Merge pull request #4866 from YosysHQ/ql_ioff

add IOFF inference for qlf_k6n10f

techlibs/quicklogic/Makefile.inc

@@ -6,6 +6,7 @@ OBJS += techlibs/quicklogic/ql_bram_merge.o
 OBJS += techlibs/quicklogic/ql_bram_types.o
 OBJS += techlibs/quicklogic/ql_dsp_simd.o
 OBJS += techlibs/quicklogic/ql_dsp_io_regs.o
+OBJS += techlibs/quicklogic/ql_ioff.o
 
 # --------------------------------------
 

techlibs/quicklogic/ql_ioff.cc

@@ -0,0 +1,125 @@
+#include "kernel/log.h"
+#include "kernel/modtools.h"
+#include "kernel/register.h"
+#include "kernel/rtlil.h"
+
+USING_YOSYS_NAMESPACE
+PRIVATE_NAMESPACE_BEGIN
+
+struct QlIoffPass : public Pass {
+	QlIoffPass() : Pass("ql_ioff", "Infer I/O FFs for qlf_k6n10f architecture") {}
+
+	void help() override
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    ql_ioff [selection]\n");
+		log("\n");
+		log("This pass promotes qlf_k6n10f registers directly connected to a top-level I/O\n");
+		log("port to I/O FFs.\n");
+		log("\n");
+	}
+
+	void execute(std::vector<std::string>, RTLIL::Design *design) override
+	{
+		log_header(design, "Executing QL_IOFF pass.\n");
+
+		ModWalker modwalker(design);
+		Module *module = design->top_module();
+		if (!module)
+			return;
+		modwalker.setup(module);
+		pool<RTLIL::Cell *> input_ffs;
+		dict<RTLIL::Wire *, std::vector<Cell*>> output_ffs;
+		dict<SigBit, pool<SigBit>> output_bit_aliases;
+
+		for (Wire* wire : module->wires())
+			if (wire->port_output) {
+				output_ffs[wire].resize(wire->width, nullptr);
+				for (SigBit bit : SigSpec(wire))
+					output_bit_aliases[modwalker.sigmap(bit)].insert(bit);
+			}
+
+		for (auto cell : module->selected_cells()) {
+			if (cell->type.in(ID(dffsre), ID(sdffsre))) {
+				log_debug("Checking cell %s.\n", cell->name.c_str());
+				bool e_const = cell->getPort(ID::E).is_fully_ones();
+				bool r_const = cell->getPort(ID::R).is_fully_ones();
+				bool s_const = cell->getPort(ID::S).is_fully_ones();
+
+				if (!(e_const && r_const && s_const)) {
+					log_debug("not promoting: E, R, or S is used\n");
+					continue;
+				}
+
+				SigSpec d = cell->getPort(ID::D);
+				log_assert(GetSize(d) == 1);
+				if (modwalker.has_inputs(d)) {
+					log_debug("Cell %s is potentially eligible for promotion to input IOFF.\n", cell->name.c_str());
+					// check that d_sig has no other consumers
+					pool<ModWalker::PortBit> portbits;
+					modwalker.get_consumers(portbits, d);
+					if (GetSize(portbits) > 1) {
+						log_debug("not promoting: D has other consumers\n");
+						continue;
+					}
+					input_ffs.insert(cell);
+					continue; // prefer input FFs over output FFs
+				}
+
+				SigSpec q = cell->getPort(ID::Q);
+				log_assert(GetSize(q) == 1);
+				if (modwalker.has_outputs(q) && !modwalker.has_consumers(q)) {
+					log_debug("Cell %s is potentially eligible for promotion to output IOFF.\n", cell->name.c_str());
+					for (SigBit bit : output_bit_aliases[modwalker.sigmap(q)]) {
+						log_assert(bit.is_wire());
+						output_ffs[bit.wire][bit.offset] = cell;
+					}
+
+				}
+			}
+		}
+
+		for (auto cell : input_ffs) {
+			log("Promoting register %s to input IOFF.\n", log_signal(cell->getPort(ID::Q)));
+			cell->type = ID(dff);
+			cell->unsetPort(ID::E);
+			cell->unsetPort(ID::R);
+			cell->unsetPort(ID::S);
+		}
+		for (auto & [old_port_output, ioff_cells] : output_ffs) {
+			if (std::any_of(ioff_cells.begin(), ioff_cells.end(), [](Cell * c) { return c != nullptr; }))
+			{
+				// create replacement output wire
+				RTLIL::Wire* new_port_output = module->addWire(NEW_ID, old_port_output->width);
+				new_port_output->start_offset = old_port_output->start_offset;
+				module->swap_names(old_port_output, new_port_output);
+				std::swap(old_port_output->port_id, new_port_output->port_id);
+				std::swap(old_port_output->port_input, new_port_output->port_input);
+				std::swap(old_port_output->port_output, new_port_output->port_output);
+				std::swap(old_port_output->upto, new_port_output->upto);
+				std::swap(old_port_output->is_signed, new_port_output->is_signed);
+				std::swap(old_port_output->attributes, new_port_output->attributes);
+
+				// create new output FFs
+				SigSpec sig_o(old_port_output);
+				SigSpec sig_n(new_port_output);
+				for (int i = 0; i < new_port_output->width; i++) {
+					if (ioff_cells[i]) {
+						log("Promoting %s to output IOFF.\n", log_signal(sig_n[i]));
+
+						RTLIL::Cell *new_cell = module->addCell(NEW_ID, ID(dff));
+						new_cell->setPort(ID::C, ioff_cells[i]->getPort(ID::C));
+						new_cell->setPort(ID::D, ioff_cells[i]->getPort(ID::D));
+						new_cell->setPort(ID::Q, sig_n[i]);
+						new_cell->set_bool_attribute(ID::keep);
+					} else {
+						module->connect(sig_n[i], sig_o[i]);
+					}
+				}
+			}
+		}
+	}
+} QlIoffPass;
+
+PRIVATE_NAMESPACE_END

