Merge pull request verilog-to-routing#3037 from AlexandreSinger/feature-ap-multithreaded

[AP][Solver] Enabled Parallel Eigen

Author: AlexandreSinger

vpr/CMakeLists.txt

@@ -12,6 +12,8 @@ set_property(CACHE VPR_PGO_CONFIG PROPERTY STRINGS prof_gen prof_use none)
 
 set(VPR_PGO_DATA_DIR "." CACHE PATH "Where to store and retrieve PGO data")
 
+set(VPR_ENABLE_OPEN_MP "on" CACHE STRING "Enable OpenMP when compiling VPR")
+
 #Handle graphics setup
 set(GRAPHICS_DEFINES "")
 
@@ -295,6 +297,21 @@ else()
     message(FATAL_ERROR "VPR: Unrecognized execution engine '${VPR_USE_EXECUTION_ENGINE}'")
 endif()
 
+#
+# OpenMP configuration
+#
+if (VPR_ENABLE_OPEN_MP STREQUAL "on")
+    find_package(OpenMP)
+    if (OpenMP_CXX_FOUND)
+        target_link_libraries(libvpr OpenMP::OpenMP_CXX)
+        message(STATUS "OpenMP: Enabled")
+    else()
+        message(STATUS "OpenMP: Disabled (requested but not found)")
+    endif()
+else()
+    message(STATUS "OpenMP: Disabled")
+endif()
+
 #
 # Signal handler configuration
 #

vpr/src/analytical_place/analytical_placement_flow.cpp

@@ -144,6 +144,7 @@ static PartialPlacement run_global_placer(const t_ap_opts& ap_opts,
                                                                          device_ctx.physical_tile_types,
                                                                          pre_cluster_timing_manager,
                                                                          ap_opts.ap_timing_tradeoff,
+                                                                         ap_opts.num_threads,
                                                                          ap_opts.log_verbosity);
         return global_placer->place();
     }

vpr/src/analytical_place/analytical_solver.cpp

@@ -11,6 +11,7 @@
 #include <cstdio>
 #include <limits>
 #include <memory>
+#include <thread>
 #include <utility>
 #include <vector>
 #include "PreClusterTimingManager.h"
@@ -32,6 +33,7 @@
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wnull-dereference"
 
+#include <Eigen/src/Core/products/Parallelizer.h>
 #include <Eigen/src/SparseCore/SparseMatrix.h>
 #include <Eigen/SVD>
 #include <Eigen/Sparse>
@@ -48,7 +50,22 @@ std::unique_ptr<AnalyticalSolver> make_analytical_solver(e_ap_analytical_solver
                                                          const AtomNetlist& atom_netlist,
                                                          const PreClusterTimingManager& pre_cluster_timing_manager,
                                                          float ap_timing_tradeoff,
+                                                         unsigned num_threads,
                                                          int log_verbosity) {
+#ifdef EIGEN_INSTALLED
+    // Set the number of threads that Eigen can use.
+    unsigned eigen_num_threads = num_threads;
+    if (num_threads == 0) {
+        eigen_num_threads = std::thread::hardware_concurrency();
+    }
+    // Set the number of threads globally used by Eigen (if OpenMP is enabled).
+    // NOTE: Since this is a global update, all solvers will have this number
+    //       of threads.
+    Eigen::setNbThreads(eigen_num_threads);
+#else
+    (void)num_threads;
+#endif // EIGEN_INSTALLED
+
     // Based on the solver type passed in, build the solver.
     switch (solver_type) {
         case e_ap_analytical_solver::QP_Hybrid:

vpr/src/analytical_place/analytical_solver.h

@@ -138,6 +138,7 @@ std::unique_ptr<AnalyticalSolver> make_analytical_solver(e_ap_analytical_solver
                                                          const AtomNetlist& atom_netlist,
                                                          const PreClusterTimingManager& pre_cluster_timing_manager,
                                                          float ap_timing_tradeoff,
+                                                         unsigned num_threads,
                                                          int log_verbosity);
 
