new file mode 100644
--- /dev/null
+++ b/src/TEMPLATE-INST/Array-jit.cc
@@ -0,0 +1,34 @@
+/*
+
+Copyright (C) 2012 Max Brister <max@2bass.com>
+
+This file is part of Octave.
+
+Octave is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 3 of the License, or (at your
+option) any later version.
+
+Octave is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with Octave; see the file COPYING.  If not, see
+<http://www.gnu.org/licenses/>.
+
+*/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "Array.h"
+#include "Array.cc"
+
+#include "pt-jit.h"
+
+NO_INSTANTIATE_ARRAY_SORT (jit_function::overload);
+
+INSTANTIATE_ARRAY (jit_function::overload, OCTINTERP_API);

--- a/src/TEMPLATE-INST/module.mk
+++ b/src/TEMPLATE-INST/module.mk
@@ -2,4 +2,5 @@
 
 TEMPLATE_INST_SRC = \
   TEMPLATE-INST/Array-os.cc \
-  TEMPLATE-INST/Array-tc.cc
+  TEMPLATE-INST/Array-tc.cc \
+  TEMPLATE-INST/Array-jit.cc

--- a/src/ov-base.h
+++ b/src/ov-base.h
@@ -755,6 +755,21 @@
   virtual bool
   fast_elem_insert_self (void *where, builtin_type_t btyp) const;
 
+  // Grab the reference count. For use by jit.
+  void
+  grab (void)
+  {
+    ++count;
+  }
+
+  // Release the reference count. For use by jit.
+  void
+  release (void)
+  {
+    if (--count == 0)
+      delete this;
+  }
+
 protected:
 
   // This should only be called for derived types.

--- a/src/pt-jit.cc
+++ b/src/pt-jit.cc
@@ -40,525 +40,1185 @@
 #include <llvm/ExecutionEngine/JIT.h>
 #include <llvm/PassManager.h>
 #include <llvm/Analysis/Verifier.h>
+#include <llvm/Analysis/CallGraph.h>
 #include <llvm/Analysis/Passes.h>
 #include <llvm/Target/TargetData.h>
 #include <llvm/Transforms/Scalar.h>
+#include <llvm/Transforms/IPO.h>
 #include <llvm/Support/TargetSelect.h>
 #include <llvm/Support/raw_os_ostream.h>
+#include <llvm/ExecutionEngine/GenericValue.h>
 
+#include "octave.h"
 #include "ov-fcn-handle.h"
 #include "ov-usr-fcn.h"
 #include "pt-all.h"
 
-using namespace llvm;
+// FIXME: Remove eventually
+// For now we leave this in so people tell when JIT actually happens
+static const bool debug_print = false;
 
 //FIXME: Move into tree_jit
-static IRBuilder<> builder (getGlobalContext ());
+static llvm::IRBuilder<> builder (llvm::getGlobalContext ());
+
+// function that jit code calls
+extern "C" void
+octave_jit_print_any (const char *name, octave_base_value *obv)
+{
+  obv->print_with_name (octave_stdout, name, true);
+}
 
 extern "C" void
-octave_print_double (const char *name, double value)
+octave_jit_print_double (const char *name, double value)
 {
   // FIXME: We should avoid allocating a new octave_scalar each time
   octave_value ov (value);
   ov.print_with_name (octave_stdout, name);
 }
 
