Fibonacci/CMakeLists.txt b/examples/Fibonacci/CMakeLists.txt
new file mode 100644
index 0000000..6937612
--- /dev/null
+++ b/examples/Fibonacci/CMakeLists.txt
@@ -0,0 +1,5 @@
+set(LLVM_LINK_COMPONENTS jit interpreter nativecodegen)
+
+add_llvm_example(Fibonacci
+  fibonacci.cpp
+  )
diff --git a/examples/Fibonacci/Makefile b/examples/Fibonacci/Makefile
new file mode 100644
index 0000000..71f6ba0
--- /dev/null
+++ b/examples/Fibonacci/Makefile
@@ -0,0 +1,17 @@
+##===- examples/Fibonacci/Makefile -------------------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+
+LEVEL = ../..
+TOOLNAME = Fibonacci
+EXAMPLE_TOOL = 1
+
+# Link in JIT support
+LINK_COMPONENTS := jit interpreter nativecodegen
+
+include $(LEVEL)/Makefile.common
diff --git a/examples/Fibonacci/fibonacci.cpp b/examples/Fibonacci/fibonacci.cpp
new file mode 100644
index 0000000..09f2203
--- /dev/null
+++ b/examples/Fibonacci/fibonacci.cpp
@@ -0,0 +1,121 @@
+//===--- examples/Fibonacci/fibonacci.cpp - An example use of the JIT -----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This small program provides an example of how to build quickly a small module
+// with function Fibonacci and execute it with the JIT.
+//
+// The goal of this snippet is to create in the memory the LLVM module
+// consisting of one function as follow:
+//
+//   int fib(int x) {
+//     if(x<=2) return 1;
+//     return fib(x-1)+fib(x-2);
+//   }
+//
+// Once we have this, we compile the module via JIT, then execute the `fib'
+// function and return result to a driver, i.e. to a "host program".
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Module.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Constants.h"
+#include "llvm/Instructions.h"
+#include "llvm/ModuleProvider.h"
+#include "llvm/Analysis/Verifier.h"
+#include "llvm/ExecutionEngine/JIT.h"
+#include "llvm/ExecutionEngine/Interpreter.h"
+#include "llvm/ExecutionEngine/GenericValue.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+static Function *CreateFibFunction(Module *M) {
+  // Create the fib function and insert it into module M.  This function is said
+  // to return an int and take an int parameter.
+  Function *FibF =
+    cast<Function>(M->getOrInsertFunction("fib", Type::Int32Ty, Type::Int32Ty,
+                                          (Type *)0));
+
+  // Add a basic block to the function.
+  BasicBlock *BB = BasicBlock::Create("EntryBlock", FibF);
+
+  // Get pointers to the constants.
+  Value *One = ConstantInt::get(Type::Int32Ty, 1);
+  Value *Two = ConstantInt::get(Type::Int32Ty, 2);
+
+  // Get pointer to the integer argument of the add1 function...
+  Argument *ArgX = FibF->arg_begin();   // Get the arg.
+  ArgX->setName("AnArg");            // Give it a nice symbolic name for fun.
+
+  // Create the true_block.
+  BasicBlock *RetBB = BasicBlock::Create("return", FibF);
+  // Create an exit block.
+  BasicBlock* RecurseBB = BasicBlock::Create("recurse", FibF);
+
+  // Create the "if (arg <= 2) goto exitbb"
+  Value *CondInst = new ICmpInst(ICmpInst::ICMP_SLE, ArgX, Two, "cond", BB);
+  BranchInst::Create(RetBB, RecurseBB, CondInst, BB);
+
+  // Create: ret int 1
+  ReturnInst::Create(One, RetBB);
+
+  // create fib(x-1)
+  Value *Sub = BinaryOperator::CreateSub(ArgX, One, "arg", RecurseBB);
+  CallInst *CallFibX1 = CallInst::Create(FibF, Sub, "fibx1", RecurseBB);
+  CallFibX1->setTailCall();
+
+  // create fib(x-2)
+  Sub = BinaryOperator::CreateSub(ArgX, Two, "arg", RecurseBB);
+  CallInst *CallFibX2 = CallInst::Create(FibF, Sub, "fibx2", RecurseBB);
+  CallFibX2->setTailCall();
+
+
+  // fib(x-1)+fib(x-2)
+  Value *Sum = BinaryOperator::CreateAdd(CallFibX1, CallFibX2,
+                                         "addresult", RecurseBB);
+
+  // Create the return instruction and add it to the basic block
+  ReturnInst::Create(Sum, RecurseBB);
+
+  return FibF;
+}
+
+
+int main(int argc, char **argv) {
+  int n = argc > 1 ? atol(argv[1]) : 24;
+
+  // Create some module to put our function into it.
+  Module *M = new Module("test");
+
+  // We are about to create the "fib" function:
+  Function *FibF = CreateFibFunction(M);
+
+  // Now we going to create JIT
+  ExistingModuleProvider *MP = new ExistingModuleProvider(M);
+  ExecutionEngine *EE = ExecutionEngine::create(MP, false);
+
+  errs() << "verifying... ";
+  if (verifyModule(*M)) {
+    errs() << argv[0] << ": Error constructing function!\n";
+    return 1;
+  }
+
+  errs() << "OK\n";
+  errs() << "We just constructed this LLVM module:\n\n---------\n" << *M;
+  errs() << "---------\nstarting fibonacci(" << n << ") with JIT...\n";
+
+  // Call the Fibonacci function with argument n:
+  std::vector<GenericValue> Args(1);
+  Args[0].IntVal = APInt(32, n);
+  GenericValue GV = EE->runFunction(FibF, Args);
+
+  // import result of execution
+  outs() << "Result: " << GV.IntVal << "\n";
+  return 0;
+}
diff --git a/examples/HowToUseJIT/CMakeLists.txt b/examples/HowToUseJIT/CMakeLists.txt
new file mode 100644
index 0000000..428b53f
--- /dev/null
+++ b/examples/HowToUseJIT/CMakeLists.txt
@@ -0,0 +1,5 @@
+set(LLVM_LINK_COMPONENTS jit interpreter nativecodegen)
+
+add_llvm_example(HowToUseJIT
+  HowToUseJIT.cpp
+  )
diff --git a/examples/HowToUseJIT/HowToUseJIT.cpp b/examples/HowToUseJIT/HowToUseJIT.cpp
new file mode 100644
index 0000000..b5c6d11
--- /dev/null
+++ b/examples/HowToUseJIT/HowToUseJIT.cpp
@@ -0,0 +1,117 @@
+//===-- examples/HowToUseJIT/HowToUseJIT.cpp - An example use of the JIT --===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This small program provides an example of how to quickly build a small
+//  module with two functions and execute it with the JIT.
+//
+// Goal:
+//  The goal of this snippet is to create in the memory
+//  the LLVM module consisting of two functions as follow:
+//
+// int add1(int x) {
+//   return x+1;
+// }
+//
+// int foo() {
+//   return add1(10);
+// }
+//
+// then compile the module via JIT, then execute the `foo'
+// function and return result to a driver, i.e. to a "host program".
+//
+// Some remarks and questions:
+//
+// - could we invoke some code using noname functions too?
+//   e.g. evaluate "foo()+foo()" without fears to introduce
+//   conflict of temporary function name with some real
+//   existing function name?
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Module.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Instructions.h"
+#include "llvm/ModuleProvider.h"
+#include "llvm/ExecutionEngine/JIT.h"
+#include "llvm/ExecutionEngine/Interpreter.h"
+#include "llvm/ExecutionEngine/GenericValue.h"
+#include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+int main() {
+  // Create some module to put our function into it.
+  Module *M = new Module("test");
+
+  // Create the add1 function entry and insert this entry into module M.  The
+  // function will have a return type of "int" and take an argument of "int".
+  // The '0' terminates the list of argument types.
+  Function *Add1F =
+    cast<Function>(M->getOrInsertFunction("add1", Type::Int32Ty, Type::Int32Ty,
+                                          (Type *)0));
+
+  // Add a basic block to the function. As before, it automatically inserts
+  // because of the last argument.
