Merge pull request #659 from rubund/sv_interfaces

Support for SystemVerilog interfaces and modports

4 files changed, 265 insertions, 14 deletions

diff --git a/frontends/ast/ast.cc b/frontends/ast/ast.cc
index e79be953a..7600e2912 100644
--- a/frontends/ast/ast.cc
+++ b/frontends/ast/ast.cc
@@ -2,6 +2,7 @@
  *  yosys -- Yosys Open SYnthesis Suite
  *
  *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *  Copyright (C) 2018  Ruben Undheim <ruben.undheim@gmail.com>
  *
  *  Permission to use, copy, modify, and/or distribute this software for any
  *  purpose with or without fee is hereby granted, provided that the above
@@ -905,7 +906,7 @@ RTLIL::Const AstNode::realAsConst(int width)
 // create a new AstModule from an AST_MODULE AST node
 static AstModule* process_module(AstNode *ast, bool defer)
 {
-	log_assert(ast->type == AST_MODULE);
+	log_assert(ast->type == AST_MODULE || ast->type == AST_INTERFACE);
 
 	if (defer)
 		log("Storing AST representation for module `%s'.\n", ast->str.c_str());
@@ -916,6 +917,7 @@ static AstModule* process_module(AstNode *ast, bool defer)
 	current_module->ast = NULL;
 	current_module->name = ast->str;
 	current_module->attributes["\\src"] = stringf("%s:%d", ast->filename.c_str(), ast->linenum);
+	current_module->set_bool_attribute("\\cells_not_processed");
 
 	current_ast_mod = ast;
 	AstNode *ast_before_simplify = ast->clone();
@@ -989,6 +991,8 @@ static AstModule* process_module(AstNode *ast, bool defer)
 		ignoreThisSignalsInInitial = RTLIL::SigSpec();
 	}
 
+	if (ast->type == AST_INTERFACE)
+		current_module->set_bool_attribute("\\is_interface");
 	current_module->ast = ast_before_simplify;
 	current_module->nolatches = flag_nolatches;
 	current_module->nomeminit = flag_nomeminit;
@@ -1031,7 +1035,7 @@ void AST::process(RTLIL::Design *design, AstNode *ast, bool dump_ast1, bool dump
 	log_assert(current_ast->type == AST_DESIGN);
 	for (auto it = current_ast->children.begin(); it != current_ast->children.end(); it++)
 	{
-		if ((*it)->type == AST_MODULE)
+		if ((*it)->type == AST_MODULE || (*it)->type == AST_INTERFACE)
 		{
 			for (auto n : design->verilog_globals)
 				(*it)->children.push_back(n->clone());
@@ -1083,8 +1087,179 @@ AstModule::~AstModule()
 		delete ast;
 }
 
