[Prepacker] Removed Valid Flag From Molecules

AlexandreSinger · AlexandreSinger · commit 49f3ab3ff485 · 2024-11-02T16:13:55.000-04:00
Pack molecules originally contained a flag called "valid" which signified that the molecule has not been clustered yet. This flag is not necessary since the Cluster Legalizer maintains this information internally. Removed the valid flag from the pack molecule struct. See issue #2791
diff --git a/vpr/src/base/vpr_types.h b/vpr/src/base/vpr_types.h
@@ -384,7 +384,6 @@ enum e_pack_pattern_molecule_type {
  *                       t_pack_pattern_block->block_id
  *      chain_info     : if this is a molecule representing a chained pack pattern, this data structure will
  *                       hold the data shared between all molecules forming a chain together.
- *      valid          : whether the molecule is still valid for packing or not.
  *      num_blocks     : maximum number of atom blocks that can fit in this molecule
  *      root           : index of the pack_pattern->root_block in the atom_blocks_ids. root_block_id = atom_block_ids[root]
  *      base_gain      : intrinsic "goodness" score for molecule independent of rest of netlist
@@ -393,7 +392,6 @@ enum e_pack_pattern_molecule_type {
 class t_pack_molecule {
   public:
     /* general molecule info */
-    bool valid;
     float base_gain;
     enum e_pack_pattern_molecule_type type;
 
diff --git a/vpr/src/pack/cluster.cpp b/vpr/src/pack/cluster.cpp
@@ -145,8 +145,6 @@ std::map<t_logical_block_type_ptr, size_t> do_clustering(const t_packer_opts& pa
 
     const t_molecule_stats max_molecule_stats = prepacker.calc_max_molecule_stats(atom_ctx.nlist);
 
-    prepacker.mark_all_molecules_valid();
-
     cluster_stats.num_molecules = prepacker.get_num_molecules();
 
     if (packer_opts.hill_climbing_flag) {
diff --git a/vpr/src/pack/cluster_legalizer.cpp b/vpr/src/pack/cluster_legalizer.cpp
@@ -997,11 +997,70 @@ static void update_molecule_chain_info(t_pack_molecule* chain_molecule, const t_
     VTR_ASSERT(false);
 }
 
+/**
+ * @brief Revalidate the molecules associated with this pb. The mol_validated
+ *        flag is used to check if the mol has already been validated.
+ */
+static void revalid_molecules(const t_pb* pb,
+                              bool &mol_validated,
+                              const Prepacker& prepacker) {
+    const t_pb_type* pb_type = pb->pb_graph_node->pb_type;
+
+    if (pb_type->blif_model == nullptr) {
+        int mode = pb->mode;
+        for (int i = 0; i < pb_type->modes[mode].num_pb_type_children && pb->child_pbs != nullptr; i++) {
+            for (int j = 0; j < pb_type->modes[mode].pb_type_children[i].num_pb && pb->child_pbs[i] != nullptr; j++) {
+                if (pb->child_pbs[i][j].name != nullptr || pb->child_pbs[i][j].child_pbs != nullptr) {
+                    revalid_molecules(&pb->child_pbs[i][j], mol_validated, prepacker);
+                }
+            }
+        }
+    } else {
+        //Primitive
+        auto& atom_ctx = g_vpr_ctx.mutable_atom();
+
+        auto blk_id = atom_ctx.lookup.pb_atom(pb);
+        if (blk_id) {
+            /* If any molecules were marked invalid because of this logic block getting packed, mark them valid */
+
+            //Update atom netlist mapping
+            atom_ctx.lookup.set_atom_clb(blk_id, ClusterBlockId::INVALID());
+            atom_ctx.lookup.set_atom_pb(blk_id, nullptr);
+
+            t_pack_molecule* cur_molecule = prepacker.get_atom_molecule(blk_id);
+            if (!mol_validated) {
+                int i;
+                for (i = 0; i < get_array_size_of_molecule(cur_molecule); i++) {
+                    if (cur_molecule->atom_block_ids[i]) {
+                        if (atom_ctx.lookup.atom_clb(cur_molecule->atom_block_ids[i]) != ClusterBlockId::INVALID()) {
+                            break;
+                        }
+                    }
+                }
+                /* All atom blocks are open for this molecule, place back in queue */
+                if (i == get_array_size_of_molecule(cur_molecule)) {
+                    mol_validated = true;
+                    // when invalidating a molecule check if it's a chain molecule
+                    // that is part of a long chain. If so, check if this molecule
+                    // have modified the chain_id value based on the stale packing
+                    // then reset the chain id and the first packed molecule pointer
+                    // this is packing is being reset
+                    if (cur_molecule->is_chain() && cur_molecule->chain_info->is_long_chain && cur_molecule->chain_info->first_packed_molecule == cur_molecule) {
+                        cur_molecule->chain_info->first_packed_molecule = nullptr;
+                        cur_molecule->chain_info->chain_id = -1;
+                    }
+                }
+            }
+        }
+    }
+}
+
 /*
  * @brief Revert trial atom block iblock and free up memory space accordingly.
  */
 static void revert_place_atom_block(const AtomBlockId blk_id,
                                     t_lb_router_data* router_data,
+                                    bool &mol_validated,
                                     const Prepacker& prepacker,
                                     vtr::vector_map<AtomBlockId, LegalizationClusterId>& atom_cluster) {
     const AtomContext& atom_ctx = g_vpr_ctx.atom();
@@ -1020,7 +1079,7 @@ static void revert_place_atom_block(const AtomBlockId blk_id,
          */
 
