diff --git a/mlir/lib/Dialect/Affine/IR/AffineOps.cpp b/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
--- a/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
+++ b/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
@@ -1578,6 +1578,7 @@
     printBlockTerminators = true;
   }
 
+  p << ' ';
   p.printRegion(op.region(),
                 /*printEntryBlockArgs=*/false, printBlockTerminators);
   p.printOptionalAttrDict(op->getAttrs(),
@@ -2142,6 +2143,7 @@
   printDimAndSymbolList(op.operand_begin(), op.operand_end(),
                         conditionAttr.getValue().getNumDims(), p);
   p.printOptionalArrowTypeList(op.getResultTypes());
+  p << ' ';
   p.printRegion(op.thenRegion(),
                 /*printEntryBlockArgs=*/false,
                 /*printBlockTerminators=*/op.getNumResults());
@@ -2149,7 +2151,7 @@
   // Print the 'else' regions if it has any blocks.
   auto &elseRegion = op.elseRegion();
   if (!elseRegion.empty()) {
-    p << " else";
+    p << " else ";
     p.printRegion(elseRegion,
                   /*printEntryBlockArgs=*/false,
                   /*printBlockTerminators=*/op.getNumResults());
@@ -3157,6 +3159,7 @@
     p << ") -> (" << op.getResultTypes() << ")";
   }
 
+  p << ' ';
   p.printRegion(op.region(), /*printEntryBlockArgs=*/false,
                 /*printBlockTerminators=*/op.getNumResults());
   p.printOptionalAttrDict(
diff --git a/mlir/lib/Dialect/Async/IR/Async.cpp b/mlir/lib/Dialect/Async/IR/Async.cpp
--- a/mlir/lib/Dialect/Async/IR/Async.cpp
+++ b/mlir/lib/Dialect/Async/IR/Async.cpp
@@ -150,6 +150,7 @@
   p.printOptionalArrowTypeList(llvm::drop_begin(op.getResultTypes()));
   p.printOptionalAttrDictWithKeyword(op->getAttrs(),
                                      {kOperandSegmentSizesAttr});
+  p << ' ';
   p.printRegion(op.body(), /*printEntryBlockArgs=*/false);
 }
 
diff --git a/mlir/lib/Dialect/GPU/IR/GPUDialect.cpp b/mlir/lib/Dialect/GPU/IR/GPUDialect.cpp
--- a/mlir/lib/Dialect/GPU/IR/GPUDialect.cpp
+++ b/mlir/lib/Dialect/GPU/IR/GPUDialect.cpp
@@ -475,6 +475,7 @@
     p << ' ' << op.getDynamicSharedMemorySizeKeyword() << ' '
       << op.dynamicSharedMemorySize();
 
+  p << ' ';
   p.printRegion(op.body(), /*printEntryBlockArgs=*/false);
   p.printOptionalAttrDict(op->getAttrs());
 }
@@ -881,6 +882,7 @@
       p, op.getOperation(), type.getNumInputs(), type.getNumResults(),
       {op.getNumWorkgroupAttributionsAttrName(),
        GPUDialect::getKernelFuncAttrName()});
+  p << ' ';
   p.printRegion(op.getBody(), /*printEntryBlockArgs=*/false);
 }
 
@@ -1005,6 +1007,7 @@
   p.printSymbolName(op.getName());
   p.printOptionalAttrDictWithKeyword(op->getAttrs(),
                                      {SymbolTable::getSymbolAttrName()});
+  p << ' ';
   p.printRegion(op->getRegion(0), /*printEntryBlockArgs=*/false,
                 /*printBlockTerminators=*/false);
 }
diff --git a/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp b/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
--- a/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
+++ b/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
@@ -1661,8 +1661,10 @@
   p << " : " << op.getType();
 
   Region &initializer = op.getInitializerRegion();
-  if (!initializer.empty())
+  if (!initializer.empty()) {
+    p << ' ';
     p.printRegion(initializer, /*printEntryBlockArgs=*/false);
+  }
 }
 
 // Parses one of the keywords provided in the list `keywords` and returns the
@@ -2092,9 +2094,11 @@
 
   // Print the body if this is not an external function.
   Region &body = op.getBody();
-  if (!body.empty())
+  if (!body.empty()) {
+    p << ' ';
     p.printRegion(body, /*printEntryBlockArgs=*/false,
                   /*printBlockTerminators=*/true);
+  }
 }
 
 // Hook for OpTrait::FunctionLike, called after verifying that the 'type'
diff --git a/mlir/lib/Dialect/Linalg/IR/LinalgOps.cpp b/mlir/lib/Dialect/Linalg/IR/LinalgOps.cpp
--- a/mlir/lib/Dialect/Linalg/IR/LinalgOps.cpp
+++ b/mlir/lib/Dialect/Linalg/IR/LinalgOps.cpp
@@ -650,8 +650,10 @@
   }
 
   // Print region.
-  if (!op.region().empty())
+  if (!op.region().empty()) {
+    p << ' ';
     p.printRegion(op.region());
+  }
 
   // Print results.
   printNamedStructuredOpResults(p, op.result_tensors().getTypes());
@@ -1805,11 +1807,12 @@
         return attr.cast<StringAttr>().getValue() !=
                getParallelIteratorTypeName();
       }))
-    p << " iterators" << op.iterator_types() << "";
+    p << " iterators" << op.iterator_types();
 
   if (op.distribution_types().hasValue())
-    p << " distribution" << op.distribution_types().getValue() << "";
+    p << " distribution" << op.distribution_types().getValue();
 
+  p << ' ';
   p.printRegion(op.region(), /*printEntryBlockArgs=*/false);
   p.printOptionalAttrDict(
       op->getAttrs(), /*elidedAttrs=*/{TiledLoopOp::getOperandSegmentSizeAttr(),
diff --git a/mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp b/mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp
--- a/mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp
+++ b/mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp
@@ -211,11 +211,12 @@
 static void print(OpAsmPrinter &p, AllocaScopeOp &op) {
   bool printBlockTerminators = false;
 