+// When an interface instance is found in a module, the whole RTLIL for the module will be rederived again
+// from AST. The interface members are copied into the AST module with the prefix of the interface.
+void AstModule::reprocess_module(RTLIL::Design *design, dict<RTLIL::IdString, RTLIL::Module*> local_interfaces)
+{
+	bool is_top = false;
+	AstNode *new_ast = ast->clone();
+	for (auto &intf : local_interfaces) {
+		std::string intfname = intf.first.str();
+		RTLIL::Module *intfmodule = intf.second;
+		for (auto &wire_it : intfmodule->wires_){
+			AstNode *wire = new AstNode(AST_WIRE, new AstNode(AST_RANGE, AstNode::mkconst_int(wire_it.second->width -1, true), AstNode::mkconst_int(0, true)));
+			std::string newname = log_id(wire_it.first);
+			newname = intfname + "." + newname;
+			wire->str = newname;
+			new_ast->children.push_back(wire);
+		}
+	}
+
+	// The old module will be deleted. Rename and mark for deletion:
+	std::string original_name = this->name.str();
+	std::string changed_name = original_name + "_before_replacing_local_interfaces";
+	design->rename(this, changed_name);
+	this->set_bool_attribute("\\to_delete");
+
+	// Check if the module was the top module. If it was, we need to remove the top attribute and put it on the
+	// new module.
+	if (this->get_bool_attribute("\\initial_top")) {
+		this->attributes.erase("\\initial_top");
+		is_top = true;
+	}
+
+	// Generate RTLIL from AST for the new module and add to the design:
+	AstModule *newmod = process_module(new_ast, false);
+	design->add(newmod);
+	RTLIL::Module* mod = design->module(original_name);
+	if (is_top)
+		mod->set_bool_attribute("\\top");
+
+	// Set the attribute "interfaces_replaced_in_module" so that it does not happen again.
+	mod->set_bool_attribute("\\interfaces_replaced_in_module");
+}
+
+// create a new parametric module (when needed) and return the name of the generated module - WITH support for interfaces
+// This method is used to explode the interface when the interface is a port of the module (not instantiated inside)
+RTLIL::IdString AstModule::derive(RTLIL::Design *design, dict<RTLIL::IdString, RTLIL::Const> parameters, dict<RTLIL::IdString, RTLIL::Module*> interfaces, dict<RTLIL::IdString, RTLIL::IdString> modports, bool mayfail)
+{
+	AstNode *new_ast = NULL;
+	std::string modname = derive_common(design, parameters, &new_ast, mayfail);
+
+	// Since interfaces themselves may be instantiated with different parameters,
+	// "modname" must also take those into account, so that unique modules
+	// are derived for any variant of interface connections:
+	std::string interf_info = "";
+
+	bool has_interfaces = false;
+	for(auto &intf : interfaces) {
+		interf_info += log_id(intf.second->name);
+		has_interfaces = true;
+	}
+
+	if (has_interfaces)
+		modname += "$interfaces$" + interf_info;
+
+
+	if (!design->has(modname)) {
+		new_ast->str = modname;
+
+		// Iterate over all interfaces which are ports in this module:
+		for(auto &intf : interfaces) {
+			RTLIL::Module * intfmodule = intf.second;
+			std::string intfname = intf.first.str();
+			// Check if a modport applies for the interface port:
+			AstNode *modport = NULL;
+			if (modports.count(intfname) > 0) {
+				std::string interface_modport = modports.at(intfname).str();
+				AstModule *ast_module_of_interface = (AstModule*)intfmodule;
+				AstNode *ast_node_of_interface = ast_module_of_interface->ast;
+				for (auto &ch : ast_node_of_interface->children) {
+					if (ch->type == AST_MODPORT) {
+						if (ch->str == interface_modport) { // Modport found
+							modport = ch;
+						}
+					}
+				}
+			}
+			// Iterate over all wires in the interface and add them to the module:
+			for (auto &wire_it : intfmodule->wires_){
+				AstNode *wire = new AstNode(AST_WIRE, new AstNode(AST_RANGE, AstNode::mkconst_int(wire_it.second->width -1, true), AstNode::mkconst_int(0, true)));
+				std::string origname = log_id(wire_it.first);
+				std::string newname = intfname + "." + origname;
+				wire->str = newname;
+				if (modport != NULL) {
+					bool found_in_modport = false;
+					// Search for the current wire in the wire list for the current modport
+					for (auto &ch : modport->children) {
+						if (ch->type == AST_MODPORTMEMBER) {
+							std::string compare_name = "\\" + origname;
+							if (ch->str == compare_name) { // Found signal. The modport decides whether it is input or output
+								found_in_modport = true;
+								wire->is_input = ch->is_input;
+								wire->is_output = ch->is_output;
+								break;
+							}
+						}
+					}
+					if (found_in_modport) {
+						new_ast->children.push_back(wire);
+					}
+					else { // If not found in modport, do not create port
+						delete wire;
+					}
+				}
+				else { // If no modport, set inout
+					wire->is_input = true;
+					wire->is_output = true;
+					new_ast->children.push_back(wire);
+				}
+			}
+		}
+
+		design->add(process_module(new_ast, false));
+		design->module(modname)->check();
+
+		RTLIL::Module* mod = design->module(modname);
+
+		// Now that the interfaces have been exploded, we can delete the dummy port related to every interface.
+		for(auto &intf : interfaces) {
+			if(mod->wires_.count(intf.first)) {
+				mod->wires_.erase(intf.first);
+				mod->fixup_ports();
+				// We copy the cell of the interface to the sub-module such that it can further be found if it is propagated
+				// down to sub-sub-modules etc.
+				RTLIL::Cell * new_subcell = mod->addCell(intf.first, intf.second->name);
+				new_subcell->set_bool_attribute("\\is_interface");
+			}
+			else {
+				log_error("No port with matching name found (%s) in %s. Stopping\n", log_id(intf.first), modname.c_str());
+			}
+		}
+
+		// If any interfaces were replaced, set the attribute 'interfaces_replaced_in_module':
+		if (interfaces.size() > 0) {
+			mod->set_bool_attribute("\\interfaces_replaced_in_module");
+		}
+
+	} else {
+		log("Found cached RTLIL representation for module `%s'.\n", modname.c_str());
+	}
+
+	delete new_ast;
+	return modname;
+}
+
+// create a new parametric module (when needed) and return the name of the generated module - without support for interfaces
+RTLIL::IdString AstModule::derive(RTLIL::Design *design, dict<RTLIL::IdString, RTLIL::Const> parameters, bool mayfail)
+{
+	AstNode *new_ast = NULL;
+	std::string modname = derive_common(design, parameters, &new_ast, mayfail);
+
+	if (!design->has(modname)) {
+		new_ast->str = modname;
+		design->add(process_module(new_ast, false));
+		design->module(modname)->check();
+	} else {
+		log("Found cached RTLIL representation for module `%s'.\n", modname.c_str());
+	}
+
+	delete new_ast;
+	return modname;
+}
+
 // create a new parametric module (when needed) and return the name of the generated module
-RTLIL::IdString AstModule::derive(RTLIL::Design *design, dict<RTLIL::IdString, RTLIL::Const> parameters, bool)
+std::string AstModule::derive_common(RTLIL::Design *design, dict<RTLIL::IdString, RTLIL::Const> parameters, AstNode **new_ast_out, bool)
 {
 	std::string stripped_name = name.str();
 
