diff --git a/mlir/lib/Pass/IRPrinting.cpp b/mlir/lib/Pass/IRPrinting.cpp
--- a/mlir/lib/Pass/IRPrinting.cpp
+++ b/mlir/lib/Pass/IRPrinting.cpp
@@ -98,7 +98,7 @@
                     OpPrintingFlags flags) {
   // Otherwise, check to see if we are not printing at module scope.
   if (!printModuleScope)
-    return op->print(out << "\n",
+    return op->print(out << " //----- //\n",
                      op->getBlock() ? flags.useLocalScope() : flags);
 
   // Otherwise, we are printing at module scope.
@@ -106,7 +106,7 @@
   if (auto symbolName =
           op->getAttrOfType<StringAttr>(SymbolTable::getSymbolAttrName()))
     out << ": @" << symbolName.getValue();
-  out << ")\n";
+  out << ") //----- //\n";
 
   // Find the top-level operation.
   auto *topLevelOp = op;
@@ -124,7 +124,7 @@
     beforePassFingerPrints.try_emplace(pass, op);
 
   config->printBeforeIfEnabled(pass, op, [&](raw_ostream &out) {
-    out << formatv("// *** IR Dump Before {0} ***", pass->getName());
+    out << "// -----// IR Dump Before " << pass->getName();
     printIR(op, config->shouldPrintAtModuleScope(), out,
             config->getOpPrintingFlags());
     out << "\n\n";
@@ -154,7 +154,7 @@
   }
 
   config->printAfterIfEnabled(pass, op, [&](raw_ostream &out) {
-    out << formatv("// *** IR Dump After {0} ***", pass->getName());
+    out << "// -----// IR Dump After " << pass->getName();
     printIR(op, config->shouldPrintAtModuleScope(), out,
             config->getOpPrintingFlags());
     out << "\n\n";
@@ -168,7 +168,7 @@
     beforePassFingerPrints.erase(pass);
 
   config->printAfterIfEnabled(pass, op, [&](raw_ostream &out) {
-    out << formatv("// *** IR Dump After {0} Failed ***", pass->getName());
+    out << formatv("// -----// IR Dump After {0} Failed", pass->getName());
     printIR(op, config->shouldPrintAtModuleScope(), out,
             OpPrintingFlags().printGenericOpForm());
     out << "\n\n";
diff --git a/mlir/test/Pass/ir-printing.mlir b/mlir/test/Pass/ir-printing.mlir
--- a/mlir/test/Pass/ir-printing.mlir
+++ b/mlir/test/Pass/ir-printing.mlir
@@ -15,52 +15,52 @@
   return
 }
 
-// BEFORE: *** IR Dump Before{{.*}}CSE ***
+// BEFORE: // -----// IR Dump Before{{.*}}CSE //----- //
 // BEFORE-NEXT: func @foo()
-// BEFORE: *** IR Dump Before{{.*}}CSE ***
+// BEFORE: // -----// IR Dump Before{{.*}}CSE //----- //
 // BEFORE-NEXT: func @bar()
-// BEFORE-NOT: *** IR Dump Before{{.*}}Canonicalizer ***
-// BEFORE-NOT: *** IR Dump After
+// BEFORE-NOT: // -----// IR Dump Before{{.*}}Canonicalizer //----- //
+// BEFORE-NOT: // -----// IR Dump After
 
-// BEFORE_ALL: *** IR Dump Before{{.*}}CSE ***
+// BEFORE_ALL: // -----// IR Dump Before{{.*}}CSE //----- //
 // BEFORE_ALL-NEXT: func @foo()
-// BEFORE_ALL: *** IR Dump Before{{.*}}Canonicalizer ***
+// BEFORE_ALL: // -----// IR Dump Before{{.*}}Canonicalizer //----- //
 // BEFORE_ALL-NEXT: func @foo()
-// BEFORE_ALL: *** IR Dump Before{{.*}}CSE ***
+// BEFORE_ALL: // -----// IR Dump Before{{.*}}CSE //----- //
 // BEFORE_ALL-NEXT: func @bar()
-// BEFORE_ALL: *** IR Dump Before{{.*}}Canonicalizer ***
+// BEFORE_ALL: // -----// IR Dump Before{{.*}}Canonicalizer //----- //
 // BEFORE_ALL-NEXT: func @bar()
-// BEFORE_ALL-NOT: *** IR Dump After
+// BEFORE_ALL-NOT: // -----// IR Dump After
 
