1 files changed, 343 insertions, 38 deletions

diff --git a/ecp5/pack.cc b/ecp5/pack.cc
index e3ddc07d..4f864b89 100644
--- a/ecp5/pack.cc
+++ b/ecp5/pack.cc
@@ -20,6 +20,7 @@
 #include <algorithm>
 #include <iterator>
 #include <unordered_set>
+#include "cells.h"
 #include "design_utils.h"
 #include "log.h"
 #include "util.h"
@@ -32,63 +33,367 @@ static bool is_nextpnr_iob(Context *ctx, CellInfo *cell)
            cell->type == ctx->id("$nextpnr_iobuf");
 }
 
-static bool is_trellis_io(const Context *ctx, const CellInfo *cell) { return cell->type == ctx->id("TRELLIS_IO"); }
-
-// Simple "packer" to remove nextpnr IOBUFs, this assumes IOBUFs are manually instantiated
-void pack_io(Context *ctx)
+class Ecp5Packer
 {
-    std::unordered_set<IdString> packed_cells;
-    std::vector<std::unique_ptr<CellInfo>> new_cells;
-    log_info("Packing IOs..\n");
+  public:
+    Ecp5Packer(Context *ctx) : ctx(ctx){};
 
-    for (auto cell : sorted(ctx->cells)) {
-        CellInfo *ci = cell.second;
-        if (is_nextpnr_iob(ctx, ci)) {
-            CellInfo *trio = nullptr;
-            if (ci->type == ctx->id("$nextpnr_ibuf") || ci->type == ctx->id("$nextpnr_iobuf")) {
-                trio = net_only_drives(ctx, ci->ports.at(ctx->id("O")).net, is_trellis_io, ctx->id("B"), true, ci);
+  private:
+    // Process the contents of packed_cells and new_cells
+    void flush_cells()
+    {
+        for (auto pcell : packed_cells) {
+            ctx->cells.erase(pcell);
+        }
+        for (auto &ncell : new_cells) {
+            ctx->cells[ncell->name] = std::move(ncell);
+        }
+        packed_cells.clear();
+        new_cells.clear();
+    }
 
-            } else if (ci->type == ctx->id("$nextpnr_obuf")) {
-                trio = net_only_drives(ctx, ci->ports.at(ctx->id("I")).net, is_trellis_io, ctx->id("B"), true, ci);
+    // Find FFs associated with LUTs, or LUT expansion muxes
+    void find_lutff_pairs()
+    {
+        log_info("Finding LUTFF pairs...\n");
+        for (auto cell : sorted(ctx->cells)) {
+            CellInfo *ci = cell.second;
+            if (is_lut(ctx, ci) || is_pfumx(ctx, ci) || is_l6mux(ctx, ci)) {
+                NetInfo *znet = ci->ports.at(ctx->id("Z")).net;
+                if (znet != nullptr) {
+                    CellInfo *ff = net_only_drives(ctx, znet, is_ff, ctx->id("DI"), false);
+                    if (ff != nullptr) {
+                        lutffPairs[ci->name] = ff->name;
+                        fflutPairs[ff->name] = ci->name;
+                    }
+                }
             }
-            if (trio != nullptr) {
-                // Trivial case, TRELLIS_IO used. Just destroy the net and the
-                // iobuf
-                log_info("%s feeds TRELLIS_IO %s, removing %s %s.\n", ci->name.c_str(ctx), trio->name.c_str(ctx),
-                         ci->type.c_str(ctx), ci->name.c_str(ctx));
-                NetInfo *net = trio->ports.at(ctx->id("B")).net;
-                if (net != nullptr) {
-                    ctx->nets.erase(net->name);
-                    trio->ports.at(ctx->id("B")).net = nullptr;
+        }
+    }
+
+    // Return whether two FFs can be packed together in the same slice
+    bool can_pack_ffs(CellInfo *ff0, CellInfo *ff1)
+    {
+        if (str_or_default(ff0->params, ctx->id("GSR"), "DISABLED") !=
+            str_or_default(ff1->params, ctx->id("GSR"), "DISABLED"))
+            return false;
+        if (str_or_default(ff0->params, ctx->id("SRMODE"), "LSR_OVER_CE") !=
+            str_or_default(ff1->params, ctx->id("SRMODE"), "LSR_OVER_CE"))
+            return false;
+        if (str_or_default(ff0->params, ctx->id("CEMUX"), "1") != str_or_default(ff1->params, ctx->id("CEMUX"), "1"))