@@ -1156,15 +1331,8 @@ RTLIL::IdString AstModule::derive(RTLIL::Design *design, dict<RTLIL::IdString, R
 	else
 		modname = "$paramod" + stripped_name + para_info;
 
-	if (!design->has(modname)) {
-		new_ast->str = modname;
-		design->add(process_module(new_ast, false));
-		design->module(modname)->check();
-	} else {
-		log("Found cached RTLIL representation for module `%s'.\n", modname.c_str());
-	}
 
-	delete new_ast;
+	(*new_ast_out) = new_ast;
 	return modname;
 }
 
diff --git a/frontends/ast/ast.h b/frontends/ast/ast.h
index 7e97bdb3b..8187b1ac6 100644
--- a/frontends/ast/ast.h
+++ b/frontends/ast/ast.h
@@ -142,6 +142,11 @@ namespace AST
 		AST_NEGEDGE,
 		AST_EDGE,
 
+		AST_INTERFACE,
+		AST_INTERFACEPORT,
+		AST_INTERFACEPORTTYPE,
+		AST_MODPORT,
+		AST_MODPORTMEMBER,
 		AST_PACKAGE
 	};
 
@@ -284,6 +289,9 @@ namespace AST
 		bool nolatches, nomeminit, nomem2reg, mem2reg, lib, noopt, icells, autowire;
 		~AstModule() YS_OVERRIDE;
 		RTLIL::IdString derive(RTLIL::Design *design, dict<RTLIL::IdString, RTLIL::Const> parameters, bool mayfail) YS_OVERRIDE;
+		RTLIL::IdString derive(RTLIL::Design *design, dict<RTLIL::IdString, RTLIL::Const> parameters, dict<RTLIL::IdString, RTLIL::Module*> interfaces, dict<RTLIL::IdString, RTLIL::IdString> modports, bool mayfail) YS_OVERRIDE;
+		std::string derive_common(RTLIL::Design *design, dict<RTLIL::IdString, RTLIL::Const> parameters, AstNode **new_ast_out, bool mayfail);
+		void reprocess_module(RTLIL::Design *design, dict<RTLIL::IdString, RTLIL::Module *> local_interfaces) YS_OVERRIDE;
 		RTLIL::Module *clone() const YS_OVERRIDE;
 	};
 
