static void createPushHeapFunction() {
    // Saving last BasicBlock;
    LLVMBasicBlockRef OldBB = LLVMGetInsertBlock(Builder);

    LLVMTypeRef ParamType    = LLVMPointerType(RAType, 0);
    LLVMTypeRef FunctionType = LLVMFunctionType(LLVMVoidType(), &ParamType, 1, 0);

    LLVMValueRef      Function = LLVMAddFunction(Module, "push.heap", FunctionType);
    LLVMBasicBlockRef Entry    = LLVMAppendBasicBlock(Function, "entry");
    LLVMPositionBuilderAtEnd(Builder, Entry);

    // Function Body
    LLVMValueRef HeapMalloc  = LLVMBuildMalloc(Builder, HeapType, "heap.malloc");

    LLVMValueRef ExPtrIdx[]   = { getSConstInt(0), getSConstInt(0) };
    LLVMValueRef LastPtrIdx[] = { getSConstInt(0), getSConstInt(1) };

    LLVMValueRef ExPtr   = LLVMBuildInBoundsGEP(Builder, HeapMalloc, ExPtrIdx, 2, "heap.exec");
    LLVMValueRef LastPtr = LLVMBuildInBoundsGEP(Builder, HeapMalloc, LastPtrIdx, 2, "heap.last");

    LLVMBuildStore(Builder, LLVMGetParam(Function, 0), ExPtr);
    LLVMBuildStore(Builder, LLVMBuildLoad(Builder, HeapHead, "ld.heap.head"), LastPtr);

    LLVMBuildStore(Builder, HeapMalloc, HeapHead);

    LLVMBuildRetVoid(Builder);

    // Restoring last BasicBlock
    LLVMPositionBuilderAtEnd(Builder, OldBB);
}

static LLVMValueRef raw_is_box(compile_t* c, ast_t* left_type,
  LLVMValueRef l_value, LLVMValueRef r_value)
{
  pony_assert(LLVMGetTypeKind(LLVMTypeOf(r_value)) == LLVMPointerTypeKind);

  LLVMValueRef r_desc = gendesc_fetch(c, r_value);
  LLVMValueRef same_type = gendesc_isentity(c, r_desc, left_type);
  pony_assert(same_type != GEN_NOVALUE);

  LLVMBasicBlockRef this_block = LLVMGetInsertBlock(c->builder);
  LLVMBasicBlockRef value_block = codegen_block(c, "is_value");
  LLVMBasicBlockRef post_block = codegen_block(c, "is_post");
  LLVMBuildCondBr(c->builder, same_type, value_block, post_block);

  LLVMPositionBuilderAtEnd(c->builder, value_block);
  r_value = gen_unbox(c, left_type, r_value);
  LLVMValueRef is_value = gen_is_value(c, left_type, left_type, l_value,
    r_value);
  LLVMBuildBr(c->builder, post_block);
  value_block = LLVMGetInsertBlock(c->builder);

  LLVMPositionBuilderAtEnd(c->builder, post_block);
  LLVMValueRef phi = LLVMBuildPhi(c->builder, c->i1, "");
  LLVMValueRef zero = LLVMConstInt(c->i1, 0, false);
  LLVMAddIncoming(phi, &is_value, &value_block, 1);
  LLVMAddIncoming(phi, &zero, &this_block, 1);
  return phi;
}

static bool check_union(compile_t* c, LLVMValueRef ptr, LLVMValueRef desc,
  ast_t* pattern_type, LLVMBasicBlockRef next_block)
{
  // We have to match some component type.
  LLVMBasicBlockRef continue_block = codegen_block(c, "pattern_continue");
  ast_t* child = ast_child(pattern_type);

  while(child != NULL)
  {
    // If we don't match, try the next type if there is one. If there is
    // no next type, jump to the next case.
    ast_t* next_type = ast_sibling(child);
    LLVMBasicBlockRef nomatch_block;

    if(next_type != NULL)
      nomatch_block = codegen_block(c, "pattern_next");
    else
      nomatch_block = next_block;

    if(!check_type(c, ptr, desc, child, nomatch_block))
      return false;

    // If we do match, jump to the continue block.
    LLVMBuildBr(c->builder, continue_block);

    // Put the next union check, if there is one, in the nomatch block.
    LLVMPositionBuilderAtEnd(c->builder, nomatch_block);
    child = next_type;
  }

  // Continue codegen in the continue block, not in the next block.
  LLVMPositionBuilderAtEnd(c->builder, continue_block);
  return true;
}

