# HG changeset patch
# User Max Brister <max@2bass.com>
# Date 1337893689 21600
# Node ID 232d8ab07932c0ac00a65a4440a0f3f95156bfe2
# Parent  0b0569667939451c8d7332fb5563c3a4df2666b6
Rewrite pt-jit.* adding new low level octave IR

* src/pt-eval.cc (tree_evaluator::visit_simple_for_command): Remove jit
(tree_evaluator::visit_statement): Add jit

* src/pt-jit.h: Rewrite
* src/pt-jit.cc: Rewrite

diff --git a/src/pt-eval.cc b/src/pt-eval.cc
--- a/src/pt-eval.cc
+++ b/src/pt-eval.cc
@@ -310,9 +310,6 @@
   if (error_state || rhs.is_undefined ())
     return;
 
-  if (jiter.execute (cmd, rhs))
-    return;
-
   {
     tree_expression *lhs = cmd.left_hand_side ();
 
@@ -687,6 +684,9 @@
   tree_command *cmd = stmt.command ();
   tree_expression *expr = stmt.expression ();
 
+  if (jiter.execute (stmt))
+    return;
+
   if (cmd || expr)
     {
       if (statement_context == function || statement_context == script)
diff --git a/src/pt-jit.cc b/src/pt-jit.cc
--- a/src/pt-jit.cc
+++ b/src/pt-jit.cc
@@ -52,6 +52,7 @@
 #include "octave.h"
 #include "ov-fcn-handle.h"
 #include "ov-usr-fcn.h"
+#include "ov-scalar.h"
 #include "pt-all.h"
 
 // FIXME: Remove eventually
@@ -60,6 +61,10 @@
 
 static llvm::IRBuilder<> builder (llvm::getGlobalContext ());
 
+static llvm::LLVMContext& context = llvm::getGlobalContext ();
+
+jit_typeinfo *jit_typeinfo::instance;
+
 // thrown when we should give up on JIT and interpret
 class jit_fail_exception : public std::exception {};
 
@@ -102,10 +107,25 @@
   obv->release ();
 }
 
-extern "C" void
+extern "C" octave_base_value *
 octave_jit_grab_any (octave_base_value *obv)
 {
   obv->grab ();
+  return obv;
+}
+
+extern "C" double
+octave_jit_cast_scalar_any (octave_base_value *obv)
+{
+  double ret = obv->double_value ();
+  obv->release ();
+  return ret;
+}
+
+extern "C" octave_base_value *
+octave_jit_cast_any_scalar (double value)
+{
+  return new octave_scalar (value);
 }
 
 // -------------------- jit_type --------------------
@@ -155,6 +175,10 @@
   if (types.size () >= overloads.size ())
     return null_overload;
 
+  for (size_t i  =0; i < types.size (); ++i)
+    if (! types[i])
+      return null_overload;
+
   const Array<overload>& over = overloads[types.size ()];
   dim_vector dv (over.dims ());
   Array<octave_idx_type> idx = to_idx (types);
@@ -187,46 +211,56 @@
 }
 
 // -------------------- jit_typeinfo --------------------
+void
+jit_typeinfo::initialize (llvm::Module *m, llvm::ExecutionEngine *e)
+{
+  instance = new jit_typeinfo (m, e);
+}
+
 jit_typeinfo::jit_typeinfo (llvm::Module *m, llvm::ExecutionEngine *e)
   : module (m), engine (e), next_id (0)
 {
   // FIXME: We should be registering types like in octave_value_typeinfo
-  llvm::LLVMContext &ctx = m->getContext ();
-
-  ov_t = llvm::StructType::create (ctx, "octave_base_value");
+  ov_t = llvm::StructType::create (context, "octave_base_value");
   ov_t = ov_t->getPointerTo ();
 
-  llvm::Type *dbl = llvm::Type::getDoubleTy (ctx);
-  llvm::Type *bool_t = llvm::Type::getInt1Ty (ctx);
+  llvm::Type *dbl = llvm::Type::getDoubleTy (context);
+  llvm::Type *bool_t = llvm::Type::getInt1Ty (context);
+  llvm::Type *string_t = llvm::Type::getInt8Ty (context);
+  string_t = string_t->getPointerTo ();
   llvm::Type *index_t = 0;
   switch (sizeof(octave_idx_type))
     {
     case 4:
-      index_t = llvm::Type::getInt32Ty (ctx);
+      index_t = llvm::Type::getInt32Ty (context);
       break;
     case 8:
-      index_t = llvm::Type::getInt64Ty (ctx);
+      index_t = llvm::Type::getInt64Ty (context);
       break;
     default:
       assert (false && "Unrecognized index type size");
     }
 
-  llvm::StructType *range_t = llvm::StructType::create (ctx, "range");
+  llvm::StructType *range_t = llvm::StructType::create (context, "range");
   std::vector<llvm::Type *> range_contents (4, dbl);
   range_contents[3] = index_t;
   range_t->setBody (range_contents);
 
   // create types
-  any = new_type ("any", true, 0, ov_t);
-  scalar = new_type ("scalar", false, any, dbl);
-  range = new_type ("range", false, any, range_t);
-  boolean = new_type ("bool", false, any, bool_t);
-  index = new_type ("index", false, any, index_t);
+  any = new_type ("any", 0, ov_t);
+  scalar = new_type ("scalar", any, dbl);
+  range = new_type ("range", any, range_t);
+  string = new_type ("string", any, string_t);
+  boolean = new_type ("bool", any, bool_t);
+  index = new_type ("index", any, index_t);
+
+  casts.resize (next_id + 1);
+  identities.resize (next_id + 1, 0);
 
   // any with anything is an any op
   llvm::Function *fn;
   llvm::Type *binary_op_type
-    = llvm::Type::getIntNTy (ctx, sizeof (octave_value::binary_op));
+    = llvm::Type::getIntNTy (context, sizeof (octave_value::binary_op));
   llvm::Function *any_binary = create_function ("octave_jit_binary_any_any",
                                                 any->to_llvm (), binary_op_type,
                                                 any->to_llvm (), any->to_llvm ());
@@ -234,12 +268,19 @@
                             reinterpret_cast<void*>(&octave_jit_binary_any_any));
 
   binary_ops.resize (octave_value::num_binary_ops);
+  for (size_t i = 0; i < octave_value::num_binary_ops; ++i)
+    {
+      octave_value::binary_op op = static_cast<octave_value::binary_op> (i);
+      std::string op_name = octave_value::binary_op_as_string (op);
+      binary_ops[i].stash_name ("binary" + op_name);
+    }
+
   for (int op = 0; op < octave_value::num_binary_ops; ++op)
     {
       llvm::Twine fn_name ("octave_jit_binary_any_any_");
       fn_name = fn_name + llvm::Twine (op);
       fn = create_function (fn_name, any, any, any);
-      llvm::BasicBlock *block = llvm::BasicBlock::Create (ctx, "body", fn);
+      llvm::BasicBlock *block = llvm::BasicBlock::Create (context, "body", fn);
       builder.SetInsertPoint (block);
       llvm::APInt op_int(sizeof (octave_value::binary_op), op,
                          std::numeric_limits<octave_value::binary_op>::is_signed);
@@ -255,18 +296,28 @@
         binary_ops[op].add_overload (overload);
     }
 
-  llvm::Type *void_t = llvm::Type::getVoidTy (ctx);
+  llvm::Type *void_t = llvm::Type::getVoidTy (context);
 
   // grab any
-  fn = create_function ("octave_jit_grab_any", void_t, any->to_llvm ());
+  fn = create_function ("octave_jit_grab_any", any, any);
                         
   engine->addGlobalMapping (fn, reinterpret_cast<void*>(&octave_jit_grab_any));
-  grab_fn.add_overload (fn, false, 0, any);
+  grab_fn.add_overload (fn, false, any, any);
+  grab_fn.stash_name ("grab");
+
+  // grab scalar
+  fn = create_identity (scalar);
+  grab_fn.add_overload (fn, false, scalar, scalar);
 
   // release any
   fn = create_function ("octave_jit_release_any", void_t, any->to_llvm ());
   engine->addGlobalMapping (fn, reinterpret_cast<void*>(&octave_jit_release_any));
   release_fn.add_overload (fn, false, 0, any);
+  release_fn.stash_name ("release");
+
+  // release scalar
+  fn = create_identity (scalar);
+  release_fn.add_overload (fn, false, 0, scalar);
 
   // now for binary scalar operations
   // FIXME: Finish all operations
@@ -287,12 +338,13 @@
   add_binary_fcmp (scalar, octave_value::op_ne, llvm::CmpInst::FCMP_UNE);
 
   // now for printing functions
+  print_fn.stash_name ("print");
   add_print (any, reinterpret_cast<void*> (&octave_jit_print_any));
   add_print (scalar, reinterpret_cast<void*> (&octave_jit_print_double));
 
   // bounds check for for loop
   fn = create_function ("octave_jit_simple_for_range", boolean, range, index);
-  llvm::BasicBlock *body = llvm::BasicBlock::Create (ctx, "body", fn);
+  llvm::BasicBlock *body = llvm::BasicBlock::Create (context, "body", fn);
   builder.SetInsertPoint (body);
   {
     llvm::Value *nelem
@@ -307,7 +359,7 @@
 
   // increment for for loop
   fn = create_function ("octave_jit_imple_for_range_incr", index, index);
-  body = llvm::BasicBlock::Create (ctx, "body", fn);
+  body = llvm::BasicBlock::Create (context, "body", fn);
   builder.SetInsertPoint (body);
   {
     llvm::Value *one = llvm::ConstantInt::get (index_t, 1);
@@ -320,7 +372,7 @@
 
   // index variabe for for loop
   fn = create_function ("octave_jit_simple_for_idx", scalar, range, index);
-  body = llvm::BasicBlock::Create (ctx, "body", fn);
+  body = llvm::BasicBlock::Create (context, "body", fn);
   builder.SetInsertPoint (body);
   {
     llvm::Value *idx = ++fn->arg_begin ();
@@ -339,7 +391,7 @@
   // logically true
   // FIXME: Check for NaN
   fn = create_function ("octave_logically_true_scalar", boolean, scalar);
-  body = llvm::BasicBlock::Create (ctx, "body", fn);
+  body = llvm::BasicBlock::Create (context, "body", fn);
   builder.SetInsertPoint (body);
   {
     llvm::Value *zero = llvm::ConstantFP::get (scalar->to_llvm (), 0);
@@ -350,11 +402,33 @@
   logically_true.add_overload (fn, true, boolean, scalar);
 
   fn = create_function ("octave_logically_true_bool", boolean, boolean);
-  body = llvm::BasicBlock::Create (ctx, "body", fn);
+  body = llvm::BasicBlock::Create (context, "body", fn);
   builder.SetInsertPoint (body);
   builder.CreateRet (fn->arg_begin ());
   llvm::verifyFunction (*fn);
   logically_true.add_overload (fn, false, boolean, boolean);
+  logically_true.stash_name ("logically_true");
+
+  casts[any->type_id ()].stash_name ("(any)");
+  casts[scalar->type_id ()].stash_name ("(scalar)");
+
+  // cast any <- scalar
+  fn = create_function ("octave_jit_cast_any_scalar", any, scalar);
+  engine->addGlobalMapping (fn, reinterpret_cast<void*> (&octave_jit_cast_any_scalar));
+  casts[any->type_id ()].add_overload (fn, false, any, scalar);
+
+  // cast scalar <- any
+  fn = create_function ("octave_jit_cast_scalar_any", scalar, any);
+  engine->addGlobalMapping (fn, reinterpret_cast<void*> (&octave_jit_cast_scalar_any));
+  casts[scalar->type_id ()].add_overload (fn, false, scalar, any);
+
+  // cast any <- any
+  fn = create_identity (any);
+  casts[any->type_id ()].add_overload (fn, false, any, any);
+
+  // cast scalar <- scalar
+  fn = create_identity (scalar);
+  casts[scalar->type_id ()].add_overload (fn, false, scalar, scalar);
 }
 
 void
@@ -363,14 +437,13 @@
   std::stringstream name;
   name << "octave_jit_print_" << ty->name ();
 
