ice40: Debugging the packer

Signed-off-by: David Shah <davey1576@gmail.com>

4 files changed, 36 insertions, 3 deletions

diff --git a/ice40/blinky_nopack.ys b/ice40/blinky_nopack.ys
new file mode 100644
index 00000000..2fea95bc
--- /dev/null
+++ b/ice40/blinky_nopack.ys
@@ -0,0 +1,3 @@
+read_verilog blinky.v
+synth_ice40 -nocarry -top blinky
+write_json blinky.json
diff --git a/ice40/cells.cc b/ice40/cells.cc
index db13a55f..6ad9d136 100644
--- a/ice40/cells.cc
+++ b/ice40/cells.cc
@@ -36,6 +36,7 @@ CellInfo *create_ice_cell(Design *design, IdString type, IdString name)
     } else {
         new_cell->name = name;
     }
+    new_cell->type = type;
     if (type == "ICESTORM_LC") {
         new_cell->params["LUT_INIT"] = "0";
         new_cell->params["NEG_CLK"] = "0";
@@ -60,7 +61,6 @@ CellInfo *create_ice_cell(Design *design, IdString type, IdString name)
     } else {
         log_error("unable to create iCE40 cell of type %s", type.c_str());
     }
-    design->cells[new_cell->name] = new_cell;
     return new_cell;
 }
 
@@ -120,4 +120,6 @@ void dff_to_lc(CellInfo *dff, CellInfo *lc, bool pass_thru_lut)
         lc->params["LUT_INIT"] = "2";
         replace_port(dff, "D", lc, "I0");
     }
+
+    replace_port(dff, "Q", lc, "O");
 }
diff --git a/ice40/main.cc b/ice40/main.cc
index cceb2b04..0e989819 100644
--- a/ice40/main.cc
+++ b/ice40/main.cc
@@ -29,6 +29,7 @@
 #include "log.h"
 #include "mainwindow.h"
 #include "nextpnr.h"
+#include "pack.h"
 #include "place.h"
 #include "pybindings.h"
 #include "route.h"
@@ -67,6 +68,10 @@ int main(int argc, char *argv[])
     options.add_options()("test", "just a check");
     options.add_options()("gui", "start gui");
     options.add_options()("svg", "dump SVG file");
+    options.add_options()("pack", "pack design prior to place and route");
+    options.add_options()("pack-only",
+                          "pack design only without placement or routing");
+
     options.add_options()("run", po::value<std::vector<std::string>>(),
                           "python file to execute");
     options.add_options()("json", po::value<std::string>(),
@@ -251,8 +256,13 @@ int main(int argc, char *argv[])
         std::istream *f = new std::ifstream(filename);
 
         parse_json_file(f, filename, &design);
-        place_design(&design);
-        route_design(&design);
+        if (vm.count("pack") || vm.count("pack-only")) {
+            pack_design(&design);
+        }
+        if (!vm.count("pack-only")) {
+            place_design(&design);
+            route_design(&design);
+        }
     }
 
     if (vm.count("asc")) {
diff --git a/ice40/pack.cc b/ice40/pack.cc
index 692bfba2..47e55b68 100644
--- a/ice40/pack.cc
+++ b/ice40/pack.cc
@@ -29,12 +29,18 @@
 static void pack_lut_lutffs(Design *design)
 {
     std::unordered_set<IdString> packed_cells;
+    std::vector<CellInfo *> new_cells;
     for (auto cell : design->cells) {
         CellInfo *ci = cell.second;
+        log_info("cell '%s' is of type '%s'\n", ci->name.c_str(),
+                 ci->type.c_str());
         if (is_lut(ci)) {
             CellInfo *packed = create_ice_cell(design, "ICESTORM_LC",
                                                std::string(ci->name) + "_LC");
             packed_cells.insert(ci->name);
+            new_cells.push_back(packed);
+            log_info("packed cell %s into %s\n", ci->name.c_str(),
+                     packed->name.c_str());
             // See if we can pack into a DFF
             // TODO: LUT cascade
             NetInfo *o = ci->ports.at("O").net;
@@ -42,7 +48,10 @@ static void pack_lut_lutffs(Design *design)
             if (dff) {
                 lut_to_lc(ci, packed, false);
                 dff_to_lc(dff, packed, false);
+                design->nets.erase(o->name);
                 packed_cells.insert(dff->name);
+                log_info("packed cell %s into %s\n", dff->name.c_str(),
+                         packed->name.c_str());
             } else {
                 lut_to_lc(ci, packed, true);
             }
@@ -51,24 +60,33 @@ static void pack_lut_lutffs(Design *design)
     for (auto pcell : packed_cells) {
         design->cells.erase(pcell);
     }
+    for (auto ncell : new_cells) {
+        design->cells[ncell->name] = ncell;
+    }
 }
 
 // Pack FFs not packed as LUTFFs
 static void pack_nonlut_ffs(Design *design)
 {
     std::unordered_set<IdString> packed_cells;
+    std::vector<CellInfo *> new_cells;
+
     for (auto cell : design->cells) {
         CellInfo *ci = cell.second;
         if (is_ff(ci)) {
             CellInfo *packed = create_ice_cell(design, "ICESTORM_LC",
                                                std::string(ci->name) + "_LC");
             packed_cells.insert(ci->name);
+            new_cells.push_back(packed);
             dff_to_lc(ci, packed, true);
         }
     }
     for (auto pcell : packed_cells) {
         design->cells.erase(pcell);
     }
+    for (auto ncell : new_cells) {
+        design->cells[ncell->name] = ncell;
+    }
 }
 
 // Main pack function