Implemented correct handling of signed module parameters

3 files changed, 7 insertions, 3 deletions

diff --git a/frontends/ast/ast.cc b/frontends/ast/ast.cc
index 29093b830..6423cae22 100644
--- a/frontends/ast/ast.cc
+++ b/frontends/ast/ast.cc
@@ -792,7 +792,7 @@ AstModule::~AstModule()
 }
 
 // create a new parametric module (when needed) and return the name of the generated module
-RTLIL::IdString AstModule::derive(RTLIL::Design *design, std::map<RTLIL::IdString, RTLIL::Const> parameters)
+RTLIL::IdString AstModule::derive(RTLIL::Design *design, std::map<RTLIL::IdString, RTLIL::Const> parameters, std::set<RTLIL::IdString> signed_parameters)
 {
 	log_header("Executing AST frontend in derive mode using pre-parsed AST for module `%s'.\n", name.c_str());
 
@@ -826,7 +826,7 @@ RTLIL::IdString AstModule::derive(RTLIL::Design *design, std::map<RTLIL::IdStrin
 	rewrite_parameter:
 			para_info += stringf("%s=%s", child->str.c_str(), log_signal(RTLIL::SigSpec(parameters[para_id])));
 			delete child->children.at(0);
-			child->children[0] = AstNode::mkconst_bits(parameters[para_id].bits, child->is_signed);
+			child->children[0] = AstNode::mkconst_bits(parameters[para_id].bits, signed_parameters.count(para_id) > 0);
 			hash_data.insert(hash_data.end(), child->str.begin(), child->str.end());
 			hash_data.push_back(0);
 			hash_data.insert(hash_data.end(), parameters[para_id].bits.begin(), parameters[para_id].bits.end());
diff --git a/frontends/ast/ast.h b/frontends/ast/ast.h
index de32a2bb9..f9f47f6a4 100644
--- a/frontends/ast/ast.h
+++ b/frontends/ast/ast.h
@@ -227,7 +227,7 @@ namespace AST
 		AstNode *ast;
 		bool nolatches, nomem2reg, mem2reg, lib, noopt;
 		virtual ~AstModule();
-		virtual RTLIL::IdString derive(RTLIL::Design *design, std::map<RTLIL::IdString, RTLIL::Const> parameters);
+		virtual RTLIL::IdString derive(RTLIL::Design *design, std::map<RTLIL::IdString, RTLIL::Const> parameters, std::set<RTLIL::IdString> signed_parameters);
 		virtual void update_auto_wires(std::map<RTLIL::IdString, int> auto_sizes);
 		virtual RTLIL::Module *clone() const;
 	};
diff --git a/frontends/ast/genrtlil.cc b/frontends/ast/genrtlil.cc
index e634a27a9..177c1ec59 100644
--- a/frontends/ast/genrtlil.cc
+++ b/frontends/ast/genrtlil.cc
@@ -1309,9 +1309,13 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint)
 					if (child->str.size() == 0) {
 						char buf[100];
 						snprintf(buf, 100, "$%d", ++para_counter);
+						if (child->children[0]->is_signed)
+							cell->signed_parameters.insert(buf);
 						cell->parameters[buf].str = child->children[0]->str;
 						cell->parameters[buf].bits = child->children[0]->bits;
 					} else {
+						if (child->children[0]->is_signed)
+							cell->signed_parameters.insert(child->str);
 						cell->parameters[child->str].str = child->children[0]->str;
 						cell->parameters[child->str].bits = child->children[0]->bits;
 					}