+            return false;
+        if (str_or_default(ff0->params, ctx->id("LSRMUX"), "LSR") !=
+            str_or_default(ff1->params, ctx->id("LSRMUX"), "LSR"))
+            return false;
+        if (str_or_default(ff0->params, ctx->id("CLKMUX"), "CLK") !=
+            str_or_default(ff1->params, ctx->id("CLKMUX"), "CLK"))
+            return false;
+        if (ff0->ports.at(ctx->id("CLK")).net != ff1->ports.at(ctx->id("CLK")).net)
+            return false;
+        if (ff0->ports.at(ctx->id("CE")).net != ff1->ports.at(ctx->id("CE")).net)
+            return false;
+        if (ff0->ports.at(ctx->id("LSR")).net != ff1->ports.at(ctx->id("LSR")).net)
+            return false;
+        return true;
+    }
+
+    // Return true if two LUTs can be paired considering FF compatibility
+    bool can_pack_lutff(IdString lut0, IdString lut1)
+    {
+        auto ff0 = lutffPairs.find(lut0), ff1 = lutffPairs.find(lut1);
+        if (ff0 != lutffPairs.end() && ff1 != lutffPairs.end()) {
+            return can_pack_ffs(ctx->cells.at(ff0->second).get(), ctx->cells.at(ff1->second).get());
+        } else {
+            return true;
+        }
+    }
+
+    // Find "closely connected" LUTs and pair them together
+    void pair_luts()
+    {
+        log_info("Finding LUT-LUT pairs...\n");
+        std::unordered_set<IdString> procdLuts;
+        for (auto cell : sorted(ctx->cells)) {
+            CellInfo *ci = cell.second;
+            if (is_lut(ctx, ci) && procdLuts.find(cell.first) == procdLuts.end()) {
+                NetInfo *znet = ci->ports.at(ctx->id("Z")).net;
+                if (znet != nullptr) {
+                    for (auto user : znet->users) {
+                        if (is_lut(ctx, user.cell) && procdLuts.find(user.cell->name) == procdLuts.end()) {
+                            if (can_pack_lutff(ci->name, user.cell->name)) {
+                                procdLuts.insert(ci->name);
+                                procdLuts.insert(user.cell->name);
+                                lutPairs[ci->name] = user.cell->name;
+                                goto paired;
+                            }
+                        }
+                    }
+                    if (false) {
+                    paired:
+                        continue;
+                    }
+                }
+                if (lutffPairs.find(ci->name) != lutffPairs.end()) {
+                    NetInfo *qnet = ctx->cells.at(lutffPairs[ci->name])->ports.at(ctx->id("Q")).net;
+                    if (qnet != nullptr) {
+                        for (auto user : qnet->users) {
+                            if (is_lut(ctx, user.cell) && procdLuts.find(user.cell->name) == procdLuts.end()) {
+                                if (can_pack_lutff(ci->name, user.cell->name)) {
+                                    procdLuts.insert(ci->name);
+                                    procdLuts.insert(user.cell->name);
+                                    lutPairs[ci->name] = user.cell->name;
+                                    goto paired_ff;
+                                }
+                            }
+                        }
+                        if (false) {
+                        paired_ff:
+                            continue;
+                        }
+                    }
+                }
+                for (char inp : "ABCD") {
+                    NetInfo *innet = ci->ports.at(ctx->id(std::string("") + inp)).net;
+                    if (innet != nullptr && innet->driver.cell != nullptr) {
+                        CellInfo *drv = innet->driver.cell;
+                        if (is_lut(ctx, drv) && innet->driver.port == ctx->id("Z")) {
