From 12ace45b89035e128ba41b10938ed2665ae30c2a Mon Sep 17 00:00:00 2001 From: Gus Smith Date: Wed, 22 Jun 2022 10:57:46 -0700 Subject: [PATCH 1/6] Support param. default values in JSON FE and SV BE --- abc | 2 +- backends/verilog/verilog_backend.cc | 11 +++++++++++ frontends/json/jsonparse.cc | 3 +++ 3 files changed, 15 insertions(+), 1 deletion(-) diff --git a/abc b/abc index 734f64d5b..799ba6322 160000 --- a/abc +++ b/abc @@ -1 +1 @@ -Subproject commit 734f64d5b907158dc4337ee82b3b74566d74ba08 +Subproject commit 799ba632239b2a4db2bacda81de4e6efdc486b0c diff --git a/backends/verilog/verilog_backend.cc b/backends/verilog/verilog_backend.cc index 3d451117c..b3029b051 100644 --- a/backends/verilog/verilog_backend.cc +++ b/backends/verilog/verilog_backend.cc @@ -421,6 +421,14 @@ void dump_attributes(std::ostream &f, std::string indent, dictattributes, "\n", /*modattr=*/false, /*regattr=*/reg_wires.count(wire->name)); @@ -2438,6 +2446,9 @@ void dump_module(std::ostream &f, std::string indent, RTLIL::Module *module) f << indent + " " << "reg " << id(initial_id) << " = 0;\n"; } + for (auto p : module->parameter_default_values) + dump_parameter(f, indent + " ", p.first, p.second); + // first dump input / output according to their order in module->ports for (auto port : module->ports) dump_wire(f, indent + " ", module->wire(port)); diff --git a/frontends/json/jsonparse.cc b/frontends/json/jsonparse.cc index 743ac5d9e..803931f32 100644 --- a/frontends/json/jsonparse.cc +++ b/frontends/json/jsonparse.cc @@ -302,6 +302,9 @@ void json_import(Design *design, string &modname, JsonNode *node) if (node->data_dict.count("attributes")) json_parse_attr_param(module->attributes, node->data_dict.at("attributes")); + if (node->data_dict.count("parameter_default_values")) + json_parse_attr_param(module->parameter_default_values, node->data_dict.at("parameter_default_values")); + dict signal_bits; if (node->data_dict.count("ports")) From 9ad7aed4a53e3467a89808544a2ac8701c6a5c9f Mon Sep 17 00:00:00 2001 From: Gus Smith Date: Tue, 6 Jan 2026 09:37:13 -0800 Subject: [PATCH 2/6] Update backends/verilog/verilog_backend.cc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Co-authored-by: Marcelina Kościelnicka <236399+mwkmwkmwk@users.noreply.github.com> --- backends/verilog/verilog_backend.cc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/backends/verilog/verilog_backend.cc b/backends/verilog/verilog_backend.cc index b3029b051..6284cdf33 100644 --- a/backends/verilog/verilog_backend.cc +++ b/backends/verilog/verilog_backend.cc @@ -426,7 +426,7 @@ void dump_parameter(std::ostream &f, std::string indent, RTLIL::IdString id_stri f << stringf("%sparameter %s", indent.c_str(), id(id_string).c_str()); f << stringf(" = "); dump_const(f, parameter); - f << stringf(";\n"); + f << ";\n"; } void dump_wire(std::ostream &f, std::string indent, RTLIL::Wire *wire) From 1ede98797f7eee220cba4fad695e41cdec05684e Mon Sep 17 00:00:00 2001 From: Gus Smith Date: Tue, 6 Jan 2026 09:37:21 -0800 Subject: [PATCH 3/6] Update backends/verilog/verilog_backend.cc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Co-authored-by: Marcelina Kościelnicka <236399+mwkmwkmwk@users.noreply.github.com> --- backends/verilog/verilog_backend.cc | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/backends/verilog/verilog_backend.cc b/backends/verilog/verilog_backend.cc index 6284cdf33..13f6acec4 100644 --- a/backends/verilog/verilog_backend.cc +++ b/backends/verilog/verilog_backend.cc @@ -423,8 +423,7 @@ void dump_attributes(std::ostream &f, std::string indent, dict Date: Tue, 6 Jan 2026 10:38:03 -0800 Subject: [PATCH 4/6] Add tests --- tests/various/json_param_defaults.v | 10 ++++++++++ tests/various/json_param_defaults.ys | 8 ++++++++ 2 files changed, 18 insertions(+) create mode 100644 tests/various/json_param_defaults.v create mode 100644 tests/various/json_param_defaults.ys diff --git a/tests/various/json_param_defaults.v b/tests/various/json_param_defaults.v new file mode 100644 index 000000000..7d3b94a68 --- /dev/null +++ b/tests/various/json_param_defaults.v @@ -0,0 +1,10 @@ +module json_param_defaults #( + parameter WIDTH = 8, + parameter SIGNED = 1 +) ( + input [WIDTH-1:0] a, + output [WIDTH-1:0] y +); + wire [WIDTH-1:0] y_int = a << SIGNED; + assign y = y_int; +endmodule diff --git a/tests/various/json_param_defaults.ys b/tests/various/json_param_defaults.ys new file mode 100644 index 000000000..2624ab884 --- /dev/null +++ b/tests/various/json_param_defaults.ys @@ -0,0 +1,8 @@ +! mkdir -p temp +read_verilog -sv json_param_defaults.v +write_json temp/json_param_defaults.json +design -reset +read_json temp/json_param_defaults.json +write_verilog -noattr temp/json_param_defaults.v +! grep -qF "parameter WIDTH = 32'd8" temp/json_param_defaults.v +! grep -qF "parameter SIGNED = 32'd1" temp/json_param_defaults.v From be9c857e7252751b77bc1548fdbde0f11906a1e8 Mon Sep 17 00:00:00 2001 From: Gus Smith Date: Wed, 11 Feb 2026 08:12:38 -0800 Subject: [PATCH 5/6] Fix ABC after merge --- abc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/abc b/abc index 799ba6322..734f64d5b 160000 --- a/abc +++ b/abc @@ -1 +1 @@ -Subproject commit 799ba632239b2a4db2bacda81de4e6efdc486b0c +Subproject commit 734f64d5b907158dc4337ee82b3b74566d74ba08 From 7a0774c3bb200d8b5d3278c7c69f9e5d893af43c Mon Sep 17 00:00:00 2001 From: Gus Smith Date: Wed, 11 Feb 2026 08:33:39 -0800 Subject: [PATCH 6/6] Don't dump params by default --- backends/verilog/verilog_backend.cc | 17 ++++++++++++++--- tests/various/json_param_defaults.ys | 2 +- 2 files changed, 15 insertions(+), 4 deletions(-) diff --git a/backends/verilog/verilog_backend.cc b/backends/verilog/verilog_backend.cc index 13f6acec4..73ffcbf3e 100644 --- a/backends/verilog/verilog_backend.cc +++ b/backends/verilog/verilog_backend.cc @@ -95,7 +95,8 @@ bool VERILOG_BACKEND::id_is_verilog_escaped(const std::string &str) { PRIVATE_NAMESPACE_BEGIN -bool verbose, norename, noattr, attr2comment, noexpr, nodec, nohex, nostr, extmem, defparam, decimal, siminit, systemverilog, simple_lhs, noparallelcase; +bool verbose, norename, noattr, attr2comment, noexpr, nodec, nohex, nostr, extmem, defparam, decimal, siminit, systemverilog, simple_lhs, + noparallelcase, default_params; int auto_name_counter, auto_name_offset, auto_name_digits, extmem_counter; dict auto_name_map; std::set reg_wires; @@ -2445,8 +2446,9 @@ void dump_module(std::ostream &f, std::string indent, RTLIL::Module *module) f << indent + " " << "reg " << id(initial_id) << " = 0;\n"; } - for (auto p : module->parameter_default_values) - dump_parameter(f, indent + " ", p.first, p.second); + if (default_params) + for (auto p : module->parameter_default_values) + dump_parameter(f, indent + " ", p.first, p.second); // first dump input / output according to their order in module->ports for (auto port : module->ports) @@ -2555,6 +2557,10 @@ struct VerilogBackend : public Backend { log(" use 'defparam' statements instead of the Verilog-2001 syntax for\n"); log(" cell parameters.\n"); log("\n"); + log(" -default_params\n"); + log(" emit module parameter declarations from\n"); + log(" parameter_default_values.\n"); + log("\n"); log(" -blackboxes\n"); log(" usually modules with the 'blackbox' attribute are ignored. with\n"); log(" this option set only the modules with the 'blackbox' attribute\n"); @@ -2592,6 +2598,7 @@ struct VerilogBackend : public Backend { siminit = false; simple_lhs = false; noparallelcase = false; + default_params = false; auto_prefix = ""; bool blackboxes = false; @@ -2652,6 +2659,10 @@ struct VerilogBackend : public Backend { defparam = true; continue; } + if (arg == "-defaultparams") { + default_params = true; + continue; + } if (arg == "-decimal") { decimal = true; continue; diff --git a/tests/various/json_param_defaults.ys b/tests/various/json_param_defaults.ys index 2624ab884..45e312de2 100644 --- a/tests/various/json_param_defaults.ys +++ b/tests/various/json_param_defaults.ys @@ -3,6 +3,6 @@ read_verilog -sv json_param_defaults.v write_json temp/json_param_defaults.json design -reset read_json temp/json_param_defaults.json -write_verilog -noattr temp/json_param_defaults.v +write_verilog -noattr -defaultparams temp/json_param_defaults.v ! grep -qF "parameter WIDTH = 32'd8" temp/json_param_defaults.v ! grep -qF "parameter SIGNED = 32'd1" temp/json_param_defaults.v