         t_pb* next = pb->parent_pb;
-        revalid_molecules(pb, prepacker);
+        revalid_molecules(pb, mol_validated, prepacker);
         free_pb(pb);
         pb = next;
 
@@ -1037,7 +1096,7 @@ static void revert_place_atom_block(const AtomBlockId blk_id,
                     /* If the code gets here, then that means that placing the initial seed molecule
                      * failed, don't free the actual complex block itself as the seed needs to find
                      * another placement */
-                    revalid_molecules(pb, prepacker);
+                    revalid_molecules(pb, mol_validated, prepacker);
                     free_pb(pb);
                 }
             }
@@ -1386,14 +1445,6 @@ e_block_pack_status ClusterLegalizer::try_pack_molecule(t_pack_molecule* molecul
                     if (!atom_blk_id.is_valid())
                         continue;
 
-                    /* invalidate all molecules that share atom block with current molecule */
-                    t_pack_molecule* cur_molecule = prepacker_.get_atom_molecule(atom_blk_id);
-                    // TODO: This should really be named better. Something like
-                    //       "is_clustered". and then it should be set to true.
-                    //       Right now, valid implies "not clustered" which is
-                    //       confusing.
-                    cur_molecule->valid = false;
-
                     commit_primitive(cluster.placement_stats, primitives_list[i]);
 
                     atom_cluster_[atom_blk_id] = cluster_id;
@@ -1421,10 +1472,11 @@ e_block_pack_status ClusterLegalizer::try_pack_molecule(t_pack_molecule* molecul
                     remove_atom_from_target(cluster.router_data, atom_blk_id);
                 }
             }
+            bool mol_validated = false;
             for (int i = 0; i < failed_location; i++) {
                 AtomBlockId atom_blk_id = molecule->atom_block_ids[i];
                 if (atom_blk_id) {
-                    revert_place_atom_block(atom_blk_id, cluster.router_data, prepacker_, atom_cluster_);
+                    revert_place_atom_block(atom_blk_id, cluster.router_data, mol_validated, prepacker_, atom_cluster_);
                 }
             }
 
@@ -1562,17 +1614,13 @@ void ClusterLegalizer::destroy_cluster(LegalizationClusterId cluster_id) {
         VTR_ASSERT_SAFE(molecule_cluster_.find(mol) != molecule_cluster_.end() &&
                         molecule_cluster_[mol] == cluster_id);
         molecule_cluster_[mol] = LegalizationClusterId::INVALID();
-        // The overall clustering algorithm uses this valid flag to indicate
-        // that a molecule has not been packed (clustered) yet. Since we are
-        // destroying a cluster, all of its molecules are now no longer clustered
-        // so they are all validated.
-        mol->valid = true;
         // Revert the placement of all blocks in the molecule.
+        bool mol_validated = false;
         int molecule_size = get_array_size_of_molecule(mol);
         for (int i = 0; i < molecule_size; i++) {
             AtomBlockId atom_blk_id = mol->atom_block_ids[i];
             if (atom_blk_id) {
-                revert_place_atom_block(atom_blk_id, cluster.router_data, prepacker_, atom_cluster_);
+                revert_place_atom_block(atom_blk_id, cluster.router_data, mol_validated, prepacker_, atom_cluster_);
             }
         }
     }
diff --git a/vpr/src/pack/cluster_legalizer.h b/vpr/src/pack/cluster_legalizer.h
@@ -434,6 +434,21 @@ class ClusterLegalizer {
         return get_atom_cluster(blk_id) != LegalizationClusterId::INVALID();
     }
 
