From d78f5a1d5b3e1dcc87767519ed9661fafce34885 Mon Sep 17 00:00:00 2001
From: Eddie Hung <eddieh@ece.ubc.ca>
Date: Mon, 3 Sep 2018 22:59:34 -0700
Subject: [PATCH] Build a pip_to_dst_wire lookup to speedup routing

---
 xc7/arch.cc | 13 +++++++++++++
 xc7/arch.h  |  7 ++-----
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/xc7/arch.cc b/xc7/arch.cc
index 1c4bc99e..7d9a4e78 100644
--- a/xc7/arch.cc
+++ b/xc7/arch.cc
@@ -37,6 +37,12 @@ std::unique_ptr<const TorcInfo> torc_info;
 TorcInfo::TorcInfo(Arch *ctx, const std::string &inDeviceName, const std::string &inPackageName)
     : ddb(new DDB(inDeviceName, inPackageName)), sites(ddb->getSites()), tiles(ddb->getTiles()), segments(ddb->getSegments()), bel_to_site_index(construct_bel_to_site_index(ctx, sites)), num_bels(bel_to_site_index.size()), site_index_to_type(construct_site_index_to_type(ctx, sites)), bel_to_loc(construct_bel_to_loc(sites, tiles, num_bels, site_index_to_type)), wire_to_tilewire(construct_wire_to_tilewire(segments, tiles, segment_to_wire, trivial_to_wire)), num_wires(wire_to_tilewire.size()), pip_to_arc(construct_pip_to_arc(wire_to_tilewire, *ddb, wire_to_pips_uphill, wire_to_pips_downhill)), num_pips(pip_to_arc.size())
 {
+    pip_to_dst_wire.reserve(num_pips);
+
+    for (const auto& arc : pip_to_arc) {
+        const auto &tw = arc.getSinkTilewire();
+        pip_to_dst_wire.push_back(tilewire_to_wire(tw));
+    }
 }
 std::vector<SiteIndex> TorcInfo::construct_bel_to_site_index(Arch* ctx, const Sites &sites)
 {
@@ -186,6 +192,13 @@ std::vector<Arc> TorcInfo::construct_pip_to_arc(const std::vector<Tilewire>& wir
     return pip_to_arc;
 }
 
+std::vector<int>
+construct_pip_to_dst_wire(const std::vector<Arc>& pip_to_arc)
+{
+    std::vector<int> pip_to_wire;
+    return pip_to_wire;
+}
+
 
 // -----------------------------------------------------------------------
 
diff --git a/xc7/arch.h b/xc7/arch.h
index bd91b79c..37523bb8 100644
--- a/xc7/arch.h
+++ b/xc7/arch.h
@@ -317,6 +317,7 @@ struct TorcInfo {
     std::vector<std::vector<int>> wire_to_pips_downhill;
     const std::vector<Arc> pip_to_arc;
     const int num_pips;
+    std::vector<int> pip_to_dst_wire;
 
 private:
     static std::vector<SiteIndex> construct_bel_to_site_index(Arch *ctx, const Sites &sites);
@@ -811,11 +812,7 @@ struct Arch : BaseCtx
     {
         WireId wire;
         NPNR_ASSERT(pip != PipId());
-
-        const auto &arc = torc_info->pip_to_arc[pip.index];
-        const auto &tw = arc.getSinkTilewire();
-        wire.index = torc_info->tilewire_to_wire(tw);
-
+        wire.index = torc_info->pip_to_dst_wire[pip.index];
         return wire;
     }