 // The Eigen library is used to solve matrix equations in the following solvers.

vpr/src/analytical_place/global_placer.cpp

@@ -37,6 +37,7 @@ std::unique_ptr<GlobalPlacer> make_global_placer(e_ap_analytical_solver analytic
                                                  const std::vector<t_physical_tile_type>& physical_tile_types,
                                                  const PreClusterTimingManager& pre_cluster_timing_manager,
                                                  float ap_timing_tradeoff,
+                                                 unsigned num_threads,
                                                  int log_verbosity) {
     return std::make_unique<SimPLGlobalPlacer>(analytical_solver_type,
                                                partial_legalizer_type,
@@ -48,6 +49,7 @@ std::unique_ptr<GlobalPlacer> make_global_placer(e_ap_analytical_solver analytic
                                                physical_tile_types,
                                                pre_cluster_timing_manager,
                                                ap_timing_tradeoff,
+                                               num_threads,
                                                log_verbosity);
 }
 
@@ -61,6 +63,7 @@ SimPLGlobalPlacer::SimPLGlobalPlacer(e_ap_analytical_solver analytical_solver_ty
                                      const std::vector<t_physical_tile_type>& physical_tile_types,
                                      const PreClusterTimingManager& pre_cluster_timing_manager,
                                      float ap_timing_tradeoff,
+                                     unsigned num_threads,
                                      int log_verbosity)
     : GlobalPlacer(ap_netlist, log_verbosity) {
     // This can be a long method. Good to time this to see how long it takes to
@@ -75,6 +78,7 @@ SimPLGlobalPlacer::SimPLGlobalPlacer(e_ap_analytical_solver analytical_solver_ty
                                      atom_netlist,
                                      pre_cluster_timing_manager,
                                      ap_timing_tradeoff,
+                                     num_threads,
                                      log_verbosity_);
 
     // Build the density manager used by the partial legalizer.

vpr/src/analytical_place/global_placer.h

@@ -83,6 +83,7 @@ std::unique_ptr<GlobalPlacer> make_global_placer(e_ap_analytical_solver analytic
                                                  const std::vector<t_physical_tile_type>& physical_tile_types,
                                                  const PreClusterTimingManager& pre_cluster_timing_manager,
                                                  float ap_timing_tradeoff,
+                                                 unsigned num_threads,
                                                  int log_verbosity);
 
 /**
@@ -148,6 +149,7 @@ class SimPLGlobalPlacer : public GlobalPlacer {
                       const std::vector<t_physical_tile_type>& physical_tile_types,
                       const PreClusterTimingManager& pre_cluster_timing_manager,
                       float ap_timing_tradeoff,
+                      unsigned num_threads,
                       int log_verbosity);
 
     /**

vpr/src/base/SetupVPR.cpp

@@ -559,6 +559,7 @@ void SetupAPOpts(const t_options& options,
     apOpts.detailed_placer_type = options.ap_detailed_placer.value();
     apOpts.ap_timing_tradeoff = options.ap_timing_tradeoff.value();
     apOpts.appack_max_dist_th = options.appack_max_dist_th.value();
+    apOpts.num_threads = options.num_workers.value();
     apOpts.log_verbosity = options.ap_verbosity.value();
 }
 

vpr/src/base/vpr_types.h

@@ -1116,6 +1116,8 @@ struct t_placer_opts {
  *   @param appack_max_dist_th
  *              Array of string passed by the user to configure the max candidate
  *              distance thresholds.
+ *   @param num_threads
+ *              The number of threads the AP flow can use.
  *   @param log_verbosity
  *              The verbosity level of log messages in the AP flow, with higher
  *              values leading to more verbose messages.
@@ -1135,6 +1137,8 @@ struct t_ap_opts {
 
     std::vector<std::string> appack_max_dist_th;
 
+    unsigned num_threads;
+
     int log_verbosity;
 };