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-rw-r--r--backends/cxxrtl/cxxrtl.cc328
-rw-r--r--backends/cxxrtl/cxxrtl.h53
2 files changed, 311 insertions, 70 deletions
diff --git a/backends/cxxrtl/cxxrtl.cc b/backends/cxxrtl/cxxrtl.cc
index 782e287ac..ca6c2a58e 100644
--- a/backends/cxxrtl/cxxrtl.cc
+++ b/backends/cxxrtl/cxxrtl.cc
@@ -171,14 +171,14 @@ struct Scheduler {
}
};
-static bool is_unary_cell(RTLIL::IdString type)
+bool is_unary_cell(RTLIL::IdString type)
{
return type.in(
ID($not), ID($logic_not), ID($reduce_and), ID($reduce_or), ID($reduce_xor), ID($reduce_xnor), ID($reduce_bool),
ID($pos), ID($neg));
}
-static bool is_binary_cell(RTLIL::IdString type)
+bool is_binary_cell(RTLIL::IdString type)
{
return type.in(
ID($and), ID($or), ID($xor), ID($xnor), ID($logic_and), ID($logic_or),
@@ -187,25 +187,25 @@ static bool is_binary_cell(RTLIL::IdString type)
ID($add), ID($sub), ID($mul), ID($div), ID($mod));
}
-static bool is_elidable_cell(RTLIL::IdString type)
+bool is_elidable_cell(RTLIL::IdString type)
{
return is_unary_cell(type) || is_binary_cell(type) || type.in(
ID($mux), ID($concat), ID($slice));
}
-static bool is_sync_ff_cell(RTLIL::IdString type)
+bool is_sync_ff_cell(RTLIL::IdString type)
{
return type.in(
ID($dff), ID($dffe));
}
-static bool is_ff_cell(RTLIL::IdString type)
+bool is_ff_cell(RTLIL::IdString type)
{
return is_sync_ff_cell(type) || type.in(
ID($adff), ID($dffsr), ID($dlatch), ID($dlatchsr), ID($sr));
}
-static bool is_internal_cell(RTLIL::IdString type)
+bool is_internal_cell(RTLIL::IdString type)
{
return type[0] == '$' && !type.begins_with("$paramod\\");
}
@@ -356,6 +356,36 @@ struct FlowGraph {
}
};
+bool is_cxxrtl_blackbox_cell(const RTLIL::Cell *cell)
+{
+ RTLIL::Module *cell_module = cell->module->design->module(cell->type);
+ log_assert(cell_module != nullptr);
+ return cell_module->get_bool_attribute(ID(cxxrtl.blackbox));
+}
+
+std::string escape_cxx_string(const std::string &input)
+{
+ std::string output = "\"";
+ for (auto c : input) {
+ if (::isprint(c)) {
+ if (c == '\\')
+ output.push_back('\\');
+ output.push_back(c);
+ } else {
+ char l = c & 0xf, h = (c >> 4) & 0xf;
+ output.append("\\x");
+ output.push_back((h < 10 ? '0' + h : 'a' + h - 10));
+ output.push_back((l < 10 ? '0' + l : 'a' + l - 10));
+ }
+ }
+ output.push_back('"');
+ if (output.find('\0') != std::string::npos) {
+ output.insert(0, "std::string {");
+ output.append(stringf(", %zu}", input.size()));
+ }
+ return output;
+}
+
struct CxxrtlWorker {
bool split_intf = false;
std::string intf_filename;
@@ -429,9 +459,11 @@ struct CxxrtlWorker {
return mangled;
}
- std::string mangle_module_name(const RTLIL::IdString &name)
+ std::string mangle_module_name(const RTLIL::IdString &name, bool is_blackbox = false)
{
// Class namespace.
