verilator/test_regress/t/t_lint_latch_3.v

56 lines
1.4 KiB
Systemverilog

// DESCRIPTION: Verilator: Verilog Test module for issue #1609
//
// This file ONLY is placed under the Creative Commons Public Domain.
// SPDX-FileCopyrightText: 2020 Julien Margetts
// SPDX-License-Identifier: Unlicense
module t ( /*AUTOARG*/
out,
out2,
in
);
input [9:0] in;
output reg [3:0] out;
output reg [3:0] out2;
// Should be no latch here since the input space is fully covered
always @* begin
casez (in)
10'b0000000000: out = 4'h0;
10'b?????????1: out = 4'h0;
10'b????????10: out = 4'h1;
10'b???????100: out = 4'h2;
10'b??????1000: out = 4'h3;
10'b?????10000: out = 4'h4;
10'b????100000: out = 4'h5;
10'b???1000000: out = 4'h6;
10'b??10000000: out = 4'h7;
10'b?100000000: out = 4'h8;
10'b1000000000: out = 4'h9;
endcase
end
// Should detect a latch here since not all paths assign
// BUT we don't because warnOff(LATCH) is set for any always containing a
// complex case statement
always @* begin
casez (in)
10'b0000000000: out2 = 4'h0;
10'b?????????1: out2 = 4'h0;
10'b????????10: out2 = 4'h1;
10'b???????100: out2 = 4'h2;
10'b??????1000: out2 = 4'h3;
10'b?????10000: /* No assignement */;
10'b????100000: out2 = 4'h5;
10'b???1000000: out2 = 4'h6;
10'b??10000000: out2 = 4'h7;
10'b?100000000: out2 = 4'h8;
10'b1000000000: out2 = 4'h9;
endcase
end
endmodule