+    /// @brief Returns true if the given molecule has been packed into a
+    ///        cluster, false otherwise.
+    inline bool is_mol_clustered(t_pack_molecule* mol) const {
+        VTR_ASSERT_SAFE(mol != nullptr);
+        // Check if the molecule has been assigned a cluster. It has not been
+        // assigned a cluster if it does not have an entry in the map or if the
+        // ID of the cluster it is assigned to is invalid.
+        const auto iter = molecule_cluster_.find(mol);
+        if (iter == molecule_cluster_.end())
+            return false;
+        if (!iter->second.is_valid())
+            return false;
+        return true;
+    }
+
     /// @brief Returns a reference to the target_external_pin_util object. This
     ///        allows the user to modify the external pin utilization if needed.
     inline t_ext_pin_util_targets& get_target_external_pin_util() {
diff --git a/vpr/src/pack/cluster_util.cpp b/vpr/src/pack/cluster_util.cpp
@@ -394,7 +394,7 @@ t_pack_molecule* get_molecule_by_num_ext_inputs(const int ext_inps,
     t_molecule_link* ptr = unclustered_list_head[ext_inps].next;
     while (ptr != nullptr) {
         /* TODO: Get better candidate atom block in future, eg. return most timing critical or some other smarter metric */
-        if (ptr->moleculeptr->valid) {
+        if (!cluster_legalizer.is_mol_clustered(ptr->moleculeptr)) {
             /* TODO: I should be using a better filtering check especially when I'm
              * dealing with multiple clock/multiple global reset signals where the clock/reset
              * packed in matters, need to do later when I have the circuits to check my work */
@@ -1197,7 +1197,7 @@ t_pack_molecule* get_highest_gain_molecule(t_pb* cur_pb,
         cur_pb->pb_stats->num_feasible_blocks--;
         int index = cur_pb->pb_stats->num_feasible_blocks;
         molecule = cur_pb->pb_stats->feasible_blocks[index];
-        VTR_ASSERT(molecule->valid == true);
+        VTR_ASSERT(!cluster_legalizer.is_mol_clustered(molecule));
         return molecule;
     }
 
@@ -1218,7 +1218,7 @@ void add_cluster_molecule_candidates_by_connectivity_and_timing(t_pb* cur_pb,
     for (AtomBlockId blk_id : cur_pb->pb_stats->marked_blocks) {
         if (!cluster_legalizer.is_atom_clustered(blk_id)) {
             t_pack_molecule* molecule = prepacker.get_atom_molecule(blk_id);
-            if (molecule->valid) {
+            if (!cluster_legalizer.is_mol_clustered(molecule)) {
                 if (cluster_legalizer.is_molecule_compatible(molecule, legalization_cluster_id)) {
                     add_molecule_to_pb_stats_candidates(molecule,
                                                         cur_pb->pb_stats->gain, cur_pb, feasible_block_array_size, attraction_groups);
@@ -1251,7 +1251,7 @@ void add_cluster_molecule_candidates_by_highfanout_connectivity(t_pb* cur_pb,
 
