Merge pull request #761 from acomodi/interchange-constrs

interchange: add user placement constraints handling

5 files changed, 174 insertions, 13 deletions

diff --git a/common/placer_heap.cc b/common/placer_heap.cc
index dbb8d36c..f8385cef 100644
--- a/common/placer_heap.cc
+++ b/common/placer_heap.cc
@@ -401,6 +401,7 @@ class HeAPPlacer
         // Initial constraints placer
         for (auto &cell_entry : ctx->cells) {
             CellInfo *cell = cell_entry.second.get();
+
             auto loc = cell->attrs.find(ctx->id("BEL"));
             if (loc != cell->attrs.end()) {
                 std::string loc_name = loc->second.as_string();
diff --git a/fpga_interchange/arch.cc b/fpga_interchange/arch.cc
index 901725d4..ccd2dfb2 100644
--- a/fpga_interchange/arch.cc
+++ b/fpga_interchange/arch.cc
@@ -787,6 +787,7 @@ bool Arch::place()
     getCtx()->check();
 #endif
 
+    place_constraints();
     place_globals();
 
     std::string placer = str_or_default(settings, id("placer"), defaultPlacer);
diff --git a/fpga_interchange/arch.h b/fpga_interchange/arch.h
index 630c4480..8afb71e1 100644
--- a/fpga_interchange/arch.h
+++ b/fpga_interchange/arch.h
@@ -720,6 +720,9 @@ struct Arch : ArchAPI<ArchRanges>
     void prepare_cluster(const ClusterPOD *cluster, uint32_t index);
     dict<ClusterId, Cluster> clusters;
 
+    // User constraints
+    void place_constraints();
+
     void decode_lut_cells();
 
     const GlobalCellPOD *global_cell_info(IdString cell_type) const;
diff --git a/fpga_interchange/arch_place_constr.cc b/fpga_interchange/arch_place_constr.cc
new file mode 100644
index 00000000..3af48656
--- /dev/null
+++ b/fpga_interchange/arch_place_constr.cc
@@ -0,0 +1,106 @@
+/*
+ *  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 "log.h"
+#include "nextpnr.h"
+#include "util.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+
+void Arch::place_constraints()
+{
+    std::vector<std::pair<IdString, BelId>> constrained_cells;
+    for (auto &cell_pair : cells) {
+        CellInfo *cell = cell_pair.second.get();
+        auto loc_constr = cell->attrs.find(id("LOC"));
+        auto bel_constr = cell->attrs.find(id("BEL"));
+
+        if (loc_constr == cell->attrs.end() || bel_constr == cell->attrs.end())
+            continue;
+
+        IdString loc_name = id(loc_constr->second.as_string());
+        IdString bel_name = id(bel_constr->second.as_string());
+
+        BelId bel;
+        for (size_t i = 0; i < chip_info->tiles.size(); ++i) {
+            const auto &tile = chip_info->tiles[i];
+            bool site_found = false;
+            for (size_t j = 0; j < tile.sites.size(); ++j) {
+                auto &site_data = chip_info->sites[tile.sites[j]];
+                if (loc_name == id(site_data.site_name.get())) {
+                    site_found = true;
+                    break;
+                }
+            }
+
+            if (!site_found)
+                continue;
+
+            const auto &tile_type = chip_info->tile_types[tile.type];
+            bool bel_found = false;
+            for (size_t j = 0; j < tile_type.bel_data.size(); ++j) {
+                const BelInfoPOD &bel_data = tile_type.bel_data[j];
+                if (bel_name == IdString(bel_data.name)) {
+                    bel.tile = i;
+                    bel.index = j;
+                    bel_found = true;
+                    break;
+                }
+            }
+
+            if (bel_found)
+                break;
+            else
+                log_error("No bel found for user constraint \'%s/%s\' for cell \'%s\'\n", loc_name.c_str(getCtx()),
+                          bel_name.c_str(getCtx()), cell->name.c_str(getCtx()));
+        }
+
+        if (!isValidBelForCellType(cell->type, bel))
+            log_error("Bel \'%s\' is invalid for cell \'%s\' (%s)\n", nameOfBel(bel), cell->name.c_str(getCtx()),
+                      cell->type.c_str(getCtx()));
+
+        auto bound_cell = getBoundBelCell(bel);
+        if (bound_cell)
+            log_error("Cell \'%s\' cannot be bound to bel \'%s\' "
+                      "since it is already bound to cell \'%s\'\n",
+                      cell->name.c_str(getCtx()), nameOfBel(bel), bound_cell->name.c_str(getCtx()));
+
+        bindBel(bel, cell, STRENGTH_USER);
+
+        cell->attrs.erase(id("BEL"));
+        constrained_cells.emplace_back(cell->name, bel);
+    }
+
+    if (constrained_cells.empty())
+        return;
+
+    log_info("Cell placed via user constraints:\n");
+    for (auto cell_bel : constrained_cells) {
+        IdString cell_name = cell_bel.first;
+        BelId bel = cell_bel.second;
+
+        if (!isBelLocationValid(bel))
+            log_error("  - Bel \'%s\' is not valid for cell \'%s\'\n", nameOfBel(bel), cell_name.c_str(getCtx()));
+
+        log_info("  - %s placed at %s\n", cell_name.c_str(getCtx()), nameOfBel(cell_bel.second));
+    }
+}
+
+NEXTPNR_NAMESPACE_END
diff --git a/fpga_interchange/xdc.cc b/fpga_interchange/xdc.cc
index ca1340b5..9085615b 100644
--- a/fpga_interchange/xdc.cc
+++ b/fpga_interchange/xdc.cc
@@ -31,7 +31,7 @@
 
