verilator/test_regress/t/t_constraint_struct_unref.v

280 lines
7.0 KiB
Systemverilog

// DESCRIPTION: Verilator: Verilog Test module
//
// This file ONLY is placed under the Creative Commons Public Domain.
// SPDX-FileCopyrightText: 2026 Wilson Snyder
// SPDX-License-Identifier: CC0-1.0
// Regression for: a random member of a rand unpacked struct that no constraint
// references must still be randomized (IEEE 1800-2023 18.4 - all random
// members of a rand unpacked struct are solved concurrently).
// 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 checkgt(gotv,minv) do if (!((gotv) > (minv))) begin \
$write("%%Error: %s:%0d: got=%0d expected > %0d\n", `__FILE__, `__LINE__, (gotv), (minv)); `stop; end while(0)
// verilog_format: on
typedef struct {
rand bit [3:0] inner_id; // UNCONSTRAINED nested random member
} inner_t;
typedef struct {
rand bit [3:0] id; // UNCONSTRAINED random member
rand bit [2:0] size; // constrained random member
rand inner_t inner; // UNCONSTRAINED nested rand struct member
bit [3:0] fixed; // non-rand member: must keep its value
} unpacked_t;
typedef struct packed {
bit [3:0] id;
bit [2:0] size;
} packed_t;
class C;
rand unpacked_t u;
rand packed_t p;
// Reference ONLY .size on each; .id, .inner.inner_id are random members left
// unmentioned, and .fixed is a non-rand member.
constraint c {
u.size inside {[0 : 2]};
p.size inside {[0 : 2]};
}
function new();
u.fixed = 4'hA;
endfunction
endclass
// Shared struct type as a non-rand member of a different randomized class.
class D;
unpacked_t m;
rand bit [3:0] z;
constraint dz {z < 5;}
endclass
// Struct-in-struct: constraint reaches into the nested struct.
typedef struct {
rand bit [3:0] a; // constrained nested member
rand bit [3:0] b; // UNCONSTRAINED nested member
} inner2_t;
typedef struct {
rand inner2_t inr;
rand bit [3:0] x; // UNCONSTRAINED outer member
} outer_t;
class E;
rand outer_t o;
constraint eo {o.inr.a < 3;}
endclass
// A rand member with an initializer, and a randc member, both unreferenced.
typedef struct {
rand bit [3:0] wi = 4'h1; // rand member with initializer
randc bit [3:0] cyc; // randc member
rand bit [3:0] r; // constrained member
} extra_t;
class F;
rand extra_t s;
constraint fc {s.r < 5;}
endclass
// Unpacked array of struct as a rand member, left unreferenced by the constraint.
typedef struct {rand bit [3:0] f;} aelem_t;
typedef struct {
rand bit [3:0] g;
rand aelem_t es[2];
} arr_t;
class G;
rand arr_t o;
constraint gc {o.g < 5;}
endclass
// Rand members reached only through a NON-rand struct member: only the
// referenced leaf is solved.
typedef struct {
rand bit [3:0] kv; // unreferenced: must keep its value
rand bit [3:0] rv; // referenced
} under_t;
typedef struct {
under_t sub; // non-rand
rand bit [3:0] hv;
} hold_t;
class H;
rand hold_t o;
constraint hc {o.sub.rv < 5;}
function new();
o.sub.kv = 4'hC;
endfunction
endclass
// Same reached through dynamic arrays of structs.
typedef struct {
rand bit ec; // unreferenced: must keep its value
rand bit [7:0] ed; // referenced
} delem_t;
typedef struct {
delem_t subs[]; // non-rand
} douter_t;
class I;
rand douter_t cfgs[];
rand bit flip;
constraint ic {
foreach (cfgs[i]) {
cfgs[i].subs[0].ed[0] != flip;
}
}
function new();
cfgs = new[3];
foreach (cfgs[i]) begin
cfgs[i].subs = new[2];
for (int j = 0; j < 2; j++) cfgs[i].subs[j].ec = 1'b1;
end
endfunction
endclass
module t_constraint_struct_unref;
initial begin
C c;
D d;
E e;
F f;
G g;
H h;
I iarr;
int uid[16];
int pid[16];
int iid[16];
int zid[16];
int bid[16];
int xid[16];
int wid[16];
int cid[16];
int e0id[16];
int e1id[16];
int hid[16];
int un;
int pn;
int inn;
int zn;
int bn;
int xn;
int wn;
int cn;
int e0n;
int e1n;
int hn;
// Non-randomized use of the shared type: must stay untouched.