-// AFTER-NOT: *** IR Dump Before
-// AFTER: *** IR Dump After{{.*}}CSE ***
+// AFTER-NOT: // -----// IR Dump Before
+// AFTER: // -----// IR Dump After{{.*}}CSE //----- //
 // AFTER-NEXT: func @foo()
-// AFTER: *** IR Dump After{{.*}}CSE ***
+// AFTER: // -----// IR Dump After{{.*}}CSE //----- //
 // AFTER-NEXT: func @bar()
-// AFTER-NOT: *** IR Dump After{{.*}}Canonicalizer ***
+// AFTER-NOT: // -----// IR Dump After{{.*}}Canonicalizer //----- //
 
-// AFTER_ALL-NOT: *** IR Dump Before
-// AFTER_ALL: *** IR Dump After{{.*}}CSE ***
+// AFTER_ALL-NOT: // -----// IR Dump Before
+// AFTER_ALL: // -----// IR Dump After{{.*}}CSE //----- //
 // AFTER_ALL-NEXT: func @foo()
-// AFTER_ALL: *** IR Dump After{{.*}}Canonicalizer ***
+// AFTER_ALL: // -----// IR Dump After{{.*}}Canonicalizer //----- //
 // AFTER_ALL-NEXT: func @foo()
-// AFTER_ALL: *** IR Dump After{{.*}}CSE ***
+// AFTER_ALL: // -----// IR Dump After{{.*}}CSE //----- //
 // AFTER_ALL-NEXT: func @bar()
-// AFTER_ALL: *** IR Dump After{{.*}}Canonicalizer ***
+// AFTER_ALL: // -----// IR Dump After{{.*}}Canonicalizer //----- //
 // AFTER_ALL-NEXT: func @bar()
 
-// BEFORE_MODULE: *** IR Dump Before{{.*}}CSE *** ('func' operation: @foo)
+// BEFORE_MODULE: // -----// IR Dump Before{{.*}}CSE ('func' operation: @foo) //----- //
 // BEFORE_MODULE: func @foo()
 // BEFORE_MODULE: func @bar()
-// BEFORE_MODULE: *** IR Dump Before{{.*}}CSE *** ('func' operation: @bar)
+// BEFORE_MODULE: // -----// IR Dump Before{{.*}}CSE ('func' operation: @bar) //----- //
 // BEFORE_MODULE: func @foo()
 // BEFORE_MODULE: func @bar()
 
-// AFTER_ALL_CHANGE: *** IR Dump After{{.*}}CSE ***
+// AFTER_ALL_CHANGE: // -----// IR Dump After{{.*}}CSE //----- //
 // AFTER_ALL_CHANGE-NEXT: func @foo()
-// AFTER_ALL_CHANGE-NOT: *** IR Dump After{{.*}}CSE ***
+// AFTER_ALL_CHANGE-NOT: // -----// IR Dump After{{.*}}CSE //----- //
 // We expect that only 'foo' changed during CSE, and the second run of CSE did
 // nothing.
 
-// AFTER_FAILURE-NOT: *** IR Dump After{{.*}}CSE
-// AFTER_FAILURE: *** IR Dump After{{.*}}TestFailurePass Failed ***
+// AFTER_FAILURE-NOT: // -----// IR Dump After{{.*}}CSE
+// AFTER_FAILURE: // -----// IR Dump After{{.*}}TestFailurePass Failed //----- //
diff --git a/mlir/test/Pass/run-reproducer.mlir b/mlir/test/Pass/run-reproducer.mlir
--- a/mlir/test/Pass/run-reproducer.mlir
+++ b/mlir/test/Pass/run-reproducer.mlir
@@ -14,9 +14,9 @@
   return
 }
 
-// BEFORE: *** IR Dump Before{{.*}}CSE ***
+// BEFORE: // -----// IR Dump Before{{.*}}CSE //----- //
 // BEFORE-NEXT: func @foo()
-// BEFORE: *** IR Dump Before{{.*}}CSE ***
+// BEFORE: // -----// IR Dump Before{{.*}}CSE //----- //
 // BEFORE-NEXT: func @bar()
-// BEFORE-NOT: *** IR Dump Before{{.*}}Canonicalizer ***
-// BEFORE-NOT: *** IR Dump After
+// BEFORE-NOT: // -----// IR Dump Before{{.*}}Canonicalizer //----- //
+// BEFORE-NOT: // -----// IR Dump After