/**
 * End a conditional.
 */
void
lp_build_endif(struct lp_build_if_state *ifthen)
{
   LLVMBuilderRef builder = ifthen->gallivm->builder;

   /* Insert branch to the merge block from current block */
   LLVMBuildBr(builder, ifthen->merge_block);

   /*
    * Now patch in the various branch instructions.
    */

   /* Insert the conditional branch instruction at the end of entry_block */
   LLVMPositionBuilderAtEnd(builder, ifthen->entry_block);
   if (ifthen->false_block) {
      /* we have an else clause */
      LLVMBuildCondBr(builder, ifthen->condition,
                      ifthen->true_block, ifthen->false_block);
   }
   else {
      /* no else clause */
      LLVMBuildCondBr(builder, ifthen->condition,
                      ifthen->true_block, ifthen->merge_block);
   }

   /* Resume building code at end of the ifthen->merge_block */
   LLVMPositionBuilderAtEnd(builder, ifthen->merge_block);
}

LLVMValueRef gen_localdecl(compile_t* c, ast_t* ast)
{
  ast_t* id = ast_child(ast);
  ast_t* type = ast_type(id);
  gentype_t g;

  if(!gentype(c, type, &g))
    return NULL;

  // All alloca should happen in the entry block of a function.
  LLVMBasicBlockRef this_block = LLVMGetInsertBlock(c->builder);
  LLVMBasicBlockRef entry_block = LLVMGetEntryBasicBlock(codegen_fun(c));
  LLVMValueRef inst = LLVMGetFirstInstruction(entry_block);

  if(inst != NULL)
    LLVMPositionBuilderBefore(c->builder, inst);
  else
    LLVMPositionBuilderAtEnd(c->builder, entry_block);

  const char* name = ast_name(id);
  LLVMValueRef l_value = LLVMBuildAlloca(c->builder, g.use_type, name);

  // Store the alloca to use when we reference this local.
  codegen_setlocal(c, name, l_value);

  // Emit debug info for local variable declaration.
  dwarf_local(&c->dwarf, ast, g.type_name, entry_block, inst, l_value);

  // Put the builder back where it was.
  LLVMPositionBuilderAtEnd(c->builder, this_block);
  return GEN_NOVALUE;
}

LLVMValueRef gen_switch(struct node *ast)
{
	LLVMValueRef func, switch_;
	LLVMBasicBlockRef this_block, switch_first_block, switch_last_block, end_block;
	int i;

	this_block = LLVMGetInsertBlock(builder);
	func = LLVMGetBasicBlockParent(this_block);
	switch_first_block = LLVMAppendBasicBlock(func, "");
	LLVMPositionBuilderAtEnd(builder, switch_first_block);

	case_count = 0;
	codegen(ast->two);

	switch_last_block = LLVMGetLastBasicBlock(func);
	end_block = LLVMAppendBasicBlock(func, "");

	LLVMPositionBuilderAtEnd(builder, switch_last_block);
	LLVMBuildBr(builder, end_block);

	LLVMPositionBuilderAtEnd(builder, this_block);
	switch_ = LLVMBuildSwitch(builder, codegen(ast->one), end_block, case_count);

	for (i = 0; i < case_count; i++)
		LLVMAddCase(switch_, case_vals[i], case_blocks[i]);

	LLVMPositionBuilderAtEnd(builder, end_block);

	return NULL;
}

/**
 * Creates a c-style for loop,
 * contrasts lp_build_loop as this checks condition on entry
 * e.g. for(i = start; i cmp_op end; i += step)
 * \param state      the for loop state, initialized here
 * \param gallivm    the gallivm state
 * \param start      starting value of iterator
 * \param cmp_op     comparison operator used for comparing current value with end value
 * \param end        value used to compare against iterator
 * \param step       value added to iterator at end of each loop
 */
void
lp_build_for_loop_begin(struct lp_build_for_loop_state *state,
                        struct gallivm_state *gallivm,
                        LLVMValueRef start,
                        LLVMIntPredicate cmp_op,
                        LLVMValueRef end,
                        LLVMValueRef step)
{
   LLVMBuilderRef builder = gallivm->builder;

   assert(LLVMTypeOf(start) == LLVMTypeOf(end));
   assert(LLVMTypeOf(start) == LLVMTypeOf(step));

   state->begin = lp_build_insert_new_block(gallivm, "loop_begin");
   state->step  = step;
   state->counter_var = lp_build_alloca(gallivm, LLVMTypeOf(start), "loop_counter");
   state->gallivm = gallivm;
   state->cond = cmp_op;
   state->end = end;