-tree_jit::tree_jit (void) : context (getGlobalContext ()), engine (0)
+extern "C" octave_base_value*
+octave_jit_binary_any_any (octave_value::binary_op op, octave_base_value *lhs,
+                           octave_base_value *rhs)
+{
+  octave_value olhs (lhs, true);
+  octave_value orhs (rhs, true);
+  octave_value result = do_binary_op (op, olhs, orhs);
+  octave_base_value *rep = result.internal_rep ();
+  rep->grab ();
+  return rep;
+}
+
+extern "C" void
+octave_jit_assign_any_any_help (octave_base_value *lhs, octave_base_value *rhs)
+{
+  if (lhs != rhs)
+    {
+      rhs->grab ();
+      lhs->release ();
+    }
+}
+
+// -------------------- jit_type --------------------
+llvm::Type *
+jit_type::to_llvm_arg (void) const
+{
+  return llvm_type ? llvm_type->getPointerTo () : 0;
+}
+
+// -------------------- jit_function --------------------
+void
+jit_function::add_overload (const overload& func,
+                            const std::vector<jit_type*>& args)
+{
+  if (args.size () >= overloads.size ())
+    overloads.resize (args.size () + 1);
+
+  Array<overload>& over = overloads[args.size ()];
+  dim_vector dv (over.dims ());
+  Array<octave_idx_type> idx = to_idx (args);
+  bool must_resize = false;
+
+  if (dv.length () != idx.numel ())
+    {
+      dv.resize (idx.numel ());
+      must_resize = true;
+    }
+
+  for (octave_idx_type i = 0; i < dv.length (); ++i)
+    if (dv(i) <= idx(i))
+      {
+        must_resize = true;
+        dv(i) = idx(i) + 1;
+      }
+
+  if (must_resize)
+    over.resize (dv);
+
+  over(idx) = func;
+}
+
+const jit_function::overload&
+jit_function::get_overload (const std::vector<jit_type*>& types) const
+{
+  // FIXME: We should search for the next best overload on failure
+  static overload null_overload;
+  if (types.size () >= overloads.size ())
+    return null_overload;
+
+  const Array<overload>& over = overloads[types.size ()];
+  dim_vector dv (over.dims ());
+  Array<octave_idx_type> idx = to_idx (types);
+  for (octave_idx_type i = 0; i < dv.length (); ++i)
+    if (idx(i) >= dv(i))
+      return null_overload;
+
+  return over(idx);
+}
+
+Array<octave_idx_type>
+jit_function::to_idx (const std::vector<jit_type*>& types) const
+{
+  octave_idx_type numel = types.size ();
+  if (numel == 1)
+    numel = 2;
+
+  Array<octave_idx_type> idx (dim_vector (1, numel));
+  for (octave_idx_type i = 0; i < static_cast<octave_idx_type> (types.size ());
+       ++i)
+    idx(i) = types[i]->type_id ();
+
+  if (types.size () == 1)
+    {
+      idx(1) = idx(0);
+      idx(0) = 0;
+    }
+
+  return idx;
+}
+
+// -------------------- jit_typeinfo --------------------
+jit_typeinfo::jit_typeinfo (llvm::Module *m, llvm::ExecutionEngine *e, llvm::Type *ov)
+  : module (m), engine (e), next_id (0), ov_t (ov)
 {
-  InitializeNativeTarget ();
-  InitializeNativeTargetAsmPrinter ();
-  module = new Module ("octave", context);
+  // FIXME: We should be registering types like in octave_value_typeinfo
+  llvm::LLVMContext &ctx = m->getContext ();
+
+  // create types
+  any = new_type ("any", true, 0, ov_t);
+  scalar = new_type ("scalar", false, any, llvm::Type::getDoubleTy (ctx));
+
+  // any with anything is an any op
+  llvm::IRBuilder<> fn_builder (ctx);
+
+  llvm::Type *binary_op_type
+    = llvm::Type::getIntNTy (ctx, sizeof (octave_value::binary_op));
+  std::vector<llvm::Type*> args (3);
+  args[0] = binary_op_type;
+  args[1] = args[2] = any->to_llvm ();
+  llvm::FunctionType *any_binary_t = llvm::FunctionType::get (ov_t, args, false);
+  llvm::Function *any_binary = llvm::Function::Create (any_binary_t,
+                                                       llvm::Function::ExternalLinkage,
+                                                       "octave_jit_binary_any_any",
+                                                       module);
+  engine->addGlobalMapping (any_binary,
+                            reinterpret_cast<void*>(&octave_jit_binary_any_any));
+
+  args.resize (2);
+  args[0] = any->to_llvm ();
+  args[1] = any->to_llvm ();
+
+  binary_ops.resize (octave_value::num_binary_ops);
+  for (int op = 0; op < octave_value::num_binary_ops; ++op)
+    {
+      llvm::FunctionType *ftype = llvm::FunctionType::get (ov_t, args, false);
+      
+      llvm::Twine fn_name ("octave_jit_binary_any_any_");
+      fn_name = fn_name + llvm::Twine (op);
+      llvm::Function *fn = llvm::Function::Create (ftype,
+                                                   llvm::Function::ExternalLinkage,
+                                                   fn_name, module);
+      llvm::BasicBlock *block = llvm::BasicBlock::Create (ctx, "body", fn);
+      fn_builder.SetInsertPoint (block);
+      llvm::APInt op_int(sizeof (octave_value::binary_op), op,
+                         std::numeric_limits<octave_value::binary_op>::is_signed);
+      llvm::Value *op_as_llvm = llvm::ConstantInt::get (binary_op_type, op_int);
+      llvm::Value *ret = fn_builder.CreateCall3 (any_binary,
+                                                 op_as_llvm,
+                                                 fn->arg_begin (),
+                                                 ++fn->arg_begin ());
+      fn_builder.CreateRet (ret);
+
+      jit_function::overload overload (fn, true, any, any, any);
+      for (octave_idx_type i = 0; i < next_id; ++i)
+        binary_ops[op].add_overload (overload);
+    }
+
+  // assign any = any
+  llvm::Type *tvoid = llvm::Type::getVoidTy (ctx);
+  args.resize (2);
+  args[0] = any->to_llvm ();
+  args[1] = any->to_llvm ();
+  llvm::FunctionType *ft = llvm::FunctionType::get (tvoid, args, false);
+  llvm::Function *fn_help = llvm::Function::Create (ft, llvm::Function::ExternalLinkage,
+                                                    "octave_jit_assign_any_any_help",
+                                                    module);
+  engine->addGlobalMapping (fn_help,
+                            reinterpret_cast<void*>(&octave_jit_assign_any_any_help));
+
+  args.resize (2);
+  args[0] = any->to_llvm_arg ();
+  args[1] = any->to_llvm ();
+  ft = llvm::FunctionType::get (tvoid, args, false);
+  llvm::Function *fn = llvm::Function::Create (ft, llvm::Function::ExternalLinkage,
+                                               "octave_jit_assign_any_any",
+                                               module);
+  fn->addFnAttr (llvm::Attribute::AlwaysInline);
+  llvm::BasicBlock *body = llvm::BasicBlock::Create (ctx, "body", fn);
+  fn_builder.SetInsertPoint (body);
+  llvm::Value *value = fn_builder.CreateLoad (fn->arg_begin ());
+  fn_builder.CreateCall2 (fn_help, value, ++fn->arg_begin ());
+  fn_builder.CreateStore (++fn->arg_begin (), fn->arg_begin ());
+  fn_builder.CreateRetVoid ();
+  llvm::verifyFunction (*fn);
+  assign_fn.add_overload (fn, false, 0, any, any);
+
+  // assign scalar = scalar
+  args.resize (2);
+  args[0] = scalar->to_llvm_arg ();
+  args[1] = scalar->to_llvm ();
+  ft = llvm::FunctionType::get (tvoid, args, false);
+  fn = llvm::Function::Create (ft, llvm::Function::ExternalLinkage,
+                               "octave_jit_assign_scalar_scalar", module);
+  fn->addFnAttr (llvm::Attribute::AlwaysInline);
+  body = llvm::BasicBlock::Create (ctx, "body", fn);
+  fn_builder.SetInsertPoint (body);
+  fn_builder.CreateStore (++fn->arg_begin (), fn->arg_begin ());
+  fn_builder.CreateRetVoid ();
+  llvm::verifyFunction (*fn);
+  assign_fn.add_overload (fn, false, 0, scalar, scalar);
+
+  // now for binary scalar operations
+  // FIXME: Finish all operations
+  add_binary_op (scalar, octave_value::op_add, llvm::Instruction::FAdd);
+  add_binary_op (scalar, octave_value::op_sub, llvm::Instruction::FSub);
+  add_binary_op (scalar, octave_value::op_mul, llvm::Instruction::FMul);
+  add_binary_op (scalar, octave_value::op_el_mul, llvm::Instruction::FMul);
+
+  // FIXME: Warn if rhs is zero
+  add_binary_op (scalar, octave_value::op_div, llvm::Instruction::FDiv);
+  add_binary_op (scalar, octave_value::op_el_div, llvm::Instruction::FDiv);
+
+  // now for printing functions
+  add_print (any, reinterpret_cast<void*> (&octave_jit_print_any));
+  add_print (scalar, reinterpret_cast<void*> (&octave_jit_print_double));
+}
+
+void
+jit_typeinfo::add_print (jit_type *ty, void *call)
+{
+  llvm::LLVMContext& ctx = llvm::getGlobalContext ();
+  llvm::Type *tvoid = llvm::Type::getVoidTy (ctx);
+  std::vector<llvm::Type *> args (2);
+  args[0] = llvm::Type::getInt8PtrTy (ctx);
+  args[1] = ty->to_llvm ();
+
+  std::stringstream name;
+  name << "octave_jit_print_" << ty->name ();
+
+  llvm::FunctionType *print_ty = llvm::FunctionType::get (tvoid, args, false);
+  llvm::Function *fn = llvm::Function::Create (print_ty,
+                                               llvm::Function::ExternalLinkage,
+                                               name.str (), module);
+  engine->addGlobalMapping (fn, call);
+
+  jit_function::overload ol (fn, false, 0, ty);
+  print_fn.add_overload (ol);
+}
+
+void
+jit_typeinfo::add_binary_op (jit_type *ty, int op, int llvm_op)
+{
+  llvm::LLVMContext& ctx = llvm::getGlobalContext ();
+  std::vector<llvm::Type *> args (2, ty->to_llvm ());
+  llvm::FunctionType *ft = llvm::FunctionType::get (ty->to_llvm (), args,
+                                                    false);
+
+  std::stringstream fname;
+  octave_value::binary_op ov_op = static_cast<octave_value::binary_op>(op);
+  fname << "octave_jit_" << octave_value::binary_op_as_string (ov_op)
+        << "_" << ty->name ();
+  
+  llvm::Function *fn = llvm::Function::Create (ft,
+                                               llvm::Function::ExternalLinkage,
+                                               fname.str (),
+                                               module);
+  fn->addFnAttr (llvm::Attribute::AlwaysInline);
+  llvm::BasicBlock *block = llvm::BasicBlock::Create (ctx, "body", fn);
+  llvm::IRBuilder<> fn_builder (block);
+  llvm::Instruction::BinaryOps temp
+    = static_cast<llvm::Instruction::BinaryOps>(llvm_op);
+  llvm::Value *ret = fn_builder.CreateBinOp (temp, fn->arg_begin (),
+                                             ++fn->arg_begin ());
+  fn_builder.CreateRet (ret);
+  llvm::verifyFunction (*fn);
+
+  jit_function::overload ol(fn, false, ty, ty, ty);
+  binary_ops[op].add_overload (ol);
+}
+
+jit_type*
+jit_typeinfo::type_of (const octave_value &ov) const
+{
+  if (ov.is_undefined () || ov.is_function ())
+    return 0;
+
+  if (ov.is_double_type () && ov.is_real_scalar ())
+    return get_scalar ();
+
+  return get_any ();
+}
+
+const jit_function&
+jit_typeinfo::binary_op (int op) const
+{
+  return binary_ops[op];
+}
+
+const jit_function::overload&
+jit_typeinfo::assign_op (jit_type *lhs, jit_type *rhs) const
+{
+  assert (lhs == rhs);
+  return assign_fn.get_overload (lhs, rhs);
+}
+
+const jit_function::overload&
+jit_typeinfo::print_value (jit_type *to_print) const
+{
+  return print_fn.get_overload (to_print);
+}
+
+void
+jit_typeinfo::to_generic (jit_type *type, llvm::GenericValue& gv)
+{
+  // duplication here can probably be removed somehow
+  if (type == any)
+    to_generic (type, gv, octave_value ());
+  else if (type == scalar)
+    to_generic (type, gv, octave_value (0));
+  else
+    assert (false && "Type not supported yet");
+}
+
+void
+jit_typeinfo::to_generic (jit_type *type, llvm::GenericValue& gv, octave_value ov)
+{
+  if (type == any)
+    {
+      octave_base_value *obv = ov.internal_rep ();
+      obv->grab ();
+      ov_out[ov_out_idx] = obv;
+      gv.PointerVal = &ov_out[ov_out_idx++];
+    }
+  else
+    {
+      scalar_out[scalar_out_idx] = ov.double_value ();
+      gv.PointerVal = &scalar_out[scalar_out_idx++];
+    }
+}
+
+octave_value
+jit_typeinfo::to_octave_value (jit_type *type, llvm::GenericValue& gv)
+{
+  if (type == any)
+    {
+      octave_base_value **ptr = reinterpret_cast<octave_base_value**>(gv.PointerVal);
+      return octave_value (*ptr);
+    }
+  else if (type == scalar)
+    {
+      double *ptr = reinterpret_cast<double*>(gv.PointerVal);
+      return octave_value (*ptr);
+    }
+  else
+    assert (false && "Type not supported yet");
+}
+
+void
+jit_typeinfo::reset_generic (size_t nargs)
+{
+  scalar_out_idx = 0;
+  ov_out_idx = 0;
+
+  if (scalar_out.size () < nargs)
+    scalar_out.resize (nargs);
+
+  if (ov_out.size () < nargs)
+    ov_out.resize (nargs);
+}
+
+jit_type*
+jit_typeinfo::new_type (const std::string& name, bool force_init,
+                        jit_type *parent, llvm::Type *llvm_type)
+{
+  jit_type *ret = new jit_type (name, force_init, parent, llvm_type, next_id++);
+  id_to_type.push_back (ret);
+  return ret;
+}
+
+tree_jit::tree_jit (void) : context (llvm::getGlobalContext ()), engine (0)
+{
+  llvm::InitializeNativeTarget ();
+  module = new llvm::Module ("octave", context);
+  assert (module);
 }
 