+  BasicBlock *BB = BasicBlock::Create("EntryBlock", Add1F);
+
+  // Get pointers to the constant `1'.
+  Value *One = ConstantInt::get(Type::Int32Ty, 1);
+
+  // Get pointers to the integer argument of the add1 function...
+  assert(Add1F->arg_begin() != Add1F->arg_end()); // Make sure there's an arg
+  Argument *ArgX = Add1F->arg_begin();  // Get the arg
+  ArgX->setName("AnArg");            // Give it a nice symbolic name for fun.
+
+  // Create the add instruction, inserting it into the end of BB.
+  Instruction *Add = BinaryOperator::CreateAdd(One, ArgX, "addresult", BB);
+
+  // Create the return instruction and add it to the basic block
+  ReturnInst::Create(Add, BB);
+
+  // Now, function add1 is ready.
+
+
+  // Now we going to create function `foo', which returns an int and takes no
+  // arguments.
+  Function *FooF =
+    cast<Function>(M->getOrInsertFunction("foo", Type::Int32Ty, (Type *)0));
+
+  // Add a basic block to the FooF function.
+  BB = BasicBlock::Create("EntryBlock", FooF);
+
+  // Get pointers to the constant `10'.
+  Value *Ten = ConstantInt::get(Type::Int32Ty, 10);
+
+  // Pass Ten to the call call:
+  CallInst *Add1CallRes = CallInst::Create(Add1F, Ten, "add1", BB);
+  Add1CallRes->setTailCall(true);
+
+  // Create the return instruction and add it to the basic block.
+  ReturnInst::Create(Add1CallRes, BB);
+
+  // Now we create the JIT.
+  ExistingModuleProvider* MP = new ExistingModuleProvider(M);
+  ExecutionEngine* EE = ExecutionEngine::create(MP, false);
+
+  outs() << "We just constructed this LLVM module:\n\n" << *M;
+  outs() << "\n\nRunning foo: ";
+  outs().flush();
+
+  // Call the `foo' function with no arguments:
+  std::vector<GenericValue> noargs;
+  GenericValue gv = EE->runFunction(FooF, noargs);
+
+  // Import result of execution:
+  outs() << "Result: " << gv.IntVal << "\n";
+  EE->freeMachineCodeForFunction(FooF);
+  delete EE;
+  llvm_shutdown();
+  return 0;
+}
diff --git a/examples/HowToUseJIT/Makefile b/examples/HowToUseJIT/Makefile
new file mode 100644
index 0000000..c8919db
--- /dev/null
+++ b/examples/HowToUseJIT/Makefile
@@ -0,0 +1,15 @@
+##===- examples/HowToUseJIT/Makefile -----------------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+LEVEL = ../..
+TOOLNAME = HowToUseJIT
+EXAMPLE_TOOL = 1
+
+LINK_COMPONENTS := jit interpreter nativecodegen
+
+include $(LEVEL)/Makefile.common
diff --git a/examples/Kaleidoscope/CMakeLists.txt b/examples/Kaleidoscope/CMakeLists.txt
new file mode 100644
index 0000000..9a18aae
--- /dev/null
+++ b/examples/Kaleidoscope/CMakeLists.txt
@@ -0,0 +1,5 @@
+set(LLVM_LINK_COMPONENTS core jit native)
+
+add_llvm_example(Kaleidoscope
+  toy.cpp
+  )
diff --git a/examples/Kaleidoscope/Makefile b/examples/Kaleidoscope/Makefile
new file mode 100644
index 0000000..c1759a0
--- /dev/null
+++ b/examples/Kaleidoscope/Makefile
@@ -0,0 +1,15 @@
+##===- examples/Kaleidoscope/Makefile ----------------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+LEVEL = ../..
+TOOLNAME = Kaleidoscope
+EXAMPLE_TOOL = 1
+
+LINK_COMPONENTS := core jit native
+
+include $(LEVEL)/Makefile.common
diff --git a/examples/Kaleidoscope/toy.cpp b/examples/Kaleidoscope/toy.cpp
new file mode 100644
index 0000000..bec430c
--- /dev/null
+++ b/examples/Kaleidoscope/toy.cpp
@@ -0,0 +1,1135 @@
+#include "llvm/DerivedTypes.h"
+#include "llvm/ExecutionEngine/ExecutionEngine.h"
+#include "llvm/Module.h"
+#include "llvm/ModuleProvider.h"
+#include "llvm/PassManager.h"
+#include "llvm/Analysis/Verifier.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/Support/IRBuilder.h"
+#include <cstdio>
+#include <string>
+#include <map>
+#include <vector>
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// Lexer
+//===----------------------------------------------------------------------===//
+
+// The lexer returns tokens [0-255] if it is an unknown character, otherwise one
+// of these for known things.
+enum Token {
+  tok_eof = -1,
+
+  // commands
+  tok_def = -2, tok_extern = -3,
+
+  // primary
+  tok_identifier = -4, tok_number = -5,
+  
+  // control
+  tok_if = -6, tok_then = -7, tok_else = -8,
+  tok_for = -9, tok_in = -10,
+  
+  // operators
+  tok_binary = -11, tok_unary = -12,
+  
+  // var definition
+  tok_var = -13
+};
+
+static std::string IdentifierStr;  // Filled in if tok_identifier
+static double NumVal;              // Filled in if tok_number
+
+/// gettok - Return the next token from standard input.
+static int gettok() {
+  static int LastChar = ' ';
+
+  // Skip any whitespace.
+  while (isspace(LastChar))
+    LastChar = getchar();
+
+  if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
+    IdentifierStr = LastChar;
+    while (isalnum((LastChar = getchar())))
+      IdentifierStr += LastChar;
+
+    if (IdentifierStr == "def") return tok_def;
+    if (IdentifierStr == "extern") return tok_extern;
+    if (IdentifierStr == "if") return tok_if;
+    if (IdentifierStr == "then") return tok_then;
+    if (IdentifierStr == "else") return tok_else;
+    if (IdentifierStr == "for") return tok_for;
+    if (IdentifierStr == "in") return tok_in;
+    if (IdentifierStr == "binary") return tok_binary;
+    if (IdentifierStr == "unary") return tok_unary;
+    if (IdentifierStr == "var") return tok_var;
+    return tok_identifier;
+  }
+
+  if (isdigit(LastChar) || LastChar == '.') {   // Number: [0-9.]+
+    std::string NumStr;
+    do {
+      NumStr += LastChar;
+      LastChar = getchar();
+    } while (isdigit(LastChar) || LastChar == '.');
+
+    NumVal = strtod(NumStr.c_str(), 0);
+    return tok_number;
+  }
+
+  if (LastChar == '#') {
+    // Comment until end of line.
+    do LastChar = getchar();
+    while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
+    
+    if (LastChar != EOF)
+      return gettok();
+  }
+  
+  // Check for end of file.  Don't eat the EOF.
+  if (LastChar == EOF)
+    return tok_eof;
+
+  // Otherwise, just return the character as its ascii value.
+  int ThisChar = LastChar;
+  LastChar = getchar();
+  return ThisChar;
+}
+
+//===----------------------------------------------------------------------===//
+// Abstract Syntax Tree (aka Parse Tree)
+//===----------------------------------------------------------------------===//
+
+/// ExprAST - Base class for all expression nodes.
+class ExprAST {
+public:
+  virtual ~ExprAST() {}
+  virtual Value *Codegen() = 0;
+};
+
+/// NumberExprAST - Expression class for numeric literals like "1.0".
+class NumberExprAST : public ExprAST {
+  double Val;
+public:
+  NumberExprAST(double val) : Val(val) {}
+  virtual Value *Codegen();
+};
+
+/// VariableExprAST - Expression class for referencing a variable, like "a".
+class VariableExprAST : public ExprAST {
+  std::string Name;
+public:
+  VariableExprAST(const std::string &name) : Name(name) {}
+  const std::string &getName() const { return Name; }
+  virtual Value *Codegen();
+};
+
+/// UnaryExprAST - Expression class for a unary operator.