techlibs/quicklogic/synth_quicklogic.cc

@@ -78,7 +78,7 @@ struct SynthQuickLogicPass : public ScriptPass {
 	}
 
 	string top_opt, blif_file, edif_file, family, currmodule, verilog_file, lib_path;
-	bool abc9, inferAdder, nobram, bramTypes, dsp;
+	bool abc9, inferAdder, nobram, bramTypes, dsp, ioff;
 
 	void clear_flags() override
 	{
@@ -94,6 +94,7 @@ struct SynthQuickLogicPass : public ScriptPass {
 		bramTypes = false;
 		lib_path = "+/quicklogic/";
 		dsp = true;
+		ioff = true;
 	}
 
 	void set_scratchpad_defaults(RTLIL::Design *design) {
@@ -158,6 +159,10 @@ struct SynthQuickLogicPass : public ScriptPass {
 				dsp = false;
 				continue;
 			}
+			if (args[argidx] == "-noioff") {
+				ioff = false;
+				continue;
+			}
 			break;
 		}
 		extra_args(args, argidx, design);
@@ -329,6 +334,13 @@ struct SynthQuickLogicPass : public ScriptPass {
 			run("opt_lut");
 		}
 		
+		if (check_label("iomap", "(for qlf_k6n10f, skip if -noioff)") && (family == "qlf_k6n10f" || help_mode)) {
+			if (ioff || help_mode) {
+				run("ql_ioff");
+				run("opt_clean");
+			}
+		}
+
 		if (check_label("check")) {
 			run("autoname");
 			run("hierarchy -check");

tests/arch/quicklogic/qlf_k6n10f/counter.ys

@@ -2,7 +2,7 @@ read_verilog ../../common/counter.v
 hierarchy -top top
 proc
 flatten
-equiv_opt -assert -multiclock -map +/quicklogic/qlf_k6n10f/cells_sim.v -map +/quicklogic/common/cells_sim.v synth_quicklogic -family qlf_k6n10f # equivalency check
+equiv_opt -assert -multiclock -map +/quicklogic/qlf_k6n10f/cells_sim.v -map +/quicklogic/common/cells_sim.v synth_quicklogic -family qlf_k6n10f -noioff # equivalency check
 design -load postopt # load the post-opt design (otherwise equiv_opt loads the pre-opt design)
 cd top # Constrain all select calls below inside the top module
 select -assert-count 4 t:$lut

