From 984c6357baada3eded62e35a5847b6ff7e53c6c0 Mon Sep 17 00:00:00 2001
From: Akash Levy <akash@silimate.com>
Date: Sun, 30 Mar 2025 17:54:35 -0700
Subject: [PATCH] Add -word mode to lut2mux and improve the naming

---
 passes/techmap/lut2mux.cc | 40 +++++++++++++++++++++++++--------------
 1 file changed, 26 insertions(+), 14 deletions(-)

diff --git a/passes/techmap/lut2mux.cc b/passes/techmap/lut2mux.cc
index ef76e0deb..f0af19b29 100644
--- a/passes/techmap/lut2mux.cc
+++ b/passes/techmap/lut2mux.cc
@@ -23,7 +23,7 @@
 USING_YOSYS_NAMESPACE
 PRIVATE_NAMESPACE_BEGIN
 
-int lut2mux(Cell *cell)
+int lut2mux(Cell *cell, bool word_mode)
 {
 	SigSpec sig_a = cell->getPort(ID::A);
 	SigSpec sig_y = cell->getPort(ID::Y);
@@ -32,22 +32,28 @@ int lut2mux(Cell *cell)
 
 	if (GetSize(sig_a) == 1)
 	{
-		cell->module->addMuxGate(NEW_ID, lut.extract(0)[0], lut.extract(1)[0], sig_a, sig_y);
+		if (!word_mode)
+			cell->module->addMuxGate(NEW_ID2, lut.extract(0)[0], lut.extract(1)[0], sig_a, sig_y, cell->get_src_attribute()); // SILIMATE: Improve the naming
+		else
+			cell->module->addMux(NEW_ID2, lut.extract(0)[0], lut.extract(1)[0], sig_a, sig_y, cell->get_src_attribute()); // SILIMATE: Improve the naming
 	}
 	else
 	{
 		SigSpec sig_a_hi = sig_a[GetSize(sig_a)-1];
 		SigSpec sig_a_lo = sig_a.extract(0, GetSize(sig_a)-1);
-		SigSpec sig_y1 = cell->module->addWire(NEW_ID);
-		SigSpec sig_y2 = cell->module->addWire(NEW_ID);
+		SigSpec sig_y1 = cell->module->addWire(NEW_ID2); // SILIMATE: Improve the naming
+		SigSpec sig_y2 = cell->module->addWire(NEW_ID2); // SILIMATE: Improve the naming
 
 		Const lut1 = lut.extract(0, GetSize(lut)/2);
 		Const lut2 = lut.extract(GetSize(lut)/2, GetSize(lut)/2);
 
-		count += lut2mux(cell->module->addLut(NEW_ID, sig_a_lo, sig_y1, lut1));
-		count += lut2mux(cell->module->addLut(NEW_ID, sig_a_lo, sig_y2, lut2));
+		count += lut2mux(cell->module->addLut(NEW_ID2, sig_a_lo, sig_y1, lut1), word_mode); // SILIMATE: Improve the naming
+		count += lut2mux(cell->module->addLut(NEW_ID2, sig_a_lo, sig_y2, lut2), word_mode); // SILIMATE: Improve the naming
 
-		cell->module->addMuxGate(NEW_ID, sig_y1, sig_y2, sig_a_hi, sig_y);
+		if (!word_mode)
+			cell->module->addMuxGate(NEW_ID2, sig_y1, sig_y2, sig_a_hi, sig_y, cell->get_src_attribute()); // SILIMATE: Improve the naming
+		else
+			cell->module->addMux(NEW_ID2, sig_y1, sig_y2, sig_a_hi, sig_y, cell->get_src_attribute()); // SILIMATE: Improve the naming
 	}
 
 	cell->module->remove(cell);
@@ -55,26 +61,32 @@ int lut2mux(Cell *cell)
 }
 
 struct Lut2muxPass : public Pass {
-	Lut2muxPass() : Pass("lut2mux", "convert $lut to $_MUX_") { }
+	Lut2muxPass() : Pass("lut2mux", "convert $lut to $mux/$_MUX_") { }
 	void help() override
 	{
 		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
 		log("\n");
 		log("    lut2mux [options] [selection]\n");
 		log("\n");
-		log("This pass converts $lut cells to $_MUX_ gates.\n");
+		log("This pass converts $lut cells to $mux/$_MUX_ gates.\n");
+		log("\n");
+		log("    -word\n");
+		log("        Convert $lut cells with a single input to word-level $mux gates.\n");
+		log("   	   The default is to convert them to bit-level $_MUX_ gates.\n");
 		log("\n");
 	}
 	void execute(std::vector<std::string> args, RTLIL::Design *design) override
 	{
-		log_header(design, "Executing LUT2MUX pass (convert $lut to $_MUX_).\n");
+		log_header(design, "Executing LUT2MUX pass (convert $lut to $mux/$_MUX_).\n");
 
 		size_t argidx;
+		bool word_mode = false;
 		for (argidx = 1; argidx < args.size(); argidx++)
 		{
-			// if (args[argidx] == "-v") {
-			// 	continue;
-			// }
+			if (args[argidx] == "-word") {
+				word_mode = true;
+				continue;
+			}
 			break;
 		}
 		extra_args(args, argidx, design);
@@ -83,7 +95,7 @@ struct Lut2muxPass : public Pass {
 		for (auto cell : module->selected_cells()) {
 			if (cell->type == ID($lut)) {
 				IdString cell_name = cell->name;
-				int count = lut2mux(cell);
+				int count = lut2mux(cell, word_mode);
 				log("Converted %s.%s to %d MUX cells.\n", log_id(module), log_id(cell_name), count);
 			}
 		}