+class UnaryExprAST : public ExprAST {
+  char Opcode;
+  ExprAST *Operand;
+public:
+  UnaryExprAST(char opcode, ExprAST *operand) 
+    : Opcode(opcode), Operand(operand) {}
+  virtual Value *Codegen();
+};
+
+/// BinaryExprAST - Expression class for a binary operator.
+class BinaryExprAST : public ExprAST {
+  char Op;
+  ExprAST *LHS, *RHS;
+public:
+  BinaryExprAST(char op, ExprAST *lhs, ExprAST *rhs) 
+    : Op(op), LHS(lhs), RHS(rhs) {}
+  virtual Value *Codegen();
+};
+
+/// CallExprAST - Expression class for function calls.
+class CallExprAST : public ExprAST {
+  std::string Callee;
+  std::vector<ExprAST*> Args;
+public:
+  CallExprAST(const std::string &callee, std::vector<ExprAST*> &args)
+    : Callee(callee), Args(args) {}
+  virtual Value *Codegen();
+};
+
+/// IfExprAST - Expression class for if/then/else.
+class IfExprAST : public ExprAST {
+  ExprAST *Cond, *Then, *Else;
+public:
+  IfExprAST(ExprAST *cond, ExprAST *then, ExprAST *_else)
+  : Cond(cond), Then(then), Else(_else) {}
+  virtual Value *Codegen();
+};
+
+/// ForExprAST - Expression class for for/in.
+class ForExprAST : public ExprAST {
+  std::string VarName;
+  ExprAST *Start, *End, *Step, *Body;
+public:
+  ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
+             ExprAST *step, ExprAST *body)
+    : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
+  virtual Value *Codegen();
+};
+
+/// VarExprAST - Expression class for var/in
+class VarExprAST : public ExprAST {
+  std::vector<std::pair<std::string, ExprAST*> > VarNames;
+  ExprAST *Body;
+public:
+  VarExprAST(const std::vector<std::pair<std::string, ExprAST*> > &varnames,
+             ExprAST *body)
+  : VarNames(varnames), Body(body) {}
+  
+  virtual Value *Codegen();
+};
+
+/// PrototypeAST - This class represents the "prototype" for a function,
+/// which captures its argument names as well as if it is an operator.
+class PrototypeAST {
+  std::string Name;
+  std::vector<std::string> Args;
+  bool isOperator;
+  unsigned Precedence;  // Precedence if a binary op.
+public:
+  PrototypeAST(const std::string &name, const std::vector<std::string> &args,
+               bool isoperator = false, unsigned prec = 0)
+  : Name(name), Args(args), isOperator(isoperator), Precedence(prec) {}
+  
+  bool isUnaryOp() const { return isOperator && Args.size() == 1; }
+  bool isBinaryOp() const { return isOperator && Args.size() == 2; }
+  
+  char getOperatorName() const {
+    assert(isUnaryOp() || isBinaryOp());
+    return Name[Name.size()-1];
+  }
+  
+  unsigned getBinaryPrecedence() const { return Precedence; }
+  
+  Function *Codegen();
+  
+  void CreateArgumentAllocas(Function *F);
+};
+
+/// FunctionAST - This class represents a function definition itself.
+class FunctionAST {
+  PrototypeAST *Proto;
+  ExprAST *Body;
+public:
+  FunctionAST(PrototypeAST *proto, ExprAST *body)
+    : Proto(proto), Body(body) {}
+  
+  Function *Codegen();
+};
+
+//===----------------------------------------------------------------------===//
+// Parser
+//===----------------------------------------------------------------------===//
+
+/// CurTok/getNextToken - Provide a simple token buffer.  CurTok is the current
+/// token the parser it looking at.  getNextToken reads another token from the
+/// lexer and updates CurTok with its results.
+static int CurTok;
+static int getNextToken() {
+  return CurTok = gettok();
+}
+
+/// BinopPrecedence - This holds the precedence for each binary operator that is
+/// defined.
+static std::map<char, int> BinopPrecedence;
+
+/// GetTokPrecedence - Get the precedence of the pending binary operator token.
+static int GetTokPrecedence() {
+  if (!isascii(CurTok))
+    return -1;
+  
+  // Make sure it's a declared binop.
+  int TokPrec = BinopPrecedence[CurTok];
+  if (TokPrec <= 0) return -1;
+  return TokPrec;
+}
+
+/// Error* - These are little helper functions for error handling.
+ExprAST *Error(const char *Str) { fprintf(stderr, "Error: %s\n", Str);return 0;}
+PrototypeAST *ErrorP(const char *Str) { Error(Str); return 0; }
+FunctionAST *ErrorF(const char *Str) { Error(Str); return 0; }
+
+static ExprAST *ParseExpression();
+
+/// identifierexpr
+///   ::= identifier
+///   ::= identifier '(' expression* ')'
+static ExprAST *ParseIdentifierExpr() {
+  std::string IdName = IdentifierStr;
+  
+  getNextToken();  // eat identifier.
+  
+  if (CurTok != '(') // Simple variable ref.
+    return new VariableExprAST(IdName);
+  
+  // Call.
+  getNextToken();  // eat (
+  std::vector<ExprAST*> Args;
+  if (CurTok != ')') {
+    while (1) {
+      ExprAST *Arg = ParseExpression();
+      if (!Arg) return 0;
+      Args.push_back(Arg);
+      
+      if (CurTok == ')') break;
+      
+      if (CurTok != ',')
+        return Error("Expected ')' or ',' in argument list");
+      getNextToken();
+    }
+  }
+
+  // Eat the ')'.
+  getNextToken();
+  
+  return new CallExprAST(IdName, Args);
+}
+
+/// numberexpr ::= number
+static ExprAST *ParseNumberExpr() {
+  ExprAST *Result = new NumberExprAST(NumVal);
+  getNextToken(); // consume the number
+  return Result;
+}
+
+/// parenexpr ::= '(' expression ')'
+static ExprAST *ParseParenExpr() {
+  getNextToken();  // eat (.
+  ExprAST *V = ParseExpression();
+  if (!V) return 0;
+  
+  if (CurTok != ')')
+    return Error("expected ')'");
+  getNextToken();  // eat ).
+  return V;
+}
+
+/// ifexpr ::= 'if' expression 'then' expression 'else' expression
+static ExprAST *ParseIfExpr() {
+  getNextToken();  // eat the if.
+  
+  // condition.
+  ExprAST *Cond = ParseExpression();
+  if (!Cond) return 0;
+  
+  if (CurTok != tok_then)
+    return Error("expected then");
+  getNextToken();  // eat the then
+  
+  ExprAST *Then = ParseExpression();
+  if (Then == 0) return 0;
+  
+  if (CurTok != tok_else)
+    return Error("expected else");
+  
+  getNextToken();
+  
+  ExprAST *Else = ParseExpression();
+  if (!Else) return 0;
+  
+  return new IfExprAST(Cond, Then, Else);
+}
+
+/// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
+static ExprAST *ParseForExpr() {
+  getNextToken();  // eat the for.
+
+  if (CurTok != tok_identifier)
+    return Error("expected identifier after for");
+  
+  std::string IdName = IdentifierStr;
+  getNextToken();  // eat identifier.
+  
+  if (CurTok != '=')
+    return Error("expected '=' after for");
+  getNextToken();  // eat '='.
+  
+  
+  ExprAST *Start = ParseExpression();
+  if (Start == 0) return 0;
+  if (CurTok != ',')
+    return Error("expected ',' after for start value");
+  getNextToken();
+  
+  ExprAST *End = ParseExpression();
+  if (End == 0) return 0;
+  
+  // The step value is optional.
+  ExprAST *Step = 0;
+  if (CurTok == ',') {
+    getNextToken();
+    Step = ParseExpression();
+    if (Step == 0) return 0;
+  }
+  
+  if (CurTok != tok_in)
+    return Error("expected 'in' after for");
+  getNextToken();  // eat 'in'.
+  
+  ExprAST *Body = ParseExpression();
+  if (Body == 0) return 0;
+
+  return new ForExprAST(IdName, Start, End, Step, Body);
+}
+
+/// varexpr ::= 'var' identifier ('=' expression)? 
