Merge pull request #2236 from verilog-to-routing/noc_placement_integration

Noc placement integration within VPRs placer

Author: Srivat97

libs/libarchfpga/src/read_xml_arch_file.cpp

@@ -4577,9 +4577,6 @@ static void ProcessNoc(pugi::xml_node noc_tag, t_arch* arch, const pugiutil::loc
     pugi::xml_node noc_topology;
     pugi::xml_node noc_mesh_topology;
 
-    // identifier that lets us know when we could not properly convert an attribute value to a integer
-    int attribute_conversion_failure = -1;
-
     // identifier that lets us know when we could not properly convert a string conversion value
     std::string attribute_conversion_failure_string = "";
 
@@ -4593,16 +4590,26 @@ static void ProcessNoc(pugi::xml_node noc_tag, t_arch* arch, const pugiutil::loc
     pugiutil::expect_only_attributes(noc_tag, expected_noc_attributes, loc_data);
 
     // now go through and parse the required attributes for noc tag
-    noc_ref->link_bandwidth = pugiutil::get_attribute(noc_tag, "link_bandwidth", loc_data, pugiutil::REQUIRED).as_double(attribute_conversion_failure);
 
-    noc_ref->link_latency = pugiutil::get_attribute(noc_tag, "link_latency", loc_data, pugiutil::REQUIRED).as_double(attribute_conversion_failure);
+    // variables below temporarily store the attribute values as string
+    // this is so that scientific notation can be used for these attributes
+    std::string link_bandwidth_intermediate_val;
+    std::string router_latency_intermediate_val;
+    std::string link_latency_intermediate_val;
+
+    link_bandwidth_intermediate_val = pugiutil::get_attribute(noc_tag, "link_bandwidth", loc_data, pugiutil::REQUIRED).as_string();
+    noc_ref->link_bandwidth = std::atof(link_bandwidth_intermediate_val.c_str());
+
+    link_latency_intermediate_val = pugiutil::get_attribute(noc_tag, "link_latency", loc_data, pugiutil::REQUIRED).as_string();
+    noc_ref->link_latency = std::atof(link_latency_intermediate_val.c_str());
 
-    noc_ref->router_latency = pugiutil::get_attribute(noc_tag, "router_latency", loc_data, pugiutil::REQUIRED).as_double(attribute_conversion_failure);
+    router_latency_intermediate_val = pugiutil::get_attribute(noc_tag, "router_latency", loc_data, pugiutil::REQUIRED).as_string();
+    noc_ref->router_latency = std::atof(router_latency_intermediate_val.c_str());
 
     noc_ref->noc_router_tile_name = pugiutil::get_attribute(noc_tag, "noc_router_tile_name", loc_data, pugiutil::REQUIRED).as_string();
 
     // the noc parameters can only be non-zero positive values
-    if ((noc_ref->link_bandwidth < 0) || (noc_ref->link_latency < 0) || (noc_ref->router_latency < 0)) {
+    if ((noc_ref->link_bandwidth <= 0.) || (noc_ref->link_latency <= 0.) || (noc_ref->router_latency <= 0.)) {
         archfpga_throw(loc_data.filename_c_str(), loc_data.line(noc_tag),
                        "The link bandwidth, link latency and router latency for the NoC must be a positive non-zero value.");
     }

vpr/src/base/SetupVPR.cpp

@@ -715,6 +715,11 @@ static void SetupNocOpts(const t_options& Options, t_noc_opts* NocOpts) {
     NocOpts->noc = Options.noc;
     NocOpts->noc_flows_file = Options.noc_flows_file;
     NocOpts->noc_routing_algorithm = Options.noc_routing_algorithm;
+    NocOpts->noc_placement_weighting = Options.noc_placement_weighting;
+    NocOpts->noc_latency_constraints_weighting = Options.noc_latency_constraints_weighting;
+    NocOpts->noc_latency_weighting = Options.noc_latency_weighting;
+    NocOpts->noc_swap_percentage = Options.noc_swap_percentage;
+    NocOpts->noc_placement_file_name = Options.noc_placement_file_name;
 
