Switch to potentially-sparse net users array

This uses a new data structure for net.users that allows gaps, so
removing a port from a net is no longer an O(n) operation on the number
of users the net has.

Signed-off-by: gatecat <gatecat@ds0.me>

1 files changed, 1 insertions, 1 deletions

diff --git a/machxo2/pack.cc b/machxo2/pack.cc
index 5051a981..56efb63f 100644
--- a/machxo2/pack.cc
+++ b/machxo2/pack.cc
@@ -160,7 +160,7 @@ static void set_net_constant(Context *ctx, NetInfo *orig, NetInfo *constnet, boo
                 uc->ports[user.port].net = constnet;
             }
 
-            constnet->users.push_back(user);
+            user.cell->ports.at(user.port).user_idx = constnet->users.add(user);
         }
     }
     orig->users.clear();