+//                    (',' identifier ('=' expression)?)* 'in' expression
+static ExprAST *ParseVarExpr() {
+  getNextToken();  // eat the var.
+
+  std::vector<std::pair<std::string, ExprAST*> > VarNames;
+
+  // At least one variable name is required.
+  if (CurTok != tok_identifier)
+    return Error("expected identifier after var");
+  
+  while (1) {
+    std::string Name = IdentifierStr;
+    getNextToken();  // eat identifier.
+
+    // Read the optional initializer.
+    ExprAST *Init = 0;
+    if (CurTok == '=') {
+      getNextToken(); // eat the '='.
+      
+      Init = ParseExpression();
+      if (Init == 0) return 0;
+    }
+    
+    VarNames.push_back(std::make_pair(Name, Init));
+    
+    // End of var list, exit loop.
+    if (CurTok != ',') break;
+    getNextToken(); // eat the ','.
+    
+    if (CurTok != tok_identifier)
+      return Error("expected identifier list after var");
+  }
+  
+  // At this point, we have to have 'in'.
+  if (CurTok != tok_in)
+    return Error("expected 'in' keyword after 'var'");
+  getNextToken();  // eat 'in'.
+  
+  ExprAST *Body = ParseExpression();
+  if (Body == 0) return 0;
+  
+  return new VarExprAST(VarNames, Body);
+}
+
+
+/// primary
+///   ::= identifierexpr
+///   ::= numberexpr
+///   ::= parenexpr
+///   ::= ifexpr
+///   ::= forexpr
+///   ::= varexpr
+static ExprAST *ParsePrimary() {
+  switch (CurTok) {
+  default: return Error("unknown token when expecting an expression");
+  case tok_identifier: return ParseIdentifierExpr();
+  case tok_number:     return ParseNumberExpr();
+  case '(':            return ParseParenExpr();
+  case tok_if:         return ParseIfExpr();
+  case tok_for:        return ParseForExpr();
+  case tok_var:        return ParseVarExpr();
+  }
+}
+
+/// unary
+///   ::= primary
+///   ::= '!' unary
+static ExprAST *ParseUnary() {
+  // If the current token is not an operator, it must be a primary expr.
+  if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
+    return ParsePrimary();
+  
+  // If this is a unary operator, read it.
+  int Opc = CurTok;
+  getNextToken();
+  if (ExprAST *Operand = ParseUnary())
+    return new UnaryExprAST(Opc, Operand);
+  return 0;
+}
+
+/// binoprhs
+///   ::= ('+' unary)*
+static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
+  // If this is a binop, find its precedence.
+  while (1) {
+    int TokPrec = GetTokPrecedence();
+    
+    // If this is a binop that binds at least as tightly as the current binop,
+    // consume it, otherwise we are done.
+    if (TokPrec < ExprPrec)
+      return LHS;
+    
+    // Okay, we know this is a binop.
+    int BinOp = CurTok;
+    getNextToken();  // eat binop
+    
+    // Parse the unary expression after the binary operator.
+    ExprAST *RHS = ParseUnary();
+    if (!RHS) return 0;
+    
+    // If BinOp binds less tightly with RHS than the operator after RHS, let
+    // the pending operator take RHS as its LHS.
+    int NextPrec = GetTokPrecedence();
+    if (TokPrec < NextPrec) {
+      RHS = ParseBinOpRHS(TokPrec+1, RHS);
+      if (RHS == 0) return 0;
+    }
+    
+    // Merge LHS/RHS.
+    LHS = new BinaryExprAST(BinOp, LHS, RHS);
+  }
+}
+
+/// expression
+///   ::= unary binoprhs
+///
+static ExprAST *ParseExpression() {
+  ExprAST *LHS = ParseUnary();
+  if (!LHS) return 0;
+  
+  return ParseBinOpRHS(0, LHS);
+}
+
+/// prototype
+///   ::= id '(' id* ')'
+///   ::= binary LETTER number? (id, id)
+///   ::= unary LETTER (id)
+static PrototypeAST *ParsePrototype() {
+  std::string FnName;
+  
+  unsigned Kind = 0;            // 0 = identifier, 1 = unary, 2 = binary.
+  unsigned BinaryPrecedence = 30;
+  
+  switch (CurTok) {
+  default:
+    return ErrorP("Expected function name in prototype");
+  case tok_identifier:
+    FnName = IdentifierStr;
+    Kind = 0;
+    getNextToken();
+    break;
+  case tok_unary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorP("Expected unary operator");
+    FnName = "unary";
+    FnName += (char)CurTok;
+    Kind = 1;
+    getNextToken();
+    break;
+  case tok_binary:
+    getNextToken();
+    if (!isascii(CurTok))
+      return ErrorP("Expected binary operator");
+    FnName = "binary";
+    FnName += (char)CurTok;
+    Kind = 2;
+    getNextToken();
+    
+    // Read the precedence if present.
+    if (CurTok == tok_number) {
+      if (NumVal < 1 || NumVal > 100)
+        return ErrorP("Invalid precedecnce: must be 1..100");
+      BinaryPrecedence = (unsigned)NumVal;
+      getNextToken();
+    }
+    break;
+  }
+  
+  if (CurTok != '(')
+    return ErrorP("Expected '(' in prototype");
+  
+  std::vector<std::string> ArgNames;
+  while (getNextToken() == tok_identifier)
+    ArgNames.push_back(IdentifierStr);
+  if (CurTok != ')')
+    return ErrorP("Expected ')' in prototype");
+  
+  // success.
+  getNextToken();  // eat ')'.
+  
+  // Verify right number of names for operator.
+  if (Kind && ArgNames.size() != Kind)
+    return ErrorP("Invalid number of operands for operator");
+  
+  return new PrototypeAST(FnName, ArgNames, Kind != 0, BinaryPrecedence);
+}
+
+/// definition ::= 'def' prototype expression
+static FunctionAST *ParseDefinition() {
+  getNextToken();  // eat def.
+  PrototypeAST *Proto = ParsePrototype();
+  if (Proto == 0) return 0;
+
+  if (ExprAST *E = ParseExpression())
+    return new FunctionAST(Proto, E);
+  return 0;
+}
+
+/// toplevelexpr ::= expression
+static FunctionAST *ParseTopLevelExpr() {
+  if (ExprAST *E = ParseExpression()) {
+    // Make an anonymous proto.
+    PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
+    return new FunctionAST(Proto, E);
+  }
+  return 0;
+}
+
+/// external ::= 'extern' prototype
+static PrototypeAST *ParseExtern() {
+  getNextToken();  // eat extern.
+  return ParsePrototype();
+}
+
+//===----------------------------------------------------------------------===//
+// Code Generation
+//===----------------------------------------------------------------------===//
+
+static Module *TheModule;
+static IRBuilder<> Builder;
+static std::map<std::string, AllocaInst*> NamedValues;
+static FunctionPassManager *TheFPM;
+
+Value *ErrorV(const char *Str) { Error(Str); return 0; }
+
+/// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
+/// the function.  This is used for mutable variables etc.
+static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
+                                          const std::string &VarName) {
+  IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
+                 TheFunction->getEntryBlock().begin());
+  return TmpB.CreateAlloca(Type::DoubleTy, 0, VarName.c_str());
+}
+
+
+Value *NumberExprAST::Codegen() {
+  return ConstantFP::get(APFloat(Val));
+}
+
+Value *VariableExprAST::Codegen() {
+  // Look this variable up in the function.
+  Value *V = NamedValues[Name];
+  if (V == 0) return ErrorV("Unknown variable name");
+
+  // Load the value.
+  return Builder.CreateLoad(V, Name.c_str());
+}
+
+Value *UnaryExprAST::Codegen() {
+  Value *OperandV = Operand->Codegen();
+  if (OperandV == 0) return 0;
+  
+  Function *F = TheModule->getFunction(std::string("unary")+Opcode);
+  if (F == 0)
+    return ErrorV("Unknown unary operator");
+  
+  return Builder.CreateCall(F, OperandV, "unop");
+}
+
+
+Value *BinaryExprAST::Codegen() {
+  // Special case '=' because we don't want to emit the LHS as an expression.
