1 files changed, 113 insertions, 0 deletions
diff --git a/tests/opt/opt_dff_srst.ys b/tests/opt/opt_dff_srst.ys
new file mode 100644
index 000000000..4a77de0b8
--- /dev/null
+++ b/tests/opt/opt_dff_srst.ys
@@ -0,0 +1,113 @@
+### Always-active SRST removal.
+
+read_verilog -icells <<EOT
+
+module top(...);
+
+input CLK;
+input [1:0] D;
+(* init=12'h555 *)
+output [11:0] Q;
+input SRST;
+input EN;
+
+$sdff #(.CLK_POLARITY(1'b1), .SRST_POLARITY(1'b1), .SRST_VALUE(2'h2), .WIDTH(2)) ff0 (.CLK(CLK), .SRST(1'b1), .D(D), .Q(Q[1:0]));
+$sdffe #(.CLK_POLARITY(1'b1), .EN_POLARITY(1'b1), .SRST_POLARITY(1'b0), .SRST_VALUE(2'h2), .WIDTH(2)) ff1 (.CLK(CLK), .SRST(1'b0), .EN(EN), .D(D), .Q(Q[3:2]));
+$sdffce #(.CLK_POLARITY(1'b1), .EN_POLARITY(1'b1), .SRST_POLARITY(1'b0), .SRST_VALUE(2'h2), .WIDTH(2)) ff2 (.CLK(CLK), .SRST(1'b0), .EN(EN), .D(D), .Q(Q[5:4]));
+$sdff #(.CLK_POLARITY(1'b1), .SRST_POLARITY(1'b1), .SRST_VALUE(2'h2), .WIDTH(2)) ff3 (.CLK(CLK), .SRST(1'bx), .D(D), .Q(Q[7:6]));
+$sdffe #(.CLK_POLARITY(1'b1), .EN_POLARITY(1'b1), .SRST_POLARITY(1'b0), .SRST_VALUE(2'h2), .WIDTH(2)) ff4 (.CLK(CLK), .SRST(1'bx), .EN(EN), .D(D), .Q(Q[9:8]));
+$sdffce #(.CLK_POLARITY(1'b1), .EN_POLARITY(1'b1), .SRST_POLARITY(1'b0), .SRST_VALUE(2'h2), .WIDTH(2)) ff5 (.CLK(CLK), .SRST(1'bx), .EN(EN), .D(D), .Q(Q[11:10]));
+
+
+endmodule
+
+EOT
+
+design -save orig
+
+equiv_opt -undef -assert -multiclock opt_dff
+design -load postopt
+select -assert-count 0 t:$sdff
+select -assert-count 0 t:$sdffe
+select -assert-count 0 t:$sdffce
+select -assert-count 4 t:$dff
+select -assert-count 2 t:$dffe
+
+design -load orig
+
+equiv_opt -undef -assert -multiclock opt_dff -keepdc
+design -load postopt
+select -assert-count 1 t:$sdff
+select -assert-count 1 t:$sdffe
+select -assert-count 1 t:$sdffce
+select -assert-count 2 t:$dff
+select -assert-count 1 t:$dffe
+
+design -load orig
+simplemap
+
+equiv_opt -undef -assert -multiclock opt_dff
+design -load postopt
+select -assert-none t:$_SDFF_???_
+select -assert-none t:$_SDFFE_????_
+select -assert-none t:$_SDFFCE_????_
+select -assert-count 8 t:$_DFF_?_
+select -assert-count 4 t:$_DFFE_??_
+
+design -load orig
+simplemap
+
+equiv_opt -undef -assert -multiclock opt_dff -keepdc
+design -load postopt
+select -assert-count 2 t:$_SDFF_???_
+select -assert-count 2 t:$_SDFFE_????_
+select -assert-count 2 t:$_SDFFCE_????_
+select -assert-count 4 t:$_DFF_?_
+select -assert-count 2 t:$_DFFE_??_
+
+design -reset
+
+
+### Never-active SRST removal.
+
+read_verilog -icells <<EOT
+
+module top(...);
+
+input CLK;
+input [1:0] D;
+output [5:0] Q;
+input SRST;
+input EN;
+
+$sdff #(.CLK_POLARITY(1'b1), .SRST_POLARITY(1'b1), .SRST_VALUE(2'h2), .WIDTH(2)) ff0 (.CLK(CLK), .SRST(1'b0), .D(D), .Q(Q[1:0]));
+$sdffe #(.CLK_POLARITY(1'b1), .EN_POLARITY(1'b1), .SRST_POLARITY(1'b0), .SRST_VALUE(2'h2), .WIDTH(2)) ff1 (.CLK(CLK), .SRST(1'b1), .EN(EN), .D(D), .Q(Q[3:2]));
+$sdffce #(.CLK_POLARITY(1'b1), .EN_POLARITY(1'b1), .SRST_POLARITY(1'b0), .SRST_VALUE(2'h2), .WIDTH(2)) ff2 (.CLK(CLK), .SRST(1'b1), .EN(EN), .D(D), .Q(Q[5:4]));
+
+endmodule
+
+EOT
+
+design -save orig
+
+equiv_opt -undef -assert -multiclock opt_dff
+design -load postopt
+select -assert-none t:$sdff
+select -assert-none t:$sdffe
+select -assert-none t:$sdffce
+select -assert-count 1 t:$dff
+select -assert-count 2 t:$dffe
+
+design -load orig
+simplemap
+
+equiv_opt -undef -assert -multiclock opt_dff
+design -load postopt
+select -assert-none t:$_SDFF_???_
+select -assert-none t:$_SDFFE_????_
+select -assert-none t:$_SDFFCE_????_
+select -assert-count 2 t:$_DFF_P_
+select -assert-count 4 t:$_DFFE_PP_
+
+design -reset
+