+ if (is_blackbox)
+ return "bb_" + mangle_name(name);
return mangle_name(name);
}
@@ -455,7 +487,7 @@ struct CxxrtlWorker {
std::string mangle(const RTLIL::Module *module)
{
- return mangle_module_name(module->name);
+ return mangle_module_name(module->name, /*is_blackbox=*/module->get_bool_attribute(ID(cxxrtl.blackbox)));
}
std::string mangle(const RTLIL::Memory *memory)
@@ -549,7 +581,8 @@ struct CxxrtlWorker {
if (is_elidable_cell(node.cell->type)) {
dump_cell_elided(node.cell);
} else {
- f << mangle(node.cell) << "." << mangle_wire_name(cell_wire_defs[node.cell][chunk.wire]) << ".curr";
+ const char *access = is_cxxrtl_blackbox_cell(node.cell) ? "->" : ".";
+ f << mangle(node.cell) << access << mangle_wire_name(cell_wire_defs[node.cell][chunk.wire]) << ".curr";
}
break;
default:
@@ -961,13 +994,14 @@ struct CxxrtlWorker {
// User cells
} else {
log_assert(cell->known());
+ const char *access = is_cxxrtl_blackbox_cell(cell) ? "->" : ".";
for (auto conn : cell->connections())
if (cell->input(conn.first)) {
- f << indent << mangle(cell) << "." << mangle_wire_name(conn.first) << ".next = ";
+ f << indent << mangle(cell) << access << mangle_wire_name(conn.first) << ".next = ";
dump_sigspec_rhs(conn.second);
f << ";\n";
}
- f << indent << mangle(cell) << ".eval();\n";
+ f << indent << mangle(cell) << access << "eval();\n";
for (auto conn : cell->connections()) {
if (conn.second.is_wire()) {
RTLIL::Wire *wire = conn.second.as_wire();
@@ -979,7 +1013,7 @@ struct CxxrtlWorker {
continue; // ignore disconnected ports
f << indent;
dump_sigspec_lhs(conn.second);
- f << " = " << mangle(cell) << "." << mangle_wire_name(conn.first) << ".curr;\n";
+ f << " = " << mangle(cell) << access << mangle_wire_name(conn.first) << ".curr;\n";
}
}
}
@@ -1212,27 +1246,73 @@ struct CxxrtlWorker {
dump_attrs(module);
f << "struct " << mangle(module) << " : public module {\n";
inc_indent();
- for (auto wire : module->wires())
- dump_wire(wire, /*is_local=*/false);
- f << "\n";
- bool has_memories = false;
- for (auto memory : module->memories) {
- dump_memory(module, memory.second);
- has_memories = true;
- }
- if (has_memories)
+ if (module->get_bool_attribute(ID(cxxrtl.blackbox))) {
+ for (auto wire : module->wires()) {
+ if (wire->port_id != 0)
+ dump_wire(wire, /*is_local=*/false);
+ }
f << "\n";
- bool has_cells = false;
- for (auto cell : module->cells()) {
- if (is_internal_cell(cell->type))
- continue;
- f << indent << mangle_module_name(cell->type) << " " << mangle(cell) << ";\n";
- has_cells = true;
- }
- if (has_cells)
+ } else {
+ for (auto wire : module->wires())
+ dump_wire(wire, /*is_local=*/false);
f << "\n";
+ bool has_memories = false;
+ for (auto memory : module->memories) {
+ dump_memory(module, memory.second);
+ has_memories = true;
+ }
+ if (has_memories)
+ f << "\n";
+ bool has_cells = false;
+ for (auto cell : module->cells()) {
+ if (is_internal_cell(cell->type))
+ continue;
+ dump_attrs(cell);
+ RTLIL::Module *cell_module = module->design->module(cell->type);
+ log_assert(cell_module != nullptr);
+ if (cell_module->get_bool_attribute(ID(cxxrtl.blackbox))) {
+ f << indent << "std::unique_ptr<" << mangle(cell_module) << "> " << mangle(cell) << " = ";
+ f << mangle(cell_module) << "::create(" << escape_cxx_string(cell->name.str()) << ", ";
+ if (!cell->parameters.empty()) {
+ f << "parameter_map({\n";
+ inc_indent();
+ for (auto param : cell->parameters) {
+ // All blackbox parameters should be in the public namespace already; strip leading slash
+ // to make it more convenient for blackbox implementations.