-  llvm::LLVMContext &ctx = llvm::getGlobalContext ();
-  llvm::Type *void_t = llvm::Type::getVoidTy (ctx);
+  llvm::Type *void_t = llvm::Type::getVoidTy (context);
   llvm::Function *fn = create_function (name.str (), void_t,
-                                        llvm::Type::getInt8PtrTy (ctx),
+                                        llvm::Type::getInt8PtrTy (context),
                                         ty->to_llvm ());
   engine->addGlobalMapping (fn, call);
 
-  jit_function::overload ol (fn, false, 0, ty);
+  jit_function::overload ol (fn, false, 0, string, ty);
   print_fn.add_overload (ol);
 }
 
@@ -383,9 +456,8 @@
   fname << "octave_jit_" << octave_value::binary_op_as_string (ov_op)
         << "_" << ty->name ();
 
-  llvm::LLVMContext &ctx = llvm::getGlobalContext ();
   llvm::Function *fn = create_function (fname.str (), ty, ty, ty);
-  llvm::BasicBlock *block = llvm::BasicBlock::Create (ctx, "body", fn);
+  llvm::BasicBlock *block = llvm::BasicBlock::Create (context, "body", fn);
   builder.SetInsertPoint (block);
   llvm::Instruction::BinaryOps temp
     = static_cast<llvm::Instruction::BinaryOps>(llvm_op);
@@ -406,9 +478,8 @@
   fname << "octave_jit" << octave_value::binary_op_as_string (ov_op)
         << "_" << ty->name ();
 
-  llvm::LLVMContext &ctx = llvm::getGlobalContext ();
   llvm::Function *fn = create_function (fname.str (), boolean, ty, ty);
-  llvm::BasicBlock *block = llvm::BasicBlock::Create (ctx, "body", fn);
+  llvm::BasicBlock *block = llvm::BasicBlock::Create (context, "body", fn);
   builder.SetInsertPoint (block);
   llvm::CmpInst::Predicate temp
     = static_cast<llvm::CmpInst::Predicate>(llvm_op);
@@ -429,9 +500,8 @@
   fname << "octave_jit" << octave_value::binary_op_as_string (ov_op)
         << "_" << ty->name ();
 
-  llvm::LLVMContext &ctx = llvm::getGlobalContext ();
   llvm::Function *fn = create_function (fname.str (), boolean, ty, ty);
-  llvm::BasicBlock *block = llvm::BasicBlock::Create (ctx, "body", fn);
+  llvm::BasicBlock *block = llvm::BasicBlock::Create (context, "body", fn);
   builder.SetInsertPoint (block);
   llvm::CmpInst::Predicate temp
     = static_cast<llvm::CmpInst::Predicate>(llvm_op);
@@ -454,10 +524,30 @@
                                                name, module);
   fn->addFnAttr (llvm::Attribute::AlwaysInline);
   return fn;
-}    
+}
+
+llvm::Function *
+jit_typeinfo::create_identity (jit_type *type)
+{
+  size_t id = type->type_id ();
+  if (id >= identities.size ())
+    identities.resize (id + 1, 0);
 
-jit_type*
-jit_typeinfo::type_of (const octave_value &ov) const
+  if (! identities[id])
+    {
+      llvm::Function *fn = create_function ("id", type, type);
+      llvm::BasicBlock *body = llvm::BasicBlock::Create (context, "body", fn);
+      builder.SetInsertPoint (body);
+      builder.CreateRet (fn->arg_begin ());
+      llvm::verifyFunction (*fn);
+      identities[id] = fn;
+    }
+
+  return identities[id];
+}
+
+jit_type *
+jit_typeinfo::do_type_of (const octave_value &ov) const
 {
   if (ov.is_undefined () || ov.is_function ())
     return 0;
@@ -471,34 +561,21 @@
   return get_any ();
 }
 
-const jit_function&
-jit_typeinfo::binary_op (int op) const
-{
-  assert (static_cast<size_t>(op) < binary_ops.size ());
-  return binary_ops[op];
-}
-
-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)
+jit_typeinfo::do_to_generic (jit_type *type, llvm::GenericValue& gv)
 {
   if (type == any)
-    to_generic (type, gv, octave_value ());
+    do_to_generic (type, gv, octave_value ());
   else if (type == scalar)
-    to_generic (type, gv, octave_value (0));
+    do_to_generic (type, gv, octave_value (0));
   else if (type == range)
-    to_generic (type, gv, octave_value (Range ()));
+    do_to_generic (type, gv, octave_value (Range ()));
   else
     assert (false && "Type not supported yet");
 }
 
 void
-jit_typeinfo::to_generic (jit_type *type, llvm::GenericValue& gv, octave_value ov)
+jit_typeinfo::do_to_generic (jit_type *type, llvm::GenericValue& gv, octave_value ov)
 {
   if (type == any)
     {
@@ -522,7 +599,7 @@
 }
 
 octave_value
-jit_typeinfo::to_octave_value (jit_type *type, llvm::GenericValue& gv)
+jit_typeinfo::do_to_octave_value (jit_type *type, llvm::GenericValue& gv)
 {
   if (type == any)
     {
@@ -545,7 +622,7 @@
 }
 
 void
-jit_typeinfo::reset_generic (void)
+jit_typeinfo::do_reset_generic (void)
 {
   scalar_out.clear ();
   ov_out.clear ();
@@ -553,926 +630,373 @@
 }
 
 jit_type*
-jit_typeinfo::new_type (const std::string& name, bool force_init,
-                        jit_type *parent, llvm::Type *llvm_type)
+jit_typeinfo::new_type (const std::string& name, jit_type *parent,
+                        llvm::Type *llvm_type)
 {
-  jit_type *ret = new jit_type (name, force_init, parent, llvm_type, next_id++);
+  jit_type *ret = new jit_type (name, parent, llvm_type, next_id++);
   id_to_type.push_back (ret);
   return ret;
 }
 
-// -------------------- jit_infer --------------------
-void
-jit_infer::infer (tree_simple_for_command& cmd, jit_type *bounds)
-{
-  infer_simple_for (cmd, bounds);
-}
-
-void
-jit_infer::visit_anon_fcn_handle (tree_anon_fcn_handle&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_argument_list (tree_argument_list&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_binary_expression (tree_binary_expression& be)
+// -------------------- jit_block --------------------
+llvm::BasicBlock *
+jit_block::to_llvm (void) const
 {
-  if (is_lvalue)
-    fail ();
-
-  if (be.op_type () >= octave_value::num_binary_ops)
-    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
-jit_infer::visit_break_command (tree_break_command&)
-{
-  fail ();
+  return llvm::cast<llvm::BasicBlock> (llvm_value);
 }
 
-void
-jit_infer::visit_colon_expression (tree_colon_expression&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_continue_command (tree_continue_command&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_global_command (tree_global_command&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_persistent_command (tree_persistent_command&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_decl_elt (tree_decl_elt&)
+// -------------------- jit_call --------------------
+bool
+jit_call::infer (void)
 {
-  fail ();
-}
-
-void
-jit_infer::visit_decl_init_list (tree_decl_init_list&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_simple_for_command (tree_simple_for_command& cmd)
-{
-  tree_expression *control = cmd.control_expr ();
-  control->accept (*this);
-
-  jit_type *control_t = type_stack.back ();
-  type_stack.pop_back ();
-
-  // FIXME: We should improve type inference so we don't have to do this
-  // to generate nested for loop code
-
-  // quick hack, check if the for loop bounds are const. If we
-  // run at least one, we don't have to merge types
-  bool atleast_once = false;
-  if (control->is_constant ())
+  // FIXME explain algorithm
+  jit_type *current = type ();
+  for (size_t i = 0; i < argument_count (); ++i)
     {
-      octave_value over = control->rvalue1 ();
-      if (over.is_range ())
+      jit_type *arg_type = argument_type (i);
+      jit_type *todo = jit_typeinfo::difference (arg_type, already_infered[i]);
+      if (todo)
         {
-          Range rng = over.range_value ();
-          atleast_once = rng.nelem () > 0;
+          already_infered[i] = todo;
+          jit_type *fresult = mfunction.get_result (already_infered);
+          current = jit_typeinfo::tunion (current, fresult);
+          already_infered[i] = arg_type;
         }
     }
 
-  if (atleast_once)
-    infer_simple_for (cmd, control_t);
-  else
+  if (current != type ())
     {
-      type_map fallthrough = types;
-      infer_simple_for (cmd, control_t);
-      merge (types, fallthrough);
+      stash_type (current);
+      return true;
+    }
+
+  return false;
+}
+
+// -------------------- jit_convert --------------------
+jit_convert::jit_convert (llvm::Module *module, tree &tee)
+{
+  jit_instruction::reset_ids ();
+
+  entry_block = new jit_block ("entry");
+  blocks.push_back (entry_block);
+  block = new jit_block ("body");
+  blocks.push_back (block);
+
+  final_block = new jit_block ("final");
+  visit (tee);
+  blocks.push_back (final_block);
+
+  entry_block->append (new jit_break (block));
+  block->append (new jit_break (final_block));
+
+  for (variable_map::iterator iter = variables.begin ();
+       iter != variables.end (); ++iter)
+    final_block->append (new jit_store_argument (iter->first, iter->second));
+
+  // FIXME: Maybe we should remove dead code here?
+
+  // initialize the worklist to instructions derived from constants
+  for (std::list<jit_value *>::iterator iter = constants.begin ();
+       iter != constants.end (); ++iter)
+    append_users (*iter);
+
+  // FIXME: Describe algorithm here
+  while (worklist.size ())
+    {
+      jit_instruction *next = worklist.front ();
+      worklist.pop_front ();
+
+      if (next->infer ())
+        append_users (next);
+    }
+
+  if (debug_print)
+    {
+      std::cout << "-------------------- Compiling tree --------------------\n";
+      std::cout << tee.str_print_code () << std::endl;
+      std::cout << "-------------------- octave jit ir --------------------\n";
+      for (std::list<jit_block *>::iterator iter = blocks.begin ();
+           iter != blocks.end (); ++iter)
+        (*iter)->print (std::cout, 0);
+      std::cout << std::endl;
+    }
+
+  convert_llvm to_llvm;
+  function = to_llvm.convert (module, arguments, blocks, constants);
+
+  if (debug_print)
+    {
+      std::cout << "-------------------- llvm ir --------------------";
+      llvm::raw_os_ostream llvm_cout (std::cout);
+      function->print (llvm_cout);
+      std::cout << std::endl;
     }
 }
 
 void
-jit_infer::visit_complex_for_command (tree_complex_for_command&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_octave_user_script (octave_user_script&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_octave_user_function (octave_user_function&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_octave_user_function_header (octave_user_function&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_octave_user_function_trailer (octave_user_function&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_function_def (tree_function_def&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_identifier (tree_identifier& ti)
-{
-  symbol_table::symbol_record_ref record = ti.symbol ();
-  handle_identifier (record);
-}
-
-void
-jit_infer::visit_if_clause (tree_if_clause&)
+jit_convert::visit_anon_fcn_handle (tree_anon_fcn_handle&)
 {
   fail ();
 }
 
