1 files changed, 196 insertions, 0 deletions
diff --git a/fpga_interchange/site_lut_mapping_cache.cc b/fpga_interchange/site_lut_mapping_cache.cc
new file mode 100644
index 00000000..0cf741f2
--- /dev/null
+++ b/fpga_interchange/site_lut_mapping_cache.cc
@@ -0,0 +1,196 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2021  Symbiflow Authors
+ *
+ *  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 "site_lut_mapping_cache.h"
+#include "nextpnr.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+
+// ============================================================================
+
+SiteLutMappingKey SiteLutMappingKey::create(const SiteInformation &siteInfo)
+{
+    const Context *ctx = siteInfo.ctx;
+
+    // Look for LUT cells in the site
+    std::vector<CellInfo *> lutCells;
+    lutCells.reserve(siteInfo.cells_in_site.size());
+
+    for (CellInfo *cellInfo : siteInfo.cells_in_site) {
+
+        // Not a LUT cell
+        if (cellInfo->lut_cell.pins.empty()) {
+            continue;
+        }
+
+        // Not bound to a LUT BEL
+        BelId bel = cellInfo->bel;
+        const auto &bel_data = bel_info(ctx->chip_info, bel);
+        if (bel_data.lut_element == -1) {
+            continue;
+        }
+
+        lutCells.push_back(cellInfo);
+    }
+
+    // Sort cells by BEL indices to maintain always the same order
+    std::sort(lutCells.begin(), lutCells.end(),
+              [](const CellInfo *a, const CellInfo *b) { return a->bel.index > b->bel.index; });
+
+    // Initialize the key
+    SiteLutMappingKey key;
+    key.tileType = siteInfo.tile_type;
+    key.siteType = ctx->chip_info->sites[siteInfo.site].site_type;
+    key.numCells = 0;
+
+    // Get bound nets. Store localized (to the LUT cluster) net indices only
+    // to get always the same key for the same LUT port configuration even
+    // when the actual global net names are different.
+    dict<IdString, int32_t> netMap;
+    for (CellInfo *cellInfo : lutCells) {
+
+        NPNR_ASSERT(key.numCells < SiteLutMappingKey::MAX_LUT_CELLS);
+        auto &cell = key.cells[key.numCells++];
+
+        cell.type = cellInfo->type;
+        cell.belIndex = cellInfo->bel.index;
+
+        cell.conns.fill(0);
+
+        size_t portId = 0;
+        for (const auto &port : cellInfo->ports) {
+            const auto &portInfo = port.second;
+
+            // Consider only LUT inputs
+            if (portInfo.type != PORT_IN) {
+                continue;
+            }
+
+            // Assign net id if any
+            int32_t netId = 0;
+            if (portInfo.net != nullptr) {
+                auto netInfo = portInfo.net;
+
+                auto it = netMap.find(netInfo->name);
+                if (it != netMap.end()) {
+                    netId = it->second;
+                } else {
+                    netId = (int32_t)netMap.size() + 1;
+                    netMap[netInfo->name] = netId;
+                }
+            }
+
+            NPNR_ASSERT(portId < SiteLutMappingKey::MAX_LUT_INPUTS);
+            cell.conns[portId++] = netId;
+        }
+    }
+
+    // Compute hash
+    key.computeHash();
+
+    return key;
+}
+
+// ============================================================================
+
+bool SiteLutMappingResult::apply(const SiteInformation &siteInfo)
+{
+
+    Context *ctx = const_cast<Context *>(siteInfo.ctx);
+    TileStatus &tileStatus = ctx->get_tile_status(siteInfo.tile);
+
+    for (auto &cell : cells) {
+
+        // Get the bound cell
+        CellInfo *cellInfo = tileStatus.boundcells[cell.belIndex];
+        NPNR_ASSERT(cellInfo);
+
+        // Double check BEL binding
+        NPNR_ASSERT(cellInfo->bel.tile == siteInfo.tile);
+        NPNR_ASSERT(cellInfo->bel.index == cell.belIndex);
+
+        // Cell <-> BEL pin map
+        size_t numPins = cellInfo->lut_cell.pins.size();
+        for (size_t pinIdx = 0; pinIdx < numPins; ++pinIdx) {
+            const IdString &cellPin = cellInfo->lut_cell.pins[pinIdx];
+            auto &belPins = cellInfo->cell_bel_pins[cellPin];
+
+            // There is only one pin
+            belPins.resize(1);
+            belPins[0] = cell.belPins[cellPin];
+        }
+
+        // LUT data
+        // FIXME: Is there any other info that is being updated than vcc_pins ?
+        cellInfo->lut_cell.vcc_pins = std::move(cell.lutCell.vcc_pins);
+    }
+
+    return true;
+}
+
+size_t SiteLutMappingResult::getSizeInBytes() const
+{
+
+    size_t size = 0;
+
+    size += sizeof(SiteLutMappingResult);
+    size += blockedWires.size() * sizeof(std::pair<IdString, IdString>);
+
+    for (const auto &cell : cells) {
+        size += sizeof(Cell);
+        size += cell.belPins.size() * sizeof(decltype(cell.belPins)::value_type);
+    }
+
+    return size;
+}
+
+// ============================================================================
+
+void SiteLutMappingCache::add(const SiteLutMappingKey &key, const SiteLutMappingResult &result)
+{
+    cache_[key] = result;
+}
+
+bool SiteLutMappingCache::get(const SiteLutMappingKey &key, SiteLutMappingResult *result)
+{
+    if (cache_.count(key) == 0) {
+        numMisses++;
+        return false;
+    }
+
+    numHits++;
+    *result = cache_[key];
+    return true;
+}
+
+void SiteLutMappingCache::clear()
+{
+    cache_.clear();
+    clearStats();
+}
+
+void SiteLutMappingCache::clearStats()
+{
+    numHits = 0;
+    numMisses = 0;
+}
+
+// ============================================================================
+
+NEXTPNR_NAMESPACE_END