+  if (Op == '=') {
+    // Assignment requires the LHS to be an identifier.
+    VariableExprAST *LHSE = dynamic_cast<VariableExprAST*>(LHS);
+    if (!LHSE)
+      return ErrorV("destination of '=' must be a variable");
+    // Codegen the RHS.
+    Value *Val = RHS->Codegen();
+    if (Val == 0) return 0;
+
+    // Look up the name.
+    Value *Variable = NamedValues[LHSE->getName()];
+    if (Variable == 0) return ErrorV("Unknown variable name");
+
+    Builder.CreateStore(Val, Variable);
+    return Val;
+  }
+  
+  
+  Value *L = LHS->Codegen();
+  Value *R = RHS->Codegen();
+  if (L == 0 || R == 0) return 0;
+  
+  switch (Op) {
+  case '+': return Builder.CreateAdd(L, R, "addtmp");
+  case '-': return Builder.CreateSub(L, R, "subtmp");
+  case '*': return Builder.CreateMul(L, R, "multmp");
+  case '<':
+    L = Builder.CreateFCmpULT(L, R, "cmptmp");
+    // Convert bool 0/1 to double 0.0 or 1.0
+    return Builder.CreateUIToFP(L, Type::DoubleTy, "booltmp");
+  default: break;
+  }
+  
+  // If it wasn't a builtin binary operator, it must be a user defined one. Emit
+  // a call to it.
+  Function *F = TheModule->getFunction(std::string("binary")+Op);
+  assert(F && "binary operator not found!");
+  
+  Value *Ops[] = { L, R };
+  return Builder.CreateCall(F, Ops, Ops+2, "binop");
+}
+
+Value *CallExprAST::Codegen() {
+  // Look up the name in the global module table.
+  Function *CalleeF = TheModule->getFunction(Callee);
+  if (CalleeF == 0)
+    return ErrorV("Unknown function referenced");
+  
+  // If argument mismatch error.
+  if (CalleeF->arg_size() != Args.size())
+    return ErrorV("Incorrect # arguments passed");
+
+  std::vector<Value*> ArgsV;
+  for (unsigned i = 0, e = Args.size(); i != e; ++i) {
+    ArgsV.push_back(Args[i]->Codegen());
+    if (ArgsV.back() == 0) return 0;
+  }
+  
+  return Builder.CreateCall(CalleeF, ArgsV.begin(), ArgsV.end(), "calltmp");
+}
+
+Value *IfExprAST::Codegen() {
+  Value *CondV = Cond->Codegen();
+  if (CondV == 0) return 0;
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  CondV = Builder.CreateFCmpONE(CondV, 
+                                ConstantFP::get(APFloat(0.0)),
+                                "ifcond");
+  
+  Function *TheFunction = Builder.GetInsertBlock()->getParent();
+  
+  // Create blocks for the then and else cases.  Insert the 'then' block at the
+  // end of the function.
+  BasicBlock *ThenBB = BasicBlock::Create("then", TheFunction);
+  BasicBlock *ElseBB = BasicBlock::Create("else");
+  BasicBlock *MergeBB = BasicBlock::Create("ifcont");
+  
+  Builder.CreateCondBr(CondV, ThenBB, ElseBB);
+  
+  // Emit then value.
+  Builder.SetInsertPoint(ThenBB);
+  
+  Value *ThenV = Then->Codegen();
+  if (ThenV == 0) return 0;
+  
+  Builder.CreateBr(MergeBB);
+  // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
+  ThenBB = Builder.GetInsertBlock();
+  
+  // Emit else block.
+  TheFunction->getBasicBlockList().push_back(ElseBB);
+  Builder.SetInsertPoint(ElseBB);
+  
+  Value *ElseV = Else->Codegen();
+  if (ElseV == 0) return 0;
+  
+  Builder.CreateBr(MergeBB);
+  // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
+  ElseBB = Builder.GetInsertBlock();
+  
+  // Emit merge block.
+  TheFunction->getBasicBlockList().push_back(MergeBB);
+  Builder.SetInsertPoint(MergeBB);
+  PHINode *PN = Builder.CreatePHI(Type::DoubleTy, "iftmp");
+  
+  PN->addIncoming(ThenV, ThenBB);
+  PN->addIncoming(ElseV, ElseBB);
+  return PN;
+}
+
+Value *ForExprAST::Codegen() {
+  // Output this as:
+  //   var = alloca double
+  //   ...
+  //   start = startexpr
+  //   store start -> var
+  //   goto loop
+  // loop: 
+  //   ...
+  //   bodyexpr
+  //   ...
+  // loopend:
+  //   step = stepexpr
+  //   endcond = endexpr
+  //
+  //   curvar = load var
+  //   nextvar = curvar + step
+  //   store nextvar -> var
+  //   br endcond, loop, endloop
+  // outloop:
+  
+  Function *TheFunction = Builder.GetInsertBlock()->getParent();
+
+  // Create an alloca for the variable in the entry block.
+  AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+  
+  // Emit the start code first, without 'variable' in scope.
+  Value *StartVal = Start->Codegen();
+  if (StartVal == 0) return 0;
+  
+  // Store the value into the alloca.
+  Builder.CreateStore(StartVal, Alloca);
+  
+  // Make the new basic block for the loop header, inserting after current
+  // block.
+  BasicBlock *LoopBB = BasicBlock::Create("loop", TheFunction);
+  
+  // Insert an explicit fall through from the current block to the LoopBB.
+  Builder.CreateBr(LoopBB);
+
+  // Start insertion in LoopBB.
+  Builder.SetInsertPoint(LoopBB);
+  
+  // Within the loop, the variable is defined equal to the PHI node.  If it
+  // shadows an existing variable, we have to restore it, so save it now.
+  AllocaInst *OldVal = NamedValues[VarName];
+  NamedValues[VarName] = Alloca;
+  
+  // Emit the body of the loop.  This, like any other expr, can change the
+  // current BB.  Note that we ignore the value computed by the body, but don't
+  // allow an error.
+  if (Body->Codegen() == 0)
+    return 0;
+  
+  // Emit the step value.
+  Value *StepVal;
+  if (Step) {
+    StepVal = Step->Codegen();
+    if (StepVal == 0) return 0;
+  } else {
+    // If not specified, use 1.0.
+    StepVal = ConstantFP::get(APFloat(1.0));
+  }
+  
+  // Compute the end condition.
+  Value *EndCond = End->Codegen();
+  if (EndCond == 0) return EndCond;
+  
+  // Reload, increment, and restore the alloca.  This handles the case where
+  // the body of the loop mutates the variable.
+  Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
+  Value *NextVar = Builder.CreateAdd(CurVar, StepVal, "nextvar");
+  Builder.CreateStore(NextVar, Alloca);
+  
+  // Convert condition to a bool by comparing equal to 0.0.
+  EndCond = Builder.CreateFCmpONE(EndCond, 
+                                  ConstantFP::get(APFloat(0.0)),
+                                  "loopcond");
+  
+  // Create the "after loop" block and insert it.
+  BasicBlock *AfterBB = BasicBlock::Create("afterloop", TheFunction);
+  
+  // Insert the conditional branch into the end of LoopEndBB.
+  Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
+  
+  // Any new code will be inserted in AfterBB.
+  Builder.SetInsertPoint(AfterBB);
+  
+  // Restore the unshadowed variable.
+  if (OldVal)
+    NamedValues[VarName] = OldVal;
+  else
+    NamedValues.erase(VarName);
+
+  
+  // for expr always returns 0.0.
+  return Constant::getNullValue(Type::DoubleTy);
+}
+
+Value *VarExprAST::Codegen() {
+  std::vector<AllocaInst *> OldBindings;
+  
+  Function *TheFunction = Builder.GetInsertBlock()->getParent();
+
+  // Register all variables and emit their initializer.
+  for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
+    const std::string &VarName = VarNames[i].first;
+    ExprAST *Init = VarNames[i].second;
+    
+    // Emit the initializer before adding the variable to scope, this prevents
+    // the initializer from referencing the variable itself, and permits stuff
+    // like this:
+    //  var a = 1 in
+    //    var a = a in ...   # refers to outer 'a'.
