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	Merge pull request #3305 from jix/sva_value_change_logic
verific: Improve logic generated for SVA value change expressions
This commit is contained in:
		
						commit
						587e09d551
					
				
					 8 changed files with 121 additions and 11 deletions
				
			
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			@ -1557,17 +1557,25 @@ void VerificImporter::import_netlist(RTLIL::Design *design, Netlist *nl, std::ma
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			SigSpec sig_d = net_map_at(inst->GetInput1());
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			SigSpec sig_o = net_map_at(inst->GetOutput());
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			SigSpec sig_q = module->addWire(new_verific_id(inst));
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			SigSpec sig_dx = module->addWire(new_verific_id(inst), 2);
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			SigSpec sig_qx = module->addWire(new_verific_id(inst), 2);
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			if (verific_verbose) {
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				log("    NEX with A=%s, B=0, Y=%s.\n",
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						log_signal(sig_d), log_signal(sig_dx[0]));
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				log("    EQX with A=%s, B=1, Y=%s.\n",
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						log_signal(sig_d), log_signal(sig_dx[1]));
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				log("    %sedge FF with D=%s, Q=%s, C=%s.\n", clocking.posedge ? "pos" : "neg",
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						log_signal(sig_d), log_signal(sig_q), log_signal(clocking.clock_sig));
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				log("    XNOR with A=%s, B=%s, Y=%s.\n",
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						log_signal(sig_d), log_signal(sig_q), log_signal(sig_o));
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						log_signal(sig_dx), log_signal(sig_qx), log_signal(clocking.clock_sig));
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				log("    EQ with A=%s, B=%s, Y=%s.\n",
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						log_signal(sig_dx), log_signal(sig_qx), log_signal(sig_o));
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			}
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			clocking.addDff(new_verific_id(inst), sig_d, sig_q);
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			module->addXnor(new_verific_id(inst), sig_d, sig_q, sig_o);
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			module->addNex(new_verific_id(inst), sig_d, State::S0, sig_dx[0]);
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			module->addEqx(new_verific_id(inst), sig_d, State::S1, sig_dx[1]);
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			clocking.addDff(new_verific_id(inst), sig_dx, sig_qx, Const(1, 2));
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			module->addEq(new_verific_id(inst), sig_dx, sig_qx, sig_o);
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			if (!mode_keep)
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				continue;
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			@ -1601,13 +1609,20 @@ void VerificImporter::import_netlist(RTLIL::Design *design, Netlist *nl, std::ma
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			SigBit sig_d = net_map_at(inst->GetInput1());
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			SigBit sig_o = net_map_at(inst->GetOutput());
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			SigBit sig_q = module->addWire(new_verific_id(inst));
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			SigBit sig_d_no_x = module->addWire(new_verific_id(inst));
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			if (verific_verbose)
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			if (verific_verbose) {
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				log("    EQX with A=%s, B=%d, Y=%s.\n",
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						log_signal(sig_d), inst->Type() == PRIM_SVA_ROSE, log_signal(sig_d_no_x));
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				log("    %sedge FF with D=%s, Q=%s, C=%s.\n", clocking.posedge ? "pos" : "neg",
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						log_signal(sig_d), log_signal(sig_q), log_signal(clocking.clock_sig));
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						log_signal(sig_d_no_x), log_signal(sig_q), log_signal(clocking.clock_sig));
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				log("    EQ with A={%s, %s}, B={0, 1}, Y=%s.\n",
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						log_signal(sig_q), log_signal(sig_d_no_x), log_signal(sig_o));
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			}
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			clocking.addDff(new_verific_id(inst), sig_d, sig_q);
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			module->addEq(new_verific_id(inst), {sig_q, sig_d}, Const(inst->Type() == PRIM_SVA_ROSE ? 1 : 2, 2), sig_o);
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			module->addEqx(new_verific_id(inst), sig_d, inst->Type() == PRIM_SVA_ROSE ? State::S1 : State::S0, sig_d_no_x);
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			clocking.addDff(new_verific_id(inst), sig_d_no_x, sig_q, State::S0);
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			module->addEq(new_verific_id(inst), {sig_q, sig_d_no_x}, Const(1, 2), sig_o);
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			if (!mode_keep)
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				continue;
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										1
									
								
								tests/sva/.gitignore
									
										
									
									
										vendored
									
									
								
							
							
						
						
									
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								tests/sva/.gitignore
									
										
									
