From 62613cb266d00e8a56698d38741b0964ab699f8e Mon Sep 17 00:00:00 2001
From: gatecat <gatecat@ds0.me>
Date: Thu, 6 May 2021 19:04:24 +0100
Subject: [PATCH] router2: Dynamicly expand bounding box based on congestion

Signed-off-by: gatecat <gatecat@ds0.me>
---
 common/router2.cc | 32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/common/router2.cc b/common/router2.cc
index 1e53d1fc..24bccec7 100644
--- a/common/router2.cc
+++ b/common/router2.cc
@@ -68,6 +68,7 @@ struct Router2
         int cx, cy, hpwl;
         int total_route_us = 0;
         float max_crit = 0;
+        int fail_count = 0;
     };
 
     struct WireScore
@@ -189,6 +190,10 @@ struct Router2
                 log_info("%s: bb=(%d, %d)->(%d, %d) c=(%d, %d) hpwl=%d\n", ctx->nameOf(ni), nets.at(i).bb.x0,
                          nets.at(i).bb.y0, nets.at(i).bb.x1, nets.at(i).bb.y1, nets.at(i).cx, nets.at(i).cy,
                          nets.at(i).hpwl);
+            nets.at(i).bb.x0 = std::max(nets.at(i).bb.x0 - cfg.bb_margin_x, 0);
+            nets.at(i).bb.y0 = std::max(nets.at(i).bb.y0 - cfg.bb_margin_y, 0);
+            nets.at(i).bb.x1 = std::min(nets.at(i).bb.x1 + cfg.bb_margin_x, ctx->getGridDimX());
+            nets.at(i).bb.y1 = std::min(nets.at(i).bb.y1 + cfg.bb_margin_y, ctx->getGridDimY());
             i++;
         }
     }
@@ -264,11 +269,7 @@ struct Router2
         };
     };
 
-    bool hit_test_pip(ArcBounds &bb, Loc l)
-    {
-        return l.x >= (bb.x0 - cfg.bb_margin_x) && l.x <= (bb.x1 + cfg.bb_margin_x) &&
-               l.y >= (bb.y0 - cfg.bb_margin_y) && l.y <= (bb.y1 + cfg.bb_margin_y);
-    }
+    bool hit_test_pip(ArcBounds &bb, Loc l) { return l.x >= bb.x0 && l.x <= bb.x1 && l.y >= bb.y0 && l.y <= bb.y1; }
 
     double curr_cong_weight, hist_cong_weight, estimate_weight;
 
@@ -684,7 +685,7 @@ struct Router2
                 if (is_bb && !hit_test_pip(ad.bb, ctx->getPipLocation(dh)) && wire_intent != ID_PSEUDO_GND && wire_intent != ID_PSEUDO_VCC)
                     continue;
 #else
-                if (is_bb && !hit_test_pip(ad.bb, ctx->getPipLocation(dh)))
+                if (is_bb && !hit_test_pip(nd.bb, ctx->getPipLocation(dh)))
                     continue;
                 if (!ctx->checkPipAvailForNet(dh, net)) {
                     ROUTE_LOG_DBG("Skipping pip %s because it is bound to net '%s' not net '%s'\n", ctx->nameOfPip(dh),
@@ -870,6 +871,17 @@ struct Router2
                     failed_nets.insert(bound.first);
             }
         }
+        for (int n : failed_nets) {
+            auto &net_data = nets.at(n);
+            ++net_data.fail_count;
+            if ((net_data.fail_count % 3) == 0) {
+                // Every three times a net fails to route, expand the bounding box to increase the search space
+                net_data.bb.x0 = std::max(net_data.bb.x0 - 1, 0);
+                net_data.bb.y0 = std::max(net_data.bb.y0 - 1, 0);
+                net_data.bb.x1 = std::min(net_data.bb.x1 + 1, ctx->getGridDimX());
+                net_data.bb.y1 = std::min(net_data.bb.y1 + 1, ctx->getGridDimY());
+            }
+        }
     }
 
     bool bind_and_check(NetInfo *net, int usr_idx, int phys_pin)
@@ -1113,10 +1125,10 @@ struct Router2
         for (auto &th : tcs) {
             th.rng.rngseed(ctx->rng64());
         }
-        int le_x = mid_x - cfg.bb_margin_x;
-        int rs_x = mid_x + cfg.bb_margin_x;
-        int le_y = mid_y - cfg.bb_margin_y;
-        int rs_y = mid_y + cfg.bb_margin_y;
+        int le_x = mid_x;
+        int rs_x = mid_x;
+        int le_y = mid_y;
+        int rs_y = mid_y;
         // Set up thread bounding boxes
         tcs.at(0).bb = ArcBounds(0, 0, mid_x, mid_y);
         tcs.at(1).bb = ArcBounds(mid_x + 1, 0, std::numeric_limits<int>::max(), le_y);