vpr: vpr_utils: prepacking: add special case for mapping .latch atom blocks into pb_types

Signed-off-by: Pawel Czarnecki <[email protected]>

Author: lpawelcz

vpr/src/util/vpr_utils.cpp

@@ -850,8 +850,20 @@ bool primitive_type_feasible(const AtomBlockId blk_id, const t_pb_type* cur_pb_t
 
     auto& atom_ctx = g_vpr_ctx.atom();
     if (cur_pb_type->model != atom_ctx.nlist.block_model(blk_id)) {
-        //Primitive and atom do not match
-        return false;
+	if ((strcmp(atom_ctx.nlist.block_model(blk_id)->name, MODEL_LATCH) == 0) &&
+	    (strcmp(atom_ctx.nlist.block_model(blk_id)->name, cur_pb_type->model->name) == 0)) {
+	   /**
+	    * Special case for .latch: this model exists in 2 variations which are
+	    * defined one after another in linked list, check if the second variant match
+	    */
+	    if (cur_pb_type->model->next != atom_ctx.nlist.block_model(blk_id)) {
+                //Next primitive and atom do not match
+                return false;
+	    }
+	} else {
+            //Primitive and atom do not match
+            return false;
+	}
     }
 
     VTR_ASSERT_MSG(atom_ctx.nlist.is_compressed(), "This function assumes a compressed/non-dirty netlist");