 void
-jit_infer::visit_if_command (tree_if_command& cmd)
-{
-  if (is_lvalue)
-    fail ();
-
-  tree_if_command_list *lst = cmd.cmd_list ();
-  assert (lst);
-  lst->accept (*this);
-}
-
-void
-jit_infer::visit_if_command_list (tree_if_command_list& lst)
-{
-  // determine the types on each branch of the if seperatly, then merge
-  type_map fallthrough = types, last;
-  bool first_time = true;
-  for (tree_if_command_list::iterator p = lst.begin (); p != lst.end(); ++p)
-    {
-      tree_if_clause *tic = *p;
-
-      if (! first_time)
-        types = fallthrough;
-
-      if (! tic->is_else_clause ())
-        {
-          tree_expression *expr = tic->condition ();
-          expr->accept (*this);
-        }
-
-      fallthrough = types;
-
-      tree_statement_list *stmt_lst = tic->commands ();
-      assert (stmt_lst);
-      stmt_lst->accept (*this);
-
-      if (first_time)
-        last = types;
-      else
-        merge (last, types);
-    }
-
-  types = last;
-
-  tree_if_clause *last_clause = lst.back ();
-  if (! last_clause->is_else_clause ())
-    merge (types, fallthrough);
-}
-
-void
-jit_infer::visit_index_expression (tree_index_expression&)
+jit_convert::visit_argument_list (tree_argument_list&)
 {
   fail ();
 }
 
 void
-jit_infer::visit_matrix (tree_matrix&)
+jit_convert::visit_binary_expression (tree_binary_expression& be)
 {
-  fail ();
-}
-
-void
-jit_infer::visit_cell (tree_cell&)
-{
-  fail ();
-}
+  if (be.op_type () >= octave_value::num_binary_ops)
+    // this is the case for bool_or and bool_and
+    fail ();
 
-void
-jit_infer::visit_multi_assignment (tree_multi_assignment&)
-{
-  fail ();
-}
+  tree_expression *lhs = be.lhs ();
+  jit_value *lhsv = visit (lhs);
 
-void
-jit_infer::visit_no_op_command (tree_no_op_command&)
-{
-  fail ();
+  tree_expression *rhs = be.rhs ();
+  jit_value *rhsv = visit (rhs);
+
+  const jit_function& fn = jit_typeinfo::binary_op (be.op_type ());
+  result = block->append (new jit_call (fn, lhsv, rhsv));
 }
 
 void
-jit_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);
-}
-
-void
-jit_infer::visit_fcn_handle (tree_fcn_handle&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_parameter_list (tree_parameter_list&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_postfix_expression (tree_postfix_expression&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_prefix_expression (tree_prefix_expression&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_return_command (tree_return_command&)
+jit_convert::visit_break_command (tree_break_command&)
 {
   fail ();
 }
 
 void
-jit_infer::visit_return_list (tree_return_list&)
+jit_convert::visit_colon_expression (tree_colon_expression&)
+{
+  fail ();
+}
+
+void
+jit_convert::visit_continue_command (tree_continue_command&)
+{
+  fail ();
+}
+
+void
+jit_convert::visit_global_command (tree_global_command&)
 {
   fail ();
 }
 
 void
-jit_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
-jit_infer::visit_statement (tree_statement& stmt)
-{
-  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 ();
-
-          symbol_table::symbol_record_ref record (symbol_table::insert ("ans"));
-          handle_identifier (record);
-
-          if (rvalue_type != type_stack.back ())
-            fail ();
-
-          is_lvalue = false;
-          rvalue_type = 0;
-        }
-
-      type_stack.pop_back ();
-    }
-}
-
-void
-jit_infer::visit_statement_list (tree_statement_list& lst)
-{
-  tree_statement_list::iterator iter;
-  for (iter = lst.begin (); iter != lst.end (); ++iter)
-    {
-      tree_statement *stmt = *iter;
-      assert (stmt); // FIXME: jwe can this be null?
-      stmt->accept (*this);
-    }
-}
-
-void
-jit_infer::visit_switch_case (tree_switch_case&)
+jit_convert::visit_persistent_command (tree_persistent_command&)
 {
   fail ();
 }
 
 void
-jit_infer::visit_switch_case_list (tree_switch_case_list&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_switch_command (tree_switch_command&)
+jit_convert::visit_decl_elt (tree_decl_elt&)
 {
   fail ();
 }
 
 void
-jit_infer::visit_try_catch_command (tree_try_catch_command&)
+jit_convert::visit_decl_init_list (tree_decl_init_list&)
 {
   fail ();
 }
 
 void
-jit_infer::visit_unwind_protect_command (tree_unwind_protect_command&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_while_command (tree_while_command&)
-{
-  fail ();
-}
-
-void
-jit_infer::visit_do_until_command (tree_do_until_command&)
+jit_convert::visit_simple_for_command (tree_simple_for_command&)
 {
   fail ();
 }
 
 void
-jit_infer::infer_simple_for (tree_simple_for_command& cmd,
-                             jit_type *bounds)
+jit_convert::visit_complex_for_command (tree_complex_for_command&)
 {
-  if (is_lvalue)
-    fail ();
-
-  jit_type *iter = tinfo->get_simple_for_index_result (bounds);
-  if (! iter)
-    fail ();
-
-  is_lvalue = true;
-  rvalue_type = iter;
-  tree_expression *lhs = cmd.left_hand_side ();
-  lhs->accept (*this);
-  if (type_stack.back () != iter)
-    fail ();
-  type_stack.pop_back ();
-  is_lvalue = false;
-  rvalue_type = 0;
-
-  tree_statement_list *body = cmd.body ();
-  body->accept (*this);
+  fail ();
 }
 
 void
-jit_infer::handle_identifier (const symbol_table::symbol_record_ref& record)
+jit_convert::visit_octave_user_script (octave_user_script&)
 {
-  type_map::iterator iter = types.find (record);
-  if (iter == types.end ())
-    {
-      jit_type *ty = tinfo->type_of (record->find ());
-      bool argin = false;
-      if (is_lvalue)
-        {
-          if (! ty)
-            ty = rvalue_type;
-        }
-      else
-        {
-          if (! ty)
-            fail ();
-          argin = true;
-        }
-
-      types[record] = type_entry (argin, ty);
-      type_stack.push_back (ty);
-    }
-  else
-    type_stack.push_back (iter->second.second);
+  fail ();
 }
 
 void
-jit_infer::merge (type_map& dest, const type_map& src)
-{
-  if (dest.size () != src.size ())
-    fail ();
-
-  type_map::iterator dest_iter;
-  type_map::const_iterator src_iter;
-  for (dest_iter = dest.begin (), src_iter = src.begin ();
-       dest_iter != dest.end (); ++dest_iter, ++src_iter)
-    {
-      if (dest_iter->first.name () != src_iter->first.name ()
-          || dest_iter->second.second != src_iter->second.second)
-        fail ();
-
-      // require argin if one path requires argin
-      dest_iter->second.first = dest_iter->second.first
-        || src_iter->second.first;
-    }
-}
-
-// -------------------- jit_generator --------------------
-jit_generator::jit_generator (jit_typeinfo *ti, llvm::Module *mod,
-                              tree_simple_for_command& cmd, jit_type *bounds,
-                              const type_map& infered_types)
-  : tinfo (ti), module (mod), is_lvalue (false)
+jit_convert::visit_octave_user_function (octave_user_function&)
 {
-  // create new vectors that include bounds
-  std::vector<std::string> names (infered_types.size () + 1);
-  std::vector<bool> argin (infered_types.size () + 1);
-  std::vector<jit_type *> types (infered_types.size () + 1);
-  names[0] = "#bounds";
-  argin[0] = true;
-  types[0] = bounds;
-  size_t i;
-  type_map::const_iterator iter;
-  for (i = 1, iter = infered_types.begin (); iter != infered_types.end ();
-       ++i, ++iter)
-    {
-      names[i] = iter->first.name ();
-      argin[i] = iter->second.first;
-      types[i] = iter->second.second;
-    }
-
-  initialize (names, argin, types);
-
-  try
-    {
-      value var_bounds = variables["#bounds"];
-      var_bounds.second = builder.CreateLoad (var_bounds.second);
-      emit_simple_for (cmd, var_bounds, true);
-    }
-  catch (const jit_fail_exception&)
-    {
-      function->eraseFromParent ();
-      function = 0;
-      return;
-    }
-
-  finalize (names);
+  fail ();
 }
 
 void
-jit_generator::visit_anon_fcn_handle (tree_anon_fcn_handle&)
+jit_convert::visit_octave_user_function_header (octave_user_function&)
+{
+  fail ();
+}
+
+void
+jit_convert::visit_octave_user_function_trailer (octave_user_function&)
+{
+  fail ();
+}
+
+void
+jit_convert::visit_function_def (tree_function_def&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_argument_list (tree_argument_list&)
+jit_convert::visit_identifier (tree_identifier& ti)
 {
-  fail ();
+  std::string name = ti.name ();
+  variable_map::iterator iter = variables.find (name);
+  jit_value *var;
+  if (iter == variables.end ())
+    {
+      octave_value var_value = ti.do_lookup ();
+      jit_type *var_type = jit_typeinfo::type_of (var_value);
+      var = entry_block->append (new jit_extract_argument (var_type, name));
+      constants.push_back (var);
+      bounds.push_back (std::make_pair (var_type, name));
+      variables[name] = var;
+      arguments.push_back (std::make_pair (name, true));
+    }
+  else
+    var = iter->second;
+
+  const jit_function& fn = jit_typeinfo::grab ();
+  result = block->append (new jit_call (fn, var));
 }
 
 void
-jit_generator::visit_binary_expression (tree_binary_expression& be)
-{
-  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);
-
-  if (! ol.function)
-    fail ();
-
-  llvm::Value *result = builder.CreateCall2 (ol.function, lhsv.second,
-                                             rhsv.second);
-  push_value (ol.result, result);
-}
-
-void
-jit_generator::visit_break_command (tree_break_command&)
-{
-  fail ();
-}
-
-void
-jit_generator::visit_colon_expression (tree_colon_expression&)
-{
-  fail ();
-}
-
-void
-jit_generator::visit_continue_command (tree_continue_command&)
-{
-  fail ();
-}
-
-void
-jit_generator::visit_global_command (tree_global_command&)
+jit_convert::visit_if_clause (tree_if_clause&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_persistent_command (tree_persistent_command&)
-{
-  fail ();
-}
-
-void
-jit_generator::visit_decl_elt (tree_decl_elt&)
-{
-  fail ();
-}
-
-void
-jit_generator::visit_decl_init_list (tree_decl_init_list&)
+jit_convert::visit_if_command (tree_if_command&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_simple_for_command (tree_simple_for_command& cmd)
-{
-  if (is_lvalue)
-    fail ();
-
-  tree_expression *control = cmd.control_expr ();
-  assert (control); // FIXME: jwe, can this be null?
-
-  control->accept (*this);
-  value over = value_stack.back ();
-  value_stack.pop_back ();
-
-  emit_simple_for (cmd, over, false);
-}
-
-void
-jit_generator::visit_complex_for_command (tree_complex_for_command&)
+jit_convert::visit_if_command_list (tree_if_command_list&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_octave_user_script (octave_user_script&)
+jit_convert::visit_index_expression (tree_index_expression&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_octave_user_function (octave_user_function&)
-{
-  fail ();
-}
-
-void
-jit_generator::visit_octave_user_function_header (octave_user_function&)
-{
-  fail ();
-}
-
-void
-jit_generator::visit_octave_user_function_trailer (octave_user_function&)
+jit_convert::visit_matrix (tree_matrix&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_function_def (tree_function_def&)
+jit_convert::visit_cell (tree_cell&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_identifier (tree_identifier& ti)
+jit_convert::visit_multi_assignment (tree_multi_assignment&)
 {
-  std::string name = ti.name ();
-  value variable = variables[name];
-  if (is_lvalue)
-    {
-      value_stack.push_back (variable);
-
-      const jit_function::overload& ol = tinfo->release (variable.first);
-      if (ol.function)
-        {
-          llvm::Value *load = builder.CreateLoad (variable.second, name);
-          builder.CreateCall (ol.function, load);
-        }
-    }
-  else
-    {
-      llvm::Value *load = builder.CreateLoad (variable.second, name);
-      push_value (variable.first, load);
-
-      const jit_function::overload& ol = tinfo->grab (variable.first);
-      if (ol.function)
-        builder.CreateCall (ol.function, load);
-    }
+  fail ();
 }
 