+ log_assert(param.first.begins_with("\\"));
+ f << indent << "{ " << escape_cxx_string(param.first.str().substr(1)) << ", ";
+ if (param.second.flags & RTLIL::CONST_FLAG_REAL) {
+ f << std::showpoint << std::stod(param.second.decode_string()) << std::noshowpoint;
+ } else if (param.second.flags & RTLIL::CONST_FLAG_STRING) {
+ f << escape_cxx_string(param.second.decode_string());
+ } else {
+ f << param.second.as_int(/*is_signed=*/param.second.flags & RTLIL::CONST_FLAG_SIGNED);
+ if (!(param.second.flags & RTLIL::CONST_FLAG_SIGNED))
+ f << "u";
+ }
+ f << " },\n";
+ }
+ dec_indent();
+ f << indent << "})";
+ } else {
+ f << "parameter_map()";
+ }
+ f << ");\n";
+ } else {
+ f << indent << mangle(cell_module) << " " << mangle(cell) << ";\n";
+ }
+ has_cells = true;
+ }
+ if (has_cells)
+ f << "\n";
+ }
f << indent << "void eval() override;\n";
f << indent << "bool commit() override;\n";
+ if (module->get_bool_attribute(ID(cxxrtl.blackbox))) {
+ f << "\n";
+ f << indent << "static std::unique_ptr<" << mangle(module) << "> ";
+ f << "create(std::string name, parameter_map parameters);\n";
+ }
dec_indent();
f << "}; // struct " << mangle(module) << "\n";
f << "\n";
@@ -1242,19 +1322,21 @@ struct CxxrtlWorker {
{
f << "void " << mangle(module) << "::eval() {\n";
inc_indent();
- for (auto wire : module->wires())
- dump_wire(wire, /*is_local=*/true);
- for (auto node : schedule[module]) {
- switch (node.type) {
- case FlowGraph::Node::Type::CONNECT:
- dump_connect(node.connect);
- break;
- case FlowGraph::Node::Type::CELL:
- dump_cell(node.cell);
- break;
- case FlowGraph::Node::Type::PROCESS:
- dump_process(node.process);
- break;
+ if (!module->get_bool_attribute(ID(cxxrtl.blackbox))) {
+ for (auto wire : module->wires())
+ dump_wire(wire, /*is_local=*/true);
+ for (auto node : schedule[module]) {
+ switch (node.type) {
+ case FlowGraph::Node::Type::CONNECT:
+ dump_connect(node.connect);
+ break;
+ case FlowGraph::Node::Type::CELL:
+ dump_cell(node.cell);
+ break;
+ case FlowGraph::Node::Type::PROCESS:
+ dump_process(node.process);
+ break;
+ }
}
}
for (auto sync_type : sync_types) {
@@ -1305,19 +1387,22 @@ struct CxxrtlWorker {
}
dec_indent();
f << indent << "}\n";
- } else {
+ } else if (!module->get_bool_attribute(ID(cxxrtl.blackbox)) || wire->port_id != 0) {
f << indent << "changed |= " << mangle(wire) << ".commit();\n";
}
}
- for (auto memory : module->memories) {
- if (!writable_memories[memory.second])
- continue;
- f << indent << "changed |= " << mangle(memory.second) << ".commit();\n";
- }
- for (auto cell : module->cells()) {
- if (is_internal_cell(cell->type))
- continue;
- f << indent << "changed |= " << mangle(cell) << ".commit();\n";
+ if (!module->get_bool_attribute(ID(cxxrtl.blackbox))) {
+ for (auto memory : module->memories) {
+ if (!writable_memories[memory.second])
+ continue;
+ f << indent << "changed |= " << mangle(memory.second) << ".commit();\n";
+ }
+ for (auto cell : module->cells()) {
+ if (is_internal_cell(cell->type))
+ continue;
+ const char *access = is_cxxrtl_blackbox_cell(cell) ? "->" : ".";
+ f << indent << "changed |= " << mangle(cell) << access << "commit();\n";
+ }
}
f << indent << "return changed;\n";
dec_indent();
@@ -1327,20 +1412,27 @@ struct CxxrtlWorker {
void dump_design(RTLIL::Design *design)
{
+ std::vector<RTLIL::Module*> modules;
TopoSort<RTLIL::Module*> topo_design;
for (auto module : design->modules()) {
- if (module->get_blackbox_attribute() || !design->selected_module(module))
+ if (!design->selected_module(module))
+ continue;
