HeAP: Add TAUCS wrapper and integration

Signed-off-by: David Shah <dave@ds0.me>

7 files changed, 175 insertions, 6 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4f29d132..2fbfa735 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -122,6 +122,8 @@ configure_file(
     ${CMAKE_CURRENT_SOURCE_DIR}/common/version.h.in ${CMAKE_CURRENT_BINARY_DIR}/generated/version.h
 )
 
+add_subdirectory(3rdparty/taucs ${CMAKE_CURRENT_BINARY_DIR}/generated/taucs EXCLUDE_FROM_ALL)
+
 if (BUILD_PYTHON)
     # Find Boost::Python of a suitable version in a cross-platform way
     # Some distributions (Arch) call it libboost_python3, others such as Ubuntu
@@ -180,7 +182,7 @@ if (BUILD_PYTHON)
     endif ()
 endif()
 
-include_directories(common/ json/ ${Boost_INCLUDE_DIRS} ${PYTHON_INCLUDE_DIRS})
+include_directories(common/ json/ ${Boost_INCLUDE_DIRS} ${PYTHON_INCLUDE_DIRS} 3rdparty/taucs/src ${CMAKE_CURRENT_BINARY_DIR}/generated/taucs/build/linux)
 aux_source_directory(common/ COMMON_SRC_FILES)
 aux_source_directory(json/ JSON_PARSER_FILES)
 set(COMMON_FILES ${COMMON_SRC_FILES} ${JSON_PARSER_FILES})
@@ -244,7 +246,7 @@ foreach (family ${ARCH})
         # Include family-specific source files to all family targets and set defines appropriately
         target_include_directories(${target} PRIVATE ${family}/ ${CMAKE_CURRENT_BINARY_DIR}/generated/)
         target_compile_definitions(${target} PRIVATE NEXTPNR_NAMESPACE=nextpnr_${family} ARCH_${ufamily} ARCHNAME=${family})
-        target_link_libraries(${target} LINK_PUBLIC ${Boost_LIBRARIES} ${link_param})
+        target_link_libraries(${target} LINK_PUBLIC ${Boost_LIBRARIES} taucs ${link_param})
         if (NOT MSVC)
             target_link_libraries(${target} LINK_PUBLIC pthread)
         endif()
diff --git a/common/placer_heap.cc b/common/placer_heap.cc
index 19d5a8e5..9f49e552 100644
--- a/common/placer_heap.cc
+++ b/common/placer_heap.cc
@@ -25,12 +25,13 @@
  */
 
 #include <deque>
+#include <numeric>
 #include <unordered_map>
 #include "log.h"
 #include "nextpnr.h"
 #include "place_common.h"
+#include "placer_math.h"
 #include "util.h"
-
 NEXTPNR_NAMESPACE_BEGIN
 
 namespace {
@@ -76,13 +77,44 @@ template <typename T> struct EquationSystem
     }
 
     void add_rhs(int row, T val) { rhs[row] += val; }
+
+    void solve(std::vector<double> &x)
+    {
+        int nnz = std::accumulate(A.begin(), A.end(), 0,
+                                  [](int a, const std::vector<std::pair<int, T>> &vec) { return a + int(vec.size()); });
+        taucif_system *sys = taucif_create_system(int(rhs.size()), int(A.size()), nnz);
+        for (int col = 0; col < int(A.size()); col++) {
+            auto &Ac = A[col];
+            for (auto &el : Ac) {
+                if (col <= el.first)
+                    taucif_set_matrix_value(sys, el.first, col, el.second);
+                // FIXME: in debug mode, assert really is symmetric
+            }
+        }
+        taucif_solve_system(sys, x.data(), rhs.data());
+        taucif_free_system(sys);
+    }
 };
+
 } // namespace
 
 class HeAPPlacer
 {
   public:
     HeAPPlacer(Context *ctx) : ctx(ctx) {}
+    bool place()
+    {
+        taucif_init_solver();
+        place_constraints();
+        build_fast_bels();
+        seed_placement();
+        update_all_chains();
+
+        EquationSystem<double> es(place_cells.size(), place_cells.size());
+        build_equations(es, false);
+        solve_equations(es, false);
+        return true;
+    }
 
   private:
     Context *ctx;
@@ -361,6 +393,19 @@ class HeAPPlacer
             });
         }
     }
+
+    // Build the system of equations for either X or Y
+    void solve_equations(EquationSystem<double> &es, bool yaxis)
+    {
+        // Return the x or y position of a cell, depending on ydir
+        auto cell_pos = [&](CellInfo *cell) { return yaxis ? cell_locs.at(cell->name).y : cell_locs.at(cell->name).x; };
+        build_equations(es, yaxis);
+        std::vector<double> vals;
+        std::transform(place_cells.begin(), place_cells.end(), std::back_inserter(vals), cell_pos);
+        es.solve(vals);
+    }
 };
 
