From 718ebd4506a21e7fda79b88beed7b64cbc2d2eb9 Mon Sep 17 00:00:00 2001
From: Yutetsu TAKATSUKASA <y.takatsukasa@gmail.com>
Date: Fri, 17 Jan 2020 06:42:09 +0900
Subject: [PATCH] Add an ovbious optimization.

---
 src/V3SplitVar.cpp | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/V3SplitVar.cpp b/src/V3SplitVar.cpp
index 1625c16d0..b6a692698 100644
--- a/src/V3SplitVar.cpp
+++ b/src/V3SplitVar.cpp
@@ -174,8 +174,10 @@ class SplitUnpackedVarVisitor : public AstNVisitor {
                 pragmap->unlinkFrBack()->deleteTree(); VL_DANGLING(vars[i].first);
             }
         }
-        iterateChildren(nodep);
-        split();
+        if (!vars.empty()) {  // need to check this module only when split_var pragma exists in this module.
+            iterateChildren(nodep);
+            split();
+        }
         m_modp = NULL;
     }
     virtual void visit(AstVarRef* nodep) VL_OVERRIDE {
@@ -494,8 +496,10 @@ class SplitPackedVarVisitor : public AstNVisitor {
             // consume the pragma here anyway.
             pragmap->unlinkFrBack()->deleteTree(); VL_DANGLING(vars[i].first);
         }
-        iterateChildren(nodep);
-        split();
+        if (!vars.empty()) {  // need to check this module only when split_var pragma exists in this module.
+            iterateChildren(nodep);
+            split();
+        }
         m_modp = NULL;
     }
     virtual void visit(AstVarRef* nodep) VL_OVERRIDE {