diff --git a/flang/lib/Lower/ConvertVariable.cpp b/flang/lib/Lower/ConvertVariable.cpp
index edf1f24a08e5c..413563fe95ca3 100644
--- a/flang/lib/Lower/ConvertVariable.cpp
+++ b/flang/lib/Lower/ConvertVariable.cpp
@@ -496,8 +496,8 @@ static fir::GlobalOp defineGlobal(Fortran::lower::AbstractConverter &converter,
   if (mlir::isa<fir::SequenceType>(symTy) &&
       !Fortran::semantics::IsAllocatableOrPointer(sym)) {
     mlir::Type eleTy = mlir::cast<fir::SequenceType>(symTy).getEleTy();
-    if (eleTy.isa<mlir::IntegerType, mlir::FloatType, fir::ComplexType,
-                  fir::LogicalType>()) {
+    if (mlir::isa<mlir::IntegerType, mlir::FloatType, fir::ComplexType,
+                  fir::LogicalType>(eleTy)) {
       const auto *details =
           sym.detailsIf<Fortran::semantics::ObjectEntityDetails>();
       if (details->init()) {
diff --git a/flang/lib/Optimizer/CodeGen/CodeGen.cpp b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
index 19628ac71b0b2..b4705aa479925 100644
--- a/flang/lib/Optimizer/CodeGen/CodeGen.cpp
+++ b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
@@ -1964,12 +1964,12 @@ struct ValueOpCommon {
                  mlir::ArrayAttr arrAttr) {
     llvm::SmallVector<int64_t> indices;
     for (auto i = arrAttr.begin(), e = arrAttr.end(); i != e; ++i) {
-      if (auto intAttr = i->dyn_cast<mlir::IntegerAttr>()) {
+      if (auto intAttr = mlir::dyn_cast<mlir::IntegerAttr>(*i)) {
         indices.push_back(intAttr.getInt());
       } else {
-        auto fieldName = i->cast<mlir::StringAttr>().getValue();
+        auto fieldName = mlir::cast<mlir::StringAttr>(*i).getValue();
         ++i;
-        auto ty = i->cast<mlir::TypeAttr>().getValue();
+        auto ty = mlir::cast<mlir::TypeAttr>(*i).getValue();
         auto index = mlir::cast<fir::RecordType>(ty).getFieldIndex(fieldName);
         indices.push_back(index);
       }
@@ -3014,7 +3014,7 @@ static void selectMatchAndRewrite(const fir::LLVMTypeConverter &lowering,
       caseValues.push_back(intAttr.getInt());
       continue;
     }
-    assert(attr.template dyn_cast_or_null<mlir::UnitAttr>());
+    assert(mlir::dyn_cast_or_null<mlir::UnitAttr>(attr));
     assert((t + 1 == conds) && "unit must be last");
     defaultDestination = dest;
     defaultOperands = destOps ? *destOps : mlir::ValueRange{};
diff --git a/flang/lib/Optimizer/Dialect/FIROps.cpp b/flang/lib/Optimizer/Dialect/FIROps.cpp
index a39087aeb358b..6773d0adced0c 100644
--- a/flang/lib/Optimizer/Dialect/FIROps.cpp
+++ b/flang/lib/Optimizer/Dialect/FIROps.cpp
@@ -2498,10 +2498,8 @@ static constexpr llvm::StringRef getTargetOffsetAttr() {
 
 template <typename OpT>
 static mlir::LogicalResult verifyIntegralSwitchTerminator(OpT op) {
-  if (!op.getSelector()
-           .getType()
-           .template isa<mlir::IntegerType, mlir::IndexType,
-                         fir::IntegerType>())
+  if (!mlir::isa<mlir::IntegerType, mlir::IndexType, fir::IntegerType>(
+          op.getSelector().getType()))
     return op.emitOpError("must be an integer");
   auto cases =
       op->template getAttrOfType<mlir::ArrayAttr>(op.getCasesAttr()).getValue();
@@ -2576,7 +2574,7 @@ static void printIntegralSwitchTerminator(OpT op, mlir::OpAsmPrinter &p) {
     if (i)
       p << ", ";
     auto &attr = cases[i];
-    if (auto intAttr = attr.template dyn_cast_or_null<mlir::IntegerAttr>())
+    if (auto intAttr = mlir::dyn_cast_or_null<mlir::IntegerAttr>(attr))
       p << intAttr.getValue();
     else
       p.printAttribute(attr);
diff --git a/flang/lib/Optimizer/Dialect/FIRType.cpp b/flang/lib/Optimizer/Dialect/FIRType.cpp
index 38a6a09d1808a..d9c387ad950e8 100644
--- a/flang/lib/Optimizer/Dialect/FIRType.cpp
+++ b/flang/lib/Optimizer/Dialect/FIRType.cpp
@@ -695,9 +695,9 @@ BoxProcType::verify(llvm::function_ref<mlir::InFlightDiagnostic()> emitError,
 }
 
 static bool cannotBePointerOrHeapElementType(mlir::Type eleTy) {
-  return eleTy.isa<BoxType, BoxCharType, BoxProcType, ShapeType, ShapeShiftType,
+  return mlir::isa<BoxType, BoxCharType, BoxProcType, ShapeType, ShapeShiftType,
                    SliceType, FieldType, LenType, HeapType, PointerType,
-                   ReferenceType, TypeDescType>();
+                   ReferenceType, TypeDescType>(eleTy);
 }
 