+bool placer_heap(Context *ctx) { return HeAPPlacer(ctx).place(); }
+
 NEXTPNR_NAMESPACE_END
\ No newline at end of file
diff --git a/common/placer_heap.h b/common/placer_heap.h
new file mode 100644
index 00000000..5eb8a9ba
--- /dev/null
+++ b/common/placer_heap.h
@@ -0,0 +1,34 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2019  David Shah <david@symbioticeda.com>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ *  [[cite]] HeAP
+ *  Analytical Placement for Heterogeneous FPGAs, Marcel Gort and Jason H. Anderson
+ *  https://janders.eecg.utoronto.ca/pdfs/marcelfpl12.pdf
+ *
+ *  [[cite]] SimPL
+ *  SimPL: An Effective Placement Algorithm, Myung-Chul Kim, Dong-Jin Lee and Igor L. Markov
+ *  http://www.ece.umich.edu/cse/awards/pdfs/iccad10-simpl.pdf
+ */
+
+#ifndef PLACER_HEAP_H
+#define PLACER_HEAP
+#include "nextpnr.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+extern bool placer_heap(Context *ctx);
+NEXTPNR_NAMESPACE_END
+#endif
\ No newline at end of file
diff --git a/common/placer_math.c b/common/placer_math.c
new file mode 100644
index 00000000..456bc0a1
--- /dev/null
+++ b/common/placer_math.c
@@ -0,0 +1,43 @@
+#include "taucs.h"
+#include "placer_math.h"
+#include <stdio.h>
+
+void taucif_init_solver() {
+    taucs_logfile("stdout");
+}
+
+struct taucif_system {
+    taucs_ccs_matrix* mat;
+    int ccs_i, ccs_col;
+};
+
+struct taucif_system *taucif_create_system(int rows, int cols, int n_nonzero) {
+    struct taucif_system *sys = taucs_malloc(sizeof(struct taucif_system));
+    sys->mat = taucs_ccs_create(cols, rows, n_nonzero, TAUCS_DOUBLE | TAUCS_SYMMETRIC);
+    // Internal pointers
+    sys->ccs_i = 0;
+    sys->ccs_col = -1;
+    return sys;
+};
+
+void taucif_set_matrix_value(struct taucif_system *sys, int row, int col, double value) {
+    while(sys->ccs_col < col) {
+        sys->mat->colptr[++sys->ccs_col] = sys->ccs_i;
+    }
+    sys->mat->rowind[sys->ccs_i] = row;
+    sys->mat->values.d[sys->ccs_i++] = value;
+}
+
+void taucif_solve_system(struct taucif_system *sys, double *x, double *rhs) {
+    // FIXME: preconditioner, droptol??
+    taucs_ccs_matrix* precond_mat = taucs_ccs_factor_llt(sys->mat, 1e-3, 0);
+    // FIXME: itermax, convergetol
+    int cjres = taucs_conjugate_gradients(sys->mat, taucs_ccs_solve_llt, precond_mat, x, rhs, 1000, 1e-6);
+    taucs_ccs_free(precond_mat);
+}
+
+void taucif_free_system(struct taucif_system *sys) {
+    taucs_ccs_free(sys->mat);
+    taucs_free(sys->mat);
+}
+
diff --git a/common/placer_math.h b/common/placer_math.h
new file mode 100644
index 00000000..3782e99f
--- /dev/null
+++ b/common/placer_math.h
@@ -0,0 +1,43 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2019  David Shah <david@symbioticeda.com>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+ */
+
+#ifndef PLACER_MATH_H
+#define PLACER_MATH_H
+// This shim is needed because Tauc is mutually incompatible with modern C++ (implementing macros and functions
+// that collide with max, min, etc)
+#ifdef __cplusplus
+extern "C" {
+#endif
+extern void taucif_init_solver();
+
+struct taucif_system;
+
+extern struct taucif_system *taucif_create_system(int rows, int cols, int n_nonzero);
+
+extern void taucif_set_matrix_value(struct taucif_system *sys, int row, int col, double value);
+
+extern void taucif_solve_system(struct taucif_system *sys, double *x, double *rhs);
+
+extern void taucif_free_system(struct taucif_system *sys);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
\ No newline at end of file
diff --git a/ecp5/arch.cc b/ecp5/arch.cc
index da0f7b1a..8ba8d28e 100644
--- a/ecp5/arch.cc
+++ b/ecp5/arch.cc
@@ -458,6 +458,7 @@ delay_t Arch::estimateDelay(WireId src, WireId dst) const
     int dx = abs(src_loc.first - dst_loc.first), dy = abs(src_loc.second - dst_loc.second);
     return (130 - 25 * args.speed) *
            (6 + std::max(dx - 5, 0) + std::max(dy - 5, 0) + 2 * (std::min(dx, 5) + std::min(dy, 5)));
+
 }
 
 delay_t Arch::predictDelay(const NetInfo *net_info, const PortRef &sink) const
@@ -467,7 +468,6 @@ delay_t Arch::predictDelay(const NetInfo *net_info, const PortRef &sink) const
         return 0;
     auto driver_loc = getBelLocation(driver.cell->bel);
     auto sink_loc = getBelLocation(sink.cell->bel);
-
     // Encourage use of direct interconnect
     if (driver_loc.x == sink_loc.x && driver_loc.y == sink_loc.y) {
         if ((sink.port == id_A0 || sink.port == id_A1) && (driver.port == id_F1) &&
diff --git a/ice40/arch.cc b/ice40/arch.cc
index fbe882fc..5688b6e6 100644
--- a/ice40/arch.cc
+++ b/ice40/arch.cc
@@ -26,10 +26,10 @@
 #include "log.h"
 #include "nextpnr.h"
 #include "placer1.h"
+#include "placer_heap.h"
 #include "router1.h"
 #include "timing_opt.h"
 #include "util.h"
-
 NEXTPNR_NAMESPACE_BEGIN
 
 // -----------------------------------------------------------------------
@@ -671,7 +671,9 @@ bool Arch::getBudgetOverride(const NetInfo *net_info, const PortRef &sink, delay
 
 bool Arch::place()
 {
-    if (!placer1(getCtx(), Placer1Cfg(getCtx())))
+    // if (!placer1(getCtx(), Placer1Cfg(getCtx())))
+    //    return false;
+    if (!placer_heap(getCtx()))
         return false;
     if (bool_or_default(settings, id("opt_timing"), false)) {
         TimingOptCfg tocfg(getCtx());