 void
-jit_generator::visit_if_clause (tree_if_clause&)
+jit_convert::visit_no_op_command (tree_no_op_command&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_if_command (tree_if_command& cmd)
+jit_convert::visit_constant (tree_constant& tc)
 {
-  tree_if_command_list *lst = cmd.cmd_list ();
-  assert (lst);
-  lst->accept (*this);
+  octave_value v = tc.rvalue1 ();
+  if (v.is_real_scalar () && v.is_double_type ())
+    {
+      double dv = v.double_value ();
+      result = get_scalar (dv);
+    }
+  else if (v.is_range ())
+    fail ();
+  else
+    fail ();
 }
 
 void
-jit_generator::visit_if_command_list (tree_if_command_list& lst)
-{
-  llvm::LLVMContext &ctx = llvm::getGlobalContext ();
-  llvm::BasicBlock *tail = llvm::BasicBlock::Create (ctx, "if_tail", function);
-  std::vector<llvm::BasicBlock *> clause_entry (lst.size ());
-  tree_if_command_list::iterator p;
-  size_t i;
-  for (p = lst.begin (), i = 0; p != lst.end (); ++p, ++i)
-    {
-      tree_if_clause *tic = *p;
-      if (tic->is_else_clause ())
-        clause_entry[i] = llvm::BasicBlock::Create (ctx, "else_body", function,
-                                                    tail);
-      else
-        clause_entry[i] = llvm::BasicBlock::Create (ctx, "if_cond", function,
-                                                    tail);
-    }
-
-  builder.CreateBr (clause_entry[0]);
-
-  for (p = lst.begin (), i = 0; p != lst.end (); ++p, ++i)
-    {
-      tree_if_clause *tic = *p;
-      llvm::BasicBlock *body;
-      if (tic->is_else_clause ())
-        body = clause_entry[i];
-      else
-        {
-          llvm::BasicBlock *cond = clause_entry[i];
-          builder.SetInsertPoint (cond);
-
-          tree_expression *expr = tic->condition ();
-          expr->accept (*this);
-
-          // FIXME: Handle undefined case
-          value condv = value_stack.back ();
-          value_stack.pop_back ();
-
-          const jit_function::overload& ol = tinfo->get_logically_true (condv.first);
-          if (! ol.function)
-            fail ();
-
-          bool last = i + 1 == clause_entry.size ();
-          llvm::BasicBlock *next = last ? tail : clause_entry[i + 1];
-          body = llvm::BasicBlock::Create (ctx, "if_body", function, tail);
-
-          llvm::Value *is_true = builder.CreateCall (ol.function, condv.second);
-          builder.CreateCondBr (is_true, body, next);
-        }
-
-      tree_statement_list *stmt_lst = tic->commands ();
-      builder.SetInsertPoint (body);
-      stmt_lst->accept (*this);
-      builder.CreateBr (tail);
-    }
-
-  builder.SetInsertPoint (tail);
-}
-
-void
-jit_generator::visit_index_expression (tree_index_expression&)
+jit_convert::visit_fcn_handle (tree_fcn_handle&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_matrix (tree_matrix&)
+jit_convert::visit_parameter_list (tree_parameter_list&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_cell (tree_cell&)
-{
-  fail ();
-}
-
-void
-jit_generator::visit_multi_assignment (tree_multi_assignment&)
-{
-  fail ();
-}
-
-void
-jit_generator::visit_no_op_command (tree_no_op_command&)
+jit_convert::visit_postfix_expression (tree_postfix_expression&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_constant (tree_constant& tc)
-{
-  octave_value v = tc.rvalue1 ();
-  llvm::LLVMContext& ctx = llvm::getGlobalContext ();
-  if (v.is_real_scalar () && v.is_double_type ())
-    {
-      double dv = v.double_value ();
-      llvm::Value *lv = llvm::ConstantFP::get (ctx, llvm::APFloat (dv));
-      push_value (tinfo->get_scalar (), lv);
-    }
-  else if (v.is_range ())
-    {
-      Range rng = v.range_value ();
-      llvm::Type *range = tinfo->get_range_llvm ();
-      llvm::Type *scalar = tinfo->get_scalar_llvm ();
-      llvm::Type *index = tinfo->get_index_llvm ();
-
-      std::vector<llvm::Constant *> values (4);
-      values[0] = llvm::ConstantFP::get (scalar, rng.base ());
-      values[1] = llvm::ConstantFP::get (scalar, rng.limit ());
-      values[2] = llvm::ConstantFP::get (scalar, rng.inc ());
-      values[3] = llvm::ConstantInt::get (index, rng.nelem ());
-
-      llvm::StructType *llvm_range = llvm::cast<llvm::StructType>(range);
-      llvm::Value *lv = llvm::ConstantStruct::get (llvm_range, values);
-      push_value (tinfo->get_range (), lv);
-    }
-  else
-    fail ();
-}
-
-void
-jit_generator::visit_fcn_handle (tree_fcn_handle&)
+jit_convert::visit_prefix_expression (tree_prefix_expression&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_parameter_list (tree_parameter_list&)
+jit_convert::visit_return_command (tree_return_command&)
+{
+  fail ();
+}
+
+void
+jit_convert::visit_return_list (tree_return_list&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_postfix_expression (tree_postfix_expression&)
+jit_convert::visit_simple_assignment (tree_simple_assignment& tsa)
 {
-  fail ();
-}
-
-void
-jit_generator::visit_prefix_expression (tree_prefix_expression&)
-{
-  fail ();
-}
+  // resolve rhs
+  tree_expression *rhs = tsa.right_hand_side ();
+  jit_value *rhsv = visit (rhs);
 
-void
-jit_generator::visit_return_command (tree_return_command&)
-{
-  fail ();
-}
+  // resolve lhs
+  tree_expression *lhs = tsa.left_hand_side ();
+  if (! lhs->is_identifier ())
+    fail ();
 
-void
-jit_generator::visit_return_list (tree_return_list&)
-{
-  fail ();
+  std::string lhs_name = lhs->name ();
+  do_assign (lhs_name, rhsv, tsa.print_result ());
+  result = rhsv;
+
+  if (jit_instruction *instr = dynamic_cast<jit_instruction *>(rhsv))
+    instr->stash_tag (lhs_name);
 }
 
 void
-jit_generator::visit_simple_assignment (tree_simple_assignment& tsa)
-{
-  if (is_lvalue)
-    fail ();
-
-  // resolve rhs
-  tree_expression *rhs = tsa.right_hand_side ();
-  rhs->accept (*this);
-
-  value rhsv = value_stack.back ();
-  value_stack.pop_back ();
-
-  // resolve lhs
-  is_lvalue = true;
-  tree_expression *lhs = tsa.left_hand_side ();
-  lhs->accept (*this);
-  is_lvalue = false;
-
-  value lhsv = value_stack.back ();
-  value_stack.pop_back ();
-
-  // do assign, then keep rhs as the result
-  builder.CreateStore (rhsv.second, lhsv.second);
-
-  if (tsa.print_result ())
-    emit_print (lhs->name (), rhsv);
-
-  value_stack.push_back (rhsv);
-}
-
-void
-jit_generator::visit_statement (tree_statement& stmt)
+jit_convert::visit_statement (tree_statement& stmt)
 {
   tree_command *cmd = stmt.command ();
   tree_expression *expr = stmt.expression ();
 
   if (cmd)
-    cmd->accept (*this);
+    visit (cmd);
   else
     {
       // stolen from tree_evaluator::visit_statement
@@ -1487,208 +1011,243 @@
       else
         do_bind_ans = (! expr->is_assignment_expression ());
 
-      expr->accept (*this);
+      jit_value *expr_result = visit (expr);
 
       if (do_bind_ans)
-        {
-          value rhs = value_stack.back ();
-          value ans = variables["ans"];
-          if (ans.first != rhs.first)
-            fail ();
-
-          builder.CreateStore (rhs.second, ans.second);
-
-          if (expr->print_result ())
-            emit_print ("ans", rhs);
-        }
+        do_assign ("ans", expr_result, expr->print_result ());
       else if (expr->is_identifier () && expr->print_result ())
         {
           // FIXME: ugly hack, we need to come up with a way to pass
           // nargout to visit_identifier
-          emit_print (expr->name (), value_stack.back ());
+          const jit_function& fn = jit_typeinfo::print_value ();
+          jit_const_string *name = get_string (expr->name ());
+          block->append (new jit_call (fn, name, expr_result));
         }
-
-
-      value_stack.pop_back ();
     }
 }
 
 void
-jit_generator::visit_statement_list (tree_statement_list& lst)
+jit_convert::visit_statement_list (tree_statement_list&)
 {
-  tree_statement_list::iterator iter;
-  for (iter = lst.begin (); iter != lst.end (); ++iter)
-    {
-      tree_statement *stmt = *iter;
-      assert (stmt); // FIXME: jwe can this be null?
-      stmt->accept (*this);
-    }
+  fail ();
 }
 
 void
-jit_generator::visit_switch_case (tree_switch_case&)
+jit_convert::visit_switch_case (tree_switch_case&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_switch_case_list (tree_switch_case_list&)
+jit_convert::visit_switch_case_list (tree_switch_case_list&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_switch_command (tree_switch_command&)
+jit_convert::visit_switch_command (tree_switch_command&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_try_catch_command (tree_try_catch_command&)
+jit_convert::visit_try_catch_command (tree_try_catch_command&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_unwind_protect_command (tree_unwind_protect_command&)
+jit_convert::visit_unwind_protect_command (tree_unwind_protect_command&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_while_command (tree_while_command&)
+jit_convert::visit_while_command (tree_while_command&)
 {
   fail ();
 }
 
 void
-jit_generator::visit_do_until_command (tree_do_until_command&)
+jit_convert::visit_do_until_command (tree_do_until_command&)
 {
   fail ();
 }
 
 void
-jit_generator::emit_simple_for (tree_simple_for_command& cmd, value over,
-                                bool atleast_once)
+jit_convert::do_assign (const std::string& lhs, jit_value *rhs, bool print)
 {
-  if (is_lvalue)
-    fail ();
+  variable_map::iterator iter = variables.find (lhs);
+  if (iter == variables.end ())
+    arguments.push_back (std::make_pair (lhs, false));
+  else
+    {
+      const jit_function& fn = jit_typeinfo::release ();
+      block->append (new jit_call (fn, iter->second));
+    }
 