diff --git a/frontends/ast/genrtlil.cc b/frontends/ast/genrtlil.cc
index c9345ff08..32b9af6e9 100644
--- a/frontends/ast/genrtlil.cc
+++ b/frontends/ast/genrtlil.cc
@@ -853,6 +853,52 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint)
 	case AST_GENIF:
 	case AST_GENCASE:
 	case AST_PACKAGE:
+	case AST_MODPORT:
+	case AST_MODPORTMEMBER:
+		break;
+	case AST_INTERFACEPORT: {
+		// If a port in a module with unknown type is found, mark it with the attribute 'is_interface'
+		// This is used by the hierarchy pass to know when it can replace interface connection with the individual
+		// signals.
+		RTLIL::Wire *wire = current_module->addWire(str, 1);
+		wire->attributes["\\src"] = stringf("%s:%d", filename.c_str(), linenum);
+		wire->start_offset = 0;
+		wire->port_id = port_id;
+		wire->port_input = true;
+		wire->port_output = true;
+		wire->set_bool_attribute("\\is_interface");
+		if (children.size() > 0) {
+			for(size_t i=0; i<children.size();i++) {
+				if(children[i]->type == AST_INTERFACEPORTTYPE) {
+					std::string name_type = children[i]->str;
+					size_t ndots = std::count(name_type.begin(), name_type.end(), '.');
+					// Separate the interface instance name from any modports:
+					if (ndots == 0) { // Does not have modport
+						wire->attributes["\\interface_type"] = name_type;
+					}
+					else {
+						std::stringstream name_type_stream(name_type);
+						std::string segment;
+						std::vector<std::string> seglist;
+						while(std::getline(name_type_stream, segment, '.')) {
+							seglist.push_back(segment);
+						}
+						if (ndots == 1) { // Has modport
+							wire->attributes["\\interface_type"] = seglist[0];
+							wire->attributes["\\interface_modport"] = seglist[1];
+						}
+						else { // Erroneous port type
+							log_error("More than two '.' in signal port type (%s)\n", name_type.c_str());
+						}
+					}
+					break;
+				}
+			}
+		}
+		wire->upto = 0;
+		}
+		break;
+	case AST_INTERFACEPORTTYPE:
 		break;
 
 	// remember the parameter, needed for example in techmap
@@ -949,6 +995,7 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint)
 		{
 			RTLIL::Wire *wire = NULL;
 			RTLIL::SigChunk chunk;
+			bool is_interface = false;
 
 			int add_undef_bits_msb = 0;
 			int add_undef_bits_lsb = 0;
@@ -969,15 +1016,41 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint)
 				chunk = RTLIL::Const(id2ast->children[0]->bits);
 				goto use_const_chunk;
 			}
-			else if (!id2ast || (id2ast->type != AST_WIRE && id2ast->type != AST_AUTOWIRE &&
-					id2ast->type != AST_MEMORY) || current_module->wires_.count(str) == 0)
+			else if (id2ast && (id2ast->type == AST_WIRE || id2ast->type == AST_AUTOWIRE || id2ast->type == AST_MEMORY) && current_module->wires_.count(str) != 0) {
+				RTLIL::Wire *current_wire = current_module->wire(str);
+				if (current_wire->get_bool_attribute("\\is_interface"))
+					is_interface = true;
+				// Ignore
+			}
+			// If an identifier is found that is not already known, assume that it is an interface:
+			else if (1) { // FIXME: Check if sv_mode first?
+				is_interface = true;
+			}
+			else {
 				log_file_error(filename, linenum, "Identifier `%s' doesn't map to any signal!\n",
 						str.c_str());
+			}
 
 			if (id2ast->type == AST_MEMORY)
 				log_file_error(filename, linenum, "Identifier `%s' does map to an unexpanded memory!\n",
 					       str.c_str());
 
+			// If identifier is an interface, create a RTLIL::SigSpec with a dummy wire with a attribute called 'is_interface'
+			// This makes it possible for the hierarchy pass to see what are interface connections and then replace them
+			// with the individual signals:
+			if (is_interface) {
+				RTLIL::Wire *dummy_wire;
+				std::string dummy_wire_name = "$dummywireforinterface" + str;
+				if (current_module->wires_.count(dummy_wire_name))
+					dummy_wire = current_module->wires_[dummy_wire_name];
+				else {
+					dummy_wire = current_module->addWire(dummy_wire_name);
+					dummy_wire->set_bool_attribute("\\is_interface");
+				}
+				RTLIL::SigSpec tmp = RTLIL::SigSpec(dummy_wire);
+				return tmp;
+			}
+
 			wire = current_module->wires_[str];
 			chunk.wire = wire;
 			chunk.width = wire->width;
@@ -1423,6 +1496,8 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint)
 
 			RTLIL::Cell *cell = current_module->addCell(str, "");
 			cell->attributes["\\src"] = stringf("%s:%d", filename.c_str(), linenum);
+			// Set attribute 'module_not_derived' which will be cleared again after the hierarchy pass
+			cell->set_bool_attribute("\\module_not_derived");
 
 			for (auto it = children.begin(); it != children.end(); it++) {
 				AstNode *child = *it;
diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index dca9da198..e56a62563 100644
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -71,7 +71,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 
 	if (stage == 0)
 	{
-		log_assert(type == AST_MODULE);
+		log_assert(type == AST_MODULE || type == AST_INTERFACE);
 		last_blocking_assignment_warn = pair<string, int>();
 
 		deep_recursion_warning = true;