tests/arch/quicklogic/qlf_k6n10f/dffs.ys

@@ -5,7 +5,7 @@ design -save read
 
 hierarchy -top my_dff
 proc
-equiv_opt -async2sync -assert -map +/quicklogic/qlf_k6n10f/cells_sim.v -map +/quicklogic/common/cells_sim.v synth_quicklogic -family qlf_k6n10f # equivalency check
+equiv_opt -async2sync -assert -map +/quicklogic/qlf_k6n10f/cells_sim.v -map +/quicklogic/common/cells_sim.v synth_quicklogic -family qlf_k6n10f -noioff # equivalency check
 design -load postopt # load the post-opt design (otherwise equiv_opt loads the pre-opt design)
 cd my_dff # Constrain all select calls below inside the top module
 select -assert-count 1 t:sdffsre
@@ -14,7 +14,7 @@ select -assert-none t:sdffsre %% t:* %D
 design -load read
 hierarchy -top my_dffe
 proc
-equiv_opt -async2sync -assert -map +/quicklogic/qlf_k6n10f/cells_sim.v -map +/quicklogic/common/cells_sim.v synth_quicklogic -family qlf_k6n10f # equivalency check
+equiv_opt -async2sync -assert -map +/quicklogic/qlf_k6n10f/cells_sim.v -map +/quicklogic/common/cells_sim.v synth_quicklogic -family qlf_k6n10f -noioff # equivalency check
 design -load postopt # load the post-opt design (otherwise equiv_opt loads the pre-opt design)
 cd my_dffe # Constrain all select calls below inside the top module
 select -assert-count 1 t:sdffsre