   LLVMBuildStore(builder, start, state->counter_var);
   LLVMBuildBr(builder, state->begin);

   LLVMPositionBuilderAtEnd(builder, state->begin);
   state->counter = LLVMBuildLoad(builder, state->counter_var, "");

   state->body = lp_build_insert_new_block(gallivm, "loop_body");
   LLVMPositionBuilderAtEnd(builder, state->body);
}

void
vm_state_destroy(struct vm_state *vm)
{
   LLVMBasicBlockRef current_block, return_block;
   char *error;

   current_block = LLVMGetInsertBlock(vm->builder);
   return_block = LLVMInsertBasicBlock(current_block, "ret");

   LLVMPositionBuilderAtEnd(vm->builder, current_block);
   LLVMBuildBr(vm->builder, return_block);

   LLVMPositionBuilderAtEnd(vm->builder, return_block);
   LLVMBuildRetVoid(vm->builder);

   LLVMMoveBasicBlockAfter(return_block, current_block);

   LLVMDumpModule(vm->module);

   error = NULL;
   LLVMVerifyModule(vm->module, LLVMAbortProcessAction, &error);
   LLVMDisposeMessage(error);

   LLVMDisposeBuilder(vm->builder);
   LLVMDisposeModule(vm->module);
   symbol_table_destroy(vm->symtab);
}

LLVMBasicBlockRef JITImpl::getOrCreateMemoryCheckBailoutBlock(unsigned index)
{
  if (index == 0) {
    if (interpretOneBB) {
      return interpretOneBB;
    }
  } else if (endTraceBB) {
    return endTraceBB;
  }
  LLVMBasicBlockRef savedInsertPoint = LLVMGetInsertBlock(builder);
  LLVMBasicBlockRef bailoutBB = LLVMAppendBasicBlock(getCurrentFunction(), "");
  LLVMPositionBuilderAtEnd(builder, bailoutBB);
  if (index == 0) {
    LLVMValueRef args[] = {
      threadParam
    };
    LLVMValueRef call = emitCallToBeInlined(functions.jitInterpretOne, args, 1);
    LLVMBuildRet(builder, call);
    interpretOneBB = bailoutBB;
  } else {
    ensureEarlyReturnBB(LLVMGetReturnType(jitFunctionType));
    earlyReturnIncomingValues.push_back(
      LLVMConstInt(LLVMGetReturnType(jitFunctionType),
                   JIT_RETURN_END_TRACE, false));
    earlyReturnIncomingBlocks.push_back(LLVMGetInsertBlock(builder));
    LLVMBuildBr(builder, earlyReturnBB);
    endTraceBB = bailoutBB;
  }
  LLVMPositionBuilderAtEnd(builder, savedInsertPoint);
  return bailoutBB;
}

bool JITImpl::
emitJumpToNextFragment(InstructionOpcode opc, const Operands &operands,
                       JITCoreInfo &coreInfo, uint32_t nextPc,
                       JITFunctionInfo *caller)
{
  std::set<uint32_t> successors;
  if (!getSuccessors(opc, operands, nextPc, successors))
    return false;
  unsigned numSuccessors = successors.size();
  if (numSuccessors == 0)
    return false;
  std::set<uint32_t>::iterator it = successors.begin();
  ++it;
  if (it != successors.end()) {
    LLVMValueRef args[] = {
      threadParam
    };
    LLVMValueRef nextPc = emitCallToBeInlined(functions.jitGetPc, args, 1);
    for (;it != successors.end(); ++it) {
      LLVMValueRef cmp =
        LLVMBuildICmp(builder, LLVMIntEQ, nextPc,
                      LLVMConstInt(LLVMTypeOf(nextPc), *it, false), "");
      LLVMBasicBlockRef trueBB = appendBBToCurrentFunction(builder, "");
      LLVMBasicBlockRef afterBB = appendBBToCurrentFunction(builder, "");
      LLVMBuildCondBr(builder, cmp, trueBB, afterBB);
      LLVMPositionBuilderAtEnd(builder, trueBB);
      emitJumpToNextFragment(coreInfo, *it, caller);
      LLVMPositionBuilderAtEnd(builder, afterBB);
    }
  }
  emitJumpToNextFragment(coreInfo, *successors.begin(), caller);
  return true;
}