     return;
 }

vpr/src/base/ShowSetup.cpp

@@ -785,5 +785,10 @@ static void ShowPackerOpts(const t_packer_opts& PackerOpts) {
 static void ShowNocOpts(const t_noc_opts& NocOpts) {
     VTR_LOG("NocOpts.noc_flows_file: %s\n", NocOpts.noc_flows_file.c_str());
     VTR_LOG("NocOpts.noc_routing_algorithm: %s\n", NocOpts.noc_routing_algorithm.c_str());
+    VTR_LOG("NocOpts.noc_placement_weighting: %f\n", NocOpts.noc_placement_weighting);
+    VTR_LOG("NocOpts.noc_latency_constraints_weighting: %f\n", NocOpts.noc_latency_constraints_weighting);
+    VTR_LOG("NocOpts.noc_latency_weighting: %f\n", NocOpts.noc_latency_weighting);
+    VTR_LOG("NocOpts.noc_swap_percentage: %d%%\n", NocOpts.noc_swap_percentage);
+    VTR_LOG("NocOpts.noc_routing_algorithm: %s\n", NocOpts.noc_placement_file_name.c_str());
     VTR_LOG("\n");
 }

vpr/src/base/place_and_route.cpp

@@ -55,6 +55,7 @@ int binary_search_place_and_route(const Netlist<>& placement_net_list,
                                   const t_annealing_sched& annealing_sched,
                                   const t_router_opts& router_opts,
                                   const t_analysis_opts& analysis_opts,
+                                  const t_noc_opts& noc_opts,
                                   const t_file_name_opts& filename_opts,
                                   const t_arch* arch,
                                   bool verify_binary_search,
@@ -185,6 +186,7 @@ int binary_search_place_and_route(const Netlist<>& placement_net_list,
                       annealing_sched,
                       router_opts,
                       analysis_opts,
+                      noc_opts,
                       arch->Chans,
                       det_routing_arch,
                       segment_inf,
@@ -327,7 +329,7 @@ int binary_search_place_and_route(const Netlist<>& placement_net_list,
                 break;
             if (placer_opts.place_freq == PLACE_ALWAYS) {
                 placer_opts.place_chan_width = current;
-                try_place(placement_net_list, placer_opts, annealing_sched, router_opts, analysis_opts,
+                try_place(placement_net_list, placer_opts, annealing_sched, router_opts, analysis_opts, noc_opts,
                           arch->Chans, det_routing_arch, segment_inf,
                           arch->Directs, arch->num_directs,
                           false);

vpr/src/base/place_and_route.h

@@ -28,6 +28,7 @@ int binary_search_place_and_route(const Netlist<>& placement_net_list,
                                   const t_annealing_sched& annealing_sched,
                                   const t_router_opts& router_opts,
                                   const t_analysis_opts& analysis_opts,
+                                  const t_noc_opts& noc_opts,
                                   const t_file_name_opts& filename_opts,
                                   const t_arch* arch,
                                   bool verify_binary_search,

vpr/src/base/read_options.cpp

@@ -2679,6 +2679,42 @@ argparse::ArgumentParser create_arg_parser(std::string prog_name, t_options& arg
             "* bfs_routing: Uses the breadth first search algorithm. The objective is to find a route that uses a minimum number of links.\n"
             "This can be used with any NoC topology\n")
         .default_value("bfs_routing")
+        .choices({"xy_routing", "bfs_routing"})
+        .show_in(argparse::ShowIn::HELP_ONLY);
+
+    noc_grp.add_argument<double>(args.noc_placement_weighting, "--noc_placement_weighting")
+        .help(
+            "Controls the importance of the NoC placement parameters relative to timing and wirelength of the design."
+            "This value can be >=0, where 0 would mean the placement is based solely on timing and wirelength, a value of 1 would mean noc placement is considered equal to timing and wirelength and a value greater than 1 would mean the placement is increasingly dominated by NoC parameters.")
+        .default_value("0.6")
+        .show_in(argparse::ShowIn::HELP_ONLY);
+
+    noc_grp.add_argument<double>(args.noc_latency_constraints_weighting, "--noc_latency_constraints_weighting")
+        .help(
+            "Controls the importance of meeting all the NoC traffic flow latency constraints."
+            "This value can be >=0, where 0 would mean the latency constraints have no relevance to placement, a value of 1 would mean the latency constraints are weighted equally to the sum of other placement cost components and a value greater than 1 would mean the placement is increasingly dominated by meeting the latency constraints of the traffic flows.")
+        .default_value("1")
+        .show_in(argparse::ShowIn::HELP_ONLY);
+
+    noc_grp.add_argument<double>(args.noc_latency_weighting, "--noc_latency_weighting")
+        .help(
+            "Controls the importance of reducing the latencies of the NoC traffic flows."
+            "This value can be >=0, where 0 would mean the latencies have no relevance to placement, a value of 1 would mean the latencies  are weighted equally to the sum of other placement cost components and a value greater than 1 would mean the placement is increasingly dominated by reducing the latencies of the traffic flows.")
+        .default_value("0.05")
+        .show_in(argparse::ShowIn::HELP_ONLY);
+
+    noc_grp.add_argument<double>(args.noc_swap_percentage, "--noc_swap_percentage")
+        .help(
+            "Sets the minimum fraction of swaps attempted by the placer that are NoC blocks."
+            "This value is an integer ranging from 0-100. 0 means NoC blocks will be moved at the same rate as other blocks. 100 means all swaps attempted by the placer are NoC router blocks.")
+        .default_value("40")
+        .show_in(argparse::ShowIn::HELP_ONLY);
+
+    noc_grp.add_argument<std::string>(args.noc_placement_file_name, "--noc_placement_file_name")
+        .help(
+            "Name of the output file that contains the NoC placement information."
+            "The default name is 'vpr_noc_placement_output.txt'")
+        .default_value("vpr_noc_placement_output.txt")
         .show_in(argparse::ShowIn::HELP_ONLY);
 
