### 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