+    Value *InitVal;
+    if (Init) {
+      InitVal = Init->Codegen();
+      if (InitVal == 0) return 0;
+    } else { // If not specified, use 0.0.
+      InitVal = ConstantFP::get(APFloat(0.0));
+    }
+    
+    AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+    Builder.CreateStore(InitVal, Alloca);
+
+    // Remember the old variable binding so that we can restore the binding when
+    // we unrecurse.
+    OldBindings.push_back(NamedValues[VarName]);
+    
+    // Remember this binding.
+    NamedValues[VarName] = Alloca;
+  }
+  
+  // Codegen the body, now that all vars are in scope.
+  Value *BodyVal = Body->Codegen();
+  if (BodyVal == 0) return 0;
+  
+  // Pop all our variables from scope.
+  for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
+    NamedValues[VarNames[i].first] = OldBindings[i];
+
+  // Return the body computation.
+  return BodyVal;
+}
+
+
+Function *PrototypeAST::Codegen() {
+  // Make the function type:  double(double,double) etc.
+  std::vector<const Type*> Doubles(Args.size(), Type::DoubleTy);
+  FunctionType *FT = FunctionType::get(Type::DoubleTy, Doubles, false);
+  
+  Function *F = Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
+  
+  // If F conflicted, there was already something named 'Name'.  If it has a
+  // body, don't allow redefinition or reextern.
+  if (F->getName() != Name) {
+    // Delete the one we just made and get the existing one.
+    F->eraseFromParent();
+    F = TheModule->getFunction(Name);
+    
+    // If F already has a body, reject this.
+    if (!F->empty()) {
+      ErrorF("redefinition of function");
+      return 0;
+    }
+    
+    // If F took a different number of args, reject.
+    if (F->arg_size() != Args.size()) {
+      ErrorF("redefinition of function with different # args");
+      return 0;
+    }
+  }
+  
+  // Set names for all arguments.
+  unsigned Idx = 0;
+  for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
+       ++AI, ++Idx)
+    AI->setName(Args[Idx]);
+    
+  return F;
+}
+
+/// CreateArgumentAllocas - Create an alloca for each argument and register the
+/// argument in the symbol table so that references to it will succeed.
+void PrototypeAST::CreateArgumentAllocas(Function *F) {
+  Function::arg_iterator AI = F->arg_begin();
+  for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
+    // Create an alloca for this variable.
+    AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
+
+    // Store the initial value into the alloca.
+    Builder.CreateStore(AI, Alloca);
+
+    // Add arguments to variable symbol table.
+    NamedValues[Args[Idx]] = Alloca;
+  }
+}
+
+
+Function *FunctionAST::Codegen() {
+  NamedValues.clear();
+  
+  Function *TheFunction = Proto->Codegen();
+  if (TheFunction == 0)
+    return 0;
+  
+  // If this is an operator, install it.
+  if (Proto->isBinaryOp())
+    BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
+  
+  // Create a new basic block to start insertion into.
+  BasicBlock *BB = BasicBlock::Create("entry", TheFunction);
+  Builder.SetInsertPoint(BB);
+  
+  // Add all arguments to the symbol table and create their allocas.
+  Proto->CreateArgumentAllocas(TheFunction);
+  
+  if (Value *RetVal = Body->Codegen()) {
+    // Finish off the function.
+    Builder.CreateRet(RetVal);
+
+    // Validate the generated code, checking for consistency.
+    verifyFunction(*TheFunction);
+
+    // Optimize the function.
+    TheFPM->run(*TheFunction);
+    
+    return TheFunction;
+  }
+  
+  // Error reading body, remove function.
+  TheFunction->eraseFromParent();
+
+  if (Proto->isBinaryOp())
+    BinopPrecedence.erase(Proto->getOperatorName());
+  return 0;
+}
+
+//===----------------------------------------------------------------------===//
+// Top-Level parsing and JIT Driver
+//===----------------------------------------------------------------------===//
+
+static ExecutionEngine *TheExecutionEngine;
+
+static void HandleDefinition() {
+  if (FunctionAST *F = ParseDefinition()) {
+    if (Function *LF = F->Codegen()) {
+      fprintf(stderr, "Read function definition:");
+      LF->dump();
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleExtern() {
+  if (PrototypeAST *P = ParseExtern()) {
+    if (Function *F = P->Codegen()) {
+      fprintf(stderr, "Read extern: ");
+      F->dump();
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+static void HandleTopLevelExpression() {
+  // Evaluate a top level expression into an anonymous function.
+  if (FunctionAST *F = ParseTopLevelExpr()) {
+    if (Function *LF = F->Codegen()) {
+      // JIT the function, returning a function pointer.
+      void *FPtr = TheExecutionEngine->getPointerToFunction(LF);
+      
+      // Cast it to the right type (takes no arguments, returns a double) so we
+      // can call it as a native function.
+      double (*FP)() = (double (*)())(intptr_t)FPtr;
+      fprintf(stderr, "Evaluated to %f\n", FP());
+    }
+  } else {
+    // Skip token for error recovery.
+    getNextToken();
+  }
+}
+
+/// top ::= definition | external | expression | ';'
+static void MainLoop() {
+  while (1) {
+    fprintf(stderr, "ready> ");
+    switch (CurTok) {
+    case tok_eof:    return;
+    case ';':        getNextToken(); break;  // ignore top level semicolons.
+    case tok_def:    HandleDefinition(); break;
+    case tok_extern: HandleExtern(); break;
+    default:         HandleTopLevelExpression(); break;
+    }
+  }
+}
+
+
+
+//===----------------------------------------------------------------------===//
+// "Library" functions that can be "extern'd" from user code.
+//===----------------------------------------------------------------------===//
+
+/// putchard - putchar that takes a double and returns 0.
+extern "C" 
+double putchard(double X) {
+  putchar((char)X);
+  return 0;
+}
+
+/// printd - printf that takes a double prints it as "%f\n", returning 0.
+extern "C" 
+double printd(double X) {
+  printf("%f\n", X);
+  return 0;
+}
+
+//===----------------------------------------------------------------------===//
+// Main driver code.
+//===----------------------------------------------------------------------===//
+
+int main() {
+  // Install standard binary operators.
+  // 1 is lowest precedence.
+  BinopPrecedence['='] = 2;
+  BinopPrecedence['<'] = 10;
+  BinopPrecedence['+'] = 20;
+  BinopPrecedence['-'] = 20;
+  BinopPrecedence['*'] = 40;  // highest.
+
+  // Prime the first token.
+  fprintf(stderr, "ready> ");
+  getNextToken();
+
+  // Make the module, which holds all the code.
+  TheModule = new Module("my cool jit");
+  
+  // Create the JIT.
+  TheExecutionEngine = ExecutionEngine::create(TheModule);
+
+  {
+    ExistingModuleProvider OurModuleProvider(TheModule);
+    FunctionPassManager OurFPM(&OurModuleProvider);
+      
+    // Set up the optimizer pipeline.  Start with registering info about how the
+    // target lays out data structures.
+    OurFPM.add(new TargetData(*TheExecutionEngine->getTargetData()));
+    // Promote allocas to registers.
+    OurFPM.add(createPromoteMemoryToRegisterPass());
+    // Do simple "peephole" optimizations and bit-twiddling optzns.
+    OurFPM.add(createInstructionCombiningPass());
+    // Reassociate expressions.
+    OurFPM.add(createReassociatePass());
+    // Eliminate Common SubExpressions.
+    OurFPM.add(createGVNPass());
+    // Simplify the control flow graph (deleting unreachable blocks, etc).
+    OurFPM.add(createCFGSimplificationPass());
+
+    // Set the global so the code gen can use this.
+    TheFPM = &OurFPM;
+
+    // Run the main "interpreter loop" now.
+    MainLoop();
+    
+    TheFPM = 0;
+    
+    // Print out all of the generated code.
+    TheModule->dump();
+    
+  }  // Free module provider (and thus the module) and pass manager.