+                            if (procdLuts.find(drv->name) == procdLuts.end()) {
+                                if (can_pack_lutff(ci->name, drv->name)) {
+                                    procdLuts.insert(ci->name);
+                                    procdLuts.insert(drv->name);
+                                    lutPairs[ci->name] = drv->name;
+                                    goto paired_inlut;
+                                }
+                            }
+                        } else if (is_ff(ctx, drv) && innet->driver.port == ctx->id("Q")) {
+                            auto fflut = fflutPairs.find(drv->name);
+                            if (fflut != fflutPairs.end() && procdLuts.find(fflut->second) == procdLuts.end()) {
+                                if (can_pack_lutff(ci->name, fflut->second)) {
+                                    procdLuts.insert(ci->name);
+                                    procdLuts.insert(fflut->second);
+                                    lutPairs[ci->name] = fflut->second;
+                                    goto paired_inlut;
+                                }
+                            }
+                        }
+                    }
+                }
+                if (false) {
+                paired_inlut:
+                    continue;
+                }
+            }
+        }
+    }
+
+    // Simple "packer" to remove nextpnr IOBUFs, this assumes IOBUFs are manually instantiated
+    void pack_io()
+    {
+        log_info("Packing IOs..\n");
+
+        for (auto cell : sorted(ctx->cells)) {
+            CellInfo *ci = cell.second;
+            if (is_nextpnr_iob(ctx, ci)) {
+                CellInfo *trio = nullptr;
+                if (ci->type == ctx->id("$nextpnr_ibuf") || ci->type == ctx->id("$nextpnr_iobuf")) {
+                    trio = net_only_drives(ctx, ci->ports.at(ctx->id("O")).net, is_trellis_io, ctx->id("B"), true, ci);
+
+                } else if (ci->type == ctx->id("$nextpnr_obuf")) {
+                    trio = net_only_drives(ctx, ci->ports.at(ctx->id("I")).net, is_trellis_io, ctx->id("B"), true, ci);
                 }
-                if (ci->type == ctx->id("$nextpnr_iobuf")) {
-                    NetInfo *net2 = ci->ports.at(ctx->id("I")).net;
-                    if (net2 != nullptr) {
-                        ctx->nets.erase(net2->name);
+                if (trio != nullptr) {
+                    // Trivial case, TRELLIS_IO used. Just destroy the net and the
+                    // iobuf
+                    log_info("%s feeds TRELLIS_IO %s, removing %s %s.\n", ci->name.c_str(ctx), trio->name.c_str(ctx),
+                             ci->type.c_str(ctx), ci->name.c_str(ctx));
+                    NetInfo *net = trio->ports.at(ctx->id("B")).net;
+                    if (net != nullptr) {
+                        ctx->nets.erase(net->name);
+                        trio->ports.at(ctx->id("B")).net = nullptr;
                     }
+                    if (ci->type == ctx->id("$nextpnr_iobuf")) {
+                        NetInfo *net2 = ci->ports.at(ctx->id("I")).net;
+                        if (net2 != nullptr) {
+                            ctx->nets.erase(net2->name);
+                        }
+                    }
+                } else {
+                    log_error("TRELLIS_IO required on all top level IOs...\n");
+                }
+                packed_cells.insert(ci->name);
+                std::copy(ci->attrs.begin(), ci->attrs.end(), std::inserter(trio->attrs, trio->attrs.begin()));
+            }
+        }
+        flush_cells();
+    }
+
+    // Pass to pack LUT5s into a newly created slice
+    void pack_lut5s()
+    {
+        log_info("Packing LUT5s...\n");
