From 3a659d460dda44e93225ac5327b7af05f1a69b39 Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Sun, 28 Jul 2024 14:40:55 -0400
Subject: [PATCH] =?UTF-8?q?Fix=20=3D=3D=3F=20and=20!=3D=3F=20with=20X=20va?=
 =?UTF-8?q?lues.?=

---
 src/V3Number.cpp           | 20 ++++++++++++--------
 test_regress/t/t_math_eq.v | 22 ++++++++++++++++++++++
 2 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/src/V3Number.cpp b/src/V3Number.cpp
index 58192c310..996de3898 100644
--- a/src/V3Number.cpp
+++ b/src/V3Number.cpp
@@ -1696,11 +1696,13 @@ V3Number& V3Number::opWildEq(const V3Number& lhs, const V3Number& rhs) {
     NUM_ASSERT_LOGIC_ARGS2(lhs, rhs);
     char outc = 1;
     for (int bit = 0; bit < std::max(lhs.width(), rhs.width()); bit++) {
-        if (!rhs.bitIsXZ(bit) && lhs.bitIs(bit) != rhs.bitIs(bit)) {
-            outc = 0;
-            goto last;
+        if (!rhs.bitIsXZ(bit)) {
+            if (lhs.bitIs(bit) != rhs.bitIs(bit)) {
+                outc = 0;
+                goto last;
+            }
+            if (lhs.bitIsXZ(bit)) outc = 'x';
         }
-        if (lhs.bitIsXZ(bit)) outc = 'x';
     }
 last:
     return setSingleBits(outc);
@@ -1711,11 +1713,13 @@ V3Number& V3Number::opWildNeq(const V3Number& lhs, const V3Number& rhs) {
     NUM_ASSERT_LOGIC_ARGS2(lhs, rhs);
     char outc = 0;
     for (int bit = 0; bit < std::max(lhs.width(), rhs.width()); bit++) {
-        if (!rhs.bitIsXZ(bit) && lhs.bitIs(bit) != rhs.bitIs(bit)) {
-            outc = 1;
-            goto last;
+        if (!rhs.bitIsXZ(bit)) {
+            if (lhs.bitIs(bit) != rhs.bitIs(bit)) {
+                outc = 1;
+                goto last;
+            }
+            if (lhs.bitIsXZ(bit)) outc = 'x';
         }
-        if (lhs.bitIsXZ(bit)) outc = 'x';
     }
 last:
     return setSingleBits(outc);
diff --git a/test_regress/t/t_math_eq.v b/test_regress/t/t_math_eq.v
index c1b5a8ae6..018f190c7 100644
--- a/test_regress/t/t_math_eq.v
+++ b/test_regress/t/t_math_eq.v
@@ -4,6 +4,9 @@
 // any use, without warranty, 2007 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*/
    // Inputs
    clk
@@ -35,6 +38,25 @@ module t (/*AUTOARG*/
    // What checksum will we end up with
 `define EXPECTED_SUM 64'h1a0d07009b6a30d2
 
+   initial begin
+      `checkh(3'b101 ==? 3'b100, 1'b0);
+      `checkh(3'b101 ==? 3'b101, 1'b1);
+      `checkh(3'b100 ==? 3'b10x, 1'b1);
+      `checkh(3'b101 ==? 3'b10x, 1'b1);
+      `checkh(3'b10x ==? 3'b10?, 1'b1);
+      `checkh(3'b110 ==? 3'b10?, 1'b0);
+      `checkh(3'b111 ==? 3'b10?, 1'b0);
+      `checkh(3'b11x ==? 3'b10?, 1'b0);
+      `checkh(3'b101 !=? 3'b100, !1'b0);
+      `checkh(3'b101 !=? 3'b101, !1'b1);
+      `checkh(3'b100 !=? 3'b10x, !1'b1);
+      `checkh(3'b101 !=? 3'b10x, !1'b1);
+      `checkh(3'b10x !=? 3'b10?, !1'b1);
+      `checkh(3'b110 !=? 3'b10?, !1'b0);
+      `checkh(3'b111 !=? 3'b10?, !1'b0);
+      `checkh(3'b11x !=? 3'b10?, !1'b0);
+   end
+
    // Test loop
    always @ (posedge clk) begin
 `ifdef TEST_VERBOSE