unpacked_t plain;
outer_t plain2;
c = new();
d = new();
e = new();
f = new();
g = new();
h = new();
iarr = new();
un = 0;
pn = 0;
inn = 0;
zn = 0;
bn = 0;
xn = 0;
wn = 0;
cn = 0;
e0n = 0;
e1n = 0;
hn = 0;
plain.id = 4'h5;
plain.size = 3'h6;
plain.inner.inner_id = 4'h7;
plain.fixed = 4'h8;
d.m.id = 4'h1;
d.m.size = 3'h2;
d.m.inner.inner_id = 4'h3;
d.m.fixed = 4'h4;
plain2.inr.a = 4'h9;
plain2.inr.b = 4'hA;
plain2.x = 4'hB;
for (int i = 0; i < 300; i++) begin
`checkd(c.randomize(), 1);
`checkd((c.u.size inside {[0 : 2]}), 1'b1);
`checkd((c.p.size inside {[0 : 2]}), 1'b1);
`checkd(c.u.fixed, 4'hA);
uid[c.u.id]++;
pid[c.p.id]++;
iid[c.u.inner.inner_id]++;
`checkd(d.randomize(), 1);
`checkd((d.z < 5), 1'b1);
`checkd(d.m.id, 4'h1);
`checkd(d.m.size, 3'h2);
`checkd(d.m.inner.inner_id, 4'h3);
`checkd(d.m.fixed, 4'h4);
zid[d.z]++;
`checkd(e.randomize(), 1);
`checkd((e.o.inr.a < 3), 1'b1);
bid[e.o.inr.b]++; // unreferenced nested member
xid[e.o.x]++; // unreferenced outer member
`checkd(f.randomize(), 1);
`checkd((f.s.r < 5), 1'b1);
wid[f.s.wi]++; // unreferenced rand member with initializer
cid[f.s.cyc]++; // unreferenced randc member
`checkd(g.randomize(), 1);
`checkd((g.o.g < 5), 1'b1);
e0id[g.o.es[0].f]++; // unreferenced array-of-struct element
e1id[g.o.es[1].f]++;
`checkd(h.randomize(), 1);
`checkd((h.o.sub.rv < 5), 1'b1);
`checkd(h.o.sub.kv, 4'hC);
hid[h.o.hv]++;
`checkd(iarr.randomize(), 1);
foreach (iarr.cfgs[k]) begin
`checkd((iarr.cfgs[k].subs[0].ed[0] != iarr.flip), 1'b1);
`checkd(iarr.cfgs[k].subs[0].ec, 1'b1);
`checkd(iarr.cfgs[k].subs[1].ec, 1'b1);
end
end
foreach (uid[k]) if (uid[k] > 0) un++;
foreach (pid[k]) if (pid[k] > 0) pn++;
foreach (iid[k]) if (iid[k] > 0) inn++;
foreach (zid[k]) if (zid[k] > 0) zn++;
foreach (bid[k]) if (bid[k] > 0) bn++;
foreach (xid[k]) if (xid[k] > 0) xn++;
foreach (wid[k]) if (wid[k] > 0) wn++;
foreach (cid[k]) if (cid[k] > 0) cn++;
foreach (e0id[k]) if (e0id[k] > 0) e0n++;
foreach (e1id[k]) if (e1id[k] > 0) e1n++;
foreach (hid[k]) if (hid[k] > 0) hn++;
// Unreferenced rand members must vary; packed struct is the control case.
`checkgt(un, 7);
`checkgt(pn, 7);
`checkgt(inn, 7);
`checkgt(zn, 3);
`checkgt(bn, 7);
`checkgt(xn, 7);
`checkgt(wn, 7);
`checkgt(cn, 7);
`checkgt(e0n, 7);
`checkgt(e1n, 7);
`checkgt(hn, 7);
`checkd(plain.id, 4'h5);
`checkd(plain.size, 3'h6);
`checkd(plain.inner.inner_id, 4'h7);
`checkd(plain.fixed, 4'h8);
`checkd(plain2.inr.a, 4'h9);
`checkd(plain2.inr.b, 4'hA);
`checkd(plain2.x, 4'hB);
$write("*-* All Finished *-*\n");
$finish;
end
endmodule