Merge branch 'master' of gitlab.com:SymbioticEDA/nextpnr

1 files changed, 122 insertions, 0 deletions

diff --git a/ice40/pack.cc b/ice40/pack.cc
new file mode 100644
index 00000000..ff421c17
--- /dev/null
+++ b/ice40/pack.cc
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+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2018  Clifford Wolf <clifford@clifford.at>
+ *  Copyright (C) 2018  David Shah <dave@ds0.me>
+ *
+ *  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.
+ *
+ */
+
+#include "pack.h"
+#include "cells.h"
+#include "design_utils.h"
+#include "log.h"
+
+#include <unordered_set>
+
+// Pack LUTs and LUT-FF pairs
+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;
+            CellInfo *dff = net_only_drives(o, is_ff, "D", true);
+            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);
+            }
+        }
+    }
+    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;
+    }
+}
+
+// Pack constants (simple implementation)
+static void pack_constants(Design *design)
+{
+    CellInfo *gnd_cell = create_ice_cell(design, "ICESTORM_LC", "$PACKER_GND");
+    gnd_cell->attrs["LUT_INIT"] = "0";
+
+    CellInfo *vcc_cell = create_ice_cell(design, "ICESTORM_LC", "$PACKER_VCC");
+    vcc_cell->attrs["LUT_INIT"] = "1";
+
+    for (auto net : design->nets) {
+        NetInfo *ni = net.second;
+        if (ni->driver.cell != nullptr && ni->driver.cell->type == "GND") {
+            ni->driver.cell = gnd_cell;
+            ni->driver.port = "O";
+            design->cells[gnd_cell->name] = gnd_cell;
+        } else if (ni->driver.cell != nullptr &&
+                   ni->driver.cell->type == "VCC") {
+            ni->driver.cell = vcc_cell;
+            ni->driver.port = "O";
+            design->cells[vcc_cell->name] = vcc_cell;
+        }
+    }
+}
+
+// Main pack function
+void pack_design(Design *design)
+{
+    pack_constants(design);
+    pack_lut_lutffs(design);
+    pack_nonlut_ffs(design);
+}