 tree_jit::~tree_jit (void)
 {
-  delete module;
+  for (compiled_map::iterator iter = compiled.begin (); iter != compiled.end ();
+       ++iter)
+    {
+      function_list& flist = iter->second;
+      for (function_list::iterator fiter = flist.begin (); fiter != flist.end ();
+           ++fiter)
+        delete *fiter;
+    }
+
+  delete tinfo;
 }
 
 bool
 tree_jit::execute (tree& tee)
 {
-  if (!engine)
+  // something funny happens during initialization with the engine
+  bool need_init = false;
+  if (! engine)
     {
-      engine = ExecutionEngine::createJIT (module);
-
-      // initialize pass manager
-      pass_manager = new FunctionPassManager (module);
-      pass_manager->add (new TargetData(*engine->getTargetData ()));
-      pass_manager->add (createBasicAliasAnalysisPass ());
-      pass_manager->add (createPromoteMemoryToRegisterPass ());
-      pass_manager->add (createInstructionCombiningPass ());
-      pass_manager->add (createReassociatePass ());
-      pass_manager->add (createGVNPass ());
-      pass_manager->add (createCFGSimplificationPass ());
-      pass_manager->doInitialization ();
-
-      // create external functions
-      Type *vtype = Type::getVoidTy (context);
-      std::vector<Type*> pd_args (2);
-      pd_args[0] = Type::getInt8PtrTy (context);
-      pd_args[1] = Type::getDoubleTy (context);
-      FunctionType *print_double_ty = FunctionType::get (vtype, pd_args, false);
-      print_double = Function::Create (print_double_ty,
-                                       Function::ExternalLinkage,
-                                       "octave_print_double", module);
-      engine->addGlobalMapping (print_double,
-                                reinterpret_cast<void*>(&octave_print_double));
+      need_init = true;
+      engine = llvm::ExecutionEngine::createJIT (module);
     }
 
-  if (!engine)
-    // sometimes this fails during early initialization
+  if (! engine)
     return false;
 
-  // find function
-  function_info *finfo;
-  finfo_map_iterator iter = compiled_functions.find (&tee);
+  if (need_init)
+    {
+      module_pass_manager = new llvm::PassManager ();
+      module_pass_manager->add (llvm::createAlwaysInlinerPass ());
+
+      pass_manager = new llvm::FunctionPassManager (module);
+      pass_manager->add (new llvm::TargetData(*engine->getTargetData ()));
+      pass_manager->add (llvm::createBasicAliasAnalysisPass ());
+      pass_manager->add (llvm::createPromoteMemoryToRegisterPass ());
+      pass_manager->add (llvm::createInstructionCombiningPass ());
+      pass_manager->add (llvm::createReassociatePass ());
+      pass_manager->add (llvm::createGVNPass ());
+      pass_manager->add (llvm::createCFGSimplificationPass ());
+      pass_manager->doInitialization ();
+
+      llvm::Type *ov_t = llvm::StructType::create (context, "octave_base_value");
+      ov_t = ov_t->getPointerTo ();
+
+      tinfo = new jit_typeinfo (module, engine, ov_t);
+    }
+
+  function_list& fnlist = compiled[&tee];
+  for (function_list::iterator iter = fnlist.begin (); iter != fnlist.end ();
+       ++iter)
+    {
+      function_info& fi = **iter;
+      if (fi.match ())
+        return fi.execute ();
+    }
+
+  function_info *fi = new function_info (*this, tee);
+  fnlist.push_back (fi);
+
+  return fi->execute ();
+}
+
+void
+tree_jit::type_infer::visit_anon_fcn_handle (tree_anon_fcn_handle&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_argument_list (tree_argument_list&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_binary_expression (tree_binary_expression& be)
+{
+  if (is_lvalue)
+    fail ();
+
+  tree_expression *lhs = be.lhs ();
+  lhs->accept (*this);
+  jit_type *tlhs = type_stack.back ();
+  type_stack.pop_back ();
+
+  tree_expression *rhs = be.rhs ();
+  rhs->accept (*this);
+  jit_type *trhs = type_stack.back ();
+
+  jit_type *result = tinfo->binary_op_result (be.op_type (), tlhs, trhs);
+  if (! result)
+    fail ();
+
+  type_stack.push_back (result);
+}
+
+void
+tree_jit::type_infer::visit_break_command (tree_break_command&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_colon_expression (tree_colon_expression&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_continue_command (tree_continue_command&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_global_command (tree_global_command&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_persistent_command (tree_persistent_command&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_decl_elt (tree_decl_elt&)
+{
+  fail ();
+}
 
-  if (iter == compiled_functions.end ())
-    finfo = compile (tee);
-  else
-    finfo = iter->second;
+void
+tree_jit::type_infer::visit_decl_init_list (tree_decl_init_list&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_simple_for_command (tree_simple_for_command&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_complex_for_command (tree_complex_for_command&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_octave_user_script (octave_user_script&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_octave_user_function (octave_user_function&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_octave_user_function_header (octave_user_function&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_octave_user_function_trailer (octave_user_function&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_function_def (tree_function_def&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_identifier (tree_identifier& ti)
+{
+  handle_identifier (ti.name (), ti.do_lookup ());
+}
 
-  return finfo->execute ();
+void
+tree_jit::type_infer::visit_if_clause (tree_if_clause&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_if_command (tree_if_command&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_if_command_list (tree_if_command_list&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_index_expression (tree_index_expression&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_matrix (tree_matrix&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_cell (tree_cell&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_multi_assignment (tree_multi_assignment&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_no_op_command (tree_no_op_command&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_constant (tree_constant& tc)
+{
+  if (is_lvalue)
+    fail ();
+
+  octave_value v = tc.rvalue1 ();
+  jit_type *type = tinfo->type_of (v);
+  if (! type)
+    fail ();
+
+  type_stack.push_back (type);
 }
 
-tree_jit::function_info*
-tree_jit::compile (tree& tee)
+void
+tree_jit::type_infer::visit_fcn_handle (tree_fcn_handle&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_parameter_list (tree_parameter_list&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_postfix_expression (tree_postfix_expression&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_prefix_expression (tree_prefix_expression&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_return_command (tree_return_command&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_return_list (tree_return_list&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_simple_assignment (tree_simple_assignment& tsa)
+{
+  if (is_lvalue)
+    fail ();
+
+  // resolve rhs
+  is_lvalue = false;
+  tree_expression *rhs = tsa.right_hand_side ();
+  rhs->accept (*this);
+
+  jit_type *trhs = type_stack.back ();
+  type_stack.pop_back ();
+
+  // resolve lhs
+  is_lvalue = true;
+  rvalue_type = trhs;
+  tree_expression *lhs = tsa.left_hand_side ();
+  lhs->accept (*this);
+
+  // we don't pop back here, as the resulting type should be the rhs type
+  // which is equal to the lhs type anways
+  jit_type *tlhs = type_stack.back ();
+  if (tlhs != trhs)
+    fail ();
+
+  is_lvalue = false;
+  rvalue_type = 0;
+}
+
+void
+tree_jit::type_infer::visit_statement (tree_statement& stmt)
 {
-  value_stack.clear ();
-  variables.clear ();
+  if (is_lvalue)
+    fail ();
+
+  tree_command *cmd = stmt.command ();
+  tree_expression *expr = stmt.expression ();
+
+  if (cmd)
+    cmd->accept (*this);
+  else
+    {
+      // ok, this check for ans appears three times as cp
+      bool do_bind_ans = false;
+
+      if (expr->is_identifier ())
+        {
+          tree_identifier *id = dynamic_cast<tree_identifier *> (expr);
+
+          do_bind_ans = (! id->is_variable ());
+        }
+      else
+        do_bind_ans = (! expr->is_assignment_expression ());
+
+      expr->accept (*this);
+
+      if (do_bind_ans)
+        {
+          is_lvalue = true;
+          rvalue_type = type_stack.back ();
+          type_stack.pop_back ();
+          handle_identifier ("ans", symbol_table::varval ("ans"));
+
+          if (rvalue_type != type_stack.back ())
+            fail ();
+
+          is_lvalue = false;
+          rvalue_type = 0;
+        }
+
+      type_stack.pop_back ();
+    }
+}
+
+void
+tree_jit::type_infer::visit_statement_list (tree_statement_list&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_switch_case (tree_switch_case&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_switch_case_list (tree_switch_case_list&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_switch_command (tree_switch_command&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_try_catch_command (tree_try_catch_command&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_unwind_protect_command (tree_unwind_protect_command&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_while_command (tree_while_command&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::visit_do_until_command (tree_do_until_command&)
+{
+  fail ();
+}
+
+void
+tree_jit::type_infer::handle_identifier (const std::string& name, octave_value v)
+{
+  type_map::iterator iter = types.find (name);
+  if (iter == types.end ())
+    {
+      jit_type *ty = tinfo->type_of (v);
+      if (is_lvalue)
+        {
+          if (! ty)
+            ty = rvalue_type;
+        }
+      else
+        {
+          if (! ty)
+            fail ();
+
+          argin.insert (name);
+        }
+
+      types[name] = ty;
+      type_stack.push_back (ty);
+    }
+  else
+    type_stack.push_back (iter->second);
+}
+
+tree_jit::code_generator::code_generator (jit_typeinfo *ti, llvm::Module *module,
+                                          tree &tee,
+                                          const std::set<std::string>& argin,
+                                          const type_map& infered_types)
+  : tinfo (ti), is_lvalue (false)
   