JITFunctionInfo *JITImpl::
getJITFunctionOrStubImpl(JITCoreInfo &coreInfo, uint32_t pc)
{
  JITFunctionInfo *&info = coreInfo.functionMap[pc];
  if (info)
    return info;
  LLVMBasicBlockRef savedInsertPoint = LLVMGetInsertBlock(builder);
  LLVMValueRef f = LLVMAddFunction(module, "", jitFunctionType);
  LLVMSetFunctionCallConv(f, LLVMFastCallConv);
  LLVMBasicBlockRef entryBB = LLVMAppendBasicBlock(f, "entry");
  LLVMPositionBuilderAtEnd(builder, entryBB);
  LLVMValueRef args[] = {
    LLVMGetParam(f, 0)
  };
  LLVMValueRef call =
    LLVMBuildCall(builder, functions.jitStubImpl, args, 1, "");
  LLVMBuildRet(builder, call);
  if (DEBUG_JIT) {
    LLVMDumpValue(f);
    LLVMVerifyFunction(f, LLVMAbortProcessAction);
  }
  JITInstructionFunction_t code =
    reinterpret_cast<JITInstructionFunction_t>(
     LLVMGetPointerToGlobal(executionEngine, f));
  info = new JITFunctionInfo(pc, f, code, true);
  LLVMPositionBuilderAtEnd(builder, savedInsertPoint);
  return info;
}

LLVMValueRef gen_if(struct node *ast)
{
	LLVMValueRef condition, func;
	LLVMBasicBlockRef then_block, else_block, end;

	condition = codegen(ast->one);
	condition = LLVMBuildICmp(builder, LLVMIntNE, condition, CONST(0), "");
	func = LLVMGetBasicBlockParent(LLVMGetInsertBlock(builder));

	then_block = LLVMAppendBasicBlock(func, "");
	else_block = LLVMAppendBasicBlock(func, "");
	end = LLVMAppendBasicBlock(func, "");
	LLVMBuildCondBr(builder, condition, then_block, else_block);

	LLVMPositionBuilderAtEnd(builder, then_block);
	codegen(ast->two);
	LLVMBuildBr(builder, end);

	LLVMPositionBuilderAtEnd(builder, else_block);
	if (ast->three)
		codegen(ast->three);
	LLVMBuildBr(builder, end);

	LLVMPositionBuilderAtEnd(builder, end);

	return NULL;
}

static void trace_dynamic_nominal(compile_t* c, LLVMValueRef ctx,
  LLVMValueRef object, ast_t* type, ast_t* orig, ast_t* tuple,
  LLVMBasicBlockRef next_block)
{
  // Skip if a primitive.
  ast_t* def = (ast_t*)ast_data(type);

  if(ast_id(def) == TK_PRIMITIVE)
    return;

  // If it's not possible to use match or as to extract this type from the
  // original type, there's no need to trace as this type.
  if(tuple != NULL)
  {
    // We are a tuple element. Our type is in the correct position in the
    // tuple, everything else is TK_DONTCARE.
    if(is_matchtype(orig, tuple) != MATCHTYPE_ACCEPT)
      return;
  } else {
    // We aren't a tuple element.
    if(is_matchtype(orig, type) != MATCHTYPE_ACCEPT)
      return;
  }

  // We aren't always this type. We need to check dynamically.
  LLVMValueRef desc = gendesc_fetch(c, object);
  LLVMValueRef test = gendesc_isnominal(c, desc, type);

  LLVMBasicBlockRef is_true = codegen_block(c, "");
  LLVMBasicBlockRef is_false = codegen_block(c, "");
  LLVMBuildCondBr(c->builder, test, is_true, is_false);

  // Trace as this type.
  LLVMPositionBuilderAtEnd(c->builder, is_true);
  gentrace(c, ctx, object, type);

  // If we have traced as known, unknown or actor, we're done with this
  // element. Otherwise, continue tracing this as if the match had been
  // unsuccessful.
  switch(trace_type(type))
  {
    case TRACE_KNOWN:
    case TRACE_UNKNOWN:
    case TRACE_KNOWN_VAL:
    case TRACE_UNKNOWN_VAL:
    case TRACE_ACTOR:
      LLVMBuildBr(c->builder, next_block);
      break;

    default:
      LLVMBuildBr(c->builder, is_false);
      break;
  }

  // Carry on, whether we have traced or not.
  LLVMPositionBuilderAtEnd(c->builder, is_false);
}

LLVMValueRef gen_localdecl(compile_t* c, ast_t* ast)
{
  ast_t* id = ast_child(ast);
  const char* name = ast_name(id);

