+ incr_marker();
+
+ /* Map a FuncInst to the its predicate */
+ HashTable<FuncInst *, Predicate *, uintptr_t, 0> inst_pred_map(128);
+
+ // Number FuncInsts to detect loops
+ HashTable<FuncInst *, uint32_t, uintptr_t, 0> inst_id_map(128);
+ uint32_t inst_counter = 0;
+
+ /* Only need to store the locations of read actions */
+ HashTable<void *, ModelAction *, uintptr_t, 0> loc_act_map(128);
+
+ sllnode<ModelAction *> *it = act_list->begin();
+ Predicate * curr_pred = predicate_tree_entry;
+ while (it != NULL) {
+ ModelAction * next_act = it->getVal();
+ FuncInst * next_inst = get_inst(next_act);
+ next_inst->set_associated_act(next_act, marker);
+
+ SnapVector<Predicate *> unset_predicates = SnapVector<Predicate *>();
+ bool branch_found = follow_branch(&curr_pred, next_inst, next_act, &unset_predicates);
+
+ // A branch with unset predicate expression is detected
+ if (!branch_found && unset_predicates.size() != 0) {
+ ASSERT(unset_predicates.size() == 1);
+ Predicate * one_branch = unset_predicates[0];
+
+ bool amended = amend_predicate_expr(&curr_pred, next_inst, next_act);
+ if (amended)
+ continue;
+ else {
+ curr_pred = one_branch;
+ branch_found = true;
+ }
+ }
+
+ // Detect loops
+ if (!branch_found && inst_id_map.contains(next_inst)) {
+ FuncInst * curr_inst = curr_pred->get_func_inst();
+ uint32_t curr_id = inst_id_map.get(curr_inst);
+ uint32_t next_id = inst_id_map.get(next_inst);
+
+ if (curr_id >= next_id) {
+ Predicate * old_pred = inst_pred_map.get(next_inst);
+ Predicate * back_pred = old_pred->get_parent();
+
+ curr_pred->add_backedge(back_pred);
+ curr_pred = back_pred;
+ continue;
+ }
+ }
+
+ // Generate new branches
+ if (!branch_found) {
+ SnapVector<struct half_pred_expr *> half_pred_expressions;
+ infer_predicates(next_inst, next_act, &loc_act_map, &half_pred_expressions);
+ generate_predicates(&curr_pred, next_inst, &half_pred_expressions);
+ continue;
+ }
+
+ if (next_act->is_write())
+ curr_pred->set_write(true);
+
+ if (next_act->is_read()) {
+ loc_act_map.put(next_act->get_location(), next_act);
+ }
+
+ inst_pred_map.put(next_inst, curr_pred);
+ if (!inst_id_map.contains(next_inst))
+ inst_id_map.put(next_inst, inst_counter++);
+
+ it = it->getNext();
+ curr_pred->incr_expl_count();
+ }
+
+ curr_pred->set_exit(predicate_tree_exit);
+}
+
+/* Given curr_pred and next_inst, find the branch following curr_pred that
+ * contains next_inst and the correct predicate.
+ * @return true if branch found, false otherwise.