-  p << " ";
+  p << ' ';
   if (!op.results().empty()) {
     p << " -> (" << op.getResultTypes() << ")";
     printBlockTerminators = true;
   }
+  p << ' ';
   p.printRegion(op.bodyRegion(),
                 /*printEntryBlockArgs=*/false,
                 /*printBlockTerminators=*/printBlockTerminators);
diff --git a/mlir/lib/Dialect/OpenACC/IR/OpenACC.cpp b/mlir/lib/Dialect/OpenACC/IR/OpenACC.cpp
--- a/mlir/lib/Dialect/OpenACC/IR/OpenACC.cpp
+++ b/mlir/lib/Dialect/OpenACC/IR/OpenACC.cpp
@@ -469,6 +469,7 @@
   printOperandList(op.gangFirstPrivateOperands(),
                    ParallelOp::getFirstPrivateKeyword(), printer);
 
+  printer << ' ';
   printer.printRegion(op.region(),
                       /*printEntryBlockArgs=*/false,
                       /*printBlockTerminators=*/true);
@@ -649,6 +650,7 @@
   if (op.getNumResults() > 0)
     printer << " -> (" << op.getResultTypes() << ")";
 
+  printer << ' ';
   printer.printRegion(op.region(),
                       /*printEntryBlockArgs=*/false,
                       /*printBlockTerminators=*/true);
diff --git a/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp b/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp
--- a/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp
+++ b/mlir/lib/Dialect/OpenMP/IR/OpenMPDialect.cpp
@@ -189,6 +189,7 @@
   if (auto bind = op.proc_bind_val())
     p << "proc_bind(" << bind << ") ";
 
+  p << ' ';
   p.printRegion(op.getRegion());
 }
 
@@ -960,8 +961,9 @@
     printAllocateAndAllocator(p, op.allocate_vars(), op.allocators_vars());
 
   if (op.nowait())
-    p << "nowait ";
+    p << "nowait";
 
+  p << ' ';
   p.printRegion(op.region());
 }
 
@@ -1094,6 +1096,7 @@
   if (!op.reduction_vars().empty())
     printReductionVarList(p, op.reductions(), op.reduction_vars());
 
+  p << ' ';
   p.printRegion(op.region(), /*printEntryBlockArgs=*/false);
 }
 
diff --git a/mlir/lib/Dialect/PDLInterp/IR/PDLInterp.cpp b/mlir/lib/Dialect/PDLInterp/IR/PDLInterp.cpp
--- a/mlir/lib/Dialect/PDLInterp/IR/PDLInterp.cpp
+++ b/mlir/lib/Dialect/PDLInterp/IR/PDLInterp.cpp
@@ -122,7 +122,7 @@
 
 static void print(OpAsmPrinter &p, ForEachOp op) {
   BlockArgument arg = op.getLoopVariable();
-  p << ' ' << arg << " : " << arg.getType() << " in " << op.values();
+  p << ' ' << arg << " : " << arg.getType() << " in " << op.values() << ' ';
   p.printRegion(op.region(), /*printEntryBlockArgs=*/false);
   p.printOptionalAttrDict(op->getAttrs());
   p << " -> ";
diff --git a/mlir/lib/Dialect/SCF/SCF.cpp b/mlir/lib/Dialect/SCF/SCF.cpp
--- a/mlir/lib/Dialect/SCF/SCF.cpp
+++ b/mlir/lib/Dialect/SCF/SCF.cpp
@@ -118,6 +118,7 @@
 static void print(OpAsmPrinter &p, ExecuteRegionOp op) {
   p.printOptionalArrowTypeList(op.getResultTypes());
 
+  p << ' ';
   p.printRegion(op.getRegion(),
                 /*printEntryBlockArgs=*/false,
                 /*printBlockTerminators=*/true);
@@ -347,6 +348,7 @@
                           " iter_args");
   if (!op.getIterOperands().empty())
     p << " -> (" << op.getIterOperands().getTypes() << ')';
+  p << ' ';
   p.printRegion(op.getRegion(),
                 /*printEntryBlockArgs=*/false,
                 /*printBlockTerminators=*/op.hasIterOperands());
@@ -1130,6 +1132,7 @@
     // Print yield explicitly if the op defines values.
     printBlockTerminators = true;
   }
+  p << ' ';
   p.printRegion(op.getThenRegion(),
                 /*printEntryBlockArgs=*/false,
                 /*printBlockTerminators=*/printBlockTerminators);
@@ -1137,7 +1140,7 @@
   // Print the 'else' regions if it exists and has a block.
   auto &elseRegion = op.getElseRegion();
   if (!elseRegion.empty()) {
-    p << " else";
+    p << " else ";
     p.printRegion(elseRegion,
                   /*printEntryBlockArgs=*/false,
                   /*printBlockTerminators=*/printBlockTerminators);
@@ -1881,6 +1884,7 @@
   if (!op.getInitVals().empty())
     p << " init (" << op.getInitVals() << ")";
   p.printOptionalArrowTypeList(op.getResultTypes());
+  p << ' ';
   p.printRegion(op.getRegion(), /*printEntryBlockArgs=*/false);
   p.printOptionalAttrDict(
       op->getAttrs(), /*elidedAttrs=*/ParallelOp::getOperandSegmentSizeAttr());
@@ -2137,7 +2141,7 @@
 
 static void print(OpAsmPrinter &p, ReduceOp op) {
   p << "(" << op.getOperand() << ") ";
-  p << " : " << op.getOperand().getType();
+  p << " : " << op.getOperand().getType() << ' ';
   p.printRegion(op.getReductionOperator());
 }
 
