diff --git a/flang/include/flang/Optimizer/Dialect/FIROps.td b/flang/include/flang/Optimizer/Dialect/FIROps.td
--- a/flang/include/flang/Optimizer/Dialect/FIROps.td
+++ b/flang/include/flang/Optimizer/Dialect/FIROps.td
@@ -529,7 +529,7 @@
     CArg<"llvm::ArrayRef<mlir::NamedAttribute>", "{}">:$attributes),
     [{
       $_state.addOperands(selector);
-      llvm::SmallVector<mlir::Attribute, 8> ivalues;
+      llvm::SmallVector<mlir::Attribute> ivalues;
       for (auto iv : compareOperands)
         ivalues.push_back($_builder.getI64IntegerAttr(iv));
       ivalues.push_back($_builder.getUnitAttr());
@@ -538,7 +538,7 @@
       for (auto d : destinations)
         $_state.addSuccessors(d);
       const auto opCount = destOperands.size();
-      llvm::SmallVector<int32_t, 8> argOffs;
+      llvm::SmallVector<int32_t> argOffs;
       int32_t sumArgs = 0;
       for (std::remove_const_t<decltype(count)> i = 0; i != count; ++i) {
         if (i < opCount) {
@@ -564,13 +564,13 @@
     if (parseSelector(parser, result, selector, type))
       return mlir::failure();
 
-    llvm::SmallVector<mlir::Attribute, 8> ivalues;
-    llvm::SmallVector<mlir::Block *, 8> dests;
-    llvm::SmallVector<llvm::SmallVector<mlir::Value, 8>, 8> destArgs;
+    llvm::SmallVector<mlir::Attribute> ivalues;
+    llvm::SmallVector<mlir::Block *> dests;
+    llvm::SmallVector<llvm::SmallVector<mlir::Value>> destArgs;
     while (true) {
       mlir::Attribute ivalue; // Integer or Unit
       mlir::Block *dest;
-      llvm::SmallVector<mlir::Value, 8> destArg;
+      llvm::SmallVector<mlir::Value> destArg;
       mlir::NamedAttrList temp;
       if (parser.parseAttribute(ivalue, "i", temp) ||
           parser.parseComma() ||
@@ -586,7 +586,7 @@
     }
     auto &bld = parser.getBuilder();
     result.addAttribute(getCasesAttr(), bld.getArrayAttr(ivalues));
-    llvm::SmallVector<int32_t, 8> argOffs;
+    llvm::SmallVector<int32_t> argOffs;
     int32_t sumArgs = 0;
     const auto count = dests.size();
     for (std::remove_const_t<decltype(count)> i = 0; i != count; ++i) {
diff --git a/flang/lib/Optimizer/Dialect/FIROps.cpp b/flang/lib/Optimizer/Dialect/FIROps.cpp
--- a/flang/lib/Optimizer/Dialect/FIROps.cpp
+++ b/flang/lib/Optimizer/Dialect/FIROps.cpp
@@ -530,7 +530,7 @@
 /// Get the result types packed in a tuple tuple
 mlir::Type fir::BoxDimsOp::getTupleType() {
   // note: triple, but 4 is nearest power of 2
-  llvm::SmallVector<mlir::Type, 4> triple{
+  llvm::SmallVector<mlir::Type> triple{
       getResult(0).getType(), getResult(1).getType(), getResult(2).getType()};
   return mlir::TupleType::get(getContext(), triple);
 }
@@ -555,14 +555,14 @@
   p << '(' << op->getOperands().drop_front(isDirect ? 0 : 1) << ')';
   p.printOptionalAttrDict(op->getAttrs(), {"callee"});
   auto resultTypes{op.getResultTypes()};
-  llvm::SmallVector<Type, 8> argTypes(
+  llvm::SmallVector<Type> argTypes(
       llvm::drop_begin(op.getOperandTypes(), isDirect ? 0 : 1));
   p << " : " << FunctionType::get(op.getContext(), argTypes, resultTypes);
 }
 
 static mlir::ParseResult parseCallOp(mlir::OpAsmParser &parser,
                                      mlir::OperationState &result) {
-  llvm::SmallVector<mlir::OpAsmParser::OperandType, 8> operands;
+  llvm::SmallVector<mlir::OpAsmParser::OperandType> operands;
   if (parser.parseOperandList(operands))
     return mlir::failure();
 
@@ -639,7 +639,7 @@
 template <typename OPTY>
 static mlir::ParseResult parseCmpOp(mlir::OpAsmParser &parser,
                                     mlir::OperationState &result) {
-  llvm::SmallVector<mlir::OpAsmParser::OperandType, 2> ops;
+  llvm::SmallVector<mlir::OpAsmParser::OperandType> ops;
   mlir::NamedAttrList attrs;
   mlir::Attribute predicateNameAttr;
   mlir::Type type;
@@ -831,10 +831,10 @@
   mlir::OpAsmParser::OperandType memref;
   if (parser.parseOperand(memref) || parser.parseComma())
     return mlir::failure();
-  llvm::SmallVector<mlir::OpAsmParser::OperandType, 8> coorOperands;
+  llvm::SmallVector<mlir::OpAsmParser::OperandType> coorOperands;
   if (parser.parseOperandList(coorOperands))
     return mlir::failure();
-  llvm::SmallVector<mlir::OpAsmParser::OperandType, 16> allOperands;
+  llvm::SmallVector<mlir::OpAsmParser::OperandType> allOperands;
   allOperands.push_back(memref);
   allOperands.append(coorOperands.begin(), coorOperands.end());
   mlir::FunctionType funcTy;
@@ -1848,8 +1848,8 @@
     result.addAttribute("unordered", builder.getUnitAttr());
 