+ */
+bool FuncNode::follow_branch(Predicate ** curr_pred, FuncInst * next_inst,
+ ModelAction * next_act, SnapVector<Predicate *> * unset_predicates)
+{
+ /* Check if a branch with func_inst and corresponding predicate exists */
+ bool branch_found = false;
+ ModelVector<Predicate *> * branches = (*curr_pred)->get_children();
+ for (uint i = 0; i < branches->size(); i++) {
+ Predicate * branch = (*branches)[i];
+ if (branch->get_func_inst() != next_inst)
+ continue;
+
+ /* Check against predicate expressions */
+ bool predicate_correct = true;
+ PredExprSet * pred_expressions = branch->get_pred_expressions();
+ PredExprSetIter * pred_expr_it = pred_expressions->iterator();
+
+ /* Only read and rmw actions my have unset predicate expressions */
+ if (pred_expressions->getSize() == 0) {
+ predicate_correct = false;
+ unset_predicates->push_back(branch);
+ }
+
+ while (pred_expr_it->hasNext()) {
+ pred_expr * pred_expression = pred_expr_it->next();
+ uint64_t last_read, next_read;
+ bool equality;
+
+ switch(pred_expression->token) {
+ case NOPREDICATE:
+ predicate_correct = true;
+ break;
+ case EQUALITY:
+ FuncInst * to_be_compared;
+ ModelAction * last_act;
+
+ to_be_compared = pred_expression->func_inst;
+ last_act = to_be_compared->get_associated_act(marker);
+
+ last_read = last_act->get_reads_from_value();
+ next_read = next_act->get_reads_from_value();
+ equality = (last_read == next_read);
+ if (equality != pred_expression->value)
+ predicate_correct = false;
+
+ break;
+ case NULLITY:
+ next_read = next_act->get_reads_from_value();
+ equality = ((void*)next_read == NULL);
+ if (equality != pred_expression->value)
+ predicate_correct = false;
+ break;
+ default:
+ predicate_correct = false;
+ model_print("unkown predicate token\n");
+ break;
+ }
+ }
+
+ if (predicate_correct) {
+ *curr_pred = branch;
+ branch_found = true;
+ break;
+ }
+ }
+
+ return branch_found;
+}
+
+/* Infer predicate expressions, which are generated in FuncNode::generate_predicates */
+void FuncNode::infer_predicates(FuncInst * next_inst, ModelAction * next_act,
+ HashTable<void *, ModelAction *, uintptr_t, 0> * loc_act_map,
+ SnapVector<struct half_pred_expr *> * half_pred_expressions)
+{
+ void * loc = next_act->get_location();
+
+ if (next_inst->is_read()) {
+ /* read + rmw */
+ if ( loc_act_map->contains(loc) ) {
+ ModelAction * last_act = loc_act_map->get(loc);
+ FuncInst * last_inst = get_inst(last_act);
+ struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
+ half_pred_expressions->push_back(expression);
+ } else if ( next_inst->is_single_location() ){
+ loc_set_t * loc_may_equal = loc_may_equal_map->get(loc);
+
+ if (loc_may_equal != NULL) {
+ loc_set_iter * loc_it = loc_may_equal->iterator();
+ while (loc_it->hasNext()) {
+ void * neighbor = loc_it->next();
+ if (loc_act_map->contains(neighbor)) {
+ ModelAction * last_act = loc_act_map->get(neighbor);
+ FuncInst * last_inst = get_inst(last_act);
+
+ struct half_pred_expr * expression = new half_pred_expr(EQUALITY, last_inst);
+ half_pred_expressions->push_back(expression);
+ }
+ }
+ }
+ } else {
+ // next_inst is not single location
+ uint64_t read_val = next_act->get_reads_from_value();
+
+ // only infer NULLITY predicate when it is actually NULL.
+ if ( (void*)read_val == NULL) {
+ struct half_pred_expr * expression = new half_pred_expr(NULLITY, NULL);
+ half_pred_expressions->push_back(expression);
+ }
+ }
+ } else {
+ /* Pure writes */
+ // TODO: do anything here?
+ }
+}
+
+/* Able to generate complex predicates when there are multiple predciate expressions */
+void FuncNode::generate_predicates(Predicate ** curr_pred, FuncInst * next_inst,
+ SnapVector<struct half_pred_expr *> * half_pred_expressions)
+{
+ if (half_pred_expressions->size() == 0) {
+ Predicate * new_pred = new Predicate(next_inst);
+ (*curr_pred)->add_child(new_pred);
+ new_pred->set_parent(*curr_pred);
+
+ /* entry predicates and predicates containing pure write actions
