verilator/test_regress/t/t_randomize_randmode_subobj.v

91 lines
2.7 KiB
Systemverilog

// DESCRIPTION: Verilator: Verilog Test module
//
// This file ONLY is placed under the Creative Commons Public Domain.
// SPDX-FileCopyrightText: 2026 PlanV GmbH
// SPDX-License-Identifier: CC0-1.0
// verilog_format: off
`define stop $stop
`define checkd(gotv,expv) do if ((gotv) !== (expv)) begin $write("%%Error: %s:%0d: got=%0d exp=%0d\n", `__FILE__,`__LINE__, (gotv), (expv)); `stop; end while(0);
`define check_range(gotv,minv,maxv) do if ((gotv) < (minv) || (gotv) > (maxv)) begin $write("%%Error: %s:%0d: got=%0d exp=%0d-%0d\n", `__FILE__,`__LINE__, (gotv), (minv), (maxv)); `stop; end while(0);
// verilog_format: on
// Test: rand_mode(0) on nested sub-object members must prevent solver
// from overwriting the variable. Previously, write_var registered the
// variable unconditionally, so the solver wrote it back even when
// rand_mode was off.
class InnerClass;
rand bit [7:0] val1;
rand bit [7:0] val2;
rand bit [7:0] val3;
constraint inner_c {
val1 inside {[8'd10 : 8'd50]};
val2 inside {[8'd60 : 8'd100]};
val3 inside {[8'd110 : 8'd150]};
}
function new();
val1 = 0;
val2 = 0;
val3 = 0;
endfunction
endclass
class OuterClass;
rand InnerClass nested;
rand bit [7:0] outer_val;
constraint outer_c { outer_val inside {[8'd1 : 8'd20]}; }
function new();
nested = new();
outer_val = 0;
endfunction
endclass
module t;
initial begin
OuterClass obj;
obj = new;
// Test 1: Normal randomize
repeat (20) begin
`checkd(obj.randomize(), 1)
`check_range(obj.nested.val1, 8'd10, 8'd50)
`check_range(obj.nested.val2, 8'd60, 8'd100)
`check_range(obj.nested.val3, 8'd110, 8'd150)
`check_range(obj.outer_val, 8'd1, 8'd20)
end
// Test 2: rand_mode(0) on val1 -- must hold assigned value
void'(obj.nested.val1.rand_mode(0));
obj.nested.val1 = 8'd42;
repeat (20) begin
`checkd(obj.randomize(), 1)
`checkd(obj.nested.val1, 8'd42)
`check_range(obj.nested.val2, 8'd60, 8'd100)
`check_range(obj.nested.val3, 8'd110, 8'd150)
end
// Test 3: rand_mode(0) on val2 as well
void'(obj.nested.val2.rand_mode(0));
obj.nested.val2 = 8'd77;
repeat (20) begin
`checkd(obj.randomize(), 1)
`checkd(obj.nested.val1, 8'd42)
`checkd(obj.nested.val2, 8'd77)
`check_range(obj.nested.val3, 8'd110, 8'd150)
end
// Test 4: Re-enable both and verify randomization resumes
void'(obj.nested.val1.rand_mode(1));
void'(obj.nested.val2.rand_mode(1));
repeat (20) begin
`checkd(obj.randomize(), 1)
`check_range(obj.nested.val1, 8'd10, 8'd50)
`check_range(obj.nested.val2, 8'd60, 8'd100)
end
$write("*-* All Finished *-*\n");
$finish;
end
endmodule