+        for (auto cell : sorted(ctx->cells)) {
+            CellInfo *ci = cell.second;
+            if (is_pfumx(ctx, ci)) {
+                std::unique_ptr<CellInfo> packed =
+                        create_ecp5_cell(ctx, ctx->id("TRELLIS_SLICE"), ci->name.str(ctx) + "_SLICE");
+                NetInfo *f0 = ci->ports.at(ctx->id("BLUT")).net;
+                if (f0 == nullptr)
+                    log_error("PFUMX '%s' has disconnected port 'BLUT'\n", ci->name.c_str(ctx));
+                NetInfo *f1 = ci->ports.at(ctx->id("ALUT")).net;
+                if (f1 == nullptr)
+                    log_error("PFUMX '%s' has disconnected port 'ALUT'\n", ci->name.c_str(ctx));
+                CellInfo *lut0 = net_driven_by(ctx, f0, is_lut, ctx->id("Z"));
+                CellInfo *lut1 = net_driven_by(ctx, f1, is_lut, ctx->id("Z"));
+                if (lut0 == nullptr)
+                    log_error("PFUMX '%s' has BLUT driven by cell other than a LUT\n", ci->name.c_str(ctx));
+                if (lut1 == nullptr)
+                    log_error("PFUMX '%s' has ALUT driven by cell other than a LUT\n", ci->name.c_str(ctx));
+                replace_port(lut0, ctx->id("A"), packed.get(), ctx->id("A0"));
+                replace_port(lut0, ctx->id("B"), packed.get(), ctx->id("B0"));
+                replace_port(lut0, ctx->id("C"), packed.get(), ctx->id("C0"));
+                replace_port(lut0, ctx->id("D"), packed.get(), ctx->id("D0"));
+                replace_port(lut1, ctx->id("A"), packed.get(), ctx->id("A1"));
+                replace_port(lut1, ctx->id("B"), packed.get(), ctx->id("B1"));
+                replace_port(lut1, ctx->id("C"), packed.get(), ctx->id("C1"));
+                replace_port(lut1, ctx->id("D"), packed.get(), ctx->id("D1"));
+                replace_port(ci, ctx->id("C0"), packed.get(), ctx->id("M0"));
+                replace_port(ci, ctx->id("Z"), packed.get(), ctx->id("OFX0"));
+                packed->params[ctx->id("LUT0_INITVAL")] = str_or_default(lut0->params, ctx->id("INIT"), "0");
+                packed->params[ctx->id("LUT1_INITVAL")] = str_or_default(lut1->params, ctx->id("INIT"), "0");
+
+                ctx->nets.erase(f0->name);
+                ctx->nets.erase(f1->name);
+                sliceUsage[packed->name].lut0_used = true;
+                sliceUsage[packed->name].lut1_used = true;
+                sliceUsage[packed->name].mux5_used = true;
+
+                if (lutffPairs.find(ci->name) != lutffPairs.end()) {
+                    CellInfo *ff = ctx->cells.at(lutffPairs[ci->name]).get();
+                    ff_to_slice(ctx, ff, packed.get(), 0, true);
+                    packed_cells.insert(ff->name);
+                    sliceUsage[packed->name].ff0_used = true;
                 }
-            } else {
-                log_error("TRELLIS_IO required on all top level IOs...\n");
+
+                new_cells.push_back(std::move(packed));
+                packed_cells.insert(lut0->name);
+                packed_cells.insert(lut1->name);
+                packed_cells.insert(ci->name);
             }
-            packed_cells.insert(ci->name);
-            std::copy(ci->attrs.begin(), ci->attrs.end(), std::inserter(trio->attrs, trio->attrs.begin()));
         }
+        flush_cells();
     }
-    for (auto pcell : packed_cells) {
-        ctx->cells.erase(pcell);
+
+    // Pack LUTs that have been paired together
+    void pack_lut_pairs()
+    {
+        log_info("Packing paired LUTs into a SLICE...\n");
+        for (auto pair : lutPairs) {
+            CellInfo *lut0 = ctx->cells.at(pair.first).get();
+            CellInfo *lut1 = ctx->cells.at(pair.second).get();
+            std::unique_ptr<CellInfo> slice =