   // Parse the optional initial iteration arguments.
-  llvm::SmallVector<mlir::OpAsmParser::OperandType, 4> regionArgs, operands;
-  llvm::SmallVector<mlir::Type, 4> argTypes;
+  llvm::SmallVector<mlir::OpAsmParser::OperandType> regionArgs, operands;
+  llvm::SmallVector<mlir::Type> argTypes;
   auto prependCount = false;
   regionArgs.push_back(inductionVariable);
 
@@ -2318,16 +2318,16 @@
   if (parseSelector(parser, result, selector, type))
     return mlir::failure();
 
-  llvm::SmallVector<mlir::Attribute, 8> attrs;
-  llvm::SmallVector<mlir::OpAsmParser::OperandType, 8> opers;
-  llvm::SmallVector<mlir::Block *, 8> dests;
-  llvm::SmallVector<llvm::SmallVector<mlir::Value, 8>, 8> destArgs;
-  llvm::SmallVector<int32_t, 8> argOffs;
+  llvm::SmallVector<mlir::Attribute> attrs;
+  llvm::SmallVector<mlir::OpAsmParser::OperandType> opers;
+  llvm::SmallVector<mlir::Block *> dests;
+  llvm::SmallVector<llvm::SmallVector<mlir::Value>> destArgs;
+  llvm::SmallVector<int32_t> argOffs;
   int32_t offSize = 0;
   while (true) {
     mlir::Attribute attr;
     mlir::Block *dest;
-    llvm::SmallVector<mlir::Value, 8> destArg;
+    llvm::SmallVector<mlir::Value> destArg;
     mlir::NamedAttrList temp;
     if (parser.parseAttribute(attr, "a", temp) || isValidCaseAttr(attr) ||
         parser.parseComma())
@@ -2366,7 +2366,7 @@
                       parser.getBuilder().getArrayAttr(attrs));
   if (parser.resolveOperands(opers, type, result.operands))
     return mlir::failure();
-  llvm::SmallVector<int32_t, 8> targOffs;
+  llvm::SmallVector<int32_t> targOffs;
   int32_t toffSize = 0;
   const auto count = dests.size();
   for (std::remove_const_t<decltype(count)> i = 0; i != count; ++i) {
@@ -2434,7 +2434,7 @@
                               llvm::ArrayRef<mlir::NamedAttribute> attributes) {
   result.addOperands(selector);
   result.addAttribute(getCasesAttr(), builder.getArrayAttr(compareAttrs));
-  llvm::SmallVector<int32_t, 8> operOffs;
+  llvm::SmallVector<int32_t> operOffs;
   int32_t operSize = 0;
   for (auto attr : compareAttrs) {
     if (attr.isa<fir::ClosedIntervalAttr>()) {
@@ -2455,7 +2455,7 @@
   for (auto d : destinations)
     result.addSuccessors(d);
   const auto opCount = destOperands.size();
-  llvm::SmallVector<int32_t, 8> argOffs;
+  llvm::SmallVector<int32_t> argOffs;
   int32_t sumArgs = 0;
   for (std::remove_const_t<decltype(count)> i = 0; i != count; ++i) {
     if (i < opCount) {
@@ -2485,7 +2485,7 @@
                               llvm::ArrayRef<mlir::Block *> destinations,
                               llvm::ArrayRef<mlir::ValueRange> destOperands,
                               llvm::ArrayRef<mlir::NamedAttribute> attributes) {
-  llvm::SmallVector<mlir::ValueRange, 16> cmpOpers;
+  llvm::SmallVector<mlir::ValueRange> cmpOpers;
   auto iter = cmpOpList.begin();
   for (auto &attr : compareAttrs) {
     if (attr.isa<fir::ClosedIntervalAttr>()) {
@@ -2603,13 +2603,13 @@
   if (parseSelector(parser, result, selector, type))
     return mlir::failure();
 
-  llvm::SmallVector<mlir::Attribute, 8> attrs;
-  llvm::SmallVector<mlir::Block *, 8> dests;
-  llvm::SmallVector<llvm::SmallVector<mlir::Value, 8>, 8> destArgs;
+  llvm::SmallVector<mlir::Attribute> attrs;
+  llvm::SmallVector<mlir::Block *> dests;
+  llvm::SmallVector<llvm::SmallVector<mlir::Value>> destArgs;
   while (true) {
     mlir::Attribute attr;
     mlir::Block *dest;
-    llvm::SmallVector<mlir::Value, 8> destArg;
+    llvm::SmallVector<mlir::Value> destArg;
     mlir::NamedAttrList temp;
     if (parser.parseAttribute(attr, "a", temp) || parser.parseComma() ||
         parser.parseSuccessorAndUseList(dest, destArg))
@@ -2625,7 +2625,7 @@
   auto &bld = parser.getBuilder();
   result.addAttribute(fir::SelectTypeOp::getCasesAttr(),
                       bld.getArrayAttr(attrs));
-  llvm::SmallVector<int32_t, 8> argOffs;
+  llvm::SmallVector<int32_t> argOffs;
   int32_t offSize = 0;
   const auto count = dests.size();
   for (std::remove_const_t<decltype(count)> i = 0; i != count; ++i) {