-  // setup function
-  std::vector<Type*> args (2);
-  args[0] = Type::getInt1PtrTy (context);
-  args[1] = Type::getDoublePtrTy (context);
-  FunctionType *ft = FunctionType::get (Type::getVoidTy (context), args, false);
-  Function *compiling = Function::Create (ft, Function::ExternalLinkage,
-                                          "test_fn", module);
+{
+  // determine the function type through the type of all variables
+  std::vector<llvm::Type *> arg_types (infered_types.size ());
+  size_t idx = 0;
+  type_map::const_iterator iter;
+  for (iter = infered_types.begin (); iter != infered_types.end (); ++iter, ++idx)
+    arg_types[idx] = iter->second->to_llvm_arg ();
+
+  // now create the LLVM function from our determined types
+  llvm::LLVMContext &ctx = llvm::getGlobalContext ();
+  llvm::Type *tvoid = llvm::Type::getVoidTy (ctx);
+  llvm::FunctionType *ft = llvm::FunctionType::get (tvoid, arg_types, false);
+  function = llvm::Function::Create (ft, llvm::Function::ExternalLinkage,
+                                     "foobar", module);
 
-  entry_block = BasicBlock::Create (context, "entry", compiling);
-  BasicBlock *body = BasicBlock::Create (context, "body",
-                                         compiling);
+  // declare each argument and copy its initial value
+  llvm::BasicBlock *body = llvm::BasicBlock::Create (ctx, "body", function);
   builder.SetInsertPoint (body);
+  llvm::Function::arg_iterator arg_iter = function->arg_begin();
+  for (iter = infered_types.begin (); iter != infered_types.end ();
+       ++iter, ++arg_iter)
+       
+    {
+      llvm::Type *vartype = iter->second->to_llvm ();
+      llvm::Value *var = builder.CreateAlloca (vartype, 0, iter->first);
+      variables[iter->first] = value (iter->second, var);
 
-  // convert tree to LLVM IR
+      if (iter->second->force_init () || argin.count (iter->first))
+        {
+          llvm::Value *loaded_arg = builder.CreateLoad (arg_iter);
+          builder.CreateStore (loaded_arg, var);
+        }
+    }
+
+  // generate body
   try
     {
       tee.accept (*this);
     }
   catch (const jit_fail_exception&)
     {
-      //FIXME: cleanup
-      return  compiled_functions[&tee] = new function_info ();
-    }
-
-  // copy input arguments
-  builder.SetInsertPoint (entry_block);
-
-  Function::arg_iterator arg_iter = compiling->arg_begin ();
-  Value *arg_defined = arg_iter;
-  Value *arg_value = ++arg_iter;
-
-  arg_defined->setName ("arg_defined");
-  arg_value->setName ("arg_value");
-
-  size_t idx = 0;
-  std::vector<std::string> arg_names;
-  std::vector<bool> arg_used;
-  for (var_map_iterator iter = variables.begin (); iter != variables.end ();
-       ++iter, ++idx)
-    {
-      arg_names.push_back (iter->first);
-      arg_used.push_back (iter->second.use);
-
-      Value *gep_defined = builder.CreateConstInBoundsGEP1_32 (arg_defined, idx);
-      Value *defined = builder.CreateLoad (gep_defined);
-      builder.CreateStore (defined, iter->second.defined);
-
-      Value *gep_value = builder.CreateConstInBoundsGEP1_32 (arg_value, idx);
-      Value *value = builder.CreateLoad (gep_value);
-      builder.CreateStore (value, iter->second.value);
-    }
-  builder.CreateBr (body);
-
-  // copy output arguments
-  BasicBlock *cleanup = BasicBlock::Create (context, "cleanup", compiling);
-  builder.SetInsertPoint (body);
-  builder.CreateBr (cleanup);
-  builder.SetInsertPoint (cleanup);
-
-  idx = 0;
-  for (var_map_iterator iter = variables.begin (); iter != variables.end ();
-       ++iter, ++idx)
-    {
-      Value *gep_defined = builder.CreateConstInBoundsGEP1_32 (arg_defined, idx);
-      Value *defined = builder.CreateLoad (iter->second.defined);
-      builder.CreateStore (defined, gep_defined);
-
-      Value *gep_value = builder.CreateConstInBoundsGEP1_32 (arg_value, idx);
-      Value *value = builder.CreateLoad (iter->second.value, iter->first);
-      builder.CreateStore (value, gep_value);
+      function->eraseFromParent ();
+      function = 0;
+      return;
     }
 
-  builder.CreateRetVoid ();
-
-  // print what we compiled (for debugging)
-  // we leave this in for now, as other people might want to view the ir created
-  // should be removed eventually though
-  const bool debug_print_ir = false;
-  if (debug_print_ir)
+  // copy computed values back into arguments
+  arg_iter = function->arg_begin ();
+  for (iter = infered_types.begin (); iter != infered_types.end ();
+       ++iter, ++arg_iter)
     {
-      raw_os_ostream os (std::cout);
-      std::cout << "Compiling --------------------\n";
-      tree_print_code tpc (std::cout);
-      std::cout << typeid (tee).name () << std::endl;
-      tee.accept (tpc);
-      std::cout << "\n--------------------\n";
-
-      std::cout << "llvm_ir\n";
-      compiling->print (os);
-      std::cout << "--------------------\n";
+      llvm::Value *var = variables[iter->first].second;
+      llvm::Value *loaded_var = builder.CreateLoad (var);
+      builder.CreateStore (loaded_var, arg_iter);
     }
-  
-  // compile code
-  verifyFunction (*compiling);
-  pass_manager->run (*compiling);
-
-  if (debug_print_ir)
-    {
-      raw_os_ostream os (std::cout);
-      std::cout << "optimized llvm_ir\n";
-      compiling->print (os);
-      std::cout << "--------------------\n";
-    }
-
-  jit_function fun =
-    reinterpret_cast<jit_function> (engine->getPointerToFunction (compiling));
-
-  return compiled_functions[&tee] = new function_info (fun, arg_names, arg_used);
+  builder.CreateRetVoid ();
 }
 
-tree_jit::variable_info
-tree_jit::find (const std::string &name, bool use)
+void
+tree_jit::code_generator::visit_anon_fcn_handle (tree_anon_fcn_handle&)
 {
-  var_map_iterator iter = variables.find (name);
-  if (iter == variables.end ())
-    {
-      // we currently just assume everything is a double
-      Type *dbl = Type::getDoubleTy (context);
-      Type *bol = Type::getInt1Ty (context);
-      IRBuilder<> tmpB (entry_block, entry_block->begin ());
+  fail ();
+}
 
-      variable_info vinfo;
-      vinfo.defined = tmpB.CreateAlloca (bol, 0);
-      vinfo.value = tmpB.CreateAlloca (dbl, 0, name);
-      vinfo.use = use;
-      variables[name] = vinfo;
-      return vinfo;
-    }
-  else
-    {
-      iter->second.use = iter->second.use || use;
-      return iter->second;
-    }
+void
+tree_jit::code_generator::visit_argument_list (tree_argument_list&)
+{
+  fail ();
 }
 
 void
-tree_jit::do_assign (variable_info vinfo, llvm::Value *value)
+tree_jit::code_generator::visit_binary_expression (tree_binary_expression& be)
 {
-  // create assign expression
-  Value *result = builder.CreateStore (value, vinfo.value);
-  value_stack.push_back (result);
+  tree_expression *lhs = be.lhs ();
+  lhs->accept (*this);
+  value lhsv = value_stack.back ();
+  value_stack.pop_back ();
+
+  tree_expression *rhs = be.rhs ();
+  rhs->accept (*this);
+  value rhsv = value_stack.back ();
+  value_stack.pop_back ();
+
+  const jit_function::overload& ol
+    = tinfo->binary_op_overload (be.op_type (), lhsv.first, rhsv.first);
 