@@ -2252,8 +2256,9 @@
                           op.getInits(), " ");
   p << " : ";
   p.printFunctionalType(op.getInits().getTypes(), op.getResults().getTypes());
+  p << ' ';
   p.printRegion(op.getBefore(), /*printEntryBlockArgs=*/false);
-  p << " do";
+  p << " do ";
   p.printRegion(op.getAfter());
   p.printOptionalAttrDictWithKeyword(op->getAttrs());
 }
diff --git a/mlir/lib/Dialect/SPIRV/IR/SPIRVOps.cpp b/mlir/lib/Dialect/SPIRV/IR/SPIRVOps.cpp
--- a/mlir/lib/Dialect/SPIRV/IR/SPIRVOps.cpp
+++ b/mlir/lib/Dialect/SPIRV/IR/SPIRVOps.cpp
@@ -2004,9 +2004,11 @@
 
   // Print the body if this is not an external function.
   Region &body = fnOp.body();
-  if (!body.empty())
+  if (!body.empty()) {
+    printer << ' ';
     printer.printRegion(body, /*printEntryBlockArgs=*/false,
                         /*printBlockTerminators=*/true);
+  }
 }
 
 LogicalResult spirv::FuncOp::verifyType() {
@@ -2485,6 +2487,7 @@
   auto control = loopOp.loop_control();
   if (control != spirv::LoopControl::None)
     printer << " control(" << spirv::stringifyLoopControl(control) << ")";
+  printer << ' ';
   printer.printRegion(op->getRegion(0), /*printEntryBlockArgs=*/false,
                       /*printBlockTerminators=*/true);
 }
@@ -2726,6 +2729,7 @@
   }
 
   printer.printOptionalAttrDictWithKeyword(moduleOp->getAttrs(), elidedAttrs);
+  printer << ' ';
   printer.printRegion(moduleOp.getRegion());
 }
 
@@ -2875,6 +2879,7 @@
   auto control = selectionOp.selection_control();
   if (control != spirv::SelectionControl::None)
     printer << " control(" << spirv::stringifySelectionControl(control) << ")";
+  printer << ' ';
   printer.printRegion(op->getRegion(0), /*printEntryBlockArgs=*/false,
                       /*printBlockTerminators=*/true);
 }
diff --git a/mlir/lib/Dialect/Shape/IR/Shape.cpp b/mlir/lib/Dialect/Shape/IR/Shape.cpp
--- a/mlir/lib/Dialect/Shape/IR/Shape.cpp
+++ b/mlir/lib/Dialect/Shape/IR/Shape.cpp
@@ -287,9 +287,9 @@
   bool yieldsResults = !op.getResults().empty();
 
   p << " " << op.getWitness();
-  if (yieldsResults) {
+  if (yieldsResults)
     p << " -> (" << op.getResultTypes() << ")";
-  }
+  p << ' ';
   p.printRegion(op.getDoRegion(),
                 /*printEntryBlockArgs=*/false,
                 /*printBlockTerminators=*/yieldsResults);
@@ -1114,6 +1114,7 @@
   p.printSymbolName(op.getName());
   p.printOptionalAttrDictWithKeyword(
       op->getAttrs(), {SymbolTable::getSymbolAttrName(), "mapping"});
+  p << ' ';
   p.printRegion(op.getOperation()->getRegion(0), /*printEntryBlockArgs=*/false,
                 /*printBlockTerminators=*/false);
   p << " mapping ";
@@ -1711,6 +1712,7 @@
   p << '(' << op.getShape() << ", " << op.getInitVals()
     << ") : " << op.getShape().getType();
   p.printOptionalArrowTypeList(op.getResultTypes());
+  p << ' ';
   p.printRegion(op.getRegion());
   p.printOptionalAttrDict(op->getAttrs());
 }
diff --git a/mlir/lib/Dialect/StandardOps/IR/Ops.cpp b/mlir/lib/Dialect/StandardOps/IR/Ops.cpp
--- a/mlir/lib/Dialect/StandardOps/IR/Ops.cpp
+++ b/mlir/lib/Dialect/StandardOps/IR/Ops.cpp
@@ -195,7 +195,7 @@
 
