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, 2 insertions, 2 deletions

diff --git a/fpga_interchange/arch.cc b/fpga_interchange/arch.cc
index 917af85e..a5e802d3 100644
--- a/fpga_interchange/arch.cc
+++ b/fpga_interchange/arch.cc
@@ -1377,7 +1377,7 @@ void Arch::merge_constant_nets()
             }
 
             NPNR_ASSERT(net->driver.port == gnd_cell_port);
-            std::vector<PortRef> users_copy = net->users;
+            indexed_store<PortRef> users_copy = net->users;
             for (const PortRef &port_ref : users_copy) {
                 IdString cell = port_ref.cell->name;
                 disconnectPort(cell, port_ref.port);
@@ -1400,7 +1400,7 @@ void Arch::merge_constant_nets()
             }
 
             NPNR_ASSERT(net->driver.port == vcc_cell_port);
-            std::vector<PortRef> users_copy = net->users;
+            indexed_store<PortRef> users_copy = net->users;
             for (const PortRef &port_ref : users_copy) {
                 IdString cell = port_ref.cell->name;
                 disconnectPort(cell, port_ref.port);