From 8e35c813992f7ccc327f09ecdcb8da19edfb8a2f Mon Sep 17 00:00:00 2001
From: Geza Lore <gezalore@gmail.com>
Date: Mon, 10 Nov 2025 17:18:33 +0000
Subject: [PATCH] Fix --expand-limit not respected for expressions (#6670)

---
 src/V3Expand.cpp                      |  5 +++++
 test_regress/t/t_flag_expand_limit.py |  2 +-
 test_regress/t/t_flag_expand_limit.v  | 19 ++++++++++++++++++-
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/src/V3Expand.cpp b/src/V3Expand.cpp
index f010aad3f..b3a57154a 100644
--- a/src/V3Expand.cpp
+++ b/src/V3Expand.cpp
@@ -907,6 +907,8 @@ class ExpandVisitor final : public VNVisitor {
         iterateChildren(nodep);
         if (nodep->lhsp()->isWide()) {
             if (isImpure(nodep)) return;
+            if (!doExpandWide(nodep->lhsp())) return;
+            if (!doExpandWide(nodep->rhsp())) return;
             UINFO(8, "    Wordize EQ/NEQ " << nodep);
             // -> (0=={or{for each_word{WORDSEL(lhs,#)^WORDSEL(rhs,#)}}}
             FileLine* const fl = nodep->fileline();
@@ -933,6 +935,7 @@ class ExpandVisitor final : public VNVisitor {
         FileLine* const fl = nodep->fileline();
         if (nodep->lhsp()->isWide()) {
             if (isImpure(nodep)) return;
+            if (!doExpandWide(nodep->lhsp())) return;
             UINFO(8, "    Wordize REDOR " << nodep);
             // -> (0!={or{for each_word{WORDSEL(lhs,#)}}}
             AstNodeExpr* newp = nullptr;
@@ -957,6 +960,7 @@ class ExpandVisitor final : public VNVisitor {
         FileLine* const fl = nodep->fileline();
         if (nodep->lhsp()->isWide()) {
             if (isImpure(nodep)) return;
+            if (!doExpandWide(nodep->lhsp())) return;
             UINFO(8, "    Wordize REDAND " << nodep);
             // -> (0!={and{for each_word{WORDSEL(lhs,#)}}}
             AstNodeExpr* newp = nullptr;
@@ -988,6 +992,7 @@ class ExpandVisitor final : public VNVisitor {
         iterateChildren(nodep);
         if (nodep->lhsp()->isWide()) {
             if (isImpure(nodep)) return;
+            if (!doExpandWide(nodep->lhsp())) return;
             UINFO(8, "    Wordize REDXOR " << nodep);
             // -> (0!={redxor{for each_word{XOR(WORDSEL(lhs,#))}}}
             FileLine* const fl = nodep->fileline();
diff --git a/test_regress/t/t_flag_expand_limit.py b/test_regress/t/t_flag_expand_limit.py
index c5e6b9338..4e3ca445a 100755
--- a/test_regress/t/t_flag_expand_limit.py
+++ b/test_regress/t/t_flag_expand_limit.py
@@ -13,6 +13,6 @@ test.scenarios('vlt')
 
 test.compile(verilator_flags2=['--expand-limit 1 --stats -fno-dfg'])
 
-test.file_grep(test.stats, r'Optimizations, expand limited\s+(\d+)', 3)
+test.file_grep(test.stats, r'Optimizations, expand limited\s+(\d+)', 8)
 
 test.passes()
diff --git a/test_regress/t/t_flag_expand_limit.v b/test_regress/t/t_flag_expand_limit.v
index 0640ce15a..5e608ea2f 100644
--- a/test_regress/t/t_flag_expand_limit.v
+++ b/test_regress/t/t_flag_expand_limit.v
@@ -14,7 +14,17 @@ module t #(parameter NV = 2000)
     output [ 31:0] o,
 
     input [319:0]  bi,
-    output [319:0]  bo
+    output [319:0]  bo,
+
+    input [319:0]  c_i1,
+    input [319:0]  c_i2,
+    output         c_eq_o,
+    output         c_neq_o,
+
+    input [319:0]  d_red_i,
+    output         d_red_and_o,
+    output         d_red_or_o,
+    output         d_red_xor_o
     );
 
    // verilator lint_off WIDTH
@@ -24,4 +34,11 @@ module t #(parameter NV = 2000)
 
    assign bo = ~bi;
 
+   assign c_eq_o  = c_i1 == c_i2;
+   assign c_neq_o = c_i1 != c_i2;
+
+   assign d_red_and_o = &d_red_i;
+   assign d_red_or_o  = |d_red_i;
+   assign d_red_xor_o = ^d_red_i;
+
 endmodule