 static void print(OpAsmPrinter &p, GenericAtomicRMWOp op) {
   p << ' ' << op.getMemref() << "[" << op.getIndices()
-    << "] : " << op.getMemref().getType();
+    << "] : " << op.getMemref().getType() << ' ';
   p.printRegion(op.getRegion());
   p.printOptionalAttrDict(op->getAttrs());
 }
diff --git a/mlir/lib/IR/AsmPrinter.cpp b/mlir/lib/IR/AsmPrinter.cpp
--- a/mlir/lib/IR/AsmPrinter.cpp
+++ b/mlir/lib/IR/AsmPrinter.cpp
@@ -2716,7 +2716,7 @@
 void OperationPrinter::printRegion(Region &region, bool printEntryBlockArgs,
                                    bool printBlockTerminators,
                                    bool printEmptyBlock) {
-  os << " {" << newLine;
+  os << "{" << newLine;
   if (!region.empty()) {
     auto restoreDefaultDialect =
         llvm::make_scope_exit([&]() { defaultDialectStack.pop_back(); });
diff --git a/mlir/lib/IR/FunctionImplementation.cpp b/mlir/lib/IR/FunctionImplementation.cpp
--- a/mlir/lib/IR/FunctionImplementation.cpp
+++ b/mlir/lib/IR/FunctionImplementation.cpp
@@ -371,7 +371,9 @@
                           {visibilityAttrName});
   // Print the body if this is not an external function.
   Region &body = op->getRegion(0);
-  if (!body.empty())
+  if (!body.empty()) {
+    p << ' ';
     p.printRegion(body, /*printEntryBlockArgs=*/false,
                   /*printBlockTerminators=*/true);
+  }
 }
diff --git a/mlir/test/Conversion/OpenMPToLLVM/convert-to-llvmir.mlir b/mlir/test/Conversion/OpenMPToLLVM/convert-to-llvmir.mlir
--- a/mlir/test/Conversion/OpenMPToLLVM/convert-to-llvmir.mlir
+++ b/mlir/test/Conversion/OpenMPToLLVM/convert-to-llvmir.mlir
@@ -50,7 +50,7 @@
   // CHECK: omp.parallel
   omp.parallel {
     // CHECK: omp.wsloop (%[[ARG6:.*]], %[[ARG7:.*]]) : i64 = (%[[ARG0]], %[[ARG1]]) to (%[[ARG2]], %[[ARG3]]) step (%[[ARG4]], %[[ARG5]]) {
-    "omp.wsloop"(%arg0, %arg1, %arg2, %arg3, %arg4, %arg5) ( {
+    "omp.wsloop"(%arg0, %arg1, %arg2, %arg3, %arg4, %arg5) ({
     ^bb0(%arg6: index, %arg7: index):  // no predecessors
       // CHECK-DAG: %[[CAST_ARG6:.*]] = builtin.unrealized_conversion_cast %[[ARG6]] : i64 to index
       // CHECK-DAG: %[[CAST_ARG7:.*]] = builtin.unrealized_conversion_cast %[[ARG7]] : i64 to index
diff --git a/mlir/test/Conversion/TosaToSCF/tosa-to-scf.mlir b/mlir/test/Conversion/TosaToSCF/tosa-to-scf.mlir
--- a/mlir/test/Conversion/TosaToSCF/tosa-to-scf.mlir
+++ b/mlir/test/Conversion/TosaToSCF/tosa-to-scf.mlir
@@ -4,7 +4,7 @@
 // CHECK-SAME: ([[ARG0:%.+]]: tensor<i32>)
 func @while_test(%arg0 : tensor<i32>) -> (tensor<i32>) {
   // CHECK: [[WHILE:%.+]] = scf.while ([[ARG1:%.+]] = [[ARG0]])
-  %1 = "tosa.while_loop"(%arg0) ( {
+  %1 = "tosa.while_loop"(%arg0) ({
   ^bb0(%arg2: tensor<i32>):
     // CHECK: "tosa.const"
     %2 = "tosa.const"() {value = dense<3> : tensor<i32>} : () -> tensor<i32>
diff --git a/mlir/test/Dialect/Affine/ops.mlir b/mlir/test/Dialect/Affine/ops.mlir
--- a/mlir/test/Dialect/Affine/ops.mlir
+++ b/mlir/test/Dialect/Affine/ops.mlir
@@ -49,7 +49,7 @@
   // CHECK: affine.for
   // CHECK-NEXT: }
   //
-  // GENERIC:      "affine.for"() ( {
+  // GENERIC:      "affine.for"() ({
   // GENERIC-NEXT: ^bb0(%{{.*}}: index):	// no predecessors
   // GENERIC-NEXT:   "affine.yield"() : () -> ()
   // GENERIC-NEXT: }) {lower_bound = #map0, step = 1 : index, upper_bound = #map1} : () -> ()
diff --git a/mlir/test/Dialect/Bufferization/Transforms/buffer-deallocation.mlir b/mlir/test/Dialect/Bufferization/Transforms/buffer-deallocation.mlir
--- a/mlir/test/Dialect/Bufferization/Transforms/buffer-deallocation.mlir
+++ b/mlir/test/Dialect/Bufferization/Transforms/buffer-deallocation.mlir
@@ -1198,9 +1198,9 @@
 
 func @noRegionBranchOpInterface() {
 // expected-error@+1 {{All operations with attached regions need to implement the RegionBranchOpInterface.}}
-  %0 = "test.bar"() ( {
+  %0 = "test.bar"() ({
 // expected-error@+1 {{All operations with attached regions need to implement the RegionBranchOpInterface.}}
-    %1 = "test.bar"() ( {
+    %1 = "test.bar"() ({
       "test.yield"() : () -> ()
     }) : () -> (i32)
     "test.yield"() : () -> ()
diff --git a/mlir/test/Dialect/GPU/invalid.mlir b/mlir/test/Dialect/GPU/invalid.mlir
--- a/mlir/test/Dialect/GPU/invalid.mlir
+++ b/mlir/test/Dialect/GPU/invalid.mlir
@@ -430,7 +430,7 @@
 module {
   gpu.module @gpu_funcs {
     // expected-error @+1 {{'gpu.func' op expected at least 5 arguments to body region}}
-    "gpu.func"() ( {
+    "gpu.func"() ({
     ^bb0(%arg0: f32, %arg1: memref<?xf32>, %arg2: memref<5xf32, 3>, %arg3: memref<5xf32, 5>):
       "gpu.return"() : () -> ()
     } ) {gpu.kernel, sym_name = "kernel_1", type = (f32, memref<?xf32>) -> (), workgroup_attributions = 3: i64} : () -> ()
diff --git a/mlir/test/Dialect/GPU/ops.mlir b/mlir/test/Dialect/GPU/ops.mlir
--- a/mlir/test/Dialect/GPU/ops.mlir
+++ b/mlir/test/Dialect/GPU/ops.mlir
@@ -155,7 +155,7 @@
 
