refine with comments

test=develop

paddle/fluid/framework/operator.cc

@@ -926,12 +926,7 @@ void OperatorWithKernel::RunImpl(const Scope& scope,
     dev_ctx = pool.Get(expected_kernel_key.place_);
   }
 
-  // If Op has attribute all_kernels_must_compute_runtime_shape,
-  // all the kernels of this Op would compute runtime shape,
-  // and skip infershape in runtime for speedup.
-  // TODO(luotao): Note that it is a temporal attribute, after all ops
-  // implement computing runtime shape, this attribute would be deleted.
-  if (!HasAttr("all_kernels_must_compute_runtime_shape")) {
+  if (!HasAttr(kAllKernelsMustComputeRuntimeShape)) {
     RuntimeInferShapeContext infer_shape_ctx(*this, exec_scope, ctx);
     this->InferShape(&infer_shape_ctx);
   }

paddle/fluid/framework/operator.h

@@ -62,6 +62,15 @@ constexpr char kZeroVarSuffix[] = "@ZERO";
 /// Variables with this suffix are the new Gradient.
 constexpr char kNewGradSuffix[] = "@NEWGRAD@";
 
+/// If an Op has this attribute, all its kernels should calculate output
+/// variable's shape in the corresponding Compute() function. And
+/// OperatorWithKernel::RunImpl() would skip call this Op's InferShape()
+/// function in its runtime for speedup.
+/// TODO(luotao): Note that this temporal attribute would be deleted after all
+/// ops contain it.
+constexpr char kAllKernelsMustComputeRuntimeShape[] =
+    "@ALL_KERNELS_MUST_COMPUTE_RUNTIME_SHAPE@";
+
 // define some kernel priority
 /* Define multiple kernel type fallback order*/
 extern std::vector<std::tuple<platform::Place, LibraryType>> kKernelPriority;

paddle/fluid/operators/fused/fused_embedding_seq_pool_op.cc

@@ -88,13 +88,7 @@ class FusedEmbeddingSeqPoolOpMaker : public framework::OpProtoAndCheckerMaker {
                   "(boolean, default false) "
                   "Sparse update.")
         .SetDefault(false);
-    AddAttr<bool>(
-        "all_kernels_must_compute_runtime_shape",
-        "(boolean, default true) "
-        "An attribute to speed up OperatorWithKernel::RunImpl."
-        "If true, all the kernels of this Op would compute runtime "
-        "shape, but skip infershape in runtime. Note that it is a temporal "
-        "attribute, please do DOT set it in python layer.")
+    AddAttr<bool>(framework::kAllKernelsMustComputeRuntimeShape, "")
         .SetDefault(true);
     AddComment(R"DOC(
 FusedEmbeddingSeqPool Operator.

paddle/fluid/operators/hash_op.cc

@@ -54,13 +54,7 @@ $$Out = scale * X$$
 )DOC");
     AddAttr<int>("num_hash", "").SetDefault(1);
     AddAttr<int>("mod_by", "").SetDefault(100000);
-    AddAttr<bool>(
-        "all_kernels_must_compute_runtime_shape",
-        "(boolean, default true) "
-        "An attribute to speed up OperatorWithKernel::RunImpl."
-        "If true, all the kernels of this Op would compute runