From 800a789f5065cb580edf2ed36a8c23b8d732caf4 Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Fri, 6 Oct 2023 21:33:31 -0400
Subject: [PATCH] Fix inlining of real functions miscasting (#4543).

---
 Changes                                |  1 +
 src/V3Cast.cpp                         |  8 ++++++--
 src/V3Const.cpp                        |  2 +-
 test_regress/t/t_func_real_exprstmt.pl | 21 +++++++++++++++++++++
 test_regress/t/t_func_real_exprstmt.v  | 23 +++++++++++++++++++++++
 5 files changed, 52 insertions(+), 3 deletions(-)
 create mode 100755 test_regress/t/t_func_real_exprstmt.pl
 create mode 100644 test_regress/t/t_func_real_exprstmt.v

diff --git a/Changes b/Changes
index 2cf70f114..2b3e63fac 100644
--- a/Changes
+++ b/Changes
@@ -31,6 +31,7 @@ Verilator 5.017 devel
 * Fix stream operations with operands of struct type (#4531) (#4532). [Ryszard Rozak, Antmicro Ltd.]
 * Fix 'this' in a constructor (#4533). [Ryszard Rozak, Antmicro Ltd.]
 * Fix stream shift operator of 32 bits (#4536). [Julien Faucher]
+* Fix inlining of real functions miscasting (#4543). [Andrew Nolte]
 
 
 Verilator 5.016 2023-09-16
diff --git a/src/V3Cast.cpp b/src/V3Cast.cpp
index 7362f9c71..4fb3b868e 100644
--- a/src/V3Cast.cpp
+++ b/src/V3Cast.cpp
@@ -58,7 +58,7 @@ class CastVisitor final : public VNVisitor {
 private:
     // NODE STATE
     // Entire netlist:
-    //   AstNode::user()                // bool.  Indicates node is of known size
+    //   AstNode::user1()               // bool.  Indicates node is of known size
     const VNUser1InUse m_inuser1;
 
     // STATE
@@ -66,12 +66,12 @@ private:
     // METHODS
 
     void insertCast(AstNodeExpr* nodep, int needsize) {  // We'll insert ABOVE passed node
-        UINFO(4, "  NeedCast " << nodep << endl);
         VNRelinker relinkHandle;
         nodep->unlinkFrBack(&relinkHandle);
         //
         AstCCast* const castp
             = new AstCCast{nodep->fileline(), nodep, needsize, nodep->widthMin()};
+        UINFO(4, "  MadeCast " << static_cast<void*>(castp) << " for " << nodep << endl);
         relinkHandle.relink(castp);
         // if (debug() > 8) castp->dumpTree("-  castins: ");
         //
@@ -170,6 +170,10 @@ private:
         ensureLower32Cast(nodep);
         nodep->user1(1);
     }
+    void visit(AstExprStmt* nodep) override {
+        iterateChildren(nodep);
+        nodep->user1(1);
+    }
     void visit(AstNegate* nodep) override {
         iterateChildren(nodep);
         nodep->user1(nodep->lhsp()->user1());
diff --git a/src/V3Const.cpp b/src/V3Const.cpp
index ea0e4bea6..087f4b3af 100644
--- a/src/V3Const.cpp
+++ b/src/V3Const.cpp
@@ -1375,7 +1375,7 @@ private:
     AstNode* afterComment(AstNode* nodep) {
         // Ignore comments, such as to determine if a AstIf is empty.
         // nodep may be null, if so return null.
-        while (nodep && VN_IS(nodep, Comment)) { nodep = nodep->nextp(); }
+        while (nodep && VN_IS(nodep, Comment)) nodep = nodep->nextp();
         return nodep;
     }
 
diff --git a/test_regress/t/t_func_real_exprstmt.pl b/test_regress/t/t_func_real_exprstmt.pl
new file mode 100755
index 000000000..859050d63
--- /dev/null
+++ b/test_regress/t/t_func_real_exprstmt.pl
@@ -0,0 +1,21 @@
+#!/usr/bin/env perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2023 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
+
+scenarios(simulator => 1);
+
+compile(
+    );
+
+execute(
+    check_finished => 1,
+    );
+
+ok(1);
+1;
diff --git a/test_regress/t/t_func_real_exprstmt.v b/test_regress/t/t_func_real_exprstmt.v
new file mode 100644
index 000000000..4df720960
--- /dev/null
+++ b/test_regress/t/t_func_real_exprstmt.v
@@ -0,0 +1,23 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2023 by Wilson Snyder
+// SPDX-License-Identifier: CC0-1.0
+
+module t;
+
+   function automatic real logWrapper(real x);
+      return $ln(x);
+   endfunction
+
+   initial begin
+      // See bug4543
+      $display("bad x=%f, y=%f", logWrapper(10.0), 1.0 * logWrapper(10.0));
+      $display("noc x=%f, y=%f", $ln(10.0), 1.0 * $ln(10.0));
+      if (logWrapper(10.0) != $ln(10.0)) $stop;
+      if (logWrapper(10.0) != 1.0 * logWrapper(10.0)) $stop;
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+
+endmodule