-  jit_type *index = tinfo->get_index ();
-  llvm::Value *init_index = 0;
-  if (over.first == tinfo->get_range ())
-    init_index = llvm::ConstantInt::get (index->to_llvm (), 0);
-  else
-    fail ();
+  variables[lhs] = rhs;
 
-  llvm::Value *llvm_index = builder.CreateAlloca (index->to_llvm (), 0, "index");
-  builder.CreateStore (init_index, llvm_index);
+  if (print)
+    {
+      const jit_function& fn = jit_typeinfo::print_value ();
+      jit_const_string *name = get_string (lhs);
+      block->append (new jit_call (fn, name, rhs));
+    }
+}
+
+jit_value *
+jit_convert::visit (tree& tee)
+{
+  result = 0;
+  tee.accept (*this);
 
-  // FIXME: Support break
-  llvm::LLVMContext &ctx = llvm::getGlobalContext ();
-  llvm::BasicBlock *body = llvm::BasicBlock::Create (ctx, "for_body", function);
-  llvm::BasicBlock *cond_check = llvm::BasicBlock::Create (ctx, "for_check", function);
-  llvm::BasicBlock *tail = llvm::BasicBlock::Create (ctx, "for_tail", function);
+  jit_value *ret = result;
+  result = 0;
+  return ret;
+}
 
-  // initialize the iter from the index
-  if (atleast_once)
-    builder.CreateBr (body);
-  else
-    builder.CreateBr (cond_check);
-
-  builder.SetInsertPoint (body);
+// -------------------- jit_convert::convert_llvm --------------------
+llvm::Function *
+jit_convert::convert_llvm::convert (llvm::Module *module,
+                                    const std::vector<std::pair< std::string, bool> >& args,
+                                    const std::list<jit_block *>& blocks,
+                                    const std::list<jit_value *>& constants)
+{
+  jit_type *any = jit_typeinfo::get_any ();
 
-  is_lvalue = true;
-  tree_expression *lhs = cmd.left_hand_side ();
-  lhs->accept (*this);
-  is_lvalue = false;
+  // argument is an array of octave_base_value*, or octave_base_value**
+  llvm::Type *arg_type = any->to_llvm (); // this is octave_base_value*
+  arg_type = arg_type->getPointerTo ();
+  llvm::FunctionType *ft = llvm::FunctionType::get (llvm::Type::getVoidTy (context),
+                                                    arg_type, false);
+  llvm::Function *function = llvm::Function::Create (ft,
+                                                     llvm::Function::ExternalLinkage,
+                                                     "foobar", module);
 
-  value lhsv = value_stack.back ();
-  value_stack.pop_back ();
+  try
+    {
+      llvm::BasicBlock *prelude = llvm::BasicBlock::Create (context, "prelude",
+                                                            function);
+      builder.SetInsertPoint (prelude);
 
-  const jit_function::overload& index_ol = tinfo->get_simple_for_index (over.first);
-  llvm::Value *lindex = builder.CreateLoad (llvm_index);
-  llvm::Value *llvm_iter = builder.CreateCall2 (index_ol.function, over.second, lindex);
-  value iter(index_ol.result, llvm_iter);
-  builder.CreateStore (iter.second, lhsv.second);
+      llvm::Value *arg = function->arg_begin ();
+      for (size_t i = 0; i < args.size (); ++i)
+        {
+          llvm::Value *loaded_arg = builder.CreateConstInBoundsGEP1_32 (arg, i);
+          arguments[args[i].first] = loaded_arg;
+        }
 
-  tree_statement_list *lst = cmd.body ();
-  lst->accept (*this);
+      // we need to generate llvm values for constants, as these don't appear in
+      // a block
+      for (std::list<jit_value *>::const_iterator iter = constants.begin ();
+           iter != constants.end (); ++iter)
+        {
+          jit_value *constant = *iter;
+          if (! dynamic_cast<jit_instruction *> (constant))
+            visit (constant);
+        }
 
-  llvm::Value *one = llvm::ConstantInt::get (index->to_llvm (), 1);
-  lindex = builder.CreateLoad (llvm_index);
-  lindex = builder.CreateAdd (lindex, one);
-  builder.CreateStore (lindex, llvm_index);
-  builder.CreateBr (cond_check);
+      std::list<jit_block *>::const_iterator biter;
+      for (biter = blocks.begin (); biter != blocks.end (); ++biter)
+        {
+          jit_block *jblock = *biter;
+          llvm::BasicBlock *block = llvm::BasicBlock::Create (context, jblock->name (),
+                                                              function);
+          jblock->stash_llvm (block);
+        }
+
+      jit_block *first = *blocks.begin ();
+      builder.CreateBr (first->to_llvm ());
 
-  builder.SetInsertPoint (cond_check);
-  lindex = builder.CreateLoad (llvm_index);
-  const jit_function::overload& check_ol = tinfo->get_simple_for_check (over.first);
-  llvm::Value *cond = builder.CreateCall2 (check_ol.function, over.second, lindex);
-  builder.CreateCondBr (cond, body, tail);
+      for (biter = blocks.begin (); biter != blocks.end (); ++biter)
+        visit (*biter);
 
-  builder.SetInsertPoint (tail);
+      builder.CreateRetVoid ();
+    } catch (const jit_fail_exception&)
+    {
+      function->eraseFromParent ();
+      throw;
+    }
+
+  llvm::verifyFunction (*function);
+
+  return function;
 }
 
 void
-jit_generator::emit_print (const std::string& name, const value& v)
+jit_convert::convert_llvm::visit_const_string (jit_const_string& cs)
+{
+  cs.stash_llvm (builder.CreateGlobalStringPtr (cs.value ()));
+}
+
+void
+jit_convert::convert_llvm::visit_const_scalar (jit_const_scalar& cs)
+{
+  llvm::Type *dbl = llvm::Type::getDoubleTy (context);
+  cs.stash_llvm (llvm::ConstantFP::get (dbl, cs.value ()));
+}
+
+void
+jit_convert::convert_llvm::visit_block (jit_block& b)
 {
-  const jit_function::overload& ol = tinfo->print_value (v.first);
-  if (! ol.function)
-    fail ();
+  llvm::BasicBlock *block = b.to_llvm ();
+  builder.SetInsertPoint (block);
+  for (jit_block::iterator iter = b.begin (); iter != b.end (); ++iter)
+    visit (*iter);
+}
 
-  llvm::Value *str = builder.CreateGlobalStringPtr (name);
-  builder.CreateCall2 (ol.function, str, v.second);
+void
+jit_convert::convert_llvm::visit_break (jit_break& b)
+{
+  builder.CreateBr (b.sucessor_llvm ());
+}
+
+void
+jit_convert::convert_llvm::visit_cond_break (jit_cond_break& cb)
+{
+  llvm::Value *cond = cb.cond_llvm ();
+  builder.CreateCondBr (cond, cb.sucessor_llvm (0), cb.sucessor_llvm (1));
 }
 
 void
-jit_generator::initialize (const std::vector<std::string>& names,
-                           const std::vector<bool>& argin,
-                           const std::vector<jit_type *> types)
+jit_convert::convert_llvm::visit_call (jit_call& call)
 {
-  std::vector<llvm::Type *> arg_types (names.size ());
-  for (size_t i = 0; i < types.size (); ++i)
-    arg_types[i] = types[i]->to_llvm_arg ();
-
-  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);
+  const jit_function::overload& ol = call.overload ();
+  if (! ol.function)
+    fail ();
+  
+  std::vector<llvm::Value *> args (call.argument_count ());
+  for (size_t i = 0; i < call.argument_count (); ++i)
+    args[i] = call.argument_llvm (i);
 
-  // create variables and copy initial values
-  llvm::BasicBlock *body = llvm::BasicBlock::Create (ctx, "body", function);
-  builder.SetInsertPoint (body);
-  llvm::Function::arg_iterator arg_iter = function->arg_begin();
-  for (size_t i = 0; i < names.size (); ++i, ++arg_iter)
-    {
-      llvm::Type *vartype = types[i]->to_llvm ();
-      const std::string& name = names[i];
-      llvm::Value *var = builder.CreateAlloca (vartype, 0, name);
-      variables[name] = value (types[i], var);
-
-      if (argin[i] || types[i]->force_init ())
-        {
-          llvm::Value *loaded_arg = builder.CreateLoad (arg_iter);
-          builder.CreateStore (loaded_arg, var);
-        }
-    }
+  call.stash_llvm (builder.CreateCall (ol.function, args));
 }
 
 void
-jit_generator::finalize (const std::vector<std::string>& names)
+jit_convert::convert_llvm::visit_extract_argument (jit_extract_argument& extract)
 {
-  // copy computed values back into arguments
-  // we use names instead of looping through variables because order is
-  // important
-  llvm::Function::arg_iterator arg_iter = function->arg_begin();
-  for (size_t i = 0; i < names.size (); ++i, ++arg_iter)
-    {
-      llvm::Value *var = variables[names[i]].second;
-      llvm::Value *loaded_var = builder.CreateLoad (var);
-      builder.CreateStore (loaded_var, arg_iter);
-    }
-  builder.CreateRetVoid ();
+  const jit_function::overload& ol = extract.overload ();
+  if (! ol.function)
+    fail ();
+
+  llvm::Value *arg = arguments[extract.tag ()];
+  arg = builder.CreateLoad (arg);
+  extract.stash_llvm (builder.CreateCall (ol.function, arg));
+}
+
+void
+jit_convert::convert_llvm::visit_store_argument (jit_store_argument& store)
+{
+  llvm::Value *arg_value = store.result_llvm ();
+  const jit_function::overload& ol = store.overload ();
+  if (! ol.function)
+    fail ();
+
+  arg_value = builder.CreateCall (ol.function, arg_value);
+
+  llvm::Value *arg = arguments[store.tag ()];
+  store.stash_llvm (builder.CreateStore (arg_value, arg));
 }
 
 // -------------------- tree_jit --------------------
@@ -1700,25 +1259,33 @@
 }
 
 tree_jit::~tree_jit (void)
-{
-  delete tinfo;
-}
+{}
 
 bool
-tree_jit::execute (tree_simple_for_command& cmd, const octave_value& bounds)
+tree_jit::execute (tree& cmd)
 {
   if (! initialize ())
     return false;
 
-  jit_type *bounds_t = tinfo->type_of (bounds);
-  jit_info *jinfo = cmd.get_info (bounds_t);
+  compiled_map::iterator iter = compiled.find (&cmd);
+  jit_info *jinfo = 0;
+  if (iter != compiled.end ())
+    {
+      jinfo = iter->second;
+      if (! jinfo->match ())
+        {
+          delete jinfo;
+          jinfo = 0;
+        }
+    }
+
   if (! jinfo)
     {
-      jinfo = new jit_info (*this, cmd, bounds_t);
-      cmd.stash_info (bounds_t, jinfo);
+      jinfo = new jit_info (*this, cmd);
+      compiled[&cmd] = jinfo;
     }
 
-  return jinfo->execute (bounds);
+  return jinfo->execute ();
 }
 
 bool
@@ -1746,7 +1313,7 @@
   pass_manager->add (llvm::createCFGSimplificationPass ());
   pass_manager->doInitialization ();
 
