Working on debugging the carry legaliser

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

common/util.h

@@ -21,6 +21,7 @@
 #define UTIL_H
 
 #include <map>
+#include <set>
 #include <string>
 #include "nextpnr.h"
 
@@ -65,6 +66,15 @@ template <typename K, typename V> std::map<K, V *> sorted(const std::unordered_m
     return retVal;
 };
 
+// Wrap an unordered_set, and allow it to be iterated over sorted by key
+template <typename K> std::set<K> sorted(const std::unordered_set<K> &orig)
+{
+    std::set<K> retVal;
+    for (auto &item : orig)
+        retVal.insert(item);
+    return retVal;
+};
+
 NEXTPNR_NAMESPACE_END
 
 #endif

ice40/carry_tests/test.sh

@@ -2,15 +2,15 @@
 set -ex
 NAME=${1%.v}
 yosys -p "synth_ice40 -top top; write_json ${NAME}.json" $1
-../../nextpnr-ice40 --json ${NAME}.json --pcf test.pcf --asc ${NAME}.asc --verbose
-icebox_vlog -p test.pcf ${NAME}.asc > ${NAME}_out.v
+../../nextpnr-ice40 --force --json ${NAME}.json --pcf test.pcf --asc ${NAME}.asc --verbose ../../python/dump_design.py
+#icebox_vlog -p test.pcf ${NAME}.asc > ${NAME}_out.v
 
-yosys -p "read_verilog +/ice40/cells_sim.v;\
-          rename chip gate;\
-          read_verilog $1;\
-          rename top gold;\
-          hierarchy;\
-          proc;\
-          clk2fflogic;\
-          miter -equiv -flatten -ignore_gold_x -make_outputs -make_outcmp gold gate miter;\
-          sat -dump_vcd equiv_${NAME}.vcd -verify-no-timeout -timeout 60 -seq 50 -prove trigger 0 -prove-skip 1 -show-inputs -show-outputs miter" ${NAME}_out.v
+#yosys -p "read_verilog +/ice40/cells_sim.v;\
+#          rename chip gate;\
+#          read_verilog $1;\
+#          rename top gold;\
+#          hierarchy;\
+#          proc;\
+#          clk2fflogic;\
+#          miter -equiv -flatten -ignore_gold_x -make_outputs -make_outcmp gold gate miter;\
+#          sat -dump_vcd equiv_${NAME}.vcd -verify-no-timeout -timeout 60 -seq 50 -prove trigger 0 -prove-skip 1 -show-inputs -show-outputs miter" ${NAME}_out.v

ice40/main.cc

@@ -45,6 +45,7 @@
 #include "route.h"
 #include "timing.h"
 #include "version.h"
+#include "place_legaliser.h"
 
 USING_NEXTPNR_NAMESPACE
 
@@ -375,6 +376,7 @@ int main(int argc, char *argv[])
             if (!vm.count("pack-only")) {
                 if (!place_design_sa(&ctx, timing_driven) && !ctx.force)
                     log_error("Placing design failed.\n");
+                legalise_design(&ctx);
                 if (!route_design(&ctx) && !ctx.force)
                     log_error("Routing design failed.\n");
             }

ice40/pack.cc

@@ -126,7 +126,6 @@ static void pack_carries(Context *ctx)
             packed_cells.insert(cell.first);
             CellInfo *carry_ci_lc = net_only_drives(ctx, ci->ports.at(ctx->id("CI")).net, is_lc, ctx->id("I3"), false);
 
-
             std::set<IdString> i0_matches, i1_matches;
             NetInfo *i0_net = ci->ports.at(ctx->id("I0")).net;
             NetInfo *i1_net = ci->ports.at(ctx->id("I1")).net;
@@ -275,7 +274,8 @@ static void set_net_constant(const Context *ctx, NetInfo *orig, NetInfo *constne
             CellInfo *uc = user.cell;
             if (ctx->verbose)
                 log_info("%s user %s\n", orig->name.c_str(ctx), uc->name.c_str(ctx));
-            if ((is_lut(ctx, uc) || is_lc(ctx, uc) || is_carry(ctx, uc)) && (user.port.str(ctx).at(0) == 'I') && !constval) {
+            if ((is_lut(ctx, uc) || is_lc(ctx, uc) || is_carry(ctx, uc)) && (user.port.str(ctx).at(0) == 'I') &&
+                !constval) {
                 uc->ports[user.port].net = nullptr;
             } else {
                 uc->ports[user.port].net = constnet;

ice40/place_legaliser.cc

@@ -93,11 +93,13 @@ class PlacementLegaliser
 
     bool legalise()
     {
+        log_info("Legalising design..\n");
         init_logic_cells();
         bool legalised_carries = legalise_carries();
         if (!legalised_carries && !ctx->force)
             return false;
-        return legalised_carries;
+        bool replaced_cells = replace_cells();
+        return legalised_carries && replaced_cells;
     }
 
   private:
@@ -313,6 +315,40 @@ class PlacementLegaliser
         return ctx->cells[name].get();
     }
 
+    // Replace ripped-up cells
+    bool replace_cells()
+    {
+        bool success = true;
+        for (auto cell : sorted(rippedCells)) {
+            CellInfo *ci = ctx->cells.at(cell).get();
+            bool placed = place_single_cell(ci);
+            if (!placed) {
+                if (ctx->force) {
+                    log_warning("failed to place cell '%s' of type '%s'\n", cell.c_str(ctx),
+                                ci->type.c_str(ctx));
+                    success = false;
+                } else {
+                    log_error("failed to place cell '%s' of type '%s'\n", cell.c_str(ctx),
+                              ci->type.c_str(ctx));
+                }
+            }
+        }
+        return success;
+    }
+
+    // Place a single cell in the first valid location
+    bool place_single_cell(CellInfo *cell)
+    {
+        BelType tgtType = ctx->belTypeFromId(cell->type);
+        for (auto bel : ctx->getBels()) {
+            if (ctx->getBelType(bel) == tgtType && ctx->checkBelAvail(bel) && ctx->isValidBelForCell(cell, bel)) {
+                ctx->bindBel(bel, cell->name, STRENGTH_WEAK);
+                return true;
+            }
+        }
+        return false;
+    }
+
     Context *ctx;
     std::unordered_set<IdString> rippedCells;
     std::unordered_set<IdString> createdCells;