+                    create_ecp5_cell(ctx, ctx->id("TRELLIS_SLICE"), lut0->name.str(ctx) + "_SLICE");
+
+            lut_to_slice(ctx, lut0, slice.get(), 0);
+            lut_to_slice(ctx, lut1, slice.get(), 1);
+
+            auto ff0 = lutffPairs.find(lut0->name), ff1 = lutffPairs.find(lut1->name);
+
+            if (ff0 != lutffPairs.end()) {
+                ff_to_slice(ctx, ctx->cells.at(ff0->second).get(), slice.get(), 0, true);
+                packed_cells.insert(ff0->second);
+            }
+            if (ff1 != lutffPairs.end()) {
+                ff_to_slice(ctx, ctx->cells.at(ff1->second).get(), slice.get(), 1, true);
+                packed_cells.insert(ff1->second);
+            }
+
+            new_cells.push_back(std::move(slice));
+            packed_cells.insert(lut0->name);
+            packed_cells.insert(lut1->name);
+        }
+        flush_cells();
     }
-    for (auto &ncell : new_cells) {
-        ctx->cells[ncell->name] = std::move(ncell);
+
+    // Pack single LUTs that weren't paired into their own slice,
+    // with an optional FF also
+    void pack_remaining_luts()
+    {
+        log_info("Packing unpaired LUTs into a SLICE...\n");
+        for (auto cell : sorted(ctx->cells)) {
+            CellInfo *ci = cell.second;
+            if (is_lut(ctx, ci)) {
+                std::unique_ptr<CellInfo> slice =
+                        create_ecp5_cell(ctx, ctx->id("TRELLIS_SLICE"), ci->name.str(ctx) + "_SLICE");
+                lut_to_slice(ctx, ci, slice.get(), 0);
+                auto ff = lutffPairs.find(ci->name);
+
+                if (ff != lutffPairs.end()) {
+                    ff_to_slice(ctx, ctx->cells.at(ff->second).get(), slice.get(), 0, true);
+                    packed_cells.insert(ff->second);
+                }
+
+                new_cells.push_back(std::move(slice));
+                packed_cells.insert(ci->name);
+            }
+        }
+        flush_cells();
     }
-}
 
+    // Pack flipflops that weren't paired with a LUT
+    void pack_remaining_ffs()
+    {
+        log_info("Packing unpaired FFs into a SLICE...\n");
+        for (auto cell : sorted(ctx->cells)) {
+            CellInfo *ci = cell.second;
+            if (is_ff(ctx, ci)) {
+                std::unique_ptr<CellInfo> slice =
+                        create_ecp5_cell(ctx, ctx->id("TRELLIS_SLICE"), ci->name.str(ctx) + "_SLICE");
+                ff_to_slice(ctx, ci, slice.get(), 0, false);
+                new_cells.push_back(std::move(slice));
+                packed_cells.insert(ci->name);
+            }
+        }
+        flush_cells();
+    }
+
+  public:
+    void pack()
+    {
+        pack_io();
+        find_lutff_pairs();
+        pack_lut5s();
+        pair_luts();
+        pack_lut_pairs();
+        pack_remaining_luts();
+        pack_remaining_ffs();
+    }
+
+  private:
+    Context *ctx;
+
+    std::unordered_set<IdString> packed_cells;
+    std::vector<std::unique_ptr<CellInfo>> new_cells;
+
+    struct SliceUsage
+    {
+        bool lut0_used = false, lut1_used = false;
+        bool ccu2_used = false, dpram_used = false, ramw_used = false;
+        bool ff0_used = false, ff1_used = false;
+        bool mux5_used = false, muxx_used = false;
+    };
+
+    std::unordered_map<IdString, SliceUsage> sliceUsage;
+    std::unordered_map<IdString, IdString> lutffPairs;
+    std::unordered_map<IdString, IdString> fflutPairs;
+    std::unordered_map<IdString, IdString> lutPairs;
+};
 // Main pack function
 bool Arch::pack()
 {
     Context *ctx = getCtx();
     try {
         log_break();
-        pack_io(ctx);
+        Ecp5Packer(ctx).pack();
         log_info("Checksum: 0x%08x\n", ctx->checksum());
         return true;
     } catch (log_execution_error_exception) {