Add constraints propagation to update the PartitionRegions of blocks …

vpr/src/place/initial_placement.cpp

@@ -82,20 +82,22 @@ static int check_macro_can_be_placed(t_pl_macro pl_macro, int itype, t_pl_loc he
     // Every macro can be placed until proven otherwise
     int macro_can_be_placed = true;
 
+    //Check whether macro contains blocks with floorplan constraints
     bool macro_constrained = is_macro_constrained(pl_macro);
-    PartitionRegion macro_pr;
-
-    if (macro_constrained) {
-        macro_pr = constrained_macro_locs(pl_macro);
-    }
 
     // Check whether all the members can be placed
     for (size_t imember = 0; imember < pl_macro.members.size(); imember++) {
         t_pl_loc member_pos = head_pos + pl_macro.members[imember].offset;
 
-        //if the macro is constrained, check if the member position is within the PartitionRegion for the macro
-        if (macro_constrained) {
-            bool member_loc_good = macro_pr.is_loc_in_part_reg(member_pos);
+        /*
+         * If the macro is constrained, check that the head member is in a legal position from
+         * a floorplanning perspective. It is enough to do this check for the head member alone,
+         * because constraints propagation was performed to calculate smallest floorplan region for the head
+         * macro, based on the constraints on all of the blocks in the macro. So, if the head macro is in a
+         * legal floorplan location, all other blocks in the macro will be as well.
+         */
+        if (macro_constrained && imember == 0) {
+            bool member_loc_good = cluster_floorplanning_legal(pl_macro.members[imember].blk_index, member_pos);
             if (!member_loc_good) {
                 macro_can_be_placed = false;
                 break;
@@ -417,6 +419,9 @@ void initial_placement(enum e_pad_loc_type pad_loc_type, const char* constraints
     vtr::vector<ClusterBlockId, t_block_score> block_scores = assign_block_scores();
     std::vector<ClusterBlockId> sorted_blocks = sort_blocks(block_scores);
 
+    //Perform constraints_propagation
+    constraints_propagation();
+
     // Loading legal placement locations
     zero_initialize_grid_blocks();
     alloc_and_load_legal_placement_locations(legal_pos);

vpr/src/place/place_constraints.cpp

@@ -54,7 +54,7 @@ bool is_macro_constrained(const t_pl_macro& pl_macro) {
 }
 
 /*Returns PartitionRegion of where the head of the macro could go*/
-PartitionRegion constrained_macro_locs(const t_pl_macro& pl_macro) {
+PartitionRegion update_macro_pr(const t_pl_macro& pl_macro) {
     PartitionRegion macro_pr;
     bool is_member_constrained = false;
     int num_constrained_members = 0;
@@ -90,7 +90,7 @@ PartitionRegion constrained_macro_locs(const t_pl_macro& pl_macro) {
 
                 modified_reg.set_region_rect(modified_min_pl_loc.x, modified_min_pl_loc.y, modified_max_pl_loc.x, modified_max_pl_loc.y);
                 //check that subtile is not an invalid value before changing, otherwise it just stays -1
-                if (block_regions[i].get_sub_tile() != -1) {
+                if (block_regions[i].get_sub_tile() != NO_SUBTILE) {
                     modified_reg.set_sub_tile(modified_min_pl_loc.sub_tile);
                 }
 
@@ -113,6 +113,25 @@ PartitionRegion constrained_macro_locs(const t_pl_macro& pl_macro) {
     return macro_pr;
 }
 
+void constraints_propagation() {
+    auto& place_ctx = g_vpr_ctx.placement();
+    auto& floorplanning_ctx = g_vpr_ctx.mutable_floorplanning();
+
+    for (auto pl_macro : place_ctx.pl_macros) {
+        if (is_macro_constrained(pl_macro)) {
+            /*
+             * Update the PartitionRegion for the head of the macro
+             * based on the constraints of all blocks contained in the macro
+             */
+            PartitionRegion macro_head_pr = update_macro_pr(pl_macro);
+
+            //Get block id of head macro member and update its PartitionRegion
+            ClusterBlockId blk_id = pl_macro.members[0].blk_index;
+            floorplanning_ctx.cluster_constraints[blk_id] = macro_head_pr;
+        }
+    }
+}
+
 /*returns true if location is compatible with floorplanning constraints, false if not*/
 /*
  * Even if the block passed in is from a macro, it will work because of the constraints

vpr/src/place/place_constraints.h

@@ -34,9 +34,19 @@ bool cluster_floorplanning_legal(ClusterBlockId blk_id, const t_pl_loc& loc);
 bool is_macro_constrained(const t_pl_macro& pl_macro);
 
 /*
- * Returns region of valid locations for the head of the macro based on floorplan constraints
+ * Returns PartitionRegion for the head of the macro based on the floorplan constraints
+ * of all blocks in the macro.
  */
-PartitionRegion constrained_macro_locs(const t_pl_macro& pl_macro);
+PartitionRegion update_macro_pr(const t_pl_macro& pl_macro);
+
+/*
+ * Updates the floorplan constraints information for all constrained macros.
+ * The head member of each constrained macro is assigned a new PartitionRegion
+ * that is calculated based on the constraints of all the blocks in the macro.
+ * This is done at the start of initial placement to ease floorplan legality checking
+ * while placing macros during initial placement.
+ */
+void constraints_propagation();
 
 inline bool floorplan_legal(const t_pl_blocks_to_be_moved& blocks_affected) {
     bool floorplan_legal;