tests/arch/quicklogic/qlf_k6n10f/ioff.ys

@@ -0,0 +1,209 @@
+# test: acceptable for output IOFF promotion
+read_verilog <<EOF
+module top (input clk, input a, output reg o);
+    always @(posedge clk) begin
+        o <= ~a;
+    end
+endmodule
+EOF
+synth_quicklogic -family qlf_k6n10f -top top
+select -assert-count 1 t:dff
+
+design -reset
+# test: acceptable for output IOFF promotion
+read_verilog <<EOF
+module top (input clk, input [3:0] a, output reg [3:0] o);
+    always @(posedge clk) begin
+        o <= ~a;
+    end
+endmodule
+EOF
+synth_quicklogic -family qlf_k6n10f -top top
+select -assert-count 4 t:dff
+
+design -reset
+# test: acceptable for output IOFF promotion; duplicate output FF
+read_verilog <<EOF
+module top (input clk, input [3:0] a, output [3:0] o, output [3:0] p);
+    reg [3:0] r;
+    always @(posedge clk) begin
+        r <= ~a;
+    end
+    assign o = r;
+    assign p = r;
+endmodule
+EOF
+synth_quicklogic -family qlf_k6n10f -top top
+select -assert-count 8 t:dff
+
+design -reset
+# test: acceptable for input IOFF promotion
+read_verilog <<EOF
+module top (input clk, input a, output o);
+    reg r;
+    always @(posedge clk) begin
+        r <= a;
+    end
+    assign o = ~r;
+endmodule
+EOF
+synth_quicklogic -family qlf_k6n10f -top top
+select -assert-count 1 t:dff
+
+design -reset
+# test: acceptable for input IOFF promotion
+read_verilog <<EOF
+module top (input clk, input [3:0] a, output [3:0] o);
+    reg [3:0] r;
+    always @(posedge clk) begin
+        r <= a;
+    end
+    assign o = ~r;
+endmodule
+EOF
+synth_quicklogic -family qlf_k6n10f -top top
+select -assert-count 4 t:dff
+
+design -reset
+# test: acceptable for either IOFF promotion
+read_verilog <<EOF
+module top (input clk, input a, output reg o);
+    always @(posedge clk) begin
+        o <= a;
+    end
+endmodule
+EOF
+synth_quicklogic -family qlf_k6n10f -top top
+select -assert-count 1 t:dff
+
+design -reset
+# test: not acceptable for output IOFF promotion: output signal is used
+read_verilog <<EOF
+module top (input clk, input a, output reg o);
+    always @(posedge clk) begin
+        o <= ~a | o;
+    end
+endmodule
+EOF
+synth_quicklogic -family qlf_k6n10f -top top
+select -assert-count 0 t:dff
+
+design -reset
+# test: not acceptable for output IOFF promotion: output signal is used
+read_verilog <<EOF
+module top (input clk, input [3:0] a, output reg [3:0] o);
+    always @(posedge clk) begin
+        o <= ~a | o;
+    end
+endmodule
+EOF
+synth_quicklogic -family qlf_k6n10f -top top
+select -assert-count 0 t:dff
+
+design -reset
+# test: not acceptable for input IOFF promotion: input signal is used
+read_verilog <<EOF
+module top (input clk, input a, output o, p);
+    reg r;
+    always @(posedge clk) begin
+        r <= a;
+    end
+    assign o = ~r;
+    assign p = ~a;
+endmodule
+EOF
+synth_quicklogic -family qlf_k6n10f -top top
+select -assert-count 0 t:dff
+
+design -reset
+# test: not acceptable for input IOFF promotion: input signal is used
+read_verilog <<EOF
+module top (input clk, input [3:0] a, output [3:0] o, output [3:0] p);
+    reg [3:0] r;
+    always @(posedge clk) begin
+        r <= a;
+    end
+    assign o = ~r;
+    assign p = ~a;
+endmodule
+EOF
+synth_quicklogic -family qlf_k6n10f -top top
+select -assert-count 0 t:dff
+
+design -reset
+# test: not acceptable for IOFF promotion: FF has reset
+read_verilog <<EOF
+module top (input clk, input rst, input a, output reg o);
+    always @(posedge clk) begin
+        if (rst)
+            o <= 1'b0;
+        else
+            o <= a;
+    end
+endmodule
+EOF
+synth_quicklogic -family qlf_k6n10f -top top
+select -assert-count 0 t:dff
+
+design -reset
+# test: not acceptable for IOFF promotion: FF has reset
+read_verilog <<EOF
+module top (input clk, input rst, input [3:0] a, output reg [3:0] o);
+    always @(posedge clk) begin
+        if (rst)
+            o <= 4'b0;
+        else
+            o <= a;
+    end
+endmodule
+EOF
+synth_quicklogic -family qlf_k6n10f -top top
+select -assert-count 0 t:dff
+
+design -reset
+# test: not acceptable for IOFF promotion: FF has enable
+read_verilog <<EOF
+module top (input clk, input en, input a, output reg o);
+    always @(posedge clk) begin
+        if (en)
+            o <= a;
+    end
+endmodule
+EOF
+synth_quicklogic -family qlf_k6n10f -top top
+select -assert-count 0 t:dff
+
+design -reset
+# test: not acceptable for IOFF promotion: FF has enable
+read_verilog <<EOF
+module top (input clk, input en, input [3:0] a, output reg [3:0] o);
+    always @(posedge clk) begin
+        if (en)
+            o <= a;
+    end
+endmodule
+EOF
+synth_quicklogic -family qlf_k6n10f -top top
+select -assert-count 0 t:dff
+
+design -reset
+# test: duplicate registers driving multiple output ports
+read_verilog <<EOF
+module top (
+    input clk,
+    input en,
+    input [3:0] a,
+    output reg [3:0] o_1,
+	output wire [3:0] o_2
+);
+always @(posedge clk) begin
+    o_1[1:0] <= ~a[1:0];
+    if (en)
+        o_1[2] <= a[2];
+end
+always @(*) o_1[3] = a[3];
+assign o_2 = o_1;
+endmodule
+EOF
+synth_quicklogic -family qlf_k6n10f -top top
+select -assert-count 4 t:dff