From 2476f116bb2709cb1c01efd358b6c2b2edfda0c8 Mon Sep 17 00:00:00 2001
From: gatecat <gatecat@ds0.me>
Date: Tue, 29 Jun 2021 14:48:47 +0100
Subject: [PATCH] interchange: Track the macros that cells have been expanded
 from

Signed-off-by: gatecat <gatecat@ds0.me>
---
 fpga_interchange/arch.h     | 1 +
 fpga_interchange/archdefs.h | 1 +
 fpga_interchange/macros.cc  | 6 ++++++
 3 files changed, 8 insertions(+)

diff --git a/fpga_interchange/arch.h b/fpga_interchange/arch.h
index fc3ea637..6e77054f 100644
--- a/fpga_interchange/arch.h
+++ b/fpga_interchange/arch.h
@@ -1152,6 +1152,7 @@ struct Arch : ArchAPI<ArchRanges>
     const DefaultCellConnsPOD *get_default_conns(IdString cell_type) const;
     void pack_default_conns();
 
+    dict<IdString, std::vector<CellInfo *>> macro_to_cells;
     void expand_macros();
 };
 
diff --git a/fpga_interchange/archdefs.h b/fpga_interchange/archdefs.h
index 057de934..4a196c29 100644
--- a/fpga_interchange/archdefs.h
+++ b/fpga_interchange/archdefs.h
@@ -120,6 +120,7 @@ struct ArchCellInfo
     dict<IdString, std::vector<IdString>> cell_bel_pins;
     dict<IdString, std::vector<IdString>> masked_cell_bel_pins;
     pool<IdString> const_ports;
+    IdString macro_parent = IdString();
     LutCell lut_cell;
 };
 
diff --git a/fpga_interchange/macros.cc b/fpga_interchange/macros.cc
index 8339829f..42c8e1ba 100644
--- a/fpga_interchange/macros.cc
+++ b/fpga_interchange/macros.cc
@@ -66,6 +66,8 @@ void Arch::expand_macros()
             const MacroPOD *macro = lookup_macro(chip_info, exp ? IdString(exp->macro_name) : cell->type);
             if (macro == nullptr)
                 continue;
+            // Get the ultimate root of this macro expansion
+            IdString parent = (cell->macro_parent == IdString()) ? cell->name : cell->macro_parent;
             // Create child instances
             for (const auto &inst : macro->cell_insts) {
                 CellInfo *inst_cell =
@@ -73,6 +75,7 @@ void Arch::expand_macros()
                 for (const auto &param : inst.parameters) {
                     inst_cell->params[IdString(param.key)] = IdString(param.value).str(ctx);
                 }
+                inst_cell->macro_parent = parent;
                 next_cells.push_back(inst_cell);
             }
             // Create and connect nets
@@ -156,6 +159,9 @@ void Arch::expand_macros()
         std::swap(next_cells, cells);
         next_cells.clear();
     } while (!cells.empty());
+    // Do this at the end, otherwise we might add cells that are later destroyed
+    for (auto &cell : ctx->cells)
+        macro_to_cells[cell.second->macro_parent].push_back(cell.second.get());
 }
 
 NEXTPNR_NAMESPACE_END