-  tinfo = new jit_typeinfo (module, engine);
+  jit_typeinfo::initialize (module, engine);
 
   return true;
 }
@@ -1760,106 +1327,80 @@
 }
 
 // -------------------- jit_info --------------------
-jit_info::jit_info (tree_jit& tjit, tree_simple_for_command& cmd,
-                    jit_type *bounds) : tinfo (tjit.get_typeinfo ()),
-                                        engine (tjit.get_engine ()),
-                                        bounds_t (bounds)
+jit_info::jit_info (tree_jit& tjit, tree& tee)
+  : engine (tjit.get_engine ())
 {
-  jit_infer infer(tinfo);
-
+  llvm::Function *fun = 0;
   try
     {
-      infer.infer (cmd, bounds);
+      jit_convert conv (tjit.get_module (), tee);
+      fun = conv.get_function ();
+      arguments = conv.get_arguments ();
+      bounds = conv.get_bounds ();
     }
   catch (const jit_fail_exception&)
+    {}
+
+  if (! fun)
     {
       function = 0;
       return;
     }
 
-  types = infer.get_types ();
-
-  jit_generator gen(tinfo, tjit.get_module (), cmd, bounds, types);
-  function = gen.get_function ();
-
-  if (function)
-    {
-      if (debug_print)
-        {
-          std::cout << "Compiled code:\n";
-          std::cout << cmd.str_print_code () << std::endl;
-
-          std::cout << "Before optimization:\n";
+  tjit.optimize (fun);
 
-          llvm::raw_os_ostream os (std::cout);
-          function->print (os);
-        }
-      llvm::verifyFunction (*function);
-      tjit.optimize (function);
+  if (debug_print)
+    {
+      std::cout << "-------------------- optimized llvm ir --------------------\n";
+      llvm::raw_os_ostream llvm_cout (std::cout);
+      fun->print (llvm_cout);
+      std::cout << std::endl;
+    }
 
-      if (debug_print)
-        {
-          std::cout << "After optimization:\n";
-
-          llvm::raw_os_ostream os (std::cout);
-          function->print (os);
-        }
-    }
+  function = reinterpret_cast<jited_function>(engine->getPointerToFunction (fun));
 }
 
 bool
-jit_info::execute (const octave_value& bounds) const
+jit_info::execute (void) const
 {
   if (! function)
     return false;
 
-  std::vector<llvm::GenericValue> args (types.size () + 1);
-  tinfo->to_generic (bounds_t, args[0], bounds);
-
-  size_t idx;
-  type_map::const_iterator iter;
-  for (idx = 1, iter = types.begin (); iter != types.end (); ++iter, ++idx)
+  std::vector<octave_base_value *> real_arguments (arguments.size ());
+  for (size_t i = 0; i < arguments.size (); ++i)
     {
-      if (iter->second.first) // argin?
+      if (arguments[i].second)
         {
-          octave_value ov = iter->first->varval ();
-          tinfo->to_generic (iter->second.second, args[idx], ov);
+          octave_value current = symbol_table::varval (arguments[i].first);
+          octave_base_value *obv = current.internal_rep ();
+          obv->grab ();
+          real_arguments[i] = obv;
         }
-      else
-        tinfo->to_generic (iter->second.second, args[idx]);
     }
 
-  engine->runFunction (function, args);
+  function (&real_arguments[0]);
 
-  for (idx = 1, iter = types.begin (); iter != types.end (); ++iter, ++idx)
-    {
-      octave_value result = tinfo->to_octave_value (iter->second.second, args[idx]);
-      octave_value &ref = iter->first->varref ();
-      ref = result;
-    }
-
-  tinfo->reset_generic ();
+  for (size_t i = 0; i < arguments.size (); ++i)
+    symbol_table::varref (arguments[i].first) = real_arguments[i];
 
   return true;
 }
 
 bool
-jit_info::match () const
+jit_info::match (void) const
 {
-  for (type_map::const_iterator iter = types.begin (); iter != types.end ();
-       ++iter)
-       
+  if (! function)
+    return true;
+
+  for (size_t i = 0; i < bounds.size (); ++i)
     {
-      if (iter->second.first) // argin?
-        {
-          jit_type *required_type = iter->second.second;
-          octave_value val = iter->first->varval ();
-          jit_type *current_type = tinfo->type_of (val);
+      const std::string& arg_name = bounds[i].second;
+      octave_value value = symbol_table::varval (arg_name);
+      jit_type *type = jit_typeinfo::type_of (value);
 
-          // FIXME: should be: ! required_type->is_parent (current_type)
-          if (required_type != current_type)
-            return false;
-        }
+      // FIXME: Check for a parent relationship
+      if (type != bounds[i].first)
+        return false;
     }
 
   return true;
diff --git a/src/pt-jit.h b/src/pt-jit.h
--- a/src/pt-jit.h
+++ b/src/pt-jit.h
@@ -46,18 +46,25 @@
 // b = a + a;
 // will compile to do_binary_op (a, a).
 //
-// for loops with ranges compile. For example,
-// for i=1:1000
-//   result = i + 1;
-// endfor
-// Will compile. Nested for loops with constant bounds are also supported.
+// for loops and if statements no longer compile! This is because work has been
+// done to introduce a new lower level IR for octave. The low level IR looks
+// a lot like llvm's IR, but it makes it much easier to infer types. You can set
+// debug_print to true in pt-jit.cc to view the IRs that are created.
 //
-// If statements/comparisons compile, but && and || do not.
+// The octave low level IR is a linear IR, it works by converting everything to
+// calls to jit_functions. This turns expressions like c = a + b into
+// c = call binary+ (a, b)
+// The jit_functions contain information about overloads for differnt types. For
+// example, if we know a and b are scalars, then c must also be a scalar.
+//
+// You will currently see a LARGE slowdown, as every statement is compiled
+// seperatly!
 //
 // TODO:
-// 1. Support iteration over matricies
-// 2. Check error state
-// 3. ...
+// 1. Support for loops
+// 2. Support if statements
+// 3. Cleanup/documentation
+// 4. ...
 // ---------------------------------------------------------
 
 
@@ -113,37 +120,44 @@
 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)
+  jit_type (const std::string& aname, jit_type *aparent, llvm::Type *allvm_type,
+            int aid) :
+    mname (aname), mparent (aparent), llvm_type (allvm_type), mid (aid),
+    mdepth (aparent ? aparent->mdepth + 1 : 0)
   {}
 
   // 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; }
+  int type_id (void) const { return mid; }
 
   // An abstract base type, may be null
-  jit_type *parent (void) const { return p; }
+  jit_type *parent (void) const { return mparent; }
 
   // 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;
+
+  size_t depth (void) const { return mdepth; }
 private:
   std::string mname;
-  bool finit;
-  jit_type *p;
+  jit_type *mparent;
   llvm::Type *llvm_type;
-  int id;
+  int mid;
+  size_t mdepth;
 };
 
+// seperate print function to allow easy printing if type is null
+static std::ostream& jit_print (std::ostream& os, jit_type *atype)
+{
+  if (! atype)
+    return os << "null";
+  return os << atype->name ();
+}
+
 // Keeps track of overloads for a builtin function. Used for both type inference
 // and code generation.
 class
@@ -223,10 +237,16 @@
     const overload& temp = get_overload (arg0, arg1);
     return temp.result;
   }
+
+  const std::string& name (void) const { return mname; }
+
+  void stash_name (const std::string& aname) { mname = aname; }
 private:
   Array<octave_idx_type> to_idx (const std::vector<jit_type*>& types) const;
 
   std::vector<Array<overload> > overloads;
+
+  std::string mname;
 };
 
 // Get information and manipulate jit types.
@@ -234,84 +254,160 @@
 jit_typeinfo
 {
 public:
+  static void initialize (llvm::Module *m, llvm::ExecutionEngine *e);
+
+  static jit_type *tunion (jit_type *lhs, jit_type *rhs)
+  {
+    return instance->do_union (lhs, rhs);
+  }
+
+  static jit_type *difference (jit_type *lhs, jit_type *rhs)
+  {
+    return instance->do_difference (lhs, rhs);
+  }
+
+  static jit_type *get_any (void) { return instance->any; }
+
+  static jit_type *get_scalar (void) { return instance->scalar; }
+
+  static jit_type *get_range (void) { return instance->range; }
+
+  static jit_type *get_string (void) { return instance->string; }
+
+  static jit_type *get_bool (void) { return instance->boolean; }
+
+  static jit_type *get_index (void) { return instance->index; }
+
+  static jit_type *type_of (const octave_value& ov)
+  {
+    return instance->do_type_of (ov);
+  }
+
+  static const jit_function& binary_op (int op)
+  {
+    return instance->do_binary_op (op);
+  }
+
+  static const jit_function& grab (void) { return instance->grab_fn; }
+
+  static const jit_function& release (void)
+  {
+    return instance->release_fn;
+  }
+
+  static const jit_function& print_value (void)
+  {
+    return instance->print_fn;
+  }
+
+  static const jit_function& cast (jit_type *result)
+  {
+    return instance->do_cast (result);
+  }
+
+  static const jit_function::overload& cast (jit_type *to, jit_type *from)
+  {
+    return instance->do_cast (to, from);
+  }
+
+  static void to_generic (jit_type *type, llvm::GenericValue& gv)
+  {
+    return instance->do_to_generic (type, gv);
+  }
+
+  static void to_generic (jit_type *type, llvm::GenericValue& gv, octave_value ov)
+  {
+    return instance->do_to_generic (type, gv, ov);
+  }
+
+  static octave_value to_octave_value (jit_type *type, llvm::GenericValue& gv)
+  {
+    return instance->do_to_octave_value (type, gv);
+  }
+
+  static void reset_generic (void)
+  {
+    instance->do_reset_generic ();
+  }
+private:
   jit_typeinfo (llvm::Module *m, llvm::ExecutionEngine *e);
 
-  jit_type *get_any (void) const { return any; }
-
-  jit_type *get_scalar (void) const { return scalar; }
-
-  llvm::Type *get_scalar_llvm (void) const { return scalar->to_llvm (); }
-
-  jit_type *get_range (void) const { return range; }
+  // FIXME: Do these methods really need to be in jit_typeinfo?
+  jit_type *do_union (jit_type *lhs, jit_type *rhs)
+  {
+    // FIXME: Actually introduce a union type
 
-  llvm::Type *get_range_llvm (void) const { return range->to_llvm (); }
-
-  jit_type *get_bool (void) const { return boolean; }
+    // empty case
+    if (! lhs)
+      return rhs;
 
-  jit_type *get_index (void) const { return index; }
-
-  llvm::Type *get_index_llvm (void) const { return index->to_llvm (); }
-
-  jit_type *type_of (const octave_value& ov) const;
+    if (! rhs)
+      return lhs;
 
-  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);
-    }
+    // check for a shared parent
+    while (lhs != rhs)
+      {
+        if (lhs->depth () > rhs->depth ())
+          lhs = lhs->parent ();
+        else if (lhs->depth () < rhs->depth ())
+          rhs = rhs->parent ();
+        else
+          {
+            // we MUST have depth > 0 as any is the base type of everything
+            do
+              {
+                lhs = lhs->parent ();
+                rhs = rhs->parent ();
+              }
+            while (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& grab (jit_type *ty) const
-  {
-    return grab_fn.get_overload (ty);
+    return lhs;
   }
 
-  const jit_function::overload& release (jit_type *ty) const
+  jit_type *do_difference (jit_type *lhs, jit_type *)
   {
-    return release_fn.get_overload (ty);
+    // FIXME: Maybe we can do something smarter?
+    return lhs;
   }
 