 //===----------------------------------------------------------------------===//
@@ -776,10 +776,10 @@ void fir::CharacterType::print(mlir::AsmPrinter &printer) const {
 mlir::LogicalResult
 fir::ClassType::verify(llvm::function_ref<mlir::InFlightDiagnostic()> emitError,
                        mlir::Type eleTy) {
-  if (eleTy.isa<fir::RecordType, fir::SequenceType, fir::HeapType,
+  if (mlir::isa<fir::RecordType, fir::SequenceType, fir::HeapType,
                 fir::PointerType, mlir::NoneType, mlir::IntegerType,
                 mlir::FloatType, fir::CharacterType, fir::LogicalType,
-                fir::ComplexType, mlir::ComplexType>())
+                fir::ComplexType, mlir::ComplexType>(eleTy))
     return mlir::success();
   return emitError() << "invalid element type\n";
 }
@@ -1050,8 +1050,8 @@ void fir::ReferenceType::print(mlir::AsmPrinter &printer) const {
 mlir::LogicalResult fir::ReferenceType::verify(
     llvm::function_ref<mlir::InFlightDiagnostic()> emitError,
     mlir::Type eleTy) {
-  if (eleTy.isa<ShapeType, ShapeShiftType, SliceType, FieldType, LenType,
-                ReferenceType, TypeDescType>())
+  if (mlir::isa<ShapeType, ShapeShiftType, SliceType, FieldType, LenType,
+                ReferenceType, TypeDescType>(eleTy))
     return emitError() << "cannot build a reference to type: " << eleTy << '\n';
   return mlir::success();
 }
@@ -1126,9 +1126,9 @@ mlir::LogicalResult fir::SequenceType::verify(
     llvm::ArrayRef<int64_t> shape, mlir::Type eleTy,
     mlir::AffineMapAttr layoutMap) {
   // DIMENSION attribute can only be applied to an intrinsic or record type
-  if (eleTy.isa<BoxType, BoxCharType, BoxProcType, ShapeType, ShapeShiftType,
+  if (mlir::isa<BoxType, BoxCharType, BoxProcType, ShapeType, ShapeShiftType,
                 ShiftType, SliceType, FieldType, LenType, HeapType, PointerType,
-                ReferenceType, TypeDescType, SequenceType>())
+                ReferenceType, TypeDescType, SequenceType>(eleTy))
     return emitError() << "cannot build an array of this element type: "
                        << eleTy << '\n';
   return mlir::success();
@@ -1199,9 +1199,9 @@ void fir::TypeDescType::print(mlir::AsmPrinter &printer) const {
 mlir::LogicalResult fir::TypeDescType::verify(
     llvm::function_ref<mlir::InFlightDiagnostic()> emitError,
     mlir::Type eleTy) {
-  if (eleTy.isa<BoxType, BoxCharType, BoxProcType, ShapeType, ShapeShiftType,
+  if (mlir::isa<BoxType, BoxCharType, BoxProcType, ShapeType, ShapeShiftType,
                 ShiftType, SliceType, FieldType, LenType, ReferenceType,
-                TypeDescType>())
+                TypeDescType>(eleTy))
     return emitError() << "cannot build a type descriptor of type: " << eleTy
                        << '\n';
   return mlir::success();
diff --git a/flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp b/flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp
index 601bf04ce5e9b..c61179a7460e3 100644
--- a/flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp
+++ b/flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp
@@ -1318,11 +1318,9 @@ void SimplifyIntrinsicsPass::runOnOperation() {
 
           // Support only floating point and integer arguments
           // now (e.g. logical is skipped here).
-          if (!arg1Type->isa<mlir::FloatType>() &&
-              !arg1Type->isa<mlir::IntegerType>())
+          if (!mlir::isa<mlir::FloatType, mlir::IntegerType>(*arg1Type))
             return;
-          if (!arg2Type->isa<mlir::FloatType>() &&
-              !arg2Type->isa<mlir::IntegerType>())
+          if (!mlir::isa<mlir::FloatType, mlir::IntegerType>(*arg2Type))
             return;
 
           auto typeGenerator = [&type](fir::FirOpBuilder &builder) {