Verify kogge stone impl.

passes/tests/CMakeLists.txt

@@ -7,6 +7,9 @@ yosys_test_pass(cell
 yosys_test_pass(abcloop
 	test_abcloop.cc
 )
+yosys_test_pass(kogge_stone
+	test_kogge_stone.cc
+)
 
 yosys_pass(raise_error
 	raise_error.cc

passes/tests/test_kogge_stone.cc

@@ -0,0 +1,101 @@
+#include "kernel/compressor_tree.h"
+#include "kernel/yosys.h"
+
+USING_YOSYS_NAMESPACE
+PRIVATE_NAMESPACE_BEGIN
+
+static void build_lcu_adder(Module *module, SigSpec a, SigSpec b, SigSpec y)
+{
+	int width = GetSize(y);
+
+	SigSpec p = module->Xor(NEW_ID, a, b);
+	SigSpec g = module->And(NEW_ID, a, b);
+
+	SigSpec co = module->addWire(NEW_ID, width);
+	Cell *lcu = module->addCell(NEW_ID, ID($lcu));
+	lcu->setParam(ID::WIDTH, width);
+	lcu->setPort(ID::P, p);
+	lcu->setPort(ID::G, g);
+	lcu->setPort(ID::CI, State::S0);
+	lcu->setPort(ID::CO, co);
+
+	SigSpec carry_in;
+	carry_in.append(State::S0);
+	carry_in.append(co.extract(0, width - 1));
+	module->addXor(NEW_ID, p, carry_in, y);
+}
+
+static Module *make_module(Design *design, IdString name, int width)
+{
+	Module *module = design->addModule(name);
+
+	Wire *a = module->addWire(ID(a), width);
+	a->port_input = true;
+	Wire *b = module->addWire(ID(b), width);
+	b->port_input = true;
+	Wire *y = module->addWire(ID(y), width);
+	y->port_output = true;
+	module->fixup_ports();
+
+	return module;
+}
+
+struct TestKoggeStonePass : public Pass {
+	TestKoggeStonePass() : Pass("test_kogge_stone", "build adders for Kogge-Stone equivalence testing") {}
+	void help() override
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    test_kogge_stone [options]\n");
+		log("\n");
+		log("Build two modules implementing an unsigned 'y = a + b' adder of a given width,\n");
+		log("and compare various internal Kogge-Stone adders.\n");
+		log("\n");
+		log("    -width N\n");
+		log("        width of the operands and result (default = 16)\n");
+		log("\n");
+		log("    -gold name\n");
+		log("        name of the $lcu-based reference module (default = gold)\n");
+		log("\n");
+		log("    -gate name\n");
+		log("        name of the emit_kogge_stone() module (default = gate)\n");
+		log("\n");
+	}
+	void execute(std::vector<std::string> args, Design *design) override
+	{
+		int width = 16;
+		IdString gold_name = ID(gold);
+		IdString gate_name = ID(gate);
+
+		size_t argidx;
+		for (argidx = 1; argidx < args.size(); argidx++) {
+			if (args[argidx] == "-width" && argidx + 1 < args.size()) {
+				width = atoi(args[++argidx].c_str());
+				continue;
+			}
+			if (args[argidx] == "-gold" && argidx + 1 < args.size()) {
+				gold_name = RTLIL::escape_id(args[++argidx]);
+				continue;
+			}
+			if (args[argidx] == "-gate" && argidx + 1 < args.size()) {
+				gate_name = RTLIL::escape_id(args[++argidx]);
+				continue;
+			}
+			break;
+		}
+		extra_args(args, argidx, design, false);
+
+		if (width < 1)
+			log_cmd_error("Width must be at least 1.\n");
+
+		log_header(design, "Executing TEST_KOGGE_STONE pass (width=%d).\n", width);
+
+		Module *gold = make_module(design, gold_name, width);
+		build_lcu_adder(gold, gold->wire(ID(a)), gold->wire(ID(b)), gold->wire(ID(y)));
+
+		Module *gate = make_module(design, gate_name, width);
+		CompressorTree::emit_kogge_stone(gate, gate->wire(ID(a)), gate->wire(ID(b)), gate->wire(ID(y)));
+	}
+} TestKoggeStonePass;
+
+PRIVATE_NAMESPACE_END

tests/arith_tree/kogge_stone_equiv.ys

@@ -0,0 +1,67 @@
+# Verify that CompressorTree::emit_kogge_stone() is eq to the implementation in techlibs/common/choices/kogge-stone.v
+
+test_kogge_stone -width 1
+techmap -map +/choices/kogge-stone.v gold
+miter -equiv -flatten -make_outputs gold gate miter
+sat -verify -prove trigger 0 miter
+design -reset
+
+test_kogge_stone -width 2
+techmap -map +/choices/kogge-stone.v gold
+miter -equiv -flatten -make_outputs gold gate miter
+sat -verify -prove trigger 0 miter
+design -reset
+
+test_kogge_stone -width 3
+techmap -map +/choices/kogge-stone.v gold
+miter -equiv -flatten -make_outputs gold gate miter
+sat -verify -prove trigger 0 miter
+design -reset
+
+test_kogge_stone -width 4
+techmap -map +/choices/kogge-stone.v gold
+miter -equiv -flatten -make_outputs gold gate miter
+sat -verify -prove trigger 0 miter
+design -reset
+
+test_kogge_stone -width 5
+techmap -map +/choices/kogge-stone.v gold
+miter -equiv -flatten -make_outputs gold gate miter
+sat -verify -prove trigger 0 miter
+design -reset
+
+test_kogge_stone -width 7
+techmap -map +/choices/kogge-stone.v gold
+miter -equiv -flatten -make_outputs gold gate miter
+sat -verify -prove trigger 0 miter
+design -reset
+
+test_kogge_stone -width 8
+techmap -map +/choices/kogge-stone.v gold
+miter -equiv -flatten -make_outputs gold gate miter
+sat -verify -prove trigger 0 miter
+design -reset
+
+test_kogge_stone -width 16
+techmap -map +/choices/kogge-stone.v gold
+miter -equiv -flatten -make_outputs gold gate miter
+sat -verify -prove trigger 0 miter
+design -reset
+
+test_kogge_stone -width 17
+techmap -map +/choices/kogge-stone.v gold
+miter -equiv -flatten -make_outputs gold gate miter
+sat -verify -prove trigger 0 miter
+design -reset
+
+test_kogge_stone -width 32
+techmap -map +/choices/kogge-stone.v gold
+miter -equiv -flatten -make_outputs gold gate miter
+sat -verify -prove trigger 0 miter
+design -reset
+
+test_kogge_stone -width 33
+techmap -map +/choices/kogge-stone.v gold
+miter -equiv -flatten -make_outputs gold gate miter
+sat -verify -prove trigger 0 miter
+design -reset