-  const jit_function::overload& print_value (jit_type *to_print) const;
-
-  const jit_function::overload& get_simple_for_check (jit_type *bounds) const
+  jit_type *do_type_of (const octave_value &ov) const;
+  
+  const jit_function& do_binary_op (int op) const
   {
-    return simple_for_check.get_overload (bounds, index);
-  }
-
-  const jit_function::overload& get_simple_for_index (jit_type *bounds) const
-  {
-    return simple_for_index.get_overload (bounds, index);
+    assert (static_cast<size_t>(op) < binary_ops.size ());
+    return binary_ops[op];
   }
 
-  jit_type *get_simple_for_index_result (jit_type *bounds) const
+  void do_to_generic (jit_type *type, llvm::GenericValue& gv);
+
+  void do_to_generic (jit_type *type, llvm::GenericValue& gv, octave_value ov);
+
+  octave_value do_to_octave_value (jit_type *type, llvm::GenericValue& gv);
+
+  void do_reset_generic (void);
+
+  const jit_function& do_cast (jit_type *to)
   {
-    const jit_function::overload& ol = get_simple_for_index (bounds);
-    return ol.result;
-  }
+    static jit_function null_function;
+    if (! to)
+      return null_function;
 
-  const jit_function::overload& get_logically_true (jit_type *conv) const
-  {
-    return logically_true.get_overload (conv);
+    size_t id = to->type_id ();
+    if (id >= casts.size ())
+      return null_function;
+    return casts[id];
   }
 
-  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 (void);
-private:
-  jit_type *new_type (const std::string& name, bool force_init,
-                      jit_type *parent, llvm::Type *llvm_type);
+  const jit_function::overload& do_cast (jit_type *to, jit_type *from)
+  {
+    return do_cast (to).get_overload (from);
+  }
+  
+  jit_type *new_type (const std::string& name, jit_type *parent,
+                      llvm::Type *llvm_type);
+                      
 
   void add_print (jit_type *ty, void *call);
 
@@ -372,6 +468,10 @@
   llvm::Function *create_function (const llvm::Twine& name, llvm::Type *ret,
                                    const std::vector<llvm::Type *>& args);
 
+  llvm::Function *create_identity (jit_type *type);
+
+  static jit_typeinfo *instance;
+
   llvm::Module *module;
   llvm::ExecutionEngine *engine;
   int next_id;
@@ -382,6 +482,7 @@
   jit_type *any;
   jit_type *scalar;
   jit_type *range;
+  jit_type *string;
   jit_type *boolean;
   jit_type *index;
 
@@ -394,27 +495,566 @@
   jit_function simple_for_index;
   jit_function logically_true;
 
+  // type id -> cast function TO that type
+  std::vector<jit_function> casts;
+
+  // type id -> identity function
+  std::vector<llvm::Function *> identities;
+
   std::list<double> scalar_out;
   std::list<octave_base_value *> ov_out;
   std::list<jit_range> range_out;
 };
 
+// The low level octave jit ir
+// this ir is close to llvm, but contains information for doing type inference.
+// We convert the octave parse tree to this IR directly.
+
+#define JIT_VISIT_IR_CLASSES                    \
+  JIT_METH(const_string);                       \
+  JIT_METH(const_scalar);                       \
+  JIT_METH(block);                              \
+  JIT_METH(break);                              \
+  JIT_METH(cond_break);                         \
+  JIT_METH(call);                               \
+  JIT_METH(extract_argument);                   \
+  JIT_METH(store_argument)
+
+
+#define JIT_METH(clname) class jit_ ## clname
+JIT_VISIT_IR_CLASSES;
+#undef JIT_METH
+
 class
-jit_infer : public tree_walker
+jit_ir_walker
+{
+public:
+  virtual ~jit_ir_walker () {}
+
+#define JIT_METH(clname) \
+  virtual void visit_ ## clname (jit_ ## clname&) = 0
+
+  JIT_VISIT_IR_CLASSES;
+
+#undef JIT_METH
+};
+
+class jit_use;
+
+class
+jit_value
+{
+  friend class jit_use;
+public:
+  jit_value (void) : llvm_value (0), ty (0), use_head (0) {}
+
+  virtual ~jit_value (void) {}
+
+  jit_type *type () const { return ty; }
+
+  void stash_type (jit_type *new_ty) { ty = new_ty; }
+
+  jit_use *first_use (void) const { return use_head; }
+
+  size_t use_count (void) const { return myuse_count; }
+
+  virtual std::ostream& print (std::ostream& os, size_t indent = 0) = 0;
+
+  virtual std::ostream& short_print (std::ostream& os)
+  { return print (os); }
+
+  virtual void accept (jit_ir_walker& walker) = 0;
+
+  llvm::Value *to_llvm (void) const
+  {
+    return llvm_value;
+  }
+
+  void stash_llvm (llvm::Value *compiled)
+  {
+    llvm_value = compiled;
+  }
+protected:
+  std::ostream& print_indent (std::ostream& os, size_t indent)
+  {
+    for (size_t i = 0; i < indent; ++i)
+      os << "\t";
+    return os;
+  }
+
+  llvm::Value *llvm_value;
+private:
+  jit_type *ty;
+  jit_use *use_head;
+  size_t myuse_count;
+};
+
+// defnie accept methods for subclasses
+#define JIT_VALUE_ACCEPT(clname)                \
+  virtual void accept (jit_ir_walker& walker)   \
+  {                                             \
+  walker.visit_ ## clname (*this);              \
+  }
+
+class
+jit_const_string : public jit_value
+{
+public:
+  jit_const_string (const std::string& v) : val (v)
+  {
+    stash_type (jit_typeinfo::get_string ());
+  }
+
+  const std::string& value (void) const { return val; }
+
+  virtual std::ostream& print (std::ostream& os, size_t indent)
+  {
+    return print_indent (os, indent) << "string: \"" << val << "\"";
+  }
+
+  JIT_VALUE_ACCEPT (const_string)
+private:
+  std::string val;
+};
+
+class
+jit_const_scalar : public jit_value
+{
+public:
+  jit_const_scalar (double avalue) : mvalue (avalue)
+  {
+    stash_type (jit_typeinfo::get_scalar ());
+  }
+
+  double value (void) const { return mvalue; }
+
+  virtual std::ostream& print (std::ostream& os, size_t indent)
+  {
+    return print_indent (os, indent) << "scalar: \"" << mvalue << "\"";
+  }
+
+  JIT_VALUE_ACCEPT (const_scalar)
+private:
+  double mvalue;
+};
+
+class jit_instruction;
+
+class
+jit_use
+{
+public:
+  jit_use (void) : used (0), next_use (0), prev_use (0) {}
+
+  ~jit_use (void) { remove (); }
+
+  jit_value *value (void) const { return used; }
+
+  size_t index (void) const { return idx; }
+
+  jit_instruction *user (void) const { return usr; }
+
+  void stash_value (jit_value *new_value, jit_instruction *u = 0,
+                    size_t use_idx = -1)
+  {
+    remove ();
+
+    used = new_value;
+
+    if (used)
+      {
+        if (used->use_head)
+          {
+            used->use_head->prev_use = this;
+            next_use = used->use_head;
+          }
+        
+        used->use_head = this;
+        ++used->myuse_count;
+      }
+
+    idx = use_idx;
+    usr = u;
+  }
+
+  jit_use *next (void) const { return next_use; }
+
+  jit_use *prev (void) const { return prev_use; }
+private:
+  void remove (void)
+  {
+    if (used)
+      {
+        if (this == used->use_head)
+            used->use_head = next_use;
+
+        if (prev_use)
+          prev_use->next_use = next_use;
+
+        if (next_use)
+          next_use->prev_use = prev_use;
+
+        next_use = prev_use = 0;
+        --used->myuse_count;
+      }
+  }
+
+  jit_value *used;
+  jit_use *next_use;
+  jit_use *prev_use;
+  jit_instruction *usr;
+  size_t idx;
+};
+
+class
+jit_instruction : public jit_value
 {
 public:
-  // pair <argin, type>
-  typedef std::pair<bool, jit_type *> type_entry;
-  typedef std::map<symbol_table::symbol_record_ref, type_entry,
-                   symbol_table::symbol_record_ref::comparator> type_map;
+  // FIXME: this code could be so much pretier with varadic templates...
+#define JIT_EXTRACT_ARG(idx) arguments[idx].stash_value (arg ## idx, this, idx)
+
+  jit_instruction (void) : id (next_id ())
+  {
+  }
+
+  jit_instruction (jit_value *arg0)
+    : already_infered (1, reinterpret_cast<jit_type *>(0)), arguments (1), 
+      id (next_id ())
+  {
+    JIT_EXTRACT_ARG (0);
+  }
+
+  jit_instruction (jit_value *arg0, jit_value *arg1)
+    : already_infered (2, reinterpret_cast<jit_type *>(0)), arguments (2), 
+      id (next_id ())
+  {
+    JIT_EXTRACT_ARG (0);
+    JIT_EXTRACT_ARG (1);
+  }
+
+  jit_instruction (jit_value *arg0, jit_value *arg1, jit_value *arg2)
+    : already_infered (3, reinterpret_cast<jit_type *>(0)), arguments (3), 
+      id (next_id ())
+  {
+    JIT_EXTRACT_ARG (0);
+    JIT_EXTRACT_ARG (1);
+    JIT_EXTRACT_ARG (2);
+  }
+
+#undef JIT_EXTRACT_ARG
+
+  static void reset_ids (void)
+  {
+    next_id (true);
+  }
+
+  jit_value *argument (size_t i) const
+  {
+    return arguments[i].value ();
+  }
+
+  llvm::Value *argument_llvm (size_t i) const
+  {
+    return arguments[i].value ()->to_llvm ();
+  }
+
+  jit_type *argument_type (size_t i) const
+  {
+    return arguments[i].value ()->type ();
+  }
+
+  size_t argument_count (void) const
+  {
+    return arguments.size ();
+  }
+
+  // argument types which have been infered already
+  const std::vector<jit_type *>& argument_types (void) const
+  { return already_infered; }
+
+  virtual bool infer (void) { return false; }
+
+  virtual std::ostream& short_print (std::ostream& os)
+  {
+    if (mtag.empty ())
+      jit_print (os, type ()) << ": #" << id;
+    else
+      jit_print (os, type ()) << ": " << mtag << "." << id;
+
+    return os;
+  }
+
+  const std::string& tag (void) const { return mtag; }
+
+  void stash_tag (const std::string& atag) { mtag = atag; }
+protected:
+  std::vector<jit_type *> already_infered;
+private:
+  static size_t next_id (bool reset = false)
+  {
+    static size_t ret = 0;
+    if (reset)
+      return ret = 0;
+
+    return ret++;
+  }
+
+  std::vector<jit_use> arguments; // DO NOT resize
+
+  std::string mtag;
+  size_t id;
+};
+
+class
+jit_block : public jit_value
+{
+public:
+  typedef std::list<jit_instruction *> instruction_list;
+  typedef instruction_list::iterator iterator;
+  typedef instruction_list::const_iterator const_iterator;
+
+  jit_block (const std::string& n) : nm (n) {}
+
+  virtual ~jit_block ()
+  {
+    for (instruction_list::iterator iter = instructions.begin ();
+         iter != instructions.end (); ++iter)
+      delete *iter;
+  }
+
+  const std::string& name (void) const { return nm; }
+
+  jit_instruction *prepend (jit_instruction *instr)
+  {
+    instructions.push_front (instr);
+    return instr;
+  }
+
+  jit_instruction *append (jit_instruction *instr)
+  {
+    instructions.push_back (instr);
+    return instr;
+  }
+
+  iterator begin () { return instructions.begin (); }
+
+  const_iterator begin () const { return instructions.begin (); }
+
+  iterator end () { return instructions.end (); }
+
+  const_iterator end () const { return instructions.begin (); }
+
+  virtual std::ostream& print (std::ostream& os, size_t indent)
+  {
+    print_indent (os, indent) << nm << ":" << std::endl;
+    for (iterator iter = begin (); iter != end (); ++iter)
+      {
+        jit_instruction *instr = *iter;
+        instr->print (os, indent + 1) << std::endl;
+      }
+    return os;
+  }
+
+  llvm::BasicBlock *to_llvm (void) const;
+
+  JIT_VALUE_ACCEPT (block)
+private:
+  std::string nm;
+  instruction_list instructions;
+};
+
+class jit_terminator : public jit_instruction
+{
+public:
+  jit_terminator (jit_value *arg0) : jit_instruction (arg0) {}
+
+  jit_terminator (jit_value *arg0, jit_value *arg1, jit_value *arg2)
+    : jit_instruction (arg0, arg1, arg2) {}
+
+  virtual jit_block *sucessor (size_t idx = 0) const = 0;
+
+  llvm::BasicBlock *sucessor_llvm (size_t idx = 0) const
+  {
+    return sucessor (idx)->to_llvm ();
+  }
+
+  virtual size_t sucessor_count (void) const = 0;
+};
 