									
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			@ -3,5 +3,6 @@
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/*_pass
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/*_fail
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/*.ok
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/*.fst
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/vhdlpsl[0-9][0-9]
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/vhdlpsl[0-9][0-9].sby
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			@ -10,4 +10,5 @@ clean:
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	rm -rf $(addsuffix .ok,$(TESTS)) $(addsuffix .sby,$(TESTS)) $(TESTS)
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	rm -rf $(addsuffix _pass.sby,$(TESTS)) $(addsuffix _pass,$(TESTS))
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	rm -rf $(addsuffix _fail.sby,$(TESTS)) $(addsuffix _fail,$(TESTS))
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	rm -rf $(addsuffix .fst,$(TESTS))
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			@ -57,7 +57,9 @@ generate_sby() {
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	fi
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}
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if [ -f $prefix.sv ]; then
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if [ -f $prefix.ys ]; then
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	$PWD/../../yosys -q -e "Assert .* failed." -s $prefix.ys
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elif [ -f $prefix.sv ]; then
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	generate_sby pass > ${prefix}_pass.sby
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	generate_sby fail > ${prefix}_fail.sby
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	sby --yosys $PWD/../../yosys -f ${prefix}_pass.sby
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										17
									
								
								tests/sva/sva_value_change_changed.sv
									
										
									
									
									
										Normal file
									
								
							
							
						
						
									
										17
									
								
								tests/sva/sva_value_change_changed.sv
									
										
									
									
									
										Normal file
									
								
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			@ -0,0 +1,17 @@
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module top (
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	input clk,
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	input a, b
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);
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	default clocking @(posedge clk); endclocking
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	assert property (
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		$changed(b)
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	);
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`ifndef FAIL
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	assume property (
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		b !== 'x ##1 $changed(b)
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	);
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`endif
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endmodule
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										20
									
								
								tests/sva/sva_value_change_rose.sv
									
										
									
									
									
										Normal file
									
								
							
							
						
						
									
										20
									
								
								tests/sva/sva_value_change_rose.sv
									
										
									
									
									
										Normal file
									
								
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			@ -0,0 +1,20 @@
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module top (
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	input clk,
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	input a, b
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);
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	default clocking @(posedge clk); endclocking
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    wire a_copy;
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    assign a_copy = a;
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	assert property (
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		$rose(a) |-> b
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	);
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`ifndef FAIL
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	assume property (
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		$rose(a_copy) |-> b
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	);
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`endif
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endmodule
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										51
									
								
								tests/sva/sva_value_change_sim.sv
									
										
									
									
									
										Normal file
									
								
							
							
						
						
									
										51
									
								
								tests/sva/sva_value_change_sim.sv
									
										
									
									
									
										Normal file
									
								
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			@ -0,0 +1,51 @@
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module top (
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	input clk
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);
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reg [7:0] counter = 0;
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reg a = 0;
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reg b = 1;
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reg c;
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wire a_fell; assign a_fell = $fell(a, @(posedge clk));
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wire a_rose; assign a_rose = $rose(a, @(posedge clk));
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wire a_stable; assign a_stable = $stable(a, @(posedge clk));
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wire b_fell; assign b_fell = $fell(b, @(posedge clk));
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wire b_rose; assign b_rose = $rose(b, @(posedge clk));
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wire b_stable; assign b_stable = $stable(b, @(posedge clk));
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wire c_fell; assign c_fell = $fell(c, @(posedge clk));
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wire c_rose; assign c_rose = $rose(c, @(posedge clk));
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wire c_stable; assign c_stable = $stable(c, @(posedge clk));
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always @(posedge clk) begin
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	counter <= counter + 1;
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	case (counter)
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		0: begin
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            assert property ( $fell(a) && !$rose(a) && !$stable(a));
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            assert property (!$fell(b) &&  $rose(b) && !$stable(b));
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            assert property (!$fell(c) && !$rose(c) &&  $stable(c));
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            a <= 1; b <= 1; c <= 1;
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        end
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		1: begin a <= 0; b <= 1; c <= 'x; end
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		2: begin
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            assert property ( $fell(a) && !$rose(a) && !$stable(a));
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            assert property (!$fell(b) && !$rose(b) &&  $stable(b));
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            assert property (!$fell(c) && !$rose(c) && !$stable(c));
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            a <= 0; b <= 0; c <= 0;
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        end
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		3: begin a <= 0; b <= 1; c <= 'x; end
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		4: begin
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            assert property (!$fell(a) && !$rose(a) &&  $stable(a));
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            assert property (!$fell(b) &&  $rose(b) && !$stable(b));
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            assert property (!$fell(c) && !$rose(c) && !$stable(c));
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            a <= 'x; b <= 'x; c <= 'x;
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        end
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		5: begin a <= 0; b <= 1; c <= 'x; counter <= 0; end
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	endcase;
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end
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endmodule
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										3
									
								
								tests/sva/sva_value_change_sim.ys
									
										
									
									
									
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								tests/sva/sva_value_change_sim.ys
									
										
									
									
									
										Normal file
									
								
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			@ -0,0 +1,3 @@
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read -sv sva_value_change_sim.sv
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hierarchy -top top
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sim -clock clk -fst sva_value_change_sim.fst
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