+ if (module->get_bool_attribute(ID(cxxrtl.blackbox)))
+ modules.push_back(module); // cxxrtl blackboxes first
+ if (module->get_blackbox_attribute() || module->get_bool_attribute(ID(cxxrtl.blackbox)))
continue;
- topo_design.node(module);
+ topo_design.node(module);
for (auto cell : module->cells()) {
- if (is_internal_cell(cell->type))
+ if (is_internal_cell(cell->type) || is_cxxrtl_blackbox_cell(cell))
continue;
- log_assert(design->has(cell->type));
- topo_design.edge(design->module(cell->type), module);
+ RTLIL::Module *cell_module = design->module(cell->type);
+ log_assert(cell_module != nullptr);
+ topo_design.edge(cell_module, module);
}
}
log_assert(topo_design.sort());
+ modules.insert(modules.end(), topo_design.sorted.begin(), topo_design.sorted.end());
if (split_intf) {
// The only thing more depraved than include guards, is mangling filenames to turn them into include guards.
@@ -1356,11 +1448,8 @@ struct CxxrtlWorker {
f << "\n";
f << "namespace " << design_ns << " {\n";
f << "\n";
- for (auto module : topo_design.sorted) {
- if (!design->selected_module(module))
- continue;
+ for (auto module : modules)
dump_module_intf(module);
- }
f << "} // namespace " << design_ns << "\n";
f << "\n";
f << "#endif\n";
@@ -1376,9 +1465,7 @@ struct CxxrtlWorker {
f << "\n";
f << "namespace " << design_ns << " {\n";
f << "\n";
- for (auto module : topo_design.sorted) {
- if (!design->selected_module(module))
- continue;
+ for (auto module : modules) {
if (!split_intf)
dump_module_intf(module);
dump_module_impl(module);
@@ -1416,10 +1503,39 @@ struct CxxrtlWorker {
if (!design->selected_module(module))
continue;
- FlowGraph flow;
SigMap &sigmap = sigmaps[module];
sigmap.set(module);
+ if (module->get_bool_attribute(ID(cxxrtl.blackbox))) {
+ for (auto port : module->ports) {
+ RTLIL::Wire *wire = module->wire(port);
+ if (wire->has_attribute(ID(cxxrtl.edge))) {
+ RTLIL::Const edge_attr = wire->attributes[ID(cxxrtl.edge)];
+ if (!(edge_attr.flags & RTLIL::CONST_FLAG_STRING) || (int)edge_attr.decode_string().size() != GetSize(wire))
+ log_cmd_error("Attribute `cxxrtl.edge' of port `%s.%s' is not a string with one character per bit.\n",
+ log_id(module), log_signal(wire));
+
+ std::string edges = wire->get_string_attribute(ID(cxxrtl.edge));
+ for (int i = 0; i < GetSize(wire); i++) {
+ RTLIL::SigSpec wire_sig = wire;
+ switch (edges[i]) {
+ case '-': break;
+ case 'p': register_edge_signal(sigmap, wire_sig[i], RTLIL::STp); break;
+ case 'n': register_edge_signal(sigmap, wire_sig[i], RTLIL::STn); break;
+ case 'a': register_edge_signal(sigmap, wire_sig[i], RTLIL::STe); break;
+ default:
+ log_cmd_error("Attribute `cxxrtl.edge' of port `%s.%s' contains specifiers "
+ "other than '-', 'p', 'n', or 'a'.\n",
+ log_id(module), log_signal(wire));
+ }
+ }
+ }
+ }
+ continue;
+ }
+
+ FlowGraph flow;
+
for (auto conn : module->connections())
flow.add_node(conn);
@@ -1427,6 +1543,13 @@ struct CxxrtlWorker {
dict<std::pair<RTLIL::SigBit, const RTLIL::Memory*>,
pool<const RTLIL::Cell*>> memwr_per_domain;
for (auto cell : module->cells()) {
+ if (!cell->known())
+ log_cmd_error("Unknown cell `%s'.\n", log_id(cell->type));
+
+ RTLIL::Module *cell_module = design->module(cell->type);
+ if (cell_module && cell_module->get_blackbox_attribute() && !cell_module->get_bool_attribute(ID(cxxrtl.blackbox)))
+ log_cmd_error("External blackbox cell `%s' is not marked as a CXXRTL blackbox.\n", log_id(cell->type));
+
FlowGraph::Node *node = flow.add_node(cell);
// Various DFF cells are treated like posedge/negedge processes, see above for details.
