From 2cc4e75914eddcf8a850bb5b7ce7bcdb093fa75e Mon Sep 17 00:00:00 2001
From: Clifford Wolf <clifford@clifford.at>
Date: Sun, 17 May 2015 15:25:03 +0200
Subject: [PATCH] Added read_blif command

---
 frontends/blif/blifparse.cc | 32 +++++++++++++++++++++++++++++++-
 kernel/yosys.cc             |  2 ++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/frontends/blif/blifparse.cc b/frontends/blif/blifparse.cc
index fb71cee16..cc06dfbd3 100644
--- a/frontends/blif/blifparse.cc
+++ b/frontends/blif/blifparse.cc
@@ -133,7 +133,7 @@ void parse_blif(RTLIL::Design *design, std::istream &f, std::string dff_name)
 				continue;
 			}
 
-			if (!strcmp(cmd, ".gate"))
+			if (!strcmp(cmd, ".gate") || !strcmp(cmd, ".subckt"))
 			{
 				char *p = strtok(NULL, " \t\r\n");
 				if (p == NULL)
@@ -268,5 +268,35 @@ error:
 	log_error("Syntax error in line %d!\n", line_count);
 }
 
+struct BlifFrontend : public Frontend {
+	BlifFrontend() : Frontend("blif", "read BLIF file") { }
+	virtual void help()
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    read_blif [filename]\n");
+		log("\n");
+		log("Load modules from a BLIF file into the current design.\n");
+		log("\n");
+	}
+	virtual void execute(std::istream *&f, std::string filename, std::vector<std::string> args, RTLIL::Design *design)
+	{
+		log_header("Executing BLIF frontend.\n");
+
+		size_t argidx;
+		for (argidx = 1; argidx < args.size(); argidx++) {
+			std::string arg = args[argidx];
+			// if (arg == "-lib") {
+			// 	flag_lib = true;
+			// 	continue;
+			// }
+			break;
+		}
+		extra_args(f, filename, args, argidx);
+
+		parse_blif(design, *f, "\\DFF");
+	}
+} BlifFrontend;
+
 YOSYS_NAMESPACE_END
 
diff --git a/kernel/yosys.cc b/kernel/yosys.cc
index 1d6e7113b..d66f33b1e 100644
--- a/kernel/yosys.cc
+++ b/kernel/yosys.cc
@@ -746,6 +746,8 @@ void run_frontend(std::string filename, std::string command, std::string *backen
 			command = "verilog";
 		else if (filename.size() > 2 && filename.substr(filename.size()-3) == ".sv")
 			command = "verilog -sv";
+		else if (filename.size() > 4 && filename.substr(filename.size()-5) == ".blif")
+			command = "blif";
 		else if (filename.size() > 3 && filename.substr(filename.size()-3) == ".il")
 			command = "ilang";
 		else if (filename.size() > 3 && filename.substr(filename.size()-3) == ".ys")