-  // update defined for lhs
-  Type *btype = Type::getInt1Ty (context);
-  Value *btrue = ConstantInt::get (btype, APInt (1, 1));
-  builder.CreateStore (btrue, vinfo.defined);
+  if (! ol.function)
+    fail ();
+
+  llvm::Value *result = builder.CreateCall2 (ol.function, lhsv.second,
+                                             rhsv.second);
+  push_value (ol.result, result);
+}
+
+void
+tree_jit::code_generator::visit_break_command (tree_break_command&)
+{
+  fail ();
 }
 
 void
-tree_jit::emit_print (const std::string& vname, llvm::Value *value)
+tree_jit::code_generator::visit_colon_expression (tree_colon_expression&)
+{
+  fail ();
+}
+
+void
+tree_jit::code_generator::visit_continue_command (tree_continue_command&)
 {
-  Value *pname = builder.CreateGlobalStringPtr (vname);
-  builder.CreateCall2 (print_double, pname, value);
+  fail ();
+}
+
+void
+tree_jit::code_generator::visit_global_command (tree_global_command&)
+{
+  fail ();
 }
 
 void
-tree_jit::visit_anon_fcn_handle (tree_anon_fcn_handle&)
+tree_jit::code_generator::visit_persistent_command (tree_persistent_command&)
+{
+  fail ();
+}
+
+void
+tree_jit::code_generator::visit_decl_elt (tree_decl_elt&)
+{
+  fail ();
+}
+
+void
+tree_jit::code_generator::visit_decl_init_list (tree_decl_init_list&)
+{
+  fail ();
+}
+
+void
+tree_jit::code_generator::visit_simple_for_command (tree_simple_for_command&)
 {
   fail ();
 }
 
 void
-tree_jit::visit_argument_list (tree_argument_list&)
+tree_jit::code_generator::visit_complex_for_command (tree_complex_for_command&)
+{
+  fail ();
+}
+
+void
+tree_jit::code_generator::visit_octave_user_script (octave_user_script&)
+{
+  fail ();
+}
+
+void
+tree_jit::code_generator::visit_octave_user_function (octave_user_function&)
+{
+  fail ();
+}
+
+void
+tree_jit::code_generator::visit_octave_user_function_header (octave_user_function&)
+{
+  fail ();
+}
+
+void
+tree_jit::code_generator::visit_octave_user_function_trailer (octave_user_function&)
+{
+  fail ();
+}
+
+void
+tree_jit::code_generator::visit_function_def (tree_function_def&)
 {
   fail ();
 }
 
 void
-tree_jit::visit_binary_expression (tree_binary_expression& be)
+tree_jit::code_generator::visit_identifier (tree_identifier& ti)
 {
-  tree_expression *lhs = be.lhs ();
-  tree_expression *rhs = be.rhs ();
-  if (lhs && rhs)
+  std::string name = ti.name ();
+  value variable = variables[name];
+  if (is_lvalue)
+    value_stack.push_back (variable);
+  else
     {
-      lhs->accept (*this);
-      rhs->accept (*this);
+      llvm::Value *load = builder.CreateLoad (variable.second, name);
+      push_value (variable.first, load);
+    }
+}
+
+void
+tree_jit::code_generator::visit_if_clause (tree_if_clause&)
+{
+  fail ();
+}
 
-      Value *lhsv = value_stack.back ();
-      value_stack.pop_back ();
+void
+tree_jit::code_generator::visit_if_command (tree_if_command&)
+{
+  fail ();
+}
 
-      Value *rhsv = value_stack.back ();
-      value_stack.pop_back ();
+void
+tree_jit::code_generator::visit_if_command_list (tree_if_command_list&)
+{
+  fail ();
+}
 
-      Value *result;
-      switch (be.op_type ())
-        {
-        case octave_value::op_add:
-          result = builder.CreateFAdd (lhsv, rhsv);
-          break;
-        case octave_value::op_sub:
-          result = builder.CreateFSub (lhsv, rhsv);
-          break;
-        case octave_value::op_mul:
-          result = builder.CreateFMul (lhsv, rhsv);
-          break;
-        case octave_value::op_div:
-          result = builder.CreateFDiv (lhsv, rhsv);
-          break;
-        default:
-          fail ();
-        }
+void
+tree_jit::code_generator::visit_index_expression (tree_index_expression&)
+{
+  fail ();
+}
+
+void
+tree_jit::code_generator::visit_matrix (tree_matrix&)
+{
+  fail ();
+}
+
+void
+tree_jit::code_generator::visit_cell (tree_cell&)
+{
+  fail ();
+}
 
-      value_stack.push_back (result);
+void
+tree_jit::code_generator::visit_multi_assignment (tree_multi_assignment&)
+{
+  fail ();
+}
+
+void
+tree_jit::code_generator::visit_no_op_command (tree_no_op_command&)
+{
+  fail ();
+}
+
+void
+tree_jit::code_generator::visit_constant (tree_constant& tc)
+{
+  octave_value v = tc.rvalue1 ();
+  if (v.is_real_scalar () && v.is_double_type ())
+    {
+      llvm::LLVMContext& ctx = llvm::getGlobalContext ();
+      double dv = v.double_value ();
+      llvm::Value *lv = llvm::ConstantFP::get (ctx, llvm::APFloat (dv));
+      push_value (tinfo->get_scalar (), lv);
     }
   else
     fail ();
 }
 
 void
-tree_jit::visit_break_command (tree_break_command&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_colon_expression (tree_colon_expression&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_continue_command (tree_continue_command&)
+tree_jit::code_generator::visit_fcn_handle (tree_fcn_handle&)
 {
   fail ();
 }
 
 void
-tree_jit::visit_global_command (tree_global_command&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_persistent_command (tree_persistent_command&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_decl_elt (tree_decl_elt&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_decl_init_list (tree_decl_init_list&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_simple_for_command (tree_simple_for_command&)
+tree_jit::code_generator::visit_parameter_list (tree_parameter_list&)
 {
   fail ();
 }
 
 void
-tree_jit::visit_complex_for_command (tree_complex_for_command&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_octave_user_script (octave_user_script&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_octave_user_function (octave_user_function&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_octave_user_function_header (octave_user_function&)
+tree_jit::code_generator::visit_postfix_expression (tree_postfix_expression&)
 {
   fail ();
 }
 
 void
-tree_jit::visit_octave_user_function_trailer (octave_user_function&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_function_def (tree_function_def&)
+tree_jit::code_generator::visit_prefix_expression (tree_prefix_expression&)
 {
   fail ();
 }
 
 void
-tree_jit::visit_identifier (tree_identifier& ti)
-{
-  octave_value ov = ti.do_lookup ();
-  if (ov.is_function ())
-    fail ();
-
-  std::string name = ti.name ();
-  variable_info vinfo = find (ti.name (), true);
-
-  // TODO check defined
-
-  Value *load_value = builder.CreateLoad (vinfo.value, name);
-  value_stack.push_back (load_value);
-}
-
-void
-tree_jit::visit_if_clause (tree_if_clause&)
+tree_jit::code_generator::visit_return_command (tree_return_command&)
 {
   fail ();
 }
 
 void
-tree_jit::visit_if_command (tree_if_command&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_if_command_list (tree_if_command_list&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_index_expression (tree_index_expression&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_matrix (tree_matrix&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_cell (tree_cell&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_multi_assignment (tree_multi_assignment&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_no_op_command (tree_no_op_command&)
+tree_jit::code_generator::visit_return_list (tree_return_list&)
 {
   fail ();
 }
 
 void
-tree_jit::visit_constant (tree_constant& tc)
+tree_jit::code_generator::visit_simple_assignment (tree_simple_assignment& tsa)
 {
-  octave_value v = tc.rvalue1 ();
-  if (v.is_real_scalar () && v.is_double_type ())
-    {
-      double dv = v.double_value ();
-      Value *lv = ConstantFP::get (context,  APFloat (dv));
-      value_stack.push_back (lv);
-    }
-  else
+  if (is_lvalue)
     fail ();
-}
+
+  // resolve lhs
+  is_lvalue = true;
+  tree_expression *lhs = tsa.left_hand_side ();
+  lhs->accept (*this);
+
+  value lhsv = value_stack.back ();
+  value_stack.pop_back ();
 
-void
-tree_jit::visit_fcn_handle (tree_fcn_handle&)
-{
-  fail ();
-}
+  // resolve rhs
+  is_lvalue = false;
+  tree_expression *rhs = tsa.right_hand_side ();
+  rhs->accept (*this);
+
+  value rhsv = value_stack.back ();
+  value_stack.pop_back ();
 
-void
-tree_jit::visit_parameter_list (tree_parameter_list&)
-{
-  fail ();
-}
+  // do assign, then store rhs as the result
+  jit_function::overload ol = tinfo->assign_op (lhsv.first, rhsv.first);
+  builder.CreateCall2 (ol.function, lhsv.second, rhsv.second);
 
