diff --git a/mlir/include/mlir/Dialect/Shape/IR/ShapeOps.td b/mlir/include/mlir/Dialect/Shape/IR/ShapeOps.td
--- a/mlir/include/mlir/Dialect/Shape/IR/ShapeOps.td
+++ b/mlir/include/mlir/Dialect/Shape/IR/ShapeOps.td
@@ -90,6 +90,8 @@
                    OptionalAttr<StrAttr>:$error);
   let results = (outs Shape_ShapeType:$result);
 
+  let assemblyFormat = "$lhs `,` $rhs attr-dict";
+
   let hasFolder = 1;
 }
 
@@ -472,6 +474,7 @@
   let arguments = (ins Shape_ShapeType:$lhs, Shape_ShapeType:$rhs);
   let results = (outs Shape_ShapeType:$result);
 
+  let assemblyFormat = "$lhs `,` $rhs attr-dict";
   let hasFolder = 1;
 }
 
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
@@ -237,12 +237,17 @@
 //===----------------------------------------------------------------------===//
 
 OpFoldResult BroadcastOp::fold(ArrayRef<Attribute> operands) {
-  if (!operands[0] || !operands[1])
+  if (!operands[1])
     return nullptr;
-  auto lhsShape = llvm::to_vector<6>(
-      operands[0].cast<DenseIntElementsAttr>().getValues<int64_t>());
+
   auto rhsShape = llvm::to_vector<6>(
       operands[1].cast<DenseIntElementsAttr>().getValues<int64_t>());
+  if (rhsShape.empty())
+    return lhs();
+
+  if (!operands[0])
+    return nullptr;
+
   SmallVector<int64_t, 6> resultShape;
   // If the shapes are not compatible, we can't fold it.
   // TODO: Fold to an "error".
diff --git a/mlir/test/Dialect/Shape/canonicalize.mlir b/mlir/test/Dialect/Shape/canonicalize.mlir
--- a/mlir/test/Dialect/Shape/canonicalize.mlir
+++ b/mlir/test/Dialect/Shape/canonicalize.mlir
@@ -54,19 +54,41 @@
   // CHECK: shape.const_shape [7, 2]
   %0 = shape.const_shape [1, 2]
   %1 = shape.const_shape [7, 1]
-  %2 = "shape.broadcast"(%0, %1) : (!shape.shape, !shape.shape) -> !shape.shape
+  %2 = shape.broadcast %0, %1
   return %2 : !shape.shape
 }
 
 // -----
 
+// Rhs is a scalar.
+// CHECK-LABEL: func @f
+func @f(%arg0 : !shape.shape) -> !shape.shape {
+  // CHECK: return %arg0
+  %0 = shape.const_shape []
+  %1 = shape.broadcast %arg0, %0
+  return %1 : !shape.shape
+}
+
+// -----
+
+// Lhs is a scalar.
+// CHECK-LABEL: func @f
+func @f(%arg0 : !shape.shape) -> !shape.shape {
+  // CHECK: return %arg0
+  %0 = shape.const_shape []
+  %1 = shape.broadcast %0, %arg0
+  return %1 : !shape.shape
+}
+
+// -----
+
 // Incompatible shapes. No folding.
 // CHECK-LABEL: func @f
 func @f() -> !shape.shape {
   // CHECK: shape.broadcast
   %0 = shape.const_shape [2]
   %1 = shape.const_shape [7]
-  %2 = "shape.broadcast"(%0, %1) : (!shape.shape, !shape.shape) -> !shape.shape
+  %2 = shape.broadcast %0, %1
   return %2 : !shape.shape
 }
 
@@ -78,7 +100,7 @@
   // CHECK: shape.const_shape [0, 1, 2, 3]
   %lhs = shape.const_shape [0, 1]
   %rhs = shape.const_shape [2, 3]
-  %0 = "shape.concat"(%lhs, %rhs) : (!shape.shape, !shape.shape) -> !shape.shape
+  %0 = shape.concat %lhs, %rhs
   return %0 : !shape.shape
 }
 
diff --git a/mlir/test/Dialect/Shape/ops.mlir b/mlir/test/Dialect/Shape/ops.mlir
--- a/mlir/test/Dialect/Shape/ops.mlir
+++ b/mlir/test/Dialect/Shape/ops.mlir
@@ -29,10 +29,10 @@
   return
 }
 
-func @test_broadcastable_fixed() {
+func @test_broadcast_fixed() {
   %0 = shape.const_shape [10, 1, 57, 92]
   %1 = shape.const_shape [4, 57, 92]
-  %2 = "shape.broadcastable"(%0, %1) : (!shape.shape, !shape.shape) -> !shape.shape
+  %2 = shape.broadcast %0, %1
   %3 = "shape.print"(%2) : (!shape.shape) -> !shape.shape
   return
 }