@@ -1564,7 +1687,7 @@ struct CxxrtlWorker {
if (!feedback_wires.empty()) {
has_feedback_arcs = true;
- log("Module `%s` contains feedback arcs through wires:\n", module->name.c_str());
+ log("Module `%s' contains feedback arcs through wires:\n", module->name.c_str());
for (auto wire : feedback_wires) {
log(" %s\n", wire->name.c_str());
}
@@ -1592,12 +1715,12 @@ struct CxxrtlWorker {
has_sync_init = has_packed_mem = false;
for (auto module : design->modules()) {
- if (module->get_blackbox_attribute())
+ if (module->get_blackbox_attribute() && !module->has_attribute(ID(cxxrtl.blackbox)))
continue;
if (!design->selected_whole_module(module))
if (design->selected_module(module))
- log_cmd_error("Can't handle partially selected module `%s`!\n", id2cstr(module->name));
+ log_cmd_error("Can't handle partially selected module `%s'!\n", id2cstr(module->name));
if (!design->selected_module(module))
continue;
@@ -1649,7 +1772,7 @@ struct CxxrtlBackend : public Backend {
log("\n");
log(" write_cxxrtl [options] [filename]\n");
log("\n");
- log("Write C++ code for simulating the design. The generated code requires a driver\n");
+ log("Write C++ code that simulates the design. The generated code requires a driver\n");
log("that instantiates the design, toggles its clock, and interacts with its ports.\n");
log("\n");
log("The following driver may be used as an example for a design with a single clock\n");
@@ -1670,9 +1793,74 @@ struct CxxrtlBackend : public Backend {
log(" }\n");
log("\n");
log("Note that CXXRTL simulations, just like the hardware they are simulating, are\n");
- log("subject to race conditions. If, in then example above, the user logic would run\n");
+ log("subject to race conditions. If, in the example above, the user logic would run\n");
log("simultaneously with the rising edge of the clock, the design would malfunction.\n");
log("\n");
+ log("This backend supports replacing parts of the design with black boxes implemented\n");
+ log("in C++. If a module marked as a CXXRTL black box, its implementation is ignored,\n");
+ log("and the generated code consists only of an interface and a factory function.\n");
+ log("The driver must implement the factory function that creates an implementation of\n");
+ log("the black box, taking into account the parameters it is instantiated with.\n");
+ log("\n");
+ log("For example, the following Verilog code defines a CXXRTL black box interface for\n");
+ log("a synchronous debug sink:\n");
+ log("\n");
+ log(" (* cxxrtl.blackbox *)\n");
+ log(" module debug(...);\n");
+ log(" (* cxxrtl.edge = \"p\" *) input clk;\n");
+ log(" input en;\n");
+ log(" input [7:0] data;\n");
+ log(" endmodule\n");
+ log("\n");
+ log("For this HDL interface, this backend will generate the following C++ interface:\n");
+ log("\n");
+ log(" struct bb_debug : public module {\n");
+ log(" wire<1> p_clk;\n");
+ log(" bool posedge_p_clk = false;\n");
+ log(" wire<1> p_en;\n");
+ log(" wire<8> p_data;\n");
+ log("\n");
+ log(" void eval() override;\n");
+ log(" bool commit() override;\n");
+ log("\n");
+ log(" static std::unique_ptr<bb_debug> create(std::string name,\n");
+ log(" parameter_map parameters);\n");
+ log(" };\n");
+ log("\n");
+ log("The `create' function must be implemented by the driver. For example, it could\n");
+ log("always provide an implementation logging the values to standard error stream:\n");
