fear: Add automatic mesh generator

Cr. to Gosh.

components/NetShim/MemoryNetworkImpl.cpp

@@ -77,7 +77,12 @@ class FLEXUS_COMPONENT(MemoryNetwork)
         }
 
         nc = new NetContainer();
-        if (nc->buildNetwork(cfg.NetworkTopologyFile.c_str())) {
+
+        if (cfg.NetworkTopologyFile == "BuildMesh") {
+            if (nc->buildMesh()) {
+                throw Flexus::Core::FlexusException("Error building the network");
+            }
+        } else if (nc->buildNetwork(cfg.NetworkTopologyFile.c_str())) {
             throw Flexus::Core::FlexusException("Error building the network");
         }
     }

components/NetShim/NetShimImpl.cpp

@@ -61,7 +61,10 @@ class FLEXUS_COMPONENT(NetShim)
         }
 
         nc = new NetContainer();
-        if (nc->buildNetwork(cfg.NetworkTopologyFile.c_str())) {
+        if (cfg.NetworkTopologyFile == "BuildMesh") {
+        if (nc->buildMesh())
+            throw Flexus::Core::FlexusException("Error building the network");
+        } else if (nc->buildNetwork(cfg.NetworkTopologyFile.c_str())) {
             throw Flexus::Core::FlexusException("Error building the network");
         }
     }

components/NetShim/netcontainer.cpp

@@ -1,4 +1,5 @@
 
+#include <core/component.hpp>
 #include "netcontainer.hpp"
 
 #include <fstream>
@@ -74,6 +75,143 @@ NetContainer::NetContainer(void)
 {
 }
 
+bool NetContainer::buildMesh() {
+  // fixed for now
+  channelLatency = 3;
+  channelLatencyData = 4;
+  channelLatencyControl = 1;
+  localChannelLatencyDivider = 1;
+  switchInputBuffers = 6;
+  switchOutputBuffers = 6;
+  switchInternalBuffersPerVC = 6;
+
+  numSwitches = Flexus::Core::ComponentManager::getComponentManager().systemWidth();
+  numNodes = numSwitches * 3;
+  switchPorts = 7; // 3 ports from/to node and 4 ports for up/down/left/right
+  switchBandwidth = 4;
+
+  if (allocateNetworkStructures())
+    return true;
+
+  // nodes to switches
+  for (int i = 0; i < numNodes; i++) {
+    auto s = i % numSwitches;
+    auto p = i / numSwitches;
+
+    if (attachNodeChannels(this, i))
+      return true;
+    if (attachSwitchChannels(this, s, p, true))
+      return true;
+    if (switches[s]->setLocalDelayOnly(p))
+      return true;
+
+    maxChannelIndex += 2;
+  }
+
+#define U 3
+#define D 4
+#define L 5
+#define R 6
+
+  // switches to switches
+  int col = -1;
+  int row = -1;
+
+  // ad hoc
+  for (int i = 1; i < 9; i++)
+    for (int j = 1; j < 3; j++)
+      if (i * i * j == numSwitches) {
+        col = i * j;
+        row = i;
+        break;
+      }
+
+  assert(col >= 0);
+
+  int col_m1 = col - 1;
+  int row_m1 = row - 1;
+
+  for (int i = 0; i < row; i++)
+    for (int j = 0; j < col; j++) {
+      auto s = i * col + j;
+
+      if (j < col_m1) {
+        auto r = s + 1;
+
+        if (attachSwitchChannels(this, s, R, false))
+          return true;
+        if (attachSwitchChannels(this, r, L, true))
+          return true;
+
+        maxChannelIndex += 2;
+      }
+
+      if (i < row_m1) {
+        auto d = s + col;
+
+        if (attachSwitchChannels(this, s, D, false))
+          return true;
+        if (attachSwitchChannels(this, d, U, true))
+          return true;
+
+        maxChannelIndex += 2;
+      }
+    }
+
+  // routes
+  for (int i = 0; i < numSwitches; i++) {
+    auto c = i % col;
+    auto r = i / col;
+
+    for (int j = 0; j < numNodes; j++) {
+      auto s  = j % numSwitches;
+      auto p  = j / numSwitches;
+
+      auto cc = s % col;
+      auto rr = s / col;
+
+      // x-y
+      if (c < cc) {
+        if (switches[i]->addRoutingEntry(j, R, 0))
+          return true;
+      } else if (c > cc) {
+        if (switches[i]->addRoutingEntry(j, L, 0))
+          return true;
+      } else if (r < rr) {
+        if (switches[i]->addRoutingEntry(j, D, 0))
+          return true;
+      } else if (r > rr) {
+        if (switches[i]->addRoutingEntry(j, U, 0))
+          return true;
+      } else {
+        if (switches[i]->addRoutingEntry(j, p, 0))
+          return true;
+      }
+
+      // y-x
+      if (r < rr) {
+        if (switches[i]->addRoutingEntry(j, D, 1))
+          return true;
+      } else if (r > rr) {
+        if (switches[i]->addRoutingEntry(j, U, 1))
+          return true;
+      } else if (c < cc) {
+        if (switches[i]->addRoutingEntry(j, R, 1))
+          return true;
+      } else if (c > cc) {
+        if (switches[i]->addRoutingEntry(j, L, 1))
+          return true;
+      } else {
+        if (switches[i]->addRoutingEntry(j, p, 1))
+          return true;
+      }
+    }
+  }
+
+  return false;
+}
+
+
 bool
 NetContainer::buildNetwork(const char* filename)
 {

components/NetShim/netcontainer.hpp

@@ -19,6 +19,7 @@ class NetContainer
     NetContainer(void);
 
   public:
+    bool buildMesh();
     bool buildNetwork(const char* filename);
 
     bool drive(void);