From 1df8a8b44091246acc8929cc803578c6d705eee1 Mon Sep 17 00:00:00 2001
From: David Shah <davey1576@gmail.com>
Date: Wed, 20 Jun 2018 20:25:48 +0200
Subject: [PATCH] place_sa: Reduce effect of rounding errors

Signed-off-by: David Shah <davey1576@gmail.com>
---
 common/place_sa.cc | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/common/place_sa.cc b/common/place_sa.cc
index 7325c557..4a2fc86e 100644
--- a/common/place_sa.cc
+++ b/common/place_sa.cc
@@ -30,7 +30,6 @@
 #include <map>
 #include <ostream>
 #include <queue>
-#include <random>
 #include <set>
 #include <stdarg.h>
 #include <stdio.h>
@@ -213,6 +212,15 @@ class SAPlacer
                         temp *= 0.8;
                 }
             }
+
+            // Recalculate total wirelength entirely to avoid rounding errors
+            // accumulating over time
+            curr_wirelength = 0;
+            for (auto net : ctx->nets) {
+                float wl = get_wirelength(net.second);
+                wirelengths[net.first] = wl;
+                curr_wirelength += wl;
+            }
         }
         // Final post-pacement validitiy check
         for (auto bel : ctx->getBels()) {