     return parser;

vpr/src/base/read_options.h

@@ -146,6 +146,11 @@ struct t_options {
     argparse::ArgValue<bool> noc;
     argparse::ArgValue<std::string> noc_flows_file;
     argparse::ArgValue<std::string> noc_routing_algorithm;
+    argparse::ArgValue<double> noc_placement_weighting;
+    argparse::ArgValue<double> noc_latency_constraints_weighting;
+    argparse::ArgValue<double> noc_latency_weighting;
+    argparse::ArgValue<double> noc_swap_percentage;
+    argparse::ArgValue<std::string> noc_placement_file_name;
 
     /* Timing-driven placement options only */
     argparse::ArgValue<float> PlaceTimingTradeoff;

vpr/src/base/setup_noc.cpp

@@ -38,6 +38,10 @@ void setup_noc(const t_arch& arch) {
         VPR_FATAL_ERROR(VPR_ERROR_OTHER, "No physical NoC routers were found on the FPGA device. Either the provided name for the physical router tile was incorrect or the FPGA device has no routers.");
     }
 
+    // store the reference to device grid with
+    // need to set this first before adding routers to the model
+    noc_ctx.noc_model.set_device_grid_width((int)device_ctx.grid.width());
+
     // generate noc model
     generate_noc(arch, noc_ctx, noc_router_tiles);
 

vpr/src/base/vpr_api.cpp

@@ -730,6 +730,7 @@ void vpr_place(const Netlist<>& net_list, t_vpr_setup& vpr_setup, const t_arch&
               vpr_setup.AnnealSched,
               vpr_setup.RouterOpts,
               vpr_setup.AnalysisOpts,
+              vpr_setup.NocOpts,
               arch.Chans,
               &vpr_setup.RoutingArch,
               vpr_setup.Segments,
@@ -944,6 +945,7 @@ RouteStatus vpr_route_min_W(const Netlist<>& net_list,
                                               vpr_setup.AnnealSched,
                                               router_opts,
                                               vpr_setup.AnalysisOpts,
+                                              vpr_setup.NocOpts,
                                               vpr_setup.FileNameOpts,
                                               &arch,
                                               router_opts.verify_binary_search,

vpr/src/base/vpr_types.h

@@ -1337,9 +1337,14 @@ struct t_analysis_opts {
 
 // used to store NoC specific options, when supplied as an input by the user
 struct t_noc_opts {
-    bool noc;                          ///<options to turn on hard NoC modeling & optimization
-    std::string noc_flows_file;        ///<name of the file that contains all the traffic flow information in the NoC
-    std::string noc_routing_algorithm; ///<controls the routing algorithm used to route packets within the NoC
+    bool noc;                                 ///<options to turn on hard NoC modeling & optimization
+    std::string noc_flows_file;               ///<name of the file that contains all the traffic flow information to be sent over the NoC in this design
+    std::string noc_routing_algorithm;        ///<controls the routing algorithm used to route packets within the NoC
+    double noc_placement_weighting;           ///<controls the significance of the NoC placement cost relative to the total placement cost range:[0-inf)
+    double noc_latency_constraints_weighting; ///<controls the significance of meeting the traffic flow contraints range:[0-inf)
+    double noc_latency_weighting;             ///<controls the significance of the traffic flow latencies relative to the other NoC placement costs range:[0-inf)
+    int noc_swap_percentage;                  ///<controls the number of NoC router block swap attemps relative to the total number of swaps attempted by the placer range:[0-100]
+    std::string noc_placement_file_name;      ///<is the name of the output file that contains the NoC placement information
 };
 
 /**