  // If this local has already been generated, don't create another copy. This
  // can happen when the same ast node is generated more than once, such as
  // the condition block of a while expression.
  LLVMValueRef value = codegen_getlocal(c, name);

  if(value != NULL)
    return GEN_NOVALUE;

  ast_t* type = deferred_reify(c->frame->reify, ast_type(id), c->opt);
  reach_type_t* t = reach_type(c->reach, type);
  ast_free_unattached(type);
  compile_type_t* c_t = (compile_type_t*)t->c_type;

  // All alloca should happen in the entry block of a function.
  LLVMBasicBlockRef this_block = LLVMGetInsertBlock(c->builder);
  LLVMBasicBlockRef entry_block = LLVMGetEntryBasicBlock(codegen_fun(c));
  LLVMValueRef inst = LLVMGetFirstInstruction(entry_block);

  if(inst != NULL)
    LLVMPositionBuilderBefore(c->builder, inst);
  else
    LLVMPositionBuilderAtEnd(c->builder, entry_block);

  LLVMValueRef alloc = LLVMBuildAlloca(c->builder, c_t->mem_type, name);

  // Store the alloca to use when we reference this local.
  codegen_setlocal(c, name, alloc);

  LLVMMetadataRef file = codegen_difile(c);
  LLVMMetadataRef scope = codegen_discope(c);

#if PONY_LLVM >= 700
  uint32_t align_bytes = LLVMABIAlignmentOfType(c->target_data, c_t->mem_type);

  LLVMMetadataRef info = LLVMDIBuilderCreateAutoVariable(c->di, scope,
    name, strlen(name), file, (unsigned)ast_line(ast), c_t->di_type,
    true, LLVMDIFlagZero, align_bytes * 8);
#else
  LLVMMetadataRef info = LLVMDIBuilderCreateAutoVariable(c->di, scope, name,
    file, (unsigned)ast_line(ast), c_t->di_type);
#endif

  LLVMMetadataRef expr = LLVMDIBuilderCreateExpression(c->di, NULL, 0);

  LLVMDIBuilderInsertDeclare(c->di, alloc, info, expr,
    (unsigned)ast_line(ast), (unsigned)ast_pos(ast), scope,
    LLVMGetInsertBlock(c->builder));

  // Put the builder back where it was.
  LLVMPositionBuilderAtEnd(c->builder, this_block);
  return GEN_NOTNEEDED;
}

int main (void) {
    LLVMModuleRef module = LLVMModuleCreateWithName("kal");
    LLVMBuilderRef builder = LLVMCreateBuilder();
//	LLVMInitializeNativeTarget();

	LLVMTypeRef funcType = LLVMFunctionType(LLVMVoidType(), NULL, 0, 0);
	LLVMValueRef func = LLVMAddFunction(module, "main", funcType);
	LLVMSetLinkage(func, LLVMExternalLinkage);
	LLVMBasicBlockRef block = LLVMAppendBasicBlock(func, "entry");
	LLVMPositionBuilderAtEnd(builder, block);

	LLVMValueRef cond = LLVMBuildICmp(builder, LLVMIntNE, LLVMConstInt(LLVMInt32Type(), 2, 0), LLVMConstInt(LLVMInt32Type(), 1, 0), "ifcond");

	LLVMValueRef owning_block = LLVMGetBasicBlockParent(LLVMGetInsertBlock(builder));	//TODO: WRONG??
	//LLVMValueRef owning_block = LLVMBasicBlockAsValue(LLVMGetPreviousBasicBlock(LLVMGetInsertBlock(builder)));
	// 2. Generate new blocks for cases.
	LLVMBasicBlockRef then_ref = LLVMAppendBasicBlock(owning_block, "then");
	LLVMBasicBlockRef else_ref = LLVMAppendBasicBlock(owning_block, "else");
	LLVMBasicBlockRef merge_ref = LLVMAppendBasicBlock(owning_block, "ifmerge");

	// 3. Branch conditionally on then or else.
	LLVMBuildCondBr(builder, cond, then_ref, else_ref);

	// 4. Build then branch prologue.
	LLVMPositionBuilderAtEnd(builder, then_ref);

	LLVMValueRef hi1 = LLVMBuildXor(builder, LLVMGetUndef(LLVMInt32Type()), LLVMGetUndef(LLVMInt32Type()), "subtmp");

	// 5. Connect then branch to merge block.
	LLVMBuildBr(builder, merge_ref);

	then_ref = LLVMGetInsertBlock(builder);

	// 6. Build else branch prologue.
	LLVMPositionBuilderAtEnd(builder, else_ref);

