Fix AstAssignW conversion (#5991) (#5992)

src/V3Const.cpp

@@ -3068,8 +3068,8 @@ class ConstVisitor final : public VNVisitor {
             varrefp->unlinkFrBack();
             AstInitial* const newinitp = new AstInitial{
                 nodep->fileline(), new AstAssign{nodep->fileline(), varrefp, exprp}};
-            m_modp->addStmtsp(newinitp);
-            VL_DO_DANGLING(pushDeletep(nodep->unlinkFrBack()), nodep);
+            nodep->replaceWith(newinitp);
+            VL_DO_DANGLING(pushDeletep(nodep), nodep);
             // Set the initial value right in the variable so we can constant propagate
             AstNode* const initvaluep = exprp->cloneTree(false);
             varrefp->varp()->valuep(initvaluep);

test_regress/t/t_math_signed3_noopt.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2024 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('simulator')
+
+test.compile(verilator_flags2=["-O0"])
+
+test.execute()
+
+test.passes()

test_regress/t/t_math_signed3_noopt.v

@@ -0,0 +1,132 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2014 by Wilson Snyder.
+// SPDX-License-Identifier: CC0-1.0
+
+`define stop $stop
+`define checkh(gotv,expv) do if ((gotv) !== (expv)) begin $write("%%Error: %s:%0d:  got='h%x exp='h%x\n", `__FILE__,`__LINE__, (gotv), (expv)); `stop; end while(0)
+
+module t (/*AUTOARG*/);
+
+   // verilator lint_off WIDTH
+   wire [1:0]        bug729_au = ~0;
+   wire signed [1:0] bug729_as = ~0;
+   wire [2:0]        bug729_b = ~0;
+   // the $signed output is unsigned because the input is unsigned; the signedness does not change.
+   wire [0:0]        bug729_yuu = $signed(2'b11)  == 3'b111;   //1'b0
+   wire [0:0]        bug729_ysu = $signed(2'SB11) == 3'b111;   //1'b0
+   wire [0:0]        bug729_yus = $signed(2'b11)  == 3'sb111;  //1'b1
+   wire [0:0]        bug729_yss = $signed(2'sb11) == 3'sb111;  //1'b1
+   wire [0:0]        bug729_zuu = 2'sb11 == 3'b111;   //1'b0
+   wire [0:0]        bug729_zsu = 2'sb11 == 3'b111;   //1'b0
+   wire [0:0]        bug729_zus = 2'sb11 == 3'sb111;  //1'b1
+   wire [0:0]        bug729_zss = 2'sb11 == 3'sb111;  //1'b1
+
+   wire [3:0]        bug733_a = 4'b0010;
+   wire [3:0]        bug733_yu = $signed(|bug733_a); // 4'b1111 note | is always unsigned
+   wire signed [3:0] bug733_ys = $signed(|bug733_a); // 4'b1111
+
+   wire [3:0]        bug733_zu = $signed(2'b11);  // 4'b1111
+   wire signed [3:0] bug733_zs = $signed(2'sb11); // 4'b1111
+
+   // When RHS of assignment is fewer bits than lhs, RHS sign or zero extends based on RHS's sign
+
+   wire [3:0]        bug733_qu = 2'sb11;  // 4'b1111
+   wire signed [3:0] bug733_qs = 2'sb11; // 4'b1111
+   reg signed [32:0] bug349_s;
+   reg signed [32:0] bug349_u;
+
+   wire signed [1:0] sb11 = 2'sb11;
+
+   wire [3:0]        subout_u;
+   sub sub (.a(2'sb11), .z(subout_u));
+   // initial `checkh(subout_u, 4'b1111);
+
+   wire [5:0]        cond_a = 1'b1 ? 3'sb111 : 5'sb11111;
+   initial `checkh(cond_a, 6'b111111);
+   wire [5:0]        cond_b = 1'b0 ? 3'sb111 : 5'sb11111;
+   initial `checkh(cond_b, 6'b111111);
+
+   bit cmp;
+
+   initial begin
+`ifndef VERILATOR
+      #1;
+`endif
+
+      // verilator lint_on WIDTH
+      `checkh(bug729_yuu, 1'b0);
+      `checkh(bug729_ysu, 1'b0);
+      `checkh(bug729_yus, 1'b1);
+      `checkh(bug729_yss, 1'b1);
+
+      `checkh(bug729_zuu, 1'b0);
+      `checkh(bug729_zsu, 1'b0);
+      `checkh(bug729_zus, 1'b1);
+      `checkh(bug729_zss, 1'b1);
+
+      // `checkh(bug733_yu, 4'b1111);
+      // `checkh(bug733_ys, 4'b1111);
+
+      `checkh(bug733_zu, 4'b1111);
+      `checkh(bug733_zs, 4'b1111);
+
+      `checkh(bug733_qu, 4'b1111);
+      `checkh(bug733_qs, 4'b1111);
+
+      // verilator lint_off WIDTH
+      bug349_s = 4'sb1111;
+      `checkh(bug349_s, 33'h1ffffffff);
+      bug349_u = 4'sb1111;
+      `checkh(bug349_u, 33'h1ffffffff);
+
+      bug349_s = 4'sb1111 - 1'b1;
+      `checkh(bug349_s,33'he);
+
+      bug349_s = 4'sb1111 - 5'b00001;
+      `checkh(bug349_s,33'he);
+
+      cmp = 3'sb111 == 4'b111;
+      `checkh(cmp, 1);
+      cmp = 3'sb111 == 4'sb111;
+      `checkh(cmp, 0);
+      cmp = 3'sb111 != 4'b111;
+      `checkh(cmp, 0);
+      cmp = 3'sb111 != 4'sb111;
+      `checkh(cmp, 1);
+
+      cmp = 3'sb111 === 4'b111;
+      `checkh(cmp, 1);
+      cmp = 3'sb111 === 4'sb111;
+      `checkh(cmp, 0);
+
+      case (2'sb11)
+        4'b1111: $stop;
+        default: ;
+      endcase
+
+      case (sb11)
+        4'b1111: $stop;
+        default: ;
+      endcase
+
+      case (2'sb11)
+        4'sb1111: ;
+        default: $stop;
+      endcase
+
+      case (sb11)
+        4'sb1111: ;
+        default: $stop;
+      endcase
+
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+endmodule
+
+module sub(input [3:0] a,
+           output [3:0] z);
+   assign z = a;
+endmodule