         if (!cluster_legalizer.is_atom_clustered(blk_id)) {
             t_pack_molecule* molecule = prepacker.get_atom_molecule(blk_id);
-            if (molecule->valid) {
+            if (!cluster_legalizer.is_mol_clustered(molecule)) {
                 if (cluster_legalizer.is_molecule_compatible(molecule, legalization_cluster_id)) {
                     add_molecule_to_pb_stats_candidates(molecule,
                                                         cur_pb->pb_stats->gain, cur_pb, std::min(feasible_block_array_size, AAPACK_MAX_HIGH_FANOUT_EXPLORE), attraction_groups);
@@ -1328,7 +1328,7 @@ void add_cluster_molecule_candidates_by_attraction_group(t_pb* cur_pb,
             if (!cluster_legalizer.is_atom_clustered(atom_id)
                 && std::find(candidate_types.begin(), candidate_types.end(), cluster_type) != candidate_types.end()) {
                 t_pack_molecule* molecule = prepacker.get_atom_molecule(atom_id);
-                if (molecule->valid) {
+                if (!cluster_legalizer.is_mol_clustered(molecule)) {
                     if (cluster_legalizer.is_molecule_compatible(molecule, legalization_cluster_id)) {
                         add_molecule_to_pb_stats_candidates(molecule,
                                                             cur_pb->pb_stats->gain, cur_pb, feasible_block_array_size, attraction_groups);
@@ -1359,7 +1359,7 @@ void add_cluster_molecule_candidates_by_attraction_group(t_pb* cur_pb,
         if (!cluster_legalizer.is_atom_clustered(blk_id)
             && std::find(candidate_types.begin(), candidate_types.end(), cluster_type) != candidate_types.end()) {
             t_pack_molecule* molecule = prepacker.get_atom_molecule(blk_id);
-            if (molecule->valid) {
+            if (!cluster_legalizer.is_mol_clustered(molecule)) {
                 if (cluster_legalizer.is_molecule_compatible(molecule, legalization_cluster_id)) {
                     add_molecule_to_pb_stats_candidates(molecule,
                                                         cur_pb->pb_stats->gain, cur_pb, feasible_block_array_size, attraction_groups);
@@ -1390,7 +1390,7 @@ void add_cluster_molecule_candidates_by_transitive_connectivity(t_pb* cur_pb,
     /* Only consider candidates that pass a very simple legality check */
     for (const auto& transitive_candidate : cur_pb->pb_stats->transitive_fanout_candidates) {
         t_pack_molecule* molecule = transitive_candidate.second;
-        if (molecule->valid) {
+        if (!cluster_legalizer.is_mol_clustered(molecule)) {
             if (cluster_legalizer.is_molecule_compatible(molecule, legalization_cluster_id)) {
                 add_molecule_to_pb_stats_candidates(molecule,
                                                     cur_pb->pb_stats->gain, cur_pb, std::min(feasible_block_array_size, AAPACK_MAX_TRANSITIVE_EXPLORE), attraction_groups);
@@ -1659,7 +1659,7 @@ t_pack_molecule* get_highest_gain_seed_molecule(int& seed_index,
             t_pack_molecule* best = nullptr;
 
             t_pack_molecule* molecule = prepacker.get_atom_molecule(blk_id);
-            if (molecule->valid) {
+            if (!cluster_legalizer.is_mol_clustered(molecule)) {
                 if (best == nullptr || (best->base_gain) < (molecule->base_gain)) {
                     best = molecule;
                 }
@@ -1764,7 +1764,7 @@ void load_transitive_fanout_candidates(LegalizationClusterId legalization_cluste
                                     pb_stats->gain[blk_id] += 0.001;
                                 }
                                 t_pack_molecule* molecule = prepacker.get_atom_molecule(blk_id);
-                                if (molecule->valid) {
+                                if (!cluster_legalizer.is_mol_clustered(molecule)) {
                                     transitive_fanout_candidates.insert({molecule->atom_block_ids[molecule->root], molecule});
                                 }
                             }
diff --git a/vpr/src/pack/prepack.cpp b/vpr/src/pack/prepack.cpp
@@ -904,7 +904,6 @@ static t_pack_molecule* alloc_and_load_pack_molecules(t_pack_patterns* list_of_p
         bool rng_empty = (rng.first == rng.second);
         if (rng_empty) {
             cur_molecule = new t_pack_molecule;
-            cur_molecule->valid = true;
             cur_molecule->type = MOLECULE_SINGLE_ATOM;
             cur_molecule->num_blocks = 1;
             cur_molecule->root = 0;
@@ -983,7 +982,6 @@ static t_pack_molecule* try_create_molecule(t_pack_patterns* list_of_pack_patter
     }
 
     molecule = new t_pack_molecule;
-    molecule->valid = true;
     molecule->type = MOLECULE_FORCED_PACK;
     molecule->pack_pattern = pack_pattern;
     molecule->atom_block_ids = std::vector<AtomBlockId>(pack_pattern->num_blocks); //Initializes invalid
diff --git a/vpr/src/pack/prepack.h b/vpr/src/pack/prepack.h
@@ -119,23 +119,6 @@ class Prepacker {
         return molecules;
     }
 