	LLVMValueRef hi2 = LLVMBuildXor(builder, LLVMGetUndef(LLVMInt32Type()), LLVMGetUndef(LLVMInt32Type()), "subtmp2");

	// 7. Connect else branch to merge block.
	LLVMBuildBr(builder, merge_ref);

	else_ref = LLVMGetInsertBlock(builder);
	// 8. Position ourselves after the merge block.
	LLVMPositionBuilderAtEnd(builder, merge_ref);
	// 9. Build the phi node.
//	LLVMValueRef phi = LLVMBuildPhi(builder, LLVMDoubleType(), "phi");
	// 10. Add incoming edges.
//	LLVMAddIncoming(phi, &hi1, &then_ref, 1);
//	LLVMAddIncoming(phi, &hi2, &else_ref, 1);

	LLVMDumpModule(module);
	LLVMDisposeBuilder(builder);
	LLVMDisposeModule(module);

	return 0;
}

static LLVMValueRef tuple_is(compile_t* c, ast_t* left_type, ast_t* right_type,
  LLVMValueRef l_value, LLVMValueRef r_value)
{
  pony_assert(ast_id(left_type) == TK_TUPLETYPE);
  pony_assert(ast_id(right_type) == TK_TUPLETYPE);
  pony_assert(ast_childcount(left_type) == ast_childcount(right_type));

  // Pairwise comparison.
  LLVMBasicBlockRef this_block = LLVMGetInsertBlock(c->builder);
  LLVMBasicBlockRef post_block = codegen_block(c, "post");

  // Set up the phi node.
  LLVMPositionBuilderAtEnd(c->builder, post_block);
  LLVMValueRef phi = LLVMBuildPhi(c->builder, c->i1, "");

  ast_t* left_child = ast_child(left_type);
  ast_t* right_child = ast_child(right_type);
  int i = 0;

  while(left_child != NULL)
  {
    // Set up the next block.
    LLVMBasicBlockRef next_block = codegen_block(c, "next");
    LLVMPositionBuilderAtEnd(c->builder, this_block);

    // Test the element.
    LLVMValueRef l_elem = LLVMBuildExtractValue(c->builder, l_value, i, "");
    LLVMValueRef r_elem = LLVMBuildExtractValue(c->builder, r_value, i, "");
    LLVMValueRef test = gen_is_value(c, left_child, right_child, l_elem,
      r_elem);

    // If false, go directly to the post block.
    LLVMBuildCondBr(c->builder, test, next_block, post_block);
    LLVMBasicBlockRef current_block = LLVMGetInsertBlock(c->builder);
    LLVMAddIncoming(phi, &test, &current_block, 1);

    // Point to the next block.
    this_block = next_block;

    left_child = ast_sibling(left_child);
    right_child = ast_sibling(right_child);
    i++;
  }

  // The last block is reached if every element returns true. Jump directly to
  // the post block.
  LLVMPositionBuilderAtEnd(c->builder, this_block);
  LLVMBuildBr(c->builder, post_block);

  LLVMPositionBuilderAtEnd(c->builder, post_block);
  LLVMValueRef one = LLVMConstInt(c->i1, 1, false);
  LLVMAddIncoming(phi, &one, &this_block, 1);

  return phi;
}

static LLVMValueRef gen_digestof_box(compile_t* c, reach_type_t* type,
  LLVMValueRef value, int boxed_subtype)
{
  pony_assert(LLVMGetTypeKind(LLVMTypeOf(value)) == LLVMPointerTypeKind);

  LLVMBasicBlockRef box_block = NULL;
  LLVMBasicBlockRef nonbox_block = NULL;
  LLVMBasicBlockRef post_block = NULL;

  LLVMValueRef desc = gendesc_fetch(c, value);

  if((boxed_subtype & SUBTYPE_KIND_UNBOXED) != 0)
  {
    box_block = codegen_block(c, "digestof_box");
    nonbox_block = codegen_block(c, "digestof_nonbox");
    post_block = codegen_block(c, "digestof_post");

    // Check if it's a boxed value.
    LLVMValueRef type_id = gendesc_typeid(c, desc);
    LLVMValueRef boxed_mask = LLVMConstInt(c->i32, 1, false);
    LLVMValueRef is_boxed = LLVMBuildAnd(c->builder, type_id, boxed_mask, "");
    LLVMValueRef zero = LLVMConstInt(c->i32, 0, false);
    is_boxed = LLVMBuildICmp(c->builder, LLVMIntEQ, is_boxed, zero, "");
    LLVMBuildCondBr(c->builder, is_boxed, box_block, nonbox_block);
    LLVMPositionBuilderAtEnd(c->builder, box_block);
  }