 NEXTPNR_NAMESPACE_BEGIN
 
-static int port_set_from_any(Tcl_Interp *interp, Tcl_Obj *objPtr) { return TCL_ERROR; }
+static int obj_set_from_any(Tcl_Interp *interp, Tcl_Obj *objPtr) { return TCL_ERROR; }
 
 static void set_tcl_obj_string(Tcl_Obj *objPtr, const std::string &s)
 {
@@ -55,12 +55,21 @@ static void port_update_string(Tcl_Obj *objPtr)
     set_tcl_obj_string(objPtr, port_name);
 }
 
-static void port_dup(Tcl_Obj *srcPtr, Tcl_Obj *dupPtr)
+static void cell_update_string(Tcl_Obj *objPtr)
+{
+    const Context *ctx = static_cast<const Context *>(objPtr->internalRep.twoPtrValue.ptr1);
+    CellInfo *cell_info = static_cast<CellInfo *>(objPtr->internalRep.twoPtrValue.ptr2);
+
+    std::string cell_name = cell_info->name.str(ctx);
+    set_tcl_obj_string(objPtr, cell_name);
+}
+
+static void obj_dup(Tcl_Obj *srcPtr, Tcl_Obj *dupPtr)
 {
     dupPtr->internalRep.twoPtrValue = srcPtr->internalRep.twoPtrValue;
 }
 
-static void port_free(Tcl_Obj *objPtr) {}
+static void obj_free(Tcl_Obj *objPtr) {}
 
 static void Tcl_SetStringResult(Tcl_Interp *interp, const std::string &s)
 {
@@ -71,7 +80,11 @@ static void Tcl_SetStringResult(Tcl_Interp *interp, const std::string &s)
 }
 
 static Tcl_ObjType port_object = {
-        "port", port_free, port_dup, port_update_string, port_set_from_any,
+        "port", obj_free, obj_dup, port_update_string, obj_set_from_any,
+};
+
+static Tcl_ObjType cell_object = {
+        "cell", obj_free, obj_dup, cell_update_string, obj_set_from_any,
 };
 
 static int get_ports(ClientData data, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[])
@@ -106,6 +119,38 @@ static int get_ports(ClientData data, Tcl_Interp *interp, int objc, Tcl_Obj *CON
     }
 }
 
+static int get_cells(ClientData data, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[])
+{
+    const Context *ctx = static_cast<const Context *>(data);
+    if (objc == 1) {
+        // Return list of all ports.
+        Tcl_SetStringResult(interp, "Unimplemented");
+        return TCL_ERROR;
+    } else if (objc == 2) {
+        const char *arg0 = Tcl_GetString(objv[1]);
+        IdString cell_name = ctx->id(arg0);
+
+        auto iter = ctx->cells.find(cell_name);
+        if (iter == ctx->cells.end()) {
+            Tcl_SetStringResult(interp, "Could not find cell " + cell_name.str(ctx));
+            return TCL_ERROR;
+        }
+
+        Tcl_Obj *result = Tcl_NewObj();
+        result->typePtr = &cell_object;
+        result->internalRep.twoPtrValue.ptr1 = (void *)(ctx);
+        result->internalRep.twoPtrValue.ptr2 = (void *)(iter->second.get());
+
+        result->bytes = nullptr;
+        cell_update_string(result);
+
+        Tcl_SetObjResult(interp, result);
+        return TCL_OK;
+    } else {
+        return TCL_ERROR;
+    }
+}
+
 static int set_property(ClientData data, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[])
 {
     // set_property <property> <value> <object>
@@ -118,17 +163,21 @@ static int set_property(ClientData data, Tcl_Interp *interp, int objc, Tcl_Obj *
     const char *value = Tcl_GetString(objv[2]);
     const Tcl_Obj *object = objv[3];
 
-    if (object->typePtr != &port_object) {
-        Tcl_SetStringResult(interp, "Only port objects are handled right now!");
-        return TCL_ERROR;
-    }
+    if (object->typePtr == &port_object) {
+        const Context *ctx = static_cast<const Context *>(object->internalRep.twoPtrValue.ptr1);
+        PortInfo *port_info = static_cast<PortInfo *>(object->internalRep.twoPtrValue.ptr2);
+        NPNR_ASSERT(port_info->net != nullptr);
+        CellInfo *cell = ctx->port_cells.at(port_info->name);
 
-    const Context *ctx = static_cast<const Context *>(object->internalRep.twoPtrValue.ptr1);
-    PortInfo *port_info = static_cast<PortInfo *>(object->internalRep.twoPtrValue.ptr2);
-    NPNR_ASSERT(port_info->net != nullptr);
-    CellInfo *cell = ctx->port_cells.at(port_info->name);
+        cell->attrs[ctx->id(property)] = Property(value);
+    } else if (object->typePtr == &cell_object) {
+        const Context *ctx = static_cast<const Context *>(object->internalRep.twoPtrValue.ptr1);
+        CellInfo *cell = static_cast<CellInfo *>(object->internalRep.twoPtrValue.ptr2);
 
-    cell->attrs[ctx->id(property)] = Property(value);
+        cell->attrs[ctx->id(property)] = Property(value);
+    } else {
+        return TCL_ERROR;
+    }
 
     return TCL_OK;
 }
@@ -150,6 +199,7 @@ TclInterp::TclInterp(Context *ctx)
                                  "  }\n"
                                  "}") == TCL_OK);
     Tcl_CreateObjCommand(interp, "get_ports", get_ports, ctx, nullptr);
+    Tcl_CreateObjCommand(interp, "get_cells", get_cells, ctx, nullptr);
     Tcl_CreateObjCommand(interp, "set_property", set_property, ctx, nullptr);
 }