yosys/tests/csa_tree/csa_tree_add_chains.ys

read_verilog <<EOT
module add3(
	input [7:0] a, b, c,
	output [7:0] y
);
	assign y = a + b + c;
endmodule
EOT
hierarchy -auto-top
proc
csa_tree
select -assert-count 1 t:$fa
select -assert-count 1 t:$add
design -reset

read_verilog <<EOT
module add5(
	input [11:0] a, b, c, d, e,
	output [11:0] y
);
	assign y = a + b + c + d + e;
endmodule
EOT
hierarchy -auto-top
proc
csa_tree
select -assert-count 3 t:$fa
select -assert-count 1 t:$add
design -reset

read_verilog <<EOT
module add8(
	input [15:0] a, b, c, d, e, f, g, h,
	output [15:0] y
);
	assign y = a + b + c + d + e + f + g + h;
endmodule
EOT
hierarchy -auto-top
proc
csa_tree
select -assert-count 6 t:$fa
select -assert-count 1 t:$add
design -reset

read_verilog <<EOT
module add16(
	input [15:0] a0, a1, a2, a3, a4, a5, a6, a7,
	input [15:0] a8, a9, a10, a11, a12, a13, a14, a15,
	output [15:0] y
);
	assign y = a0 + a1 + a2 + a3 + a4 + a5 + a6 + a7
	+ a8 + a9 + a10 + a11 + a12 + a13 + a14 + a15;
endmodule
EOT
hierarchy -auto-top
proc
csa_tree
select -assert-count 14 t:$fa
select -assert-count 1 t:$add
design -reset