   gpu.module @explicit_attributions {
     // CHECK-LABEL: gpu.func @kernel_1({{.*}}: f32, {{.*}}: memref<?xf32>) workgroup({{.*}}: memref<5xf32, 3>) private({{.*}}: memref<5xf32, 5>)
-    "gpu.func"() ( {
+    "gpu.func"() ({
     ^bb0(%arg0: f32, %arg1: memref<?xf32>, %arg2: memref<5xf32, 3>, %arg3: memref<5xf32, 5>):
       "gpu.return"() : () -> ()
     } ) {gpu.kernel, sym_name = "kernel_1", type = (f32, memref<?xf32>) -> (), workgroup_attributions = 1: i64} : () -> ()
diff --git a/mlir/test/Dialect/Linalg/invalid.mlir b/mlir/test/Dialect/Linalg/invalid.mlir
--- a/mlir/test/Dialect/Linalg/invalid.mlir
+++ b/mlir/test/Dialect/Linalg/invalid.mlir
@@ -542,7 +542,7 @@
   %c0 = arith.constant 0 : index
   %c192 = arith.constant 192 : index
   // expected-error @+1 {{expected iterator types array attribute size = 1 to match the number of loops = 2}}
-  %0 = "linalg.tiled_loop"(%c0, %c0, %c192, %c192, %c24, %c24, %A, %B, %C_tensor, %C) ( {
+  %0 = "linalg.tiled_loop"(%c0, %c0, %c192, %c192, %c24, %c24, %A, %B, %C_tensor, %C) ({
     ^bb0(%arg4: index, %arg5: index, %A_: memref<192x192xf32>,
          %B_: memref<192x192xf32>, %CT_: tensor<192x192xf32>,
          %C_: memref<192x192xf32>):
@@ -567,7 +567,7 @@
   %c192 = arith.constant 192 : index
   %c24 = arith.constant 24 : index
   // expected-error @+1 {{expected output arg 0 with type = 'memref<192xf32>' to match region arg 1 type = 'memref<100xf32>'}}
-  "linalg.tiled_loop"(%c0, %c192, %c24, %A) ( {
+  "linalg.tiled_loop"(%c0, %c192, %c24, %A) ({
     ^bb0(%arg4: index, %A_: memref<100xf32>):
       call @foo(%A_) : (memref<100xf32>)-> ()
       linalg.yield
diff --git a/mlir/test/Dialect/Linalg/named-ops.mlir b/mlir/test/Dialect/Linalg/named-ops.mlir
--- a/mlir/test/Dialect/Linalg/named-ops.mlir
+++ b/mlir/test/Dialect/Linalg/named-ops.mlir
@@ -565,7 +565,7 @@
 func @conv_interface_wrong_input_indexing_map(
     %arg0 : tensor<?x?x?x?xf32>, %arg2 : tensor<?x?x?x?xf32>, %arg1 : tensor<?x?x?x?xf32>) -> tensor<?x?x?x?xf32> {
   // expected-error @+1 {{unexpected input index map for convolutions}}
-  %0 = "linalg.conv_2d_nhwc_hwcf"(%arg0, %arg1, %arg2) ( {
+  %0 = "linalg.conv_2d_nhwc_hwcf"(%arg0, %arg1, %arg2) ({
     ^bb0(%arg3: f32, %arg4: f32, %arg5 : f32):  // no predecessors
       %1 = "arith.mulf"(%arg3, %arg4) : (f32, f32) -> f32
       %2 = "arith.addf"(%arg5, %1) : (f32, f32) -> f32
@@ -582,7 +582,7 @@
 func @conv_interface_wrong_num_operands(
     %arg0 : tensor<?x?x?x?xf32>, %arg1 : tensor<?x?x?x?x?xf32>, %arg2 : tensor<?x?x?x?xf32>) -> tensor<?x?x?x?xf32> {
   // expected-error @+1 {{expected output/filter indexing maps to be projected permutations}}
-  %0 = "linalg.conv_2d_nhwc_hwcf"(%arg0, %arg1, %arg2) ( {
+  %0 = "linalg.conv_2d_nhwc_hwcf"(%arg0, %arg1, %arg2) ({
     ^bb0(%arg3: f32, %arg4: f32, %arg5 : f32):  // no predecessors
       %1 = "arith.mulf"(%arg3, %arg4) : (f32, f32) -> f32
       %2 = "arith.addf"(%arg5, %1) : (f32, f32) -> f32
diff --git a/mlir/test/Dialect/MemRef/invalid.mlir b/mlir/test/Dialect/MemRef/invalid.mlir
--- a/mlir/test/Dialect/MemRef/invalid.mlir
+++ b/mlir/test/Dialect/MemRef/invalid.mlir
@@ -814,7 +814,7 @@
 
