diff --git a/mlir/lib/Bindings/Python/IRCore.cpp b/mlir/lib/Bindings/Python/IRCore.cpp
index b9d31b27b6bce..6861532272036 100644
--- a/mlir/lib/Bindings/Python/IRCore.cpp
+++ b/mlir/lib/Bindings/Python/IRCore.cpp
@@ -1107,13 +1107,12 @@ void PyOperation::erase() {
 // PyOpView
 //------------------------------------------------------------------------------
 
-py::object
-PyOpView::buildGeneric(const py::object &cls, py::list resultTypeList,
-                       py::list operandList,
-                       llvm::Optional<py::dict> attributes,
-                       llvm::Optional<std::vector<PyBlock *>> successors,
-                       llvm::Optional<int> regions,
-                       DefaultingPyLocation location, py::object maybeIp) {
+py::object PyOpView::buildGeneric(
+    const py::object &cls, py::list resultTypeList, py::list operandList,
+    llvm::Optional<py::dict> attributes,
+    llvm::Optional<std::vector<PyBlock *>> successors,
+    llvm::Optional<int> regions, DefaultingPyLocation location,
+    const py::object &maybeIp) {
   PyMlirContextRef context = location->getContext();
   // Class level operation construction metadata.
   std::string name = py::cast<std::string>(cls.attr("OPERATION_NAME"));
diff --git a/mlir/lib/Bindings/Python/IRModule.h b/mlir/lib/Bindings/Python/IRModule.h
index df4aaebf30360..117435d633b16 100644
--- a/mlir/lib/Bindings/Python/IRModule.h
+++ b/mlir/lib/Bindings/Python/IRModule.h
@@ -539,7 +539,7 @@ class PyOpView : public PyOperationBase {
                llvm::Optional<pybind11::dict> attributes,
                llvm::Optional<std::vector<PyBlock *>> successors,
                llvm::Optional<int> regions, DefaultingPyLocation location,
-               pybind11::object maybeIp);
+               const pybind11::object &maybeIp);
 
 private:
   PyOperation &operation;           // For efficient, cast-free access from C++
diff --git a/mlir/lib/Conversion/TosaToLinalg/TosaToLinalgNamed.cpp b/mlir/lib/Conversion/TosaToLinalg/TosaToLinalgNamed.cpp
index 90220ef44e974..a9c525f43aa37 100644
--- a/mlir/lib/Conversion/TosaToLinalg/TosaToLinalgNamed.cpp
+++ b/mlir/lib/Conversion/TosaToLinalg/TosaToLinalgNamed.cpp
@@ -82,7 +82,7 @@ static mlir::Value applyPad(Location loc, Value input, ArrayRef<int64_t> pad,
       .result();
 }
 
-static SmallVector<Value> filterDynamicDims(SmallVector<Value> dynDims) {
+static SmallVector<Value> filterDynamicDims(const SmallVector<Value> &dynDims) {
   SmallVector<Value> filteredDims;
   for (auto dim : dynDims)
     if (dim)
diff --git a/mlir/lib/Reducer/ReductionNode.cpp b/mlir/lib/Reducer/ReductionNode.cpp
index 1555bce333252..2288b0ac0be15 100644
--- a/mlir/lib/Reducer/ReductionNode.cpp
+++ b/mlir/lib/Reducer/ReductionNode.cpp
@@ -52,7 +52,7 @@ LogicalResult ReductionNode::initialize(ModuleOp parentModule,
 ArrayRef<ReductionNode *> ReductionNode::generateNewVariants() {
   int oldNumVariant = getVariants().size();
 
-  auto createNewNode = [this](std::vector<Range> ranges) {
+  auto createNewNode = [this](const std::vector<Range> &ranges) {
     return new (allocator.Allocate()) ReductionNode(this, ranges, allocator);
   };
 
diff --git a/mlir/lib/Target/Cpp/TranslateToCpp.cpp b/mlir/lib/Target/Cpp/TranslateToCpp.cpp
index a51bf16e3c8ae..1fc120a7dcd96 100644
--- a/mlir/lib/Target/Cpp/TranslateToCpp.cpp
+++ b/mlir/lib/Target/Cpp/TranslateToCpp.cpp
@@ -736,7 +736,7 @@ LogicalResult CppEmitter::emitAttribute(Location loc, Attribute attr) {
   }
   if (auto dense = attr.dyn_cast<DenseFPElementsAttr>()) {
     os << '{';
-    interleaveComma(dense, os, [&](APFloat val) { printFloat(val); });
+    interleaveComma(dense, os, [&](const APFloat &val) { printFloat(val); });
     os << '}';
     return success();
   }
@@ -758,7 +758,7 @@ LogicalResult CppEmitter::emitAttribute(Location loc, Attribute attr) {
                          .getElementType()
                          .dyn_cast<IntegerType>()) {
       os << '{';
-      interleaveComma(dense, os, [&](APInt val) {
+      interleaveComma(dense, os, [&](const APInt &val) {
         printInt(val, shouldMapToUnsigned(iType.getSignedness()));
       });
       os << '}';
@@ -769,7 +769,8 @@ LogicalResult CppEmitter::emitAttribute(Location loc, Attribute attr) {
                          .getElementType()
                          .dyn_cast<IndexType>()) {
       os << '{';
-      interleaveComma(dense, os, [&](APInt val) { printInt(val, false); });
+      interleaveComma(dense, os,
+                      [&](const APInt &val) { printInt(val, false); });
       os << '}';
       return success();
     }
diff --git a/mlir/unittests/Dialect/SparseTensor/MergerTest.cpp b/mlir/unittests/Dialect/SparseTensor/MergerTest.cpp
index fe69878c82839..6ea9960428f0e 100644
--- a/mlir/unittests/Dialect/SparseTensor/MergerTest.cpp
+++ b/mlir/unittests/Dialect/SparseTensor/MergerTest.cpp
@@ -99,14 +99,15 @@ class MergerTestBase : public ::testing::Test {
 
   /// Wrapper over latPointWithinRange for readability of tests.
   void expectLatPointWithinRange(unsigned s, unsigned p, unsigned n,
-                                 std::shared_ptr<Pattern> pattern,
-                                 llvm::BitVector bits) {
+                                 const std::shared_ptr<Pattern> &pattern,
+                                 const llvm::BitVector &bits) {
     EXPECT_TRUE(latPointWithinRange(s, p, n, pattern, bits));
   }
 
   /// Wrapper over expectLatPointWithinRange for a single lat point.
-  void expectLatPoint(unsigned s, unsigned p, std::shared_ptr<Pattern> pattern,
-                      llvm::BitVector bits) {
+  void expectLatPoint(unsigned s, unsigned p,
+                      const std::shared_ptr<Pattern> &pattern,
+                      const llvm::BitVector &bits) {
     EXPECT_TRUE(latPointWithinRange(s, p, 1, pattern, bits));
   }