  // Call the type-specific __digestof function, which will unbox the value.
  reach_method_t* digest_fn = reach_method(type, TK_BOX,
    stringtab("__digestof"), NULL);
  pony_assert(digest_fn != NULL);
  LLVMValueRef func = gendesc_vtable(c, desc, digest_fn->vtable_index);
  LLVMTypeRef fn_type = LLVMFunctionType(c->intptr, &c->object_ptr, 1, false);
  func = LLVMBuildBitCast(c->builder, func, LLVMPointerType(fn_type, 0), "");
  LLVMValueRef box_digest = codegen_call(c, func, &value, 1, true);

  if((boxed_subtype & SUBTYPE_KIND_UNBOXED) != 0)
  {
    LLVMBuildBr(c->builder, post_block);

    // Just cast the address.
    LLVMPositionBuilderAtEnd(c->builder, nonbox_block);
    LLVMValueRef nonbox_digest = LLVMBuildPtrToInt(c->builder, value, c->intptr,
      "");
    LLVMBuildBr(c->builder, post_block);

    LLVMPositionBuilderAtEnd(c->builder, post_block);
    LLVMValueRef phi = LLVMBuildPhi(c->builder, c->intptr, "");
    LLVMAddIncoming(phi, &box_digest, &box_block, 1);
    LLVMAddIncoming(phi, &nonbox_digest, &nonbox_block, 1);
    return phi;
  } else {
    return box_digest;
  }
}

LLVMValueRef gendesc_istrait(compile_t* c, LLVMValueRef desc, ast_t* type)
{
  // Get the trait identifier.
  reach_type_t* t = reach_type(c->reach, type);
  assert(t != NULL);
  LLVMValueRef trait_id = LLVMConstInt(c->i32, t->type_id, false);

  // Read the count and the trait list from the descriptor.
  LLVMValueRef count = desc_field(c, desc, DESC_TRAIT_COUNT);
  LLVMValueRef list = desc_field(c, desc, DESC_TRAITS);

  LLVMBasicBlockRef entry_block = LLVMGetInsertBlock(c->builder);
  LLVMBasicBlockRef cond_block = codegen_block(c, "cond");
  LLVMBasicBlockRef body_block = codegen_block(c, "body");
  LLVMBasicBlockRef post_block = codegen_block(c, "post");
  LLVMBuildBr(c->builder, cond_block);

  // While the index is less than the count, check an ID.
  LLVMPositionBuilderAtEnd(c->builder, cond_block);
  LLVMValueRef phi = LLVMBuildPhi(c->builder, c->i32, "");
  LLVMValueRef zero = LLVMConstInt(c->i32, 0, false);
  LLVMAddIncoming(phi, &zero, &entry_block, 1);

  LLVMValueRef test = LLVMBuildICmp(c->builder, LLVMIntULT, phi, count, "");
  LLVMBuildCondBr(c->builder, test, body_block, post_block);

  // The phi node is the index. Get ID and compare it.
  LLVMPositionBuilderAtEnd(c->builder, body_block);

  LLVMValueRef gep[2];
  gep[0] = LLVMConstInt(c->i32, 0, false);
  gep[1] = phi;

  LLVMValueRef id_ptr = LLVMBuildInBoundsGEP(c->builder, list, gep, 2, "");
  LLVMValueRef id = LLVMBuildLoad(c->builder, id_ptr, "");
  LLVMValueRef test_id = LLVMBuildICmp(c->builder, LLVMIntEQ, id, trait_id,
    "");

  // Add one to the phi node.
  LLVMValueRef one = LLVMConstInt(c->i32, 1, false);
  LLVMValueRef inc = LLVMBuildAdd(c->builder, phi, one, "");
  LLVMAddIncoming(phi, &inc, &body_block, 1);

  // Either to the post block or back to the condition.
  LLVMBuildCondBr(c->builder, test_id, post_block, cond_block);

  LLVMPositionBuilderAtEnd(c->builder, post_block);
  LLVMValueRef result = LLVMBuildPhi(c->builder, c->i1, "");
  LLVMAddIncoming(result, &test, &cond_block, 1);
  LLVMAddIncoming(result, &test_id, &body_block, 1);

  return result;
}

static bool check_tuple(compile_t* c, LLVMValueRef ptr, LLVMValueRef desc,
  ast_t* pattern_type, LLVMBasicBlockRef next_block)
{
  // First check cardinality.
  size_t size = ast_childcount(pattern_type);
  check_cardinality(c, desc, size, next_block);