 // -----
 
-"alloca_without_scoped_alloc_parent"() ( {
+"alloca_without_scoped_alloc_parent"() ({
   memref.alloca() : memref<1xf32>
   // expected-error@-1 {{requires an ancestor op with AutomaticAllocationScope trait}}
   return
diff --git a/mlir/test/Dialect/Tosa/inlining.mlir b/mlir/test/Dialect/Tosa/inlining.mlir
--- a/mlir/test/Dialect/Tosa/inlining.mlir
+++ b/mlir/test/Dialect/Tosa/inlining.mlir
@@ -8,7 +8,7 @@
 // CHECK-NOT: @add
 // CHECK-NOT: @sub
 func @inlined_if_fn(%arg0: tensor<f32>, %arg1: tensor<f32>, %arg2: tensor<i1>) -> tensor<f32> {
-  %0 = "tosa.cond_if"(%arg2, %arg0, %arg1) ( {
+  %0 = "tosa.cond_if"(%arg2, %arg0, %arg1) ({
   ^bb0(%arg3: tensor<f32>, %arg4: tensor<f32>):  // no predecessors
     %1 = call @add(%arg3, %arg4) : (tensor<f32>, tensor<f32>) -> tensor<f32>
     "tosa.yield"(%1) : (tensor<f32>) -> ()
@@ -34,7 +34,7 @@
 func @inlined_while_fn(%arg0: tensor<i32>, %arg1: tensor<i32>, %arg2: tensor<i32>, %arg3: tensor<10xi32>) -> tensor<10xi32> {
   // Check that calls are inlined and functions eliminated:
   // CHECK-NOT: @while
-  %1:4 = "tosa.while_loop"(%arg0, %arg1, %arg2, %arg3) ( {
+  %1:4 = "tosa.while_loop"(%arg0, %arg1, %arg2, %arg3) ({
   ^bb0(%arg4: tensor<i32>, %arg5: tensor<i32>, %arg6: tensor<i32>, %arg7: tensor<10xi32>):  // no predecessors
     %2 = call @while_cond_40(%arg4, %arg5, %arg6, %arg7) : (tensor<i32>, tensor<i32>, tensor<i32>, tensor<10xi32>) -> tensor<i1>
     "tosa.yield"(%2) : (tensor<i1>) -> ()
diff --git a/mlir/test/Dialect/Tosa/ops.mlir b/mlir/test/Dialect/Tosa/ops.mlir
--- a/mlir/test/Dialect/Tosa/ops.mlir
+++ b/mlir/test/Dialect/Tosa/ops.mlir
@@ -505,7 +505,7 @@
 // -----
 // CHECK-LABEL: cond_if
 func @test_cond_if(%arg0: tensor<f32>, %arg1: tensor<f32>, %arg2: tensor<i1>) -> tensor<f32> {
-  %0 = "tosa.cond_if"(%arg2, %arg0, %arg1) ( {
+  %0 = "tosa.cond_if"(%arg2, %arg0, %arg1) ({
   ^bb0(%arg3: tensor<f32>, %arg4: tensor<f32>):  // no predecessors
     %1 = "tosa.add"(%arg3, %arg4) : (tensor<f32>, tensor<f32>) -> tensor<f32>
     "tosa.yield"(%1) : (tensor<f32>) -> ()
@@ -521,7 +521,7 @@
 // CHECK-LABEL: while_loop
 func @test_while_loop(%arg0: tensor<10xi32>, %arg1: tensor<i32>) {
   %0 = "tosa.const"() {value = dense<0> : tensor<i32>} : () -> tensor<i32>
-  %1:3 = "tosa.while_loop"(%0, %0, %arg0) ( {
+  %1:3 = "tosa.while_loop"(%0, %0, %arg0) ({
   ^bb0(%arg2: tensor<i32>, %arg3: tensor<i32>, %arg4: tensor<10xi32>):  // no predecessors
     %2 = "tosa.greater_equal"(%arg3, %arg1) : (tensor<i32>, tensor<i32>) -> tensor<i1>
     %3 = "tosa.logical_not"(%2) : (tensor<i1>) -> tensor<i1>
diff --git a/mlir/test/Dialect/Tosa/tosa-infer-shapes.mlir b/mlir/test/Dialect/Tosa/tosa-infer-shapes.mlir
--- a/mlir/test/Dialect/Tosa/tosa-infer-shapes.mlir
+++ b/mlir/test/Dialect/Tosa/tosa-infer-shapes.mlir
@@ -1130,7 +1130,7 @@
   %0 = "tosa.add"(%arg0, %arg0) : (tensor<i32>, tensor<i32>) -> tensor<*xi32>
 
   // CHECK:      "tosa.while_loop"
-  %1 = "tosa.while_loop"(%0) ( {
+  %1 = "tosa.while_loop"(%0) ({
 
   // CHECK:      ^bb0
   // CHECK-SAME: tensor<i32>
@@ -1168,7 +1168,7 @@
 // CHECK-LABEL: @while_test
 func @while_test(%arg0 : tensor<i32>, %arg1 : tensor<1xi32>) -> () {
   // CHECK:      "tosa.while_loop"
-  %1:2 = "tosa.while_loop"(%arg0, %arg1) ( {
+  %1:2 = "tosa.while_loop"(%arg0, %arg1) ({
 
   // CHECK:      ^bb0
   // CHECK-SAME: tensor<i32>
diff --git a/mlir/test/IR/invalid-ops.mlir b/mlir/test/IR/invalid-ops.mlir
--- a/mlir/test/IR/invalid-ops.mlir
+++ b/mlir/test/IR/invalid-ops.mlir
@@ -156,7 +156,7 @@
 
 func @generic_atomic_rmw_result_type_mismatch(%I: memref<10xf32>, %i : index) {
  // expected-error@+1 {{failed to verify that result type matches element type of memref}}
- %0 = "std.generic_atomic_rmw"(%I, %i) ( {
+ %0 = "std.generic_atomic_rmw"(%I, %i) ({
     ^bb0(%old_value: f32):
       %c1 = arith.constant 1.0 : f32
       atomic_yield %c1 : f32
diff --git a/mlir/test/IR/parser.mlir b/mlir/test/IR/parser.mlir
--- a/mlir/test/IR/parser.mlir
+++ b/mlir/test/IR/parser.mlir
@@ -864,7 +864,7 @@
 // CHECK-LABEL: func @terminator_with_regions
 func @terminator_with_regions() {
   // Combine successors and regions in the same operation.
-  // CHECK: "region"()[^bb1] ( {
+  // CHECK: "region"()[^bb1] ({
   // CHECK: }) : () -> ()
   "region"()[^bb2] ({}) : () -> ()
 ^bb2:
@@ -1132,7 +1132,7 @@
 
 // CHECK-LABEL: func @op_with_region_args
 func @op_with_region_args() {
-  // CHECK: "test.polyfor"() ( {
+  // CHECK: "test.polyfor"() ({
   // CHECK-NEXT: ^bb{{.*}}(%{{.*}}: index, %{{.*}}: index, %{{.*}}: index):
   test.polyfor %i, %j, %k {
     "foo"() : () -> ()
@@ -1399,7 +1399,7 @@
 // CHECK: test.graph_region {
 test.graph_region {
 // CHECK:   [[VAL1:%.*]] = "op1"([[VAL3:%.*]]) : (i32) -> i32
-// CHECK:   [[VAL2:%.*]] = "test.ssacfg_region"([[VAL1]], [[VAL2]], [[VAL3]], [[VAL4:%.*]]) ( {
+// CHECK:   [[VAL2:%.*]] = "test.ssacfg_region"([[VAL1]], [[VAL2]], [[VAL3]], [[VAL4:%.*]]) ({
 // CHECK:     [[VAL5:%.*]] = "op2"([[VAL1]], [[VAL2]], [[VAL3]], [[VAL4]]) : (i32, i32, i32, i32) -> i32
 // CHECK:   }) : (i32, i32, i32, i32) -> i32
 // CHECK:   [[VAL3]] = "op2"([[VAL1]], [[VAL4]]) : (i32, i32) -> i32
@@ -1413,10 +1413,10 @@
   %4 = "op3"(%1) : (i32) -> (i32)
 }
 