-void
-tree_jit::visit_postfix_expression (tree_postfix_expression&)
-{
-  fail ();
+  if (tsa.print_result ())
+    emit_print (lhs->name (), rhsv);
+
+  value_stack.push_back (rhsv);
 }
 
 void
-tree_jit::visit_prefix_expression (tree_prefix_expression&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_return_command (tree_return_command&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_return_list (tree_return_list&)
-{
-  fail ();
-}
-
-void
-tree_jit::visit_simple_assignment (tree_simple_assignment& tsa)
-{
-  // only support an identifier as lhs
-  tree_identifier *lhs = dynamic_cast<tree_identifier*> (tsa.left_hand_side ());
-  if (!lhs)
-    fail ();
-
-  variable_info lhsv = find (lhs->name (), false);
-  
-  // resolve rhs as normal
-  tree_expression *rhs = tsa.right_hand_side ();
-  rhs->accept (*this);
-
-  Value *rhsv = value_stack.back ();
-  value_stack.pop_back ();
-
-  do_assign (lhsv, rhsv);
-
-  if (tsa.print_result ())
-    emit_print (lhs->name (), rhsv);
-}
-
-void
-tree_jit::visit_statement (tree_statement& stmt)
+tree_jit::code_generator::visit_statement (tree_statement& stmt)
 {
   tree_command *cmd = stmt.command ();
   tree_expression *expr = stmt.expression ();
@@ -567,8 +1227,6 @@
     cmd->accept (*this);
   else
     {
-      // TODO deal with printing
-
       // stolen from tree_evaluator::visit_statement
       bool do_bind_ans = false;
 
@@ -585,11 +1243,15 @@
 
       if (do_bind_ans)
         {
-          Value *rhs = value_stack.back ();
-          value_stack.pop_back ();
+          value rhs = value_stack.back ();
+          value ans = variables["ans"];
+          if (ans.first != rhs.first)
+            fail ();
 
-          variable_info ans = find ("ans", false);
-          do_assign (ans, rhs);
+          builder.CreateStore (rhs.second, ans.second);
+
+          if (expr->print_result ())
+            emit_print ("ans", rhs);
         }
       else if (expr->is_identifier () && expr->print_result ())
         {
@@ -604,100 +1266,151 @@
 }
 
 void
-tree_jit::visit_statement_list (tree_statement_list&)
+tree_jit::code_generator::visit_statement_list (tree_statement_list&)
 {
   fail ();
 }
 
 void
-tree_jit::visit_switch_case (tree_switch_case&)
+tree_jit::code_generator::visit_switch_case (tree_switch_case&)
 {
   fail ();
 }
 
 void
-tree_jit::visit_switch_case_list (tree_switch_case_list&)
+tree_jit::code_generator::visit_switch_case_list (tree_switch_case_list&)
 {
   fail ();
 }
 
 void
-tree_jit::visit_switch_command (tree_switch_command&)
+tree_jit::code_generator::visit_switch_command (tree_switch_command&)
 {
   fail ();
 }
 
 void
-tree_jit::visit_try_catch_command (tree_try_catch_command&)
+tree_jit::code_generator::visit_try_catch_command (tree_try_catch_command&)
 {
   fail ();
 }
 
 void
-tree_jit::visit_unwind_protect_command (tree_unwind_protect_command&)
+tree_jit::code_generator::visit_unwind_protect_command (tree_unwind_protect_command&)
 {
   fail ();
 }
 
 void
-tree_jit::visit_while_command (tree_while_command&)
+tree_jit::code_generator::visit_while_command (tree_while_command&)
 {
   fail ();
 }
 
 void
-tree_jit::visit_do_until_command (tree_do_until_command&)
+tree_jit::code_generator::visit_do_until_command (tree_do_until_command&)
 {
   fail ();
 }
 
 void
-tree_jit::fail (void)
+tree_jit::code_generator::emit_print (const std::string& name, const value& v)
 {
-  throw jit_fail_exception ();
+  const jit_function::overload& ol = tinfo->print_value (v.first);
+  if (! ol.function)
+    fail ();
+
+  llvm::Value *str = builder.CreateGlobalStringPtr (name);
+  builder.CreateCall2 (ol.function, str, v.second);
 }
 
-tree_jit::function_info::function_info (void) : function (0)
-{}
+tree_jit::function_info::function_info (tree_jit& tjit, tree& tee) :
+  tinfo (tjit.tinfo), engine (tjit.engine)
+{
+  type_infer infer(tjit.tinfo);
+
+  try
+    {
+      tee.accept (infer);
+    }
+  catch (const jit_fail_exception&)
+    {
+      function = 0;
+      return;
+    }
+
+  argin = infer.get_argin ();
+  types = infer.get_types ();
+
+  code_generator gen(tjit.tinfo, tjit.module, tee, argin, types);
+  function = gen.get_function ();
 
-tree_jit::function_info::function_info (jit_function fun,
-                                        const std::vector<std::string>& args,
-                                        const std::vector<bool>& arg_used) :
-  function (fun), arguments (args), argument_used (arg_used)
-{}
+  if (function)
+    {
+      llvm::verifyFunction (*function);
+      tjit.module_pass_manager->run (*tjit.module);
+      tjit.pass_manager->run (*function);
+
+      if (debug_print)
+        {
+          std::cout << "Compiled:\n";
+          std::cout << tee.str_print_code () << std::endl;
 
-bool tree_jit::function_info::execute ()
+          std::cout << "Code:\n";
+
+          llvm::raw_os_ostream os (std::cout);
+          function->print (os);
+        }
+    }
+}
+
+bool
+tree_jit::function_info::execute () const
 {
   if (! function)
     return false;
 
-  // FIXME: we are doing hash lookups every time, this has got to be slow
-  unwind_protect up;
-  bool *args_defined = new bool[arguments.size ()];   // vector<bool> sucks
-  up.add_delete (args_defined);
+  tinfo->reset_generic (types.size ());
 
-  std::vector<double>  args_values (arguments.size ());
-  for (size_t i = 0; i < arguments.size (); ++i)
+  std::vector<llvm::GenericValue> args (types.size ());
+  size_t idx;
+  type_map::const_iterator iter;
+  for (idx = 0, iter = types.begin (); iter != types.end (); ++iter, ++idx)
     {
-      octave_value ov = symbol_table::varval (arguments[i]);
-
-      if (argument_used[i])
+      if (argin.count (iter->first))
         {
-          if (! (ov.is_double_type () && ov.is_real_scalar ()))
-            return false;
-
-          args_defined[i] = ov.is_defined ();
-          args_values[i] = ov.double_value ();
+          octave_value ov = symbol_table::varval (iter->first);
+          tinfo->to_generic (iter->second, args[idx], ov);
         }
       else
-        args_defined[i] = false;
+        tinfo->to_generic (iter->second, args[idx]);
     }
 
-  function (args_defined, &args_values[0]);
+  engine->runFunction (function, args);
 
-  for (size_t i = 0; i < arguments.size (); ++i)
-    if (args_defined[i])
-      symbol_table::varref (arguments[i]) = octave_value (args_values[i]);
+  for (idx = 0, iter = types.begin (); iter != types.end (); ++iter, ++idx)
+    {
+      octave_value result = tinfo->to_octave_value (iter->second, args[idx]);
+      symbol_table::varref (iter->first) = result;
+    }
 
   return true;
 }
+
+bool
+tree_jit::function_info::match () const
+{
+  for (std::set<std::string>::iterator iter = argin.begin ();
+       iter != argin.end (); ++iter)
+    {
+      jit_type *required_type = types.find (*iter)->second;
+      octave_value val = symbol_table::varref (*iter);
+      jit_type *current_type = tinfo->type_of (val);
+
+      // FIXME: should be: ! required_type->is_parent (current_type)
+      if (required_type != current_type)
+        return false;
+    }
+
+  return true;
+}

--- a/src/pt-jit.h
+++ b/src/pt-jit.h
@@ -23,31 +23,247 @@
 #if !defined (octave_tree_jit_h)
 #define octave_tree_jit_h 1
 
+#include <list>
 #include <map>
+#include <set>
 #include <stdexcept>
 #include <vector>
 
+#include "Array.h"
 #include "pt-walk.h"
 
-class jit_fail_exception : public std::exception {};
+// -------------------- Current status --------------------
+// Simple binary operations (+-*/) on octave_scalar's (doubles) are optimized.
+// However, there is no warning emitted on divide by 0. For example,
+// a = 5;
+// b = a * 5 + a;
+//
+// For other types all binary operations are compiled but not optimized. For
+// example,
+// a = [1 2 3]
+// b = a + a;
+// will compile to do_binary_op (a, a).
+// ---------------------------------------------------------
 
-// LLVM forward declares
+
+// we don't want to include llvm headers here, as they require __STDC_LIMIT_MACROS
+// and __STDC_CONSTANT_MACROS be defined in the entire compilation unit
 namespace llvm
 {
   class Value;
   class Module;
   class FunctionPassManager;
+  class PassManager;
   class ExecutionEngine;
   class Function;
   class BasicBlock;
   class LLVMContext;
+  class Type;
+  class GenericValue;
 }
 