  // If we get here, the match expression has the right cardinality.
  ast_t* pattern_child = ast_child(pattern_type);

  for(int i = 0; pattern_child != NULL; i++)
  {
    // Get the field offset and field descriptor from the tuple descriptor.
    LLVMValueRef field_info = gendesc_fieldinfo(c, desc, i);
    LLVMValueRef field_ptr = gendesc_fieldptr(c, ptr, field_info);
    LLVMValueRef field_desc = gendesc_fielddesc(c, field_info);

    // If we have a null descriptor, load the object.
    LLVMBasicBlockRef null_block = codegen_block(c, "null_desc");
    LLVMBasicBlockRef nonnull_block = codegen_block(c, "nonnull_desc");
    LLVMBasicBlockRef continue_block = codegen_block(c, "merge_desc");
    LLVMValueRef test = LLVMBuildIsNull(c->builder, field_desc, "");
    LLVMBuildCondBr(c->builder, test, null_block, nonnull_block);

    // Load the object, load its descriptor, and continue from there.
    LLVMPositionBuilderAtEnd(c->builder, null_block);
    LLVMTypeRef ptr_type = LLVMPointerType(c->object_ptr, 0);
    LLVMValueRef object_ptr = LLVMBuildIntToPtr(c->builder, field_ptr,
      ptr_type, "");
    LLVMValueRef object = LLVMBuildLoad(c->builder, object_ptr, "");
    LLVMValueRef object_desc = gendesc_fetch(c, object);
    object_ptr = gendesc_ptr_to_fields(c, object, object_desc);

    if(!check_type(c, object_ptr, object_desc, pattern_child, next_block))
      return false;

    LLVMBuildBr(c->builder, continue_block);

    // Continue with the pointer and descriptor.
    LLVMPositionBuilderAtEnd(c->builder, nonnull_block);

    if(!check_type(c, field_ptr, field_desc, pattern_child, next_block))
      return false;

    LLVMBuildBr(c->builder, continue_block);

    // Merge the two branches.
    LLVMPositionBuilderAtEnd(c->builder, continue_block);
    pattern_child = ast_sibling(pattern_child);
  }

  return true;
}

static bool dynamic_tuple_element(compile_t* c, LLVMValueRef ptr,
  LLVMValueRef desc, ast_t* pattern, LLVMBasicBlockRef next_block, int elem)
{
  // If we have a capture, generate the alloca now.
  switch(ast_id(pattern))
  {
    case TK_MATCH_CAPTURE:
      if(gen_localdecl(c, pattern) == NULL)
        return false;
      break;

    default: {}
  }

  // Get the field offset and field descriptor from the tuple descriptor.
  LLVMValueRef field_info = gendesc_fieldinfo(c, desc, elem);
  LLVMValueRef field_ptr = gendesc_fieldptr(c, ptr, field_info);
  LLVMValueRef field_desc = gendesc_fielddesc(c, field_info);

  // If we have a null descriptor, load the object.
  LLVMBasicBlockRef null_block = codegen_block(c, "null_desc");
  LLVMBasicBlockRef nonnull_block = codegen_block(c, "nonnull_desc");
  LLVMBasicBlockRef continue_block = codegen_block(c, "merge_desc");
  LLVMValueRef test = LLVMBuildIsNull(c->builder, field_desc, "");
  LLVMBuildCondBr(c->builder, test, null_block, nonnull_block);

  // Load the object, load its descriptor, and continue from there.
  LLVMPositionBuilderAtEnd(c->builder, null_block);
  LLVMTypeRef ptr_type = LLVMPointerType(c->object_ptr, 0);
  LLVMValueRef object_ptr = LLVMBuildIntToPtr(c->builder, field_ptr, ptr_type,
    "");
  LLVMValueRef object = LLVMBuildLoad(c->builder, object_ptr, "");
  LLVMValueRef object_desc = gendesc_fetch(c, object);

  if(!dynamic_match_object(c, object, object_desc, pattern, next_block))
    return false;

  LLVMBuildBr(c->builder, continue_block);

  // Continue with the pointer and descriptor.
  LLVMPositionBuilderAtEnd(c->builder, nonnull_block);

  if(!dynamic_match_ptr(c, field_ptr, field_desc, pattern, next_block))
    return false;

  LLVMBuildBr(c->builder, continue_block);

  // Merge the two branches.
  LLVMPositionBuilderAtEnd(c->builder, continue_block);
  return true;
}