-// CHECK: "unregistered_func_might_have_graph_region"() ( {
+// CHECK: "unregistered_func_might_have_graph_region"() ({
 // CHECK: [[VAL1:%.*]] = "foo"([[VAL1]], [[VAL2:%.*]]) : (i64, i64) -> i64
 // CHECK: [[VAL2]] = "bar"([[VAL1]])
-"unregistered_func_might_have_graph_region"() ( {
+"unregistered_func_might_have_graph_region"() ({
   %1 = "foo"(%1, %2) : (i64, i64) -> i64
   %2 = "bar"(%1) : (i64) -> i64
   "unregistered_terminator"() : () -> ()
diff --git a/mlir/test/IR/pretty-region-args.mlir b/mlir/test/IR/pretty-region-args.mlir
--- a/mlir/test/IR/pretty-region-args.mlir
+++ b/mlir/test/IR/pretty-region-args.mlir
@@ -2,7 +2,7 @@
 
 // CHECK-LABEL: func @custom_region_names
 func @custom_region_names() -> () {
-  "test.polyfor"() ( {
+  "test.polyfor"() ({
   ^bb0(%arg0: index, %arg1: index, %arg2: index):
     "foo"() : () -> ()
   }) { arg_names = ["i", "j", "k"] } : () -> ()
@@ -14,7 +14,7 @@
 // CHECK-LABEL: func @weird_names
 // Make sure the asmprinter handles weird names correctly.
 func @weird_names() -> () {
-  "test.polyfor"() ( {
+  "test.polyfor"() ({
   ^bb0(%arg0: i32, %arg1: i32, %arg2: index):
     "foo"() : () -> i32
   }) { arg_names = ["a .^x", "0"] } : () -> ()
diff --git a/mlir/test/IR/pretty_printed_region_op.mlir b/mlir/test/IR/pretty_printed_region_op.mlir
--- a/mlir/test/IR/pretty_printed_region_op.mlir
+++ b/mlir/test/IR/pretty_printed_region_op.mlir
@@ -25,7 +25,7 @@
 // CHECK:            "test.return"(%[[RES]]) : (f32) -> ()
 // CHECK:          : (f32, f32) -> f32
 
-  %0 = test.pretty_printed_region %arg1, %arg0 ( {
+  %0 = test.pretty_printed_region %arg1, %arg0 ({
     ^bb0(%arg2: f32, %arg3: f32):
       %1 = "non.special.op"(%arg2, %arg3) : (f32, f32) -> f32
       "test.return"(%1) : (f32) -> ()
diff --git a/mlir/test/IR/region.mlir b/mlir/test/IR/region.mlir
--- a/mlir/test/IR/region.mlir
+++ b/mlir/test/IR/region.mlir
@@ -78,7 +78,7 @@
 
 // Region with single block and not terminator.
 // CHECK: unregistered_without_terminator
-"test.unregistered_without_terminator"() ( {
+"test.unregistered_without_terminator"() ({
   ^bb0:  // no predecessors
 }) : () -> ()
 
diff --git a/mlir/test/IR/wrapping_op.mlir b/mlir/test/IR/wrapping_op.mlir
--- a/mlir/test/IR/wrapping_op.mlir
+++ b/mlir/test/IR/wrapping_op.mlir
@@ -5,7 +5,7 @@
 // CHECK-GENERIC: "builtin.func"
 func @wrapping_op(%arg0 : i32, %arg1 : f32) -> (i3, i2, i1) {
 // CHECK: %0:3 = test.wrapping_region wraps "some.op"(%arg1, %arg0) {test.attr = "attr"} : (f32, i32) -> (i1, i2, i3)
-// CHECK-GENERIC: "test.wrapping_region"() ( {
+// CHECK-GENERIC: "test.wrapping_region"() ({
 // CHECK-GENERIC:   %[[NESTED_RES:.*]]:3 = "some.op"(%arg1, %arg0) {test.attr = "attr"} : (f32, i32) -> (i1, i2, i3) loc("some_NameLoc")
 // CHECK-GENERIC:   "test.return"(%[[NESTED_RES]]#0, %[[NESTED_RES]]#1, %[[NESTED_RES]]#2) : (i1, i2, i3) -> () loc("some_NameLoc")
 // CHECK-GENERIC: }) : () -> (i1, i2, i3) loc("some_NameLoc")
diff --git a/mlir/test/Target/LLVMIR/openmp-llvm.mlir b/mlir/test/Target/LLVMIR/openmp-llvm.mlir
--- a/mlir/test/Target/LLVMIR/openmp-llvm.mlir
+++ b/mlir/test/Target/LLVMIR/openmp-llvm.mlir
@@ -368,7 +368,7 @@
   %1 = llvm.mlir.constant(10 : index) : i64
   %2 = llvm.mlir.constant(1 : index) : i64
   omp.parallel {
-    "omp.wsloop"(%1, %0, %2) ( {
+    "omp.wsloop"(%1, %0, %2) ({
     ^bb0(%arg1: i64):
       // The form of the emitted IR is controlled by OpenMPIRBuilder and
       // tested there. Just check that the right functions are called.
@@ -393,7 +393,7 @@
   %1 = llvm.mlir.constant(10 : index) : i64
   %2 = llvm.mlir.constant(1 : index) : i64
   // CHECK: store i64 31, i64* %{{.*}}upperbound
-  "omp.wsloop"(%1, %0, %2) ( {
+  "omp.wsloop"(%1, %0, %2) ({
   ^bb0(%arg1: i64):
     %3 = llvm.mlir.constant(2.000000e+00 : f32) : f32
     %4 = llvm.getelementptr %arg0[%arg1] : (!llvm.ptr<f32>, i64) -> !llvm.ptr<f32>
@@ -411,7 +411,7 @@
   %1 = llvm.mlir.constant(10 : index) : i64
   %2 = llvm.mlir.constant(1 : index) : i64
   // CHECK: store i64 32, i64* %{{.*}}upperbound
-  "omp.wsloop"(%1, %0, %2) ( {
+  "omp.wsloop"(%1, %0, %2) ({
   ^bb0(%arg1: i64):
     %3 = llvm.mlir.constant(2.000000e+00 : f32) : f32
     %4 = llvm.getelementptr %arg0[%arg1] : (!llvm.ptr<f32>, i64) -> !llvm.ptr<f32>
diff --git a/mlir/test/Transforms/test-merge-blocks.mlir b/mlir/test/Transforms/test-merge-blocks.mlir
--- a/mlir/test/Transforms/test-merge-blocks.mlir
+++ b/mlir/test/Transforms/test-merge-blocks.mlir
@@ -2,7 +2,7 @@
 