+class octave_base_value;
+class octave_value;
 class tree;
 
+// thrown when we should give up on JIT and interpret
+class jit_fail_exception : public std::exception {};
+
+// Used to keep track of estimated (infered) types during JIT. This is a
+// hierarchical type system which includes both concrete and abstract types.
+//
+// Current, we only support any and scalar types. If we can't figure out what
+// type a variable is, we assign it the any type. This allows us to generate
+// code even for the case of poor type inference.
+class
+OCTINTERP_API
+jit_type
+{
+public:
+  jit_type (const std::string& n, bool fi, jit_type *mparent, llvm::Type *lt,
+            int tid) :
+    mname (n), finit (fi), p (mparent), llvm_type (lt), id (tid)
+  {}
+
+  // a user readable type name
+  const std::string& name (void) const { return mname; }
+
+  // do we need to initialize variables of this type, even if they are not
+  // input arguments?
+  bool force_init (void) const { return finit; }
+
+  // a unique id for the type
+  int type_id (void) const { return id; }
+
+  // An abstract base type, may be null
+  jit_type *parent (void) const { return p; }
+
+  // convert to an llvm type
+  llvm::Type *to_llvm (void) const { return llvm_type; }
+
+  // how this type gets passed as a function argument
+  llvm::Type *to_llvm_arg (void) const;
+private:
+  std::string mname;
+  bool finit;
+  jit_type *p;
+  llvm::Type *llvm_type;
+  int id;
+  int depth;
+};
+
+
+// Keeps track of overloads for a builtin function. Used for both type inference
+// and code generation.
+class
+jit_function
+{
+public:
+  struct overload
+  {
+    overload (void) : function (0), can_error (true), result (0) {}
+
+    overload (llvm::Function *f, bool e, jit_type *r, jit_type *arg0) :
+      function (f), can_error (e), result (r), arguments (1)
+    {
+      arguments[0] = arg0;
+    }
+
+    overload (llvm::Function *f, bool e, jit_type *r, jit_type *arg0,
+              jit_type *arg1) : function (f), can_error (e), result (r),
+                                arguments (2)
+    {
+      arguments[0] = arg0;
+      arguments[1] = arg1;
+    }
+
+    llvm::Function *function;
+    bool can_error;
+    jit_type *result;
+    std::vector<jit_type*> arguments;
+  };
+
+  void add_overload (const overload& func)
+  {
+    add_overload (func, func.arguments);
+  }
+
+  void add_overload (llvm::Function *f, bool e, jit_type *r, jit_type *arg0,
+                     jit_type *arg1)
+  {
+    overload ol (f, e, r, arg0, arg1);
+    add_overload (ol);
+  }
+
+  void add_overload (const overload& func,
+                     const std::vector<jit_type*>& args);
+
+  const overload& get_overload (const std::vector<jit_type *>& types) const;
+
+  const overload& get_overload (jit_type *arg0) const
+  {
+    std::vector<jit_type *> types (1);
+    types[0] = arg0;
+    return get_overload (types);
+  }
+
+  const overload& get_overload (jit_type *arg0, jit_type *arg1) const
+  {
+    std::vector<jit_type *> types (2);
+    types[0] = arg0;
+    types[1] = arg1;
+    return get_overload (types);
+  }
+
+  jit_type *get_result (const std::vector<jit_type *>& types) const
+  {
+    const overload& temp = get_overload (types);
+    return temp.result;
+  }
+
+  jit_type *get_result (jit_type *arg0, jit_type *arg1) const
+  {
+    const overload& temp = get_overload (arg0, arg1);
+    return temp.result;
+  }
+private:
+  Array<octave_idx_type> to_idx (const std::vector<jit_type*>& types) const;
+
+  std::vector<Array<overload> > overloads;
+};
+
+// Get information and manipulate jit types.
+class
+OCTINTERP_API
+jit_typeinfo
+{
+public:
+  jit_typeinfo (llvm::Module *m, llvm::ExecutionEngine *e, llvm::Type *ov);
+
+  jit_type *get_any (void) const { return any; }
+
+  jit_type *get_scalar (void) const { return scalar; }
+
+  jit_type *type_of (const octave_value& ov) const;
+
+  const jit_function& binary_op (int op) const;
+
+  const jit_function::overload& binary_op_overload (int op, jit_type *lhs,
+                                                    jit_type *rhs) const
+    {
+      const jit_function& jf = binary_op (op);
+      return jf.get_overload (lhs, rhs);
+    }
+
+  jit_type *binary_op_result (int op, jit_type *lhs, jit_type *rhs) const
+    {
+      const jit_function::overload& ol = binary_op_overload (op, lhs, rhs);
+      return ol.result;
+    }
+
+  const jit_function::overload& assign_op (jit_type *lhs, jit_type *rhs) const;
+
+  const jit_function::overload& print_value (jit_type *to_print) const;
+
+  // FIXME: generic creation should probably be handled seperatly
+  void to_generic (jit_type *type, llvm::GenericValue& gv);
+  void to_generic (jit_type *type, llvm::GenericValue& gv, octave_value ov);
+
+  octave_value to_octave_value (jit_type *type, llvm::GenericValue& gv);
+
+  void reset_generic (size_t nargs);
+private:
+  jit_type *new_type (const std::string& name, bool force_init,
+                      jit_type *parent, llvm::Type *llvm_type);
+
+  void add_print (jit_type *ty, void *call);
+
+  void add_binary_op (jit_type *ty, int op, int llvm_op);
+
+  llvm::Module *module;
+  llvm::ExecutionEngine *engine;
+  int next_id;
+
+  llvm::Type *ov_t;
+
+  std::vector<jit_type*> id_to_type;
+  jit_type *any;
+  jit_type *scalar;
+
+  std::vector<jit_function> binary_ops;
+  jit_function assign_fn;
+  jit_function print_fn;
+
+  size_t scalar_out_idx;
+  std::vector<double> scalar_out;
+
+  size_t ov_out_idx;
+  std::vector<octave_base_value*> ov_out;
+};
+
 class
 OCTINTERP_API
-tree_jit : private tree_walker
+tree_jit
 {
 public:
   tree_jit (void);
@@ -56,146 +272,265 @@
 