-    /**
-     * @brief Marks all of the molecules as valid.
-     *
-     * Within clustering, the valid flag of a molecule is used to signify if any
-     * of the atoms in the molecule has been packed into a cluster yet or not.
-     * If any atom in the molecule has been packed, the flag will be false.
-     *
-     * This method is used before clustering to mark all the molecules as
-     * unpacked.
-     */
-    inline void mark_all_molecules_valid() {
-        t_pack_molecule* molecule_head = list_of_pack_molecules;
-        for (auto cur_molecule = molecule_head; cur_molecule != nullptr; cur_molecule = cur_molecule->next) {
-            cur_molecule->valid = true;
-        }
-    }
-
     /**
      * @brief Calculates maximum molecule statistics accross all molecules,
      */
diff --git a/vpr/src/util/vpr_utils.cpp b/vpr/src/util/vpr_utils.cpp
@@ -1539,58 +1539,6 @@ void free_pb(t_pb* pb) {
     free_pb_stats(pb);
 }
 
-void revalid_molecules(const t_pb* pb, const Prepacker& prepacker) {
-    const t_pb_type* pb_type = pb->pb_graph_node->pb_type;
-
-    if (pb_type->blif_model == nullptr) {
-        int mode = pb->mode;
-        for (int i = 0; i < pb_type->modes[mode].num_pb_type_children && pb->child_pbs != nullptr; i++) {
-            for (int j = 0; j < pb_type->modes[mode].pb_type_children[i].num_pb && pb->child_pbs[i] != nullptr; j++) {
-                if (pb->child_pbs[i][j].name != nullptr || pb->child_pbs[i][j].child_pbs != nullptr) {
-                    revalid_molecules(&pb->child_pbs[i][j], prepacker);
-                }
-            }
-        }
-    } else {
-        //Primitive
-        auto& atom_ctx = g_vpr_ctx.mutable_atom();
-
-        auto blk_id = atom_ctx.lookup.pb_atom(pb);
-        if (blk_id) {
-            /* If any molecules were marked invalid because of this logic block getting packed, mark them valid */
-
-            //Update atom netlist mapping
-            atom_ctx.lookup.set_atom_clb(blk_id, ClusterBlockId::INVALID());
-            atom_ctx.lookup.set_atom_pb(blk_id, nullptr);
-
-            t_pack_molecule* cur_molecule = prepacker.get_atom_molecule(blk_id);
-            if (cur_molecule->valid == false) {
-                int i;
-                for (i = 0; i < get_array_size_of_molecule(cur_molecule); i++) {
-                    if (cur_molecule->atom_block_ids[i]) {
-                        if (atom_ctx.lookup.atom_clb(cur_molecule->atom_block_ids[i]) != ClusterBlockId::INVALID()) {
-                            break;
-                        }
-                    }
-                }
-                /* All atom blocks are open for this molecule, place back in queue */
-                if (i == get_array_size_of_molecule(cur_molecule)) {
-                    cur_molecule->valid = true;
-                    // when invalidating a molecule check if it's a chain molecule
-                    // that is part of a long chain. If so, check if this molecule
-                    // have modified the chain_id value based on the stale packing
-                    // then reset the chain id and the first packed molecule pointer
-                    // this is packing is being reset
-                    if (cur_molecule->is_chain() && cur_molecule->chain_info->is_long_chain && cur_molecule->chain_info->first_packed_molecule == cur_molecule) {
-                        cur_molecule->chain_info->first_packed_molecule = nullptr;
-                        cur_molecule->chain_info->chain_id = -1;
-                    }
-                }
-            }
-        }
-    }
-}
-
 void free_pb_stats(t_pb* pb) {
     if (pb) {
         if (pb->pb_stats == nullptr) {
diff --git a/vpr/src/util/vpr_utils.h b/vpr/src/util/vpr_utils.h
@@ -222,7 +222,6 @@ void parse_direct_pin_name(char* src_string, int line, int* start_pin_index, int
 
 void free_pb_stats(t_pb* pb);
 void free_pb(t_pb* pb);
-void revalid_molecules(const t_pb* pb, const Prepacker& prepacker);
 
 void print_switch_usage();
 void print_usage_by_wire_length();