-  jit_infer (jit_typeinfo *ti) : tinfo (ti), is_lvalue (false),
-                                  rvalue_type (0)
-  {}
+class
+jit_break : public jit_terminator
+{
+public:
+  jit_break (jit_block *succ) : jit_terminator (succ) {}
+
+  jit_block *sucessor (size_t idx = 0) const
+  {
+    jit_value *arg = argument (idx);
+    return reinterpret_cast<jit_block *> (arg);
+  }
+
+  size_t sucessor_count (void) const { return 1; }
+
+  virtual std::ostream& print (std::ostream& os, size_t indent)
+  {
+    jit_block *succ = sucessor ();
+    return print_indent (os, indent) << "break: " << succ->name ();
+  }
+
+  JIT_VALUE_ACCEPT (break)
+};
+
+class
+jit_cond_break : public jit_terminator
+{
+public:
+  jit_cond_break (jit_value *c, jit_block *ctrue, jit_block *cfalse)
+    : jit_terminator (c, ctrue, cfalse) {}
+
+  jit_value *cond (void) const { return argument (0); }
+
+  llvm::Value *cond_llvm (void) const
+  {
+    return cond ()->to_llvm ();
+  }
+
+  jit_block *sucessor (size_t idx) const
+  {
+    jit_value *arg = argument (idx + 1);
+    return reinterpret_cast<jit_block *> (arg);
+  }
+
+  size_t sucessor_count (void) const { return 2; }
+
+  JIT_VALUE_ACCEPT (cond_break)
+};
+
+class
+jit_call : public jit_instruction
+{
+public:
+  jit_call (const jit_function& afunction,
+            jit_value *arg0) : jit_instruction (arg0), mfunction (afunction) {}
+
+  jit_call (const jit_function& afunction,
+            jit_value *arg0, jit_value *arg1) : jit_instruction (arg0, arg1),
+                                                mfunction (afunction) {}
+
+  const jit_function& function (void) const { return mfunction; }
+
+  const jit_function::overload& overload (void) const
+  {
+    return mfunction.get_overload (argument_types ());
+  }
+
+  virtual std::ostream& print (std::ostream& os, size_t indent)
+  {
+    print_indent (os, indent);
+
+    if (use_count ())
+      short_print (os) << " = ";
+    os << "call " << mfunction.name () << " (";
+
+    for (size_t i = 0; i < argument_count (); ++i)
+      {
+        jit_value *arg = argument (i);
+        arg->short_print (os);
+        if (i + 1 < argument_count ())
+          os << ", ";
+      }
+    return os << ")";
+  }
+
+  virtual bool infer (void);
 
-  const type_map& get_types () const { return types; }
+  JIT_VALUE_ACCEPT (call)
+private:
+  const jit_function& mfunction;
+};
+
+class
+jit_extract_argument : public jit_instruction
+{
+public:
+  jit_extract_argument (jit_type *atype, const std::string& aname)
+    : jit_instruction ()
+  {
+    stash_type (atype);
+    stash_tag (aname);
+  }
+
+  const jit_function::overload& overload (void) const
+  {
+    return jit_typeinfo::cast (type (), jit_typeinfo::get_any ());
+  }
+
+  virtual std::ostream& print (std::ostream& os, size_t indent)
+  {
+    print_indent (os, indent);
+    return short_print (os) << " = extract: " << tag ();
+  }
+
+  JIT_VALUE_ACCEPT (extract_argument)
+};
+
+class
+jit_store_argument : public jit_instruction
+{
+public:
+  jit_store_argument (const std::string& aname, jit_value *aresult)
+    : jit_instruction (aresult)
+  {
+    stash_tag (aname);
+  }
 
-  void infer (tree_simple_for_command& cmd, jit_type *bounds);
+  const jit_function::overload& overload (void) const
+  {
+    return jit_typeinfo::cast (jit_typeinfo::get_any (), result_type ());
+  }
+
+  jit_value *result (void) const
+  {
+    return argument (0);
+  }
+
+  jit_type *result_type (void) const
+  {
+    return result ()->type ();
+  }
+
+  llvm::Value *result_llvm (void) const
+  {
+    return result ()->to_llvm ();
+  }
+
+  virtual std::ostream& print (std::ostream& os, size_t indent)
+  {
+    jit_value *res = result ();
+    print_indent (os, indent) << tag () << " <- ";
+    return res->short_print (os);
+  }
+
+  JIT_VALUE_ACCEPT (store_argument)
+};
+
+// convert between IRs
+// FIXME: Class relationships are messy from here on down. They need to be
+// cleaned up.
+class
+jit_convert : public tree_walker
+{
+public:
+  typedef std::pair<jit_type *, std::string> type_bound;
+  typedef std::vector<type_bound> type_bound_vector;
+
+  jit_convert (llvm::Module *module, tree &tee);
+
+  llvm::Function *get_function (void) const { return function; }
+
+  const std::vector<std::pair<std::string, bool> >& get_arguments(void) const
+  { return arguments; }
+
+  const type_bound_vector& get_bounds (void) const { return bounds; }
 
   void visit_anon_fcn_handle (tree_anon_fcn_handle&);
 
@@ -502,146 +1142,87 @@
 
   void visit_do_until_command (tree_do_until_command&);
 private:
-  void infer_simple_for (tree_simple_for_command& cmd,
-                         jit_type *bounds);
+  std::vector<std::pair<std::string, bool> > arguments;
+  type_bound_vector bounds;
+
+  typedef std::map<std::string, jit_value *> variable_map;
+  variable_map variables;
+
+  // used instead of return values from visit_* functions
+  jit_value *result;
+
+  jit_block *block;
+  jit_block *entry_block;
+  jit_block *final_block;
+
+  llvm::Function *function;
 
-  void handle_identifier (const symbol_table::symbol_record_ref& record);
+  std::list<jit_block *> blocks;
+
+  std::list<jit_instruction *> worklist;
+
+  std::list<jit_value *> constants;
+
+  void do_assign (const std::string& lhs, jit_value *rhs, bool print);
 
-  void merge (type_map& dest, const type_map& src);
+  jit_value *visit (tree *tee) { return visit (*tee); }
+
+  jit_value *visit (tree& tee);
+
+  void append_users (jit_value *v)
+  {
+    for (jit_use *use = v->first_use (); use; use = use->next ())
+      worklist.push_back (use->user ());
+  }
 
-  jit_typeinfo *tinfo;
+  jit_const_scalar *get_scalar (double v)
+  {
+    jit_const_scalar *ret = new jit_const_scalar (v);
+    constants.push_back (ret);
+    return ret;
+  }
+
+  jit_const_string *get_string (const std::string& v)
+  {
+    jit_const_string *ret = new jit_const_string (v);
+    constants.push_back (ret);
+    return ret;
+  }
 
-  bool is_lvalue;
-  jit_type *rvalue_type;
+  // this case is much simpler, just convert from the jit ir to llvm
+  class
+  convert_llvm : public jit_ir_walker
+  {
+  public:
+    llvm::Function *convert (llvm::Module *module,
+                             const std::vector<std::pair<std::string, bool> >& args,
+                             const std::list<jit_block *>& blocks,
+                             const std::list<jit_value *>& constants);
+
+#define JIT_METH(clname)                        \
+    virtual void visit_ ## clname (jit_ ## clname&);
+
+    JIT_VISIT_IR_CLASSES;
 
-  type_map types;
+#undef JIT_METH
+  private:
+    // name -> llvm argument
+    std::map<std::string, llvm::Value *> arguments;
+
 
-  std::vector<jit_type *> type_stack;
+    void visit (jit_value *jvalue)
+    {
+      return visit (*jvalue);
+    }
+
+    void visit (jit_value &jvalue)
+    {
+      jvalue.accept (*this);
+    }
+  };
 };
 
-class
-jit_generator : public tree_walker
-{
-public:
-  typedef jit_infer::type_map type_map;
-
-  jit_generator (jit_typeinfo *ti, llvm::Module *mod, tree_simple_for_command &cmd,
-                 jit_type *bounds, 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_simple_for (tree_simple_for_command& cmd, value over,
-                        bool atleast_once);
-
-  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));
-  }
-
-  void initialize (const std::vector<std::string>& names,
-                   const std::vector<bool>& argin,
-                   const std::vector<jit_type *> types);
-
-  void finalize (const std::vector<std::string>& names);
-
-  jit_typeinfo *tinfo;
-  llvm::Module *module;
-  llvm::Function *function;
-
-  bool is_lvalue;
-  std::map<std::string, value> variables;
-  std::vector<value> value_stack;
-};
+class jit_info;
 
 class
 tree_jit
@@ -651,9 +1232,7 @@
 
   ~tree_jit (void);
 
-  bool execute (tree_simple_for_command& cmd, const octave_value& bounds);
-
-  jit_typeinfo *get_typeinfo (void) const { return tinfo; }
+  bool execute (tree& cmd);
 
   llvm::ExecutionEngine *get_engine (void) const { return engine; }
 
@@ -663,32 +1242,36 @@
  private:
   bool initialize (void);
 
+  // FIXME: Temorary hack to test
+  typedef std::map<tree *, jit_info *> compiled_map;
+  compiled_map compiled;
+
   llvm::LLVMContext &context;
   llvm::Module *module;
   llvm::PassManager *module_pass_manager;
   llvm::FunctionPassManager *pass_manager;
   llvm::ExecutionEngine *engine;
-
-  jit_typeinfo *tinfo;
 };
 
 class
 jit_info
 {
 public:
-  typedef jit_infer::type_map type_map;
+  jit_info (tree_jit& tjit, tree& tee);
 
-  jit_info (tree_jit& tjit, tree_simple_for_command& cmd, jit_type *bounds);
-
-  bool execute (const octave_value& bounds) const;
+  bool execute (void) const;
 
   bool match (void) const;
 private:
-  jit_typeinfo *tinfo;
+  typedef jit_convert::type_bound type_bound;
+  typedef jit_convert::type_bound_vector type_bound_vector;
+  typedef void (*jited_function)(octave_base_value**);
+
   llvm::ExecutionEngine *engine;
-  type_map types;
-  llvm::Function *function;
-  jit_type *bounds_t;
+  jited_function function;
+
+  std::vector<std::pair<std::string, bool> > arguments;
+  type_bound_vector bounds;
 };
 
 #endif