 // CHECK-LABEL: @merge_blocks
 func @merge_blocks(%arg0: i32, %arg1 : i32) -> () {
-  //      CHECK: "test.merge_blocks"() ( {
+  //      CHECK: "test.merge_blocks"() ({
   // CHECK-NEXT:   "test.return"
   // CHECK-NEXT: })
   // CHECK-NEXT: "test.return"
diff --git a/mlir/test/lib/Dialect/Test/TestDialect.cpp b/mlir/test/lib/Dialect/Test/TestDialect.cpp
--- a/mlir/test/lib/Dialect/Test/TestDialect.cpp
+++ b/mlir/test/lib/Dialect/Test/TestDialect.cpp
@@ -603,6 +603,7 @@
   p << "test.isolated_region ";
   p.printOperand(op.getOperand());
   p.shadowRegionArgs(op.getRegion(), op.getOperand());
+  p << ' ';
   p.printRegion(op.getRegion(), /*printEntryBlockArgs=*/false);
 }
 
diff --git a/mlir/test/mlir-lsp-server/hover.test b/mlir/test/mlir-lsp-server/hover.test
--- a/mlir/test/mlir-lsp-server/hover.test
+++ b/mlir/test/mlir-lsp-server/hover.test
@@ -114,7 +114,7 @@
 // CHECK-NEXT:  "result": {
 // CHECK-NEXT:    "contents": {
 // CHECK-NEXT:      "kind": "markdown",
-// CHECK-NEXT:      "value": "\"builtin.func\" : public @foo\n\nGeneric Form:\n\n```mlir\n\"builtin.func\"() ( {\n}) {sym_name = \"foo\", type = (i1) -> ()} : () -> ()\n```\n"
+// CHECK-NEXT:      "value": "\"builtin.func\" : public @foo\n\nGeneric Form:\n\n```mlir\n\"builtin.func\"() ({\n}) {sym_name = \"foo\", type = (i1) -> ()} : () -> ()\n```\n"
 // CHECK-NEXT:    },
 // CHECK-NEXT:    "range": {
 // CHECK-NEXT:      "end": {
@@ -138,7 +138,7 @@
 // CHECK-NEXT:  "result": {
 // CHECK-NEXT:    "contents": {
 // CHECK-NEXT:      "kind": "markdown",
-// CHECK-NEXT:      "value": "\"builtin.func\" : public @foo\n\nGeneric Form:\n\n```mlir\n\"builtin.func\"() ( {\n}) {sym_name = \"foo\", type = (i1) -> ()} : () -> ()\n```\n"
+// CHECK-NEXT:      "value": "\"builtin.func\" : public @foo\n\nGeneric Form:\n\n```mlir\n\"builtin.func\"() ({\n}) {sym_name = \"foo\", type = (i1) -> ()} : () -> ()\n```\n"
 // CHECK-NEXT:    },
 // CHECK-NEXT:    "range": {
 // CHECK-NEXT:      "end": {
diff --git a/mlir/test/mlir-tblgen/op-format.mlir b/mlir/test/mlir-tblgen/op-format.mlir
--- a/mlir/test/mlir-tblgen/op-format.mlir
+++ b/mlir/test/mlir-tblgen/op-format.mlir
@@ -161,7 +161,7 @@
 // Format successors
 //===----------------------------------------------------------------------===//
 
-"foo.successor_test_region"() ( {
+"foo.successor_test_region"() ({
   ^bb0:
     // CHECK: test.format_successor_a_op ^bb1 {attr}
     test.format_successor_a_op ^bb1 {attr}
diff --git a/mlir/test/python/ir/operation.py b/mlir/test/python/ir/operation.py
--- a/mlir/test/python/ir/operation.py
+++ b/mlir/test/python/ir/operation.py
@@ -306,7 +306,7 @@
             "foo": StringAttr.get("foo_value"),
             "bar": StringAttr.get("bar_value"),
         })
-    # CHECK: %0:2 = "custom.op1"() ( {
+    # CHECK: %0:2 = "custom.op1"() ({
     # CHECK: }) {bar = "bar_value", foo = "foo_value"} : () -> (si32, si32)
     print(op1)
 
@@ -360,7 +360,7 @@
     i32 = IntegerType.get_signed(32)
     op1 = Operation.create("custom.op1", regions=1)
     block = op1.regions[0].blocks.append(i32, i32)
-    # CHECK: "custom.op1"() ( {
+    # CHECK: "custom.op1"() ({
     # CHECK: ^bb0(%arg0: si32, %arg1: si32):  // no predecessors
     # CHECK:   "custom.terminator"() : () -> ()
     # CHECK: }) : () -> ()
@@ -645,7 +645,7 @@
     invalid_op = create_invalid_operation()
     # Verify that we fallback to the generic printer for safety.
     # CHECK: // Verification failed, printing generic form
-    # CHECK: "builtin.module"() ( {
+    # CHECK: "builtin.module"() ({
     # CHECK: }) : () -> ()
     print(invalid_op)
     # CHECK: .verify = False