From c6fa1a179aa8c79d335ba03814ea71d871c87577 Mon Sep 17 00:00:00 2001
From: gatecat <gatecat@ds0.me>
Date: Thu, 6 May 2021 12:25:32 +0100
Subject: [PATCH] nexus: Use new cluster API

Signed-off-by: gatecat <gatecat@ds0.me>
---
 nexus/archdefs.h    |  5 ++++-
 nexus/pack.cc       | 20 ++++++++++++--------
 nexus/post_place.cc |  5 +----
 3 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/nexus/archdefs.h b/nexus/archdefs.h
index b9ac3c77..660f166c 100644
--- a/nexus/archdefs.h
+++ b/nexus/archdefs.h
@@ -23,6 +23,7 @@
 #include <boost/functional/hash.hpp>
 #include <unordered_map>
 
+#include "base_clusterinfo.h"
 #include "idstring.h"
 #include "nextpnr_namespaces.h"
 
@@ -157,7 +158,9 @@ inline bool operator!=(const FFControlSet &a, const FFControlSet &b)
            (a.ce != b.ce);
 }
 
-struct ArchCellInfo
+typedef IdString ClusterId;
+
+struct ArchCellInfo : BaseClusterInfo
 {
     union
     {
diff --git a/nexus/pack.cc b/nexus/pack.cc
index ffec29bd..66ab4b09 100644
--- a/nexus/pack.cc
+++ b/nexus/pack.cc
@@ -1000,12 +1000,13 @@ struct NexusPacker
             // Setup relative constraints
             combs[0]->constr_z = 0;
             combs[0]->constr_abs_z = true;
+            combs[0]->cluster = combs[0]->name;
             for (int i = 1; i < 4; i++) {
                 combs[i]->constr_x = 0;
                 combs[i]->constr_y = 0;
                 combs[i]->constr_z = ((i / 2) << 3) | (i % 2);
                 combs[i]->constr_abs_z = true;
-                combs[i]->constr_parent = combs[0];
+                combs[i]->cluster = combs[0]->name;
                 combs[0]->constr_children.push_back(combs[i]);
             }
 
@@ -1013,7 +1014,7 @@ struct NexusPacker
             ramw->constr_y = 0;
             ramw->constr_z = (2 << 3) | Arch::BEL_RAMW;
             ramw->constr_abs_z = true;
-            ramw->constr_parent = combs[0];
+            ramw->cluster = combs[0]->name;
             combs[0]->constr_children.push_back(ramw);
             // Remove now-packed cell
             ctx->cells.erase(ci->name);
@@ -1182,11 +1183,12 @@ struct NexusPacker
             combs[0]->params[id_INIT] = ctx->parse_lattice_param(ci, id_INIT0, 16, 0);
             combs[1]->params[id_INIT] = ctx->parse_lattice_param(ci, id_INIT1, 16, 0);
 
-            combs[1]->constr_parent = combs[0];
+            combs[1]->cluster = combs[0]->name;
             combs[1]->constr_x = 0;
             combs[1]->constr_y = 0;
             combs[1]->constr_z = 1;
             combs[1]->constr_abs_z = false;
+            combs[0]->cluster = combs[0]->name;
             combs[0]->constr_children.push_back(combs[1]);
 
             ctx->cells.erase(ci->name);
@@ -1253,10 +1255,11 @@ struct NexusPacker
                     if (constr_base == nullptr) {
                         // This is the very first cell in the chain
                         constr_base = combs[i];
+                        constr_base->cluster = constr_base->name;
                     } else {
                         combs[i]->constr_x = (idx / 8);
                         combs[i]->constr_y = 0;
-                        combs[i]->constr_parent = constr_base;
+                        combs[i]->cluster = constr_base->name;
                         constr_base->constr_children.push_back(combs[i]);
                     }
 
@@ -1455,19 +1458,20 @@ struct NexusPacker
         CellInfo *cell = ctx->createCell(name, type);
         if (constr_base != nullptr) {
             // We might be constraining against an already-constrained cell
-            if (constr_base->constr_parent != nullptr) {
+            if (constr_base->cluster != ClusterId() && constr_base->cluster != constr_base->name) {
                 cell->constr_x = dx + constr_base->constr_x;
                 cell->constr_y = constr_base->constr_y;
                 cell->constr_z = dz + constr_base->constr_z;
                 cell->constr_abs_z = false;
-                cell->constr_parent = constr_base->constr_parent;
-                constr_base->constr_parent->constr_children.push_back(cell);
+                cell->cluster = constr_base->cluster;
+                ctx->cells.at(constr_base->cluster)->constr_children.push_back(cell);
             } else {
                 cell->constr_x = dx;
                 cell->constr_y = 0;
                 cell->constr_z = dz;
                 cell->constr_abs_z = false;
-                cell->constr_parent = constr_base;
+                cell->cluster = constr_base->name;
+                constr_base->cluster = constr_base->name;
                 constr_base->constr_children.push_back(cell);
             }
         }
diff --git a/nexus/post_place.cc b/nexus/post_place.cc
index b712aea3..b6817b57 100644
--- a/nexus/post_place.cc
+++ b/nexus/post_place.cc
@@ -32,10 +32,7 @@ struct NexusPostPlaceOpt
 
     NexusPostPlaceOpt(Context *ctx) : ctx(ctx), tmg(ctx){};
 
-    inline bool is_constrained(CellInfo *cell)
-    {
-        return cell->constr_parent != nullptr || !cell->constr_children.empty();
-    }
+    inline bool is_constrained(CellInfo *cell) { return cell->cluster != ClusterId(); }
 
     bool swap_cell_placement(CellInfo *cell, BelId new_bel)
     {