+ * have no predicate expressions */
+ if ( (*curr_pred)->is_entry_predicate() )
+ new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
+ else if (next_inst->is_write()) {
+ /* next_inst->is_write() <==> pure writes */
+ new_pred->add_predicate_expr(NOPREDICATE, NULL, true);
+ }
+
+ return;
+ }
+
+ SnapVector<Predicate *> predicates;
+
+ struct half_pred_expr * half_expr = (*half_pred_expressions)[0];
+ predicates.push_back(new Predicate(next_inst));
+ predicates.push_back(new Predicate(next_inst));
+
+ predicates[0]->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
+ predicates[1]->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
+
+ for (uint i = 1; i < half_pred_expressions->size(); i++) {
+ half_expr = (*half_pred_expressions)[i];
+
+ uint old_size = predicates.size();
+ for (uint j = 0; j < old_size; j++) {
+ Predicate * pred = predicates[j];
+ Predicate * new_pred = new Predicate(next_inst);
+ new_pred->copy_predicate_expr(pred);
+
+ pred->add_predicate_expr(half_expr->token, half_expr->func_inst, true);
+ new_pred->add_predicate_expr(half_expr->token, half_expr->func_inst, false);
+
+ predicates.push_back(new_pred);
+ }
+ }
+
+ for (uint i = 0; i < predicates.size(); i++) {
+ Predicate * pred= predicates[i];
+ (*curr_pred)->add_child(pred);
+ pred->set_parent(*curr_pred);
+ }
+
+ /* Free memories allocated by infer_predicate */
+ for (uint i = 0; i < half_pred_expressions->size(); i++) {
+ struct half_pred_expr * tmp = (*half_pred_expressions)[i];
+ snapshot_free(tmp);
+ }
+}
+
+/* Amend predicates that contain no predicate expressions. Currenlty only amend with NULLITY predicates */
+bool FuncNode::amend_predicate_expr(Predicate ** curr_pred, FuncInst * next_inst, ModelAction * next_act)
+{
+ // there should only be only child
+ Predicate * unset_pred = (*curr_pred)->get_children()->back();
+ uint64_t read_val = next_act->get_reads_from_value();
+
+ // only generate NULLITY predicate when it is actually NULL.
+ if ( !next_inst->is_single_location() && (void*)read_val == NULL ) {
+ Predicate * new_pred = new Predicate(next_inst);
+
+ (*curr_pred)->add_child(new_pred);
+ new_pred->set_parent(*curr_pred);
+
+ unset_pred->add_predicate_expr(NULLITY, NULL, false);
+ new_pred->add_predicate_expr(NULLITY, NULL, true);
+
+ return true;
+ }
+
+ return false;
+}
+
+void FuncNode::add_to_val_loc_map(uint64_t val, void * loc)
+{
+ loc_set_t * locations = val_loc_map->get(val);
+
+ if (locations == NULL) {
+ locations = new loc_set_t();
+ val_loc_map->put(val, locations);
+ }
+
+ update_loc_may_equal_map(loc, locations);
+ locations->add(loc);
+ // values_may_read_from->add(val);
+}
+
+void FuncNode::add_to_val_loc_map(value_set_t * values, void * loc)
+{
+ if (values == NULL)
+ return;
+
+ value_set_iter * it = values->iterator();
+ while (it->hasNext()) {
+ uint64_t val = it->next();
+ add_to_val_loc_map(val, loc);
+ }
+}
+
+void FuncNode::update_loc_may_equal_map(void * new_loc, loc_set_t * old_locations)
+{
+ if ( old_locations->contains(new_loc) )
+ return;
+
+ loc_set_t * neighbors = loc_may_equal_map->get(new_loc);
+
+ if (neighbors == NULL) {
+ neighbors = new loc_set_t();
+ loc_may_equal_map->put(new_loc, neighbors);
+ }
+
+ loc_set_iter * loc_it = old_locations->iterator();
+ while (loc_it->hasNext()) {
+ // new_loc: { old_locations, ... }
+ void * member = loc_it->next();
+ neighbors->add(member);
+
+ // for each i in old_locations, i : { new_loc, ... }
+ loc_set_t * _neighbors = loc_may_equal_map->get(member);
+ if (_neighbors == NULL) {
+ _neighbors = new loc_set_t();
+ loc_may_equal_map->put(member, _neighbors);
+ }
+ _neighbors->add(new_loc);
+ }
+}
+
+/* Every time a thread enters a function, set its position to the predicate tree entry */
+void FuncNode::init_predicate_tree_position(thread_id_t tid)
+{
+ int thread_id = id_to_int(tid);
+ if (predicate_tree_position.size() <= (uint) thread_id)
+ predicate_tree_position.resize(thread_id + 1);
