yosys/tests/various/peepopt.ys

read_verilog <<EOT
module peepopt_shiftmul_0 #(parameter N=3, parameter W=3) (input [N*W-1:0] i, input [$clog2(N)-1:0] s, output [W-1:0] o);
assign o = i[s*W+:W];
endmodule
EOT

prep -nokeepdc
equiv_opt -assert peepopt
design -load postopt
clean
select -assert-count 1 t:$shiftx
select -assert-count 0 t:$shiftx t:* %D

####################

design -reset
read_verilog <<EOT
module peepopt_shiftmul_1 (output [7:0] y, input [2:0] w);
assign y = 1'b1 >> (w * (3'b110));
endmodule
EOT

prep -nokeepdc
equiv_opt -assert peepopt
design -load postopt
clean
select -assert-count 1 t:$shr
select -assert-count 1 t:$mul
select -assert-count 0 t:$shr t:$mul %% t:* %D

####################

design -reset
read_verilog <<EOT
module peepopt_muldiv_0(input [1:0] i, output [1:0] o);
wire [3:0] t;
assign t = i * 3;
assign o = t / 3;
endmodule
EOT

prep -nokeepdc
equiv_opt -assert peepopt
design -load postopt
clean
select -assert-count 0 t:*

####################

design -reset
read_verilog <<EOT
module peepopt_dffmuxext_signed(input clk, ce, input signed [1:0] i, output reg signed [3:0] o);
    always @(posedge clk) if (ce) o <= i;
endmodule
EOT

prep -nokeepdc
equiv_opt peepopt
design -load postopt
clean
select -assert-count 1 t:$dff r:WIDTH=2 %i
select -assert-count 1 t:$mux r:WIDTH=2 %i
select -assert-count 0 t:$dff t:$mux %% t:* %D