+  
+  return 0;
+}
+
diff --git a/examples/Makefile b/examples/Makefile
new file mode 100644
index 0000000..eb5dabd
--- /dev/null
+++ b/examples/Makefile
@@ -0,0 +1,19 @@
+##===- examples/Makefile -----------------------------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+LEVEL=..
+
+include $(LEVEL)/Makefile.config
+
+PARALLEL_DIRS:= BrainF Fibonacci HowToUseJIT Kaleidoscope ModuleMaker
+
+ifeq ($(HAVE_PTHREAD),1)
+PARALLEL_DIRS += ParallelJIT 
+endif
+
+include $(LEVEL)/Makefile.common
diff --git a/examples/ModuleMaker/CMakeLists.txt b/examples/ModuleMaker/CMakeLists.txt
new file mode 100644
index 0000000..81e9115
--- /dev/null
+++ b/examples/ModuleMaker/CMakeLists.txt
@@ -0,0 +1,5 @@
+set(LLVM_LINK_COMPONENTS bitwriter)
+
+add_llvm_example(ModuleMaker
+  ModuleMaker.cpp
+  )
diff --git a/examples/ModuleMaker/Makefile b/examples/ModuleMaker/Makefile
new file mode 100644
index 0000000..9454cf5
--- /dev/null
+++ b/examples/ModuleMaker/Makefile
@@ -0,0 +1,14 @@
+##===- examples/ModuleMaker/Makefile -----------------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+LEVEL=../..
+TOOLNAME=ModuleMaker
+EXAMPLE_TOOL = 1
+LINK_COMPONENTS := bitwriter
+
+include $(LEVEL)/Makefile.common
diff --git a/examples/ModuleMaker/ModuleMaker.cpp b/examples/ModuleMaker/ModuleMaker.cpp
new file mode 100644
index 0000000..154e2406
--- /dev/null
+++ b/examples/ModuleMaker/ModuleMaker.cpp
@@ -0,0 +1,61 @@
+//===- examples/ModuleMaker/ModuleMaker.cpp - Example project ---*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This programs is a simple example that creates an LLVM module "from scratch",
+// emitting it as a bitcode file to standard out.  This is just to show how
+// LLVM projects work and to demonstrate some of the LLVM APIs.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Module.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Constants.h"
+#include "llvm/Instructions.h"
+#include "llvm/Bitcode/ReaderWriter.h"
+#include <iostream>
+using namespace llvm;
+
+int main() {
+  // Create the "module" or "program" or "translation unit" to hold the
+  // function
+  Module *M = new Module("test");
+
+  // Create the main function: first create the type 'int ()'
+  FunctionType *FT = FunctionType::get(Type::Int32Ty, std::vector<const Type*>(),
+                                       /*not vararg*/false);
+
+  // By passing a module as the last parameter to the Function constructor,
+  // it automatically gets appended to the Module.
+  Function *F = Function::Create(FT, Function::ExternalLinkage, "main", M);
+
+  // Add a basic block to the function... again, it automatically inserts
+  // because of the last argument.
+  BasicBlock *BB = BasicBlock::Create("EntryBlock", F);
+
+  // Get pointers to the constant integers...
+  Value *Two = ConstantInt::get(Type::Int32Ty, 2);
+  Value *Three = ConstantInt::get(Type::Int32Ty, 3);
+
+  // Create the add instruction... does not insert...
+  Instruction *Add = BinaryOperator::Create(Instruction::Add, Two, Three,
+                                            "addresult");
+
+  // explicitly insert it into the basic block...
+  BB->getInstList().push_back(Add);
+
+  // Create the return instruction and add it to the basic block
+  BB->getInstList().push_back(ReturnInst::Create(Add));
+
+  // Output the bitcode file to stdout
+  WriteBitcodeToFile(M, std::cout);
+
+  // Delete the module and all of its contents.
+  delete M;
+  return 0;
+}
diff --git a/examples/ModuleMaker/README.txt b/examples/ModuleMaker/README.txt
new file mode 100644
index 0000000..ecbe30e
--- /dev/null
+++ b/examples/ModuleMaker/README.txt
@@ -0,0 +1,8 @@
+//===----------------------------------------------------------------------===//
+//                         ModuleMaker Sample project
+//===----------------------------------------------------------------------===//
+
+This project is an extremely simple example of using some simple pieces of the 
+LLVM API.  The actual executable generated by this project simply emits an 
+LLVM bytecode file to standard output.  It is designed to show some basic 
+usage of LLVM APIs, and how to link to LLVM libraries.
diff --git a/examples/ParallelJIT/CMakeLists.txt b/examples/ParallelJIT/CMakeLists.txt
new file mode 100644
index 0000000..d8dd708
--- /dev/null
+++ b/examples/ParallelJIT/CMakeLists.txt
@@ -0,0 +1,7 @@
+set(LLVM_LINK_COMPONENTS jit interpreter nativecodegen)
+
+add_llvm_example(ParallelJIT
+  ParallelJIT.cpp
+  )
+
+target_link_libraries(ParallelJIT pthread)
diff --git a/examples/ParallelJIT/Makefile b/examples/ParallelJIT/Makefile
new file mode 100644
index 0000000..8a49d42
--- /dev/null
+++ b/examples/ParallelJIT/Makefile
@@ -0,0 +1,17 @@
+##===- examples/ParallelJIT/Makefile -----------------------*- Makefile -*-===##
+# 
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+# 
+##===----------------------------------------------------------------------===##
+LEVEL = ../..
+TOOLNAME = ParallelJIT
+EXAMPLE_TOOL = 1
+
+LINK_COMPONENTS := jit interpreter nativecodegen
+
+include $(LEVEL)/Makefile.common
+
+LIBS += -lpthread
diff --git a/examples/ParallelJIT/ParallelJIT.cpp b/examples/ParallelJIT/ParallelJIT.cpp
new file mode 100644
index 0000000..e812d84
--- /dev/null
+++ b/examples/ParallelJIT/ParallelJIT.cpp
@@ -0,0 +1,298 @@
+//===-- examples/ParallelJIT/ParallelJIT.cpp - Exercise threaded-safe JIT -===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Parallel JIT
+//
+// This test program creates two LLVM functions then calls them from three
+// separate threads.  It requires the pthreads library.
+// The three threads are created and then block waiting on a condition variable.
+// Once all threads are blocked on the conditional variable, the main thread
+// wakes them up. This complicated work is performed so that all three threads
+// call into the JIT at the same time (or the best possible approximation of the
+// same time). This test had assertion errors until I got the locking right.
+
+#include <pthread.h>
+#include "llvm/Module.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Instructions.h"
+#include "llvm/ModuleProvider.h"
+#include "llvm/ExecutionEngine/JIT.h"
+#include "llvm/ExecutionEngine/Interpreter.h"
+#include "llvm/ExecutionEngine/GenericValue.h"
+#include <iostream>
+using namespace llvm;
+
+static Function* createAdd1(Module *M) {
+  // Create the add1 function entry and insert this entry into module M.  The
+  // function will have a return type of "int" and take an argument of "int".
+  // The '0' terminates the list of argument types.
+  Function *Add1F =
+    cast<Function>(M->getOrInsertFunction("add1", Type::Int32Ty, Type::Int32Ty,
+                                          (Type *)0));
+
+  // Add a basic block to the function. As before, it automatically inserts
+  // because of the last argument.
+  BasicBlock *BB = BasicBlock::Create("EntryBlock", Add1F);
+
+  // Get pointers to the constant `1'.
+  Value *One = ConstantInt::get(Type::Int32Ty, 1);
+
+  // Get pointers to the integer argument of the add1 function...
+  assert(Add1F->arg_begin() != Add1F->arg_end()); // Make sure there's an arg
+  Argument *ArgX = Add1F->arg_begin();  // Get the arg
+  ArgX->setName("AnArg");            // Give it a nice symbolic name for fun.
+
+  // Create the add instruction, inserting it into the end of BB.
+  Instruction *Add = BinaryOperator::CreateAdd(One, ArgX, "addresult", BB);
+
+  // Create the return instruction and add it to the basic block
+  ReturnInst::Create(Add, BB);
+
+  // Now, function add1 is ready.