+
+ predicate_tree_position[thread_id] = predicate_tree_entry;
+}
+
+void FuncNode::set_predicate_tree_position(thread_id_t tid, Predicate * pred)
+{
+ int thread_id = id_to_int(tid);
+ predicate_tree_position[thread_id] = pred;
+}
+
+/* @return The position of a thread in a predicate tree */
+Predicate * FuncNode::get_predicate_tree_position(thread_id_t tid)
+{
+ int thread_id = id_to_int(tid);
+ return predicate_tree_position[thread_id];
+}
+
+/* Make sure elements of thrd_inst_act_map are initialized properly when threads enter functions */
+void FuncNode::init_inst_act_map(thread_id_t tid)
+{
+ int thread_id = id_to_int(tid);
+ SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
+ uint old_size = thrd_inst_act_map->size();
+
+ if (thrd_inst_act_map->size() <= (uint) thread_id) {
+ uint new_size = thread_id + 1;
+ thrd_inst_act_map->resize(new_size);
+
+ for (uint i = old_size; i < new_size; i++)
+ (*thrd_inst_act_map)[i] = new inst_act_map_t(128);
+ }
+}
+
+/* Reset elements of thrd_inst_act_map when threads exit functions */
+void FuncNode::reset_inst_act_map(thread_id_t tid)
+{
+ int thread_id = id_to_int(tid);
+ SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
+
+ inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
+ map->reset();
+}
+
+void FuncNode::update_inst_act_map(thread_id_t tid, ModelAction * read_act)
+{
+ int thread_id = id_to_int(tid);
+ SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
+
+ inst_act_map_t * map = (*thrd_inst_act_map)[thread_id];
+ FuncInst * read_inst = get_inst(read_act);
+ map->put(read_inst, read_act);
+}
+
+inst_act_map_t * FuncNode::get_inst_act_map(thread_id_t tid)
+{
+ int thread_id = id_to_int(tid);
+ SnapVector<inst_act_map_t *> * thrd_inst_act_map = history->getThrdInstActMap(func_id);
+
+ return (*thrd_inst_act_map)[thread_id];
+}
+
+/* Add FuncNodes that this node may follow */
+void FuncNode::add_out_edge(FuncNode * other)
+{
+ if ( !edge_table.contains(other) ) {
+ edge_table.put(other, OUT_EDGE);
+ out_edges.push_back(other);
+ return;
+ }
+
+ edge_type_t edge = edge_table.get(other);
+ if (edge == IN_EDGE) {
+ edge_table.put(other, BI_EDGE);
+ out_edges.push_back(other);
+ }
+}
+
+/* Compute the distance between this FuncNode and the target node.
+ * Return -1 if the target node is unreachable or the actual distance
+ * is greater than max_step.
+ */
+int FuncNode::compute_distance(FuncNode * target, int max_step)
+{
+ if (target == NULL)
+ return -1;
+ else if (target == this)
+ return 0;
+
+ SnapList<FuncNode *> queue;
+ HashTable<FuncNode *, int, uintptr_t, 0> distances(128);
+
+ queue.push_back(this);
+ distances.put(this, 0);
+
+ while (!queue.empty()) {
+ FuncNode * curr = queue.front();
+ queue.pop_front();
+ int dist = distances.get(curr);
+
+ if (max_step <= dist)
+ return -1;
+
+ ModelList<FuncNode *> * outEdges = curr->get_out_edges();
+ mllnode<FuncNode *> * it;
+ for (it = outEdges->begin(); it != NULL; it = it->getNext()) {
+ FuncNode * out_node = it->getVal();
+
+ /* This node has not been visited before */
+ if ( !distances.contains(out_node) ) {
+ if (out_node == target)
+ return dist + 1;
+
+ queue.push_back(out_node);
+ distances.put(out_node, dist + 1);
+ }
+ }
+ }
+
+ /* Target node is unreachable */
+ return -1;
+}
+
+void FuncNode::print_predicate_tree()
+{
+ model_print("digraph function_%s {\n", func_name);
+ predicate_tree_entry->print_pred_subtree();
+ predicate_tree_exit->print_predicate();
+ model_print("}\n"); // end of graph
+}
+
+void FuncNode::print_val_loc_map()
+{
+/*
+ value_set_iter * val_it = values_may_read_from->iterator();
+ while (val_it->hasNext()) {
+ uint64_t value = val_it->next();
+ model_print("val %llx: ", value);
+
+ loc_set_t * locations = val_loc_map->get(value);
+ loc_set_iter * loc_it = locations->iterator();
+ while (loc_it->hasNext()) {
+ void * location = loc_it->next();
+ model_print("%p ", location);
+ }
+ model_print("\n");
+ }
+*/