+ log("\n");
+ log(" namespace cxxrtl_design {\n");
+ log("\n");
+ log(" struct stderr_debug : public bb_debug {\n");
+ log(" void eval() override {\n");
+ log(" if (posedge_p_clk && p_en.curr)\n");
+ log(" fprintf(stderr, \"debug: %%02x\\n\", p_data.curr.data[0]);\n");
+ log(" bb_debug::eval();\n");
+ log(" }\n");
+ log(" };\n");
+ log("\n");
+ log(" std::unique_ptr<bb_debug>\n");
+ log(" bb_debug::create(std::string name, cxxrtl::parameter_map parameters) {\n");
+ log(" return std::make_unique<stderr_debug>();\n");
+ log(" }\n");
+ log("\n");
+ log(" }\n");
+ log("\n");
+ log("The following attributes are recognized by this backend:\n");
+ log("\n");
+ log(" cxxrtl.blackbox\n");
+ log(" only valid on modules. if specified, the module contents are ignored,\n");
+ log(" and the generated code includes only the module interface and a factory\n");
+ log(" function, which will be called to instantiate the module.\n");
+ log("\n");
+ log(" cxxrtl.edge\n");
+ log(" only valid on inputs of black boxes. must be one of \"p\", \"n\", \"a\".\n");
+ log(" if specified on signal `clk`, the generated code includes boolean fields\n");
+ log(" `posedge_p_clk` (if \"p\"), `negedge_p_clk` (if \"n\"), or both (if \"a\"),\n");
+ log(" as well as edge detection logic, simplifying implementation of clocked\n");
+ log(" black boxes.\n");
+ log("\n");
log("The following options are supported by this backend:\n");
log("\n");
log(" -header\n");
diff --git a/backends/cxxrtl/cxxrtl.h b/backends/cxxrtl/cxxrtl.h
index fd390db79..0b330fa8f 100644
--- a/backends/cxxrtl/cxxrtl.h
+++ b/backends/cxxrtl/cxxrtl.h
@@ -28,7 +28,9 @@
#include <type_traits>
#include <tuple>
#include <vector>
+#include <map>
#include <algorithm>
+#include <memory>
#include <sstream>
// The cxxrtl support library implements compile time specialized arbitrary width arithmetics, as well as provides
@@ -657,6 +659,57 @@ struct memory {
}
};
+struct parameter {
+ const enum {
+ MISSING = 0,
+ UINT = 1,
+ SINT = 2,
+ STRING = 3,
+ DOUBLE = 4,
+ } value_type;
+
+ // In debug mode, using the wrong .as_*() function will assert.
+ // In release mode, using the wrong .as_*() function will safely return a default value.
+ union {
+ const unsigned uint_value = 0;
+ const signed sint_value;
+ };
+ const std::string string_value = "";
+ const double double_value = 0.0;
+
+ parameter() : value_type(MISSING) {}
+ parameter(unsigned value) : value_type(UINT), uint_value(value) {}
+ parameter(signed value) : value_type(SINT), sint_value(value) {}
+ parameter(const std::string &value) : value_type(STRING), string_value(value) {}
+ parameter(const char *value) : value_type(STRING), string_value(value) {}
+ parameter(double value) : value_type(DOUBLE), double_value(value) {}
+
+ parameter(const parameter &) = default;
+ parameter &operator=(const parameter &) = delete;
+
+ unsigned as_uint() const {
+ assert(value_type == UINT);
+ return uint_value;
+ }
+
+ signed as_sint() const {
+ assert(value_type == SINT);
+ return sint_value;
+ }
+
+ const std::string &as_string() const {
+ assert(value_type == STRING);
+ return string_value;
+ }
+
+ double as_double() const {
+ assert(value_type == DOUBLE);
+ return double_value;
+ }
+};
+
+typedef std::map<std::string, parameter> parameter_map;
+
struct module {
module() {}
virtual ~module() {}
generated by cgit v1.2.3 (git 2.25.1) at 2025-04-02 14:21:56 +0000