+  return Add1F;
+}
+
+static Function *CreateFibFunction(Module *M) {
+  // Create the fib function and insert it into module M.  This function is said
+  // to return an int and take an int parameter.
+  Function *FibF = 
+    cast<Function>(M->getOrInsertFunction("fib", Type::Int32Ty, Type::Int32Ty,
+                                          (Type *)0));
+
+  // Add a basic block to the function.
+  BasicBlock *BB = BasicBlock::Create("EntryBlock", FibF);
+
+  // Get pointers to the constants.
+  Value *One = ConstantInt::get(Type::Int32Ty, 1);
+  Value *Two = ConstantInt::get(Type::Int32Ty, 2);
+
+  // Get pointer to the integer argument of the add1 function...
+  Argument *ArgX = FibF->arg_begin();   // Get the arg.
+  ArgX->setName("AnArg");            // Give it a nice symbolic name for fun.
+
+  // Create the true_block.
+  BasicBlock *RetBB = BasicBlock::Create("return", FibF);
+  // Create an exit block.
+  BasicBlock* RecurseBB = BasicBlock::Create("recurse", FibF);
+
+  // Create the "if (arg < 2) goto exitbb"
+  Value *CondInst = new ICmpInst(ICmpInst::ICMP_SLE, ArgX, Two, "cond", BB);
+  BranchInst::Create(RetBB, RecurseBB, CondInst, BB);
+
+  // Create: ret int 1
+  ReturnInst::Create(One, RetBB);
+
+  // create fib(x-1)
+  Value *Sub = BinaryOperator::CreateSub(ArgX, One, "arg", RecurseBB);
+  Value *CallFibX1 = CallInst::Create(FibF, Sub, "fibx1", RecurseBB);
+
+  // create fib(x-2)
+  Sub = BinaryOperator::CreateSub(ArgX, Two, "arg", RecurseBB);
+  Value *CallFibX2 = CallInst::Create(FibF, Sub, "fibx2", RecurseBB);
+
+  // fib(x-1)+fib(x-2)
+  Value *Sum =
+    BinaryOperator::CreateAdd(CallFibX1, CallFibX2, "addresult", RecurseBB);
+
+  // Create the return instruction and add it to the basic block
+  ReturnInst::Create(Sum, RecurseBB);
+
+  return FibF;
+}
+
+struct threadParams {
+  ExecutionEngine* EE;
+  Function* F;
+  int value;
+};
+
+// We block the subthreads just before they begin to execute:
+// we want all of them to call into the JIT at the same time,
+// to verify that the locking is working correctly.
+class WaitForThreads
+{
+public:
+  WaitForThreads()
+  {
+    n = 0;
+    waitFor = 0;
+
+    int result = pthread_cond_init( &condition, NULL );
+    assert( result == 0 );
+
+    result = pthread_mutex_init( &mutex, NULL );
+    assert( result == 0 );
+  }
+
+  ~WaitForThreads()
+  {
+    int result = pthread_cond_destroy( &condition );
+    assert( result == 0 );
+
+    result = pthread_mutex_destroy( &mutex );
+    assert( result == 0 );
+  }
+
+  // All threads will stop here until another thread calls releaseThreads
+  void block()
+  {
+    int result = pthread_mutex_lock( &mutex );
+    assert( result == 0 );
+    n ++;
+    //~ std::cout << "block() n " << n << " waitFor " << waitFor << std::endl;
+
+    assert( waitFor == 0 || n <= waitFor );
+    if ( waitFor > 0 && n == waitFor )
+    {
+      // There are enough threads blocked that we can release all of them
+      std::cout << "Unblocking threads from block()" << std::endl;
+      unblockThreads();
+    }
+    else
+    {
+      // We just need to wait until someone unblocks us
+      result = pthread_cond_wait( &condition, &mutex );
+      assert( result == 0 );
+    }
+
+    // unlock the mutex before returning
+    result = pthread_mutex_unlock( &mutex );
+    assert( result == 0 );
+  }
+
+  // If there are num or more threads blocked, it will signal them all
+  // Otherwise, this thread blocks until there are enough OTHER threads
+  // blocked
+  void releaseThreads( size_t num )
+  {
+    int result = pthread_mutex_lock( &mutex );
+    assert( result == 0 );
+
+    if ( n >= num ) {
+      std::cout << "Unblocking threads from releaseThreads()" << std::endl;
+      unblockThreads();
+    }
+    else
+    {
+      waitFor = num;
+      pthread_cond_wait( &condition, &mutex );
+    }
+
+    // unlock the mutex before returning
+    result = pthread_mutex_unlock( &mutex );
+    assert( result == 0 );
+  }
+
+private:
+  void unblockThreads()
+  {
+    // Reset the counters to zero: this way, if any new threads
+    // enter while threads are exiting, they will block instead
+    // of triggering a new release of threads
+    n = 0;
+
+    // Reset waitFor to zero: this way, if waitFor threads enter
+    // while threads are exiting, they will block instead of
+    // triggering a new release of threads
+    waitFor = 0;
+
+    int result = pthread_cond_broadcast( &condition );
+    assert(result == 0); result=result;
+  }
+
+  size_t n;
+  size_t waitFor;
+  pthread_cond_t condition;
+  pthread_mutex_t mutex;
+};
+
+static WaitForThreads synchronize;
+
+void* callFunc( void* param )
+{
+  struct threadParams* p = (struct threadParams*) param;
+
+  // Call the `foo' function with no arguments:
+  std::vector<GenericValue> Args(1);
+  Args[0].IntVal = APInt(32, p->value);
+
+  synchronize.block(); // wait until other threads are at this point
+  GenericValue gv = p->EE->runFunction(p->F, Args);
+
+  return (void*)(intptr_t)gv.IntVal.getZExtValue();
+}
+
+int main()
+{
+  // Create some module to put our function into it.
+  Module *M = new Module("test");
+
+  Function* add1F = createAdd1( M );
+  Function* fibF = CreateFibFunction( M );
+
+  // Now we create the JIT.
+  ExistingModuleProvider* MP = new ExistingModuleProvider(M);
+  ExecutionEngine* EE = ExecutionEngine::create(MP, false);
+
+  //~ std::cout << "We just constructed this LLVM module:\n\n" << *M;
+  //~ std::cout << "\n\nRunning foo: " << std::flush;
+
+  // Create one thread for add1 and two threads for fib
+  struct threadParams add1 = { EE, add1F, 1000 };
+  struct threadParams fib1 = { EE, fibF, 39 };
+  struct threadParams fib2 = { EE, fibF, 42 };
+
+  pthread_t add1Thread;
+  int result = pthread_create( &add1Thread, NULL, callFunc, &add1 );
+  if ( result != 0 ) {
+          std::cerr << "Could not create thread" << std::endl;
+          return 1;
+  }
+
+  pthread_t fibThread1;
+  result = pthread_create( &fibThread1, NULL, callFunc, &fib1 );
+  if ( result != 0 ) {
+          std::cerr << "Could not create thread" << std::endl;
+          return 1;
+  }
+
+  pthread_t fibThread2;
+  result = pthread_create( &fibThread2, NULL, callFunc, &fib2 );
+  if ( result != 0 ) {
+          std::cerr << "Could not create thread" << std::endl;
+          return 1;
+  }
+
+  synchronize.releaseThreads(3); // wait until other threads are at this point
+
+  void* returnValue;
+  result = pthread_join( add1Thread, &returnValue );
+  if ( result != 0 ) {
+          std::cerr << "Could not join thread" << std::endl;
+          return 1;
+  }
+  std::cout << "Add1 returned " << intptr_t(returnValue) << std::endl;
+
+  result = pthread_join( fibThread1, &returnValue );
+  if ( result != 0 ) {
+          std::cerr << "Could not join thread" << std::endl;
+          return 1;
+  }
+  std::cout << "Fib1 returned " << intptr_t(returnValue) << std::endl;
+
+  result = pthread_join( fibThread2, &returnValue );
+  if ( result != 0 ) {
+          std::cerr << "Could not join thread" << std::endl;
+          return 1;
+  }
+  std::cout << "Fib2 returned " << intptr_t(returnValue) << std::endl;
+
+  return 0;
+}