   bool execute (tree& tee);
  private:
-  typedef void (*jit_function)(bool*, double*);
+  typedef std::map<std::string, jit_type *> type_map;
+
+  class
+  type_infer : public tree_walker
+  {
+  public:
+    type_infer (jit_typeinfo *ti) : tinfo (ti), is_lvalue (false),
+                                    rvalue_type (0)
+    {}
+
+    const std::set<std::string>& get_argin () const { return argin; }
+
+    const type_map& get_types () const { return types; }
+
+    void visit_anon_fcn_handle (tree_anon_fcn_handle&);
+
+    void visit_argument_list (tree_argument_list&);
+
+    void visit_binary_expression (tree_binary_expression&);
+
+    void visit_break_command (tree_break_command&);
+
+    void visit_colon_expression (tree_colon_expression&);
+
+    void visit_continue_command (tree_continue_command&);
+
+    void visit_global_command (tree_global_command&);
+
+    void visit_persistent_command (tree_persistent_command&);
+
+    void visit_decl_elt (tree_decl_elt&);
+
+    void visit_decl_init_list (tree_decl_init_list&);
+
+    void visit_simple_for_command (tree_simple_for_command&);
+
+    void visit_complex_for_command (tree_complex_for_command&);
+
+    void visit_octave_user_script (octave_user_script&);
+
+    void visit_octave_user_function (octave_user_function&);
+
+    void visit_octave_user_function_header (octave_user_function&);
+
+    void visit_octave_user_function_trailer (octave_user_function&);
+
+    void visit_function_def (tree_function_def&);
+
+    void visit_identifier (tree_identifier&);
+
+    void visit_if_clause (tree_if_clause&);
+
+    void visit_if_command (tree_if_command&);
+
+    void visit_if_command_list (tree_if_command_list&);
+
+    void visit_index_expression (tree_index_expression&);
+
+    void visit_matrix (tree_matrix&);
+
+    void visit_cell (tree_cell&);
+
+    void visit_multi_assignment (tree_multi_assignment&);
+
+    void visit_no_op_command (tree_no_op_command&);
+
+    void visit_constant (tree_constant&);
+
+    void visit_fcn_handle (tree_fcn_handle&);
+
+    void visit_parameter_list (tree_parameter_list&);
+
+    void visit_postfix_expression (tree_postfix_expression&);
+
+    void visit_prefix_expression (tree_prefix_expression&);
+
+    void visit_return_command (tree_return_command&);
+
+    void visit_return_list (tree_return_list&);
+
+    void visit_simple_assignment (tree_simple_assignment&);
+
+    void visit_statement (tree_statement&);
+
+    void visit_statement_list (tree_statement_list&);
+
+    void visit_switch_case (tree_switch_case&);
+
+    void visit_switch_case_list (tree_switch_case_list&);
+
+    void visit_switch_command (tree_switch_command&);
+
+    void visit_try_catch_command (tree_try_catch_command&);
+
+    void visit_unwind_protect_command (tree_unwind_protect_command&);
+
+    void visit_while_command (tree_while_command&);
+
+    void visit_do_until_command (tree_do_until_command&);
+  private:
+    void handle_identifier (const std::string& name, octave_value v);
+
+    jit_typeinfo *tinfo;
+
+    bool is_lvalue;
+    jit_type *rvalue_type;
+
+    type_map types;
+    std::set<std::string> argin;
+
+    std::vector<jit_type *> type_stack;
+  };
+
+  class
+  code_generator : public tree_walker
+  {
+  public:
+    code_generator (jit_typeinfo *ti, llvm::Module *module, tree &tee,
+                    const std::set<std::string>& argin,
+                    const type_map& infered_types);
+
+    llvm::Function *get_function () const { return function; }
+
+    void visit_anon_fcn_handle (tree_anon_fcn_handle&);
+
+    void visit_argument_list (tree_argument_list&);
+
+    void visit_binary_expression (tree_binary_expression&);
+
+    void visit_break_command (tree_break_command&);
+
+    void visit_colon_expression (tree_colon_expression&);
+
+    void visit_continue_command (tree_continue_command&);
+
+    void visit_global_command (tree_global_command&);
+
+    void visit_persistent_command (tree_persistent_command&);
+
+    void visit_decl_elt (tree_decl_elt&);
+
+    void visit_decl_init_list (tree_decl_init_list&);
+
+    void visit_simple_for_command (tree_simple_for_command&);
+
+    void visit_complex_for_command (tree_complex_for_command&);
+
+    void visit_octave_user_script (octave_user_script&);
+
+    void visit_octave_user_function (octave_user_function&);
+
+    void visit_octave_user_function_header (octave_user_function&);
+
+    void visit_octave_user_function_trailer (octave_user_function&);
+
+    void visit_function_def (tree_function_def&);
+
+    void visit_identifier (tree_identifier&);
+
+    void visit_if_clause (tree_if_clause&);
+
+    void visit_if_command (tree_if_command&);
+
+    void visit_if_command_list (tree_if_command_list&);
+
+    void visit_index_expression (tree_index_expression&);
+
+    void visit_matrix (tree_matrix&);
+
+    void visit_cell (tree_cell&);
+
+    void visit_multi_assignment (tree_multi_assignment&);
+
+    void visit_no_op_command (tree_no_op_command&);
+
+    void visit_constant (tree_constant&);
+
+    void visit_fcn_handle (tree_fcn_handle&);
+
+    void visit_parameter_list (tree_parameter_list&);
+
+    void visit_postfix_expression (tree_postfix_expression&);
+
+    void visit_prefix_expression (tree_prefix_expression&);
+
+    void visit_return_command (tree_return_command&);
+
+    void visit_return_list (tree_return_list&);
+
+    void visit_simple_assignment (tree_simple_assignment&);
+
+    void visit_statement (tree_statement&);
+
+    void visit_statement_list (tree_statement_list&);
+
+    void visit_switch_case (tree_switch_case&);
+
+    void visit_switch_case_list (tree_switch_case_list&);
+
+    void visit_switch_command (tree_switch_command&);
+
+    void visit_try_catch_command (tree_try_catch_command&);
+
+    void visit_unwind_protect_command (tree_unwind_protect_command&);
+
+    void visit_while_command (tree_while_command&);
+
+    void visit_do_until_command (tree_do_until_command&);
+  private:
+    typedef std::pair<jit_type *, llvm::Value *> value;
+
+    void emit_print (const std::string& name, const value& v);
+
+    void push_value (jit_type *type, llvm::Value *v)
+    {
+      value_stack.push_back (value (type, v));
+    }
+
+    jit_typeinfo *tinfo;
+    llvm::Function *function;
+
+    bool is_lvalue;
+    std::map<std::string, value> variables;
+    std::vector<value> value_stack;
+  };
 
   class function_info
   {
   public:
-    function_info (void);
-    function_info (jit_function fn, const std::vector<std::string>& args,
-                   const std::vector<bool>& args_used);
+    function_info (tree_jit& tjit, tree& tee);
 
-    bool execute ();
+    bool execute () const;
+
+    bool match () const;
   private:
-    jit_function function;
-    std::vector<std::string> arguments;
-    
-    // is the argument used? or is it just declared?
-    std::vector<bool> argument_used;
-  };
-
-  struct variable_info
-  {
-    llvm::Value *defined;
-    llvm::Value *value;
-    bool use;
+    jit_typeinfo *tinfo;
+    llvm::ExecutionEngine *engine;
+    std::set<std::string> argin;
+    type_map types;
+    llvm::Function *function;
   };
 
-  function_info *compile (tree& tee);
-
-  variable_info find (const std::string &name, bool use);
-
-  void do_assign (variable_info vinfo, llvm::Value *value);
-
-  void emit_print (const std::string& vname, llvm::Value *value);
-
-  // tree_walker
-  void visit_anon_fcn_handle (tree_anon_fcn_handle&);
-
-  void visit_argument_list (tree_argument_list&);
-
-  void visit_binary_expression (tree_binary_expression&);
-
-  void visit_break_command (tree_break_command&);
-
-  void visit_colon_expression (tree_colon_expression&);
-
-  void visit_continue_command (tree_continue_command&);
-
-  void visit_global_command (tree_global_command&);
-
-  void visit_persistent_command (tree_persistent_command&);
-
-  void visit_decl_elt (tree_decl_elt&);
-
-  void visit_decl_init_list (tree_decl_init_list&);
-
-  void visit_simple_for_command (tree_simple_for_command&);
-
-  void visit_complex_for_command (tree_complex_for_command&);
-
-  void visit_octave_user_script (octave_user_script&);
-
-  void visit_octave_user_function (octave_user_function&);
-
-  void visit_octave_user_function_header (octave_user_function&);
-
-  void visit_octave_user_function_trailer (octave_user_function&);
-
-  void visit_function_def (tree_function_def&);
-
-  void visit_identifier (tree_identifier&);
-
-  void visit_if_clause (tree_if_clause&);
-
-  void visit_if_command (tree_if_command&);
-
-  void visit_if_command_list (tree_if_command_list&);
-
-  void visit_index_expression (tree_index_expression&);
+  typedef std::list<function_info *> function_list;
+  typedef std::map<tree *, function_list> compiled_map;
 
-  void visit_matrix (tree_matrix&);
-
-  void visit_cell (tree_cell&);
-
-  void visit_multi_assignment (tree_multi_assignment&);
-
-  void visit_no_op_command (tree_no_op_command&);
-
-  void visit_constant (tree_constant&);
-
-  void visit_fcn_handle (tree_fcn_handle&);
-
-  void visit_parameter_list (tree_parameter_list&);
-
-  void visit_postfix_expression (tree_postfix_expression&);
-
-  void visit_prefix_expression (tree_prefix_expression&);
-
-  void visit_return_command (tree_return_command&);
-
-  void visit_return_list (tree_return_list&);
-
-  void visit_simple_assignment (tree_simple_assignment&);
-
-  void visit_statement (tree_statement&);
-
-  void visit_statement_list (tree_statement_list&);
-
-  void visit_switch_case (tree_switch_case&);
-
-  void visit_switch_case_list (tree_switch_case_list&);
-
-  void visit_switch_command (tree_switch_command&);
-
-  void visit_try_catch_command (tree_try_catch_command&);
-
-  void do_unwind_protect_cleanup_code (tree_statement_list *list);
-
-  void visit_unwind_protect_command (tree_unwind_protect_command&);
-
-  void visit_while_command (tree_while_command&);
-
-  void visit_do_until_command (tree_do_until_command&);
-
-  void fail (void);
-
-  typedef std::map<std::string, variable_info> var_map;
-  typedef var_map::iterator var_map_iterator;
-  typedef std::map<tree*, function_info*> finfo_map;
-  typedef finfo_map::iterator finfo_map_iterator;
-
-  std::vector<llvm::Value*> value_stack;
-  var_map variables;
-  finfo_map compiled_functions;
+  static void fail (void)
+  {
+    throw jit_fail_exception ();
+  }
 
   llvm::LLVMContext &context;
   llvm::Module *module;
+  llvm::PassManager *module_pass_manager;
   llvm::FunctionPassManager *pass_manager;
   llvm::ExecutionEngine *engine;
-  llvm::BasicBlock *entry_block;
 
-  llvm::Function *print_double;
+  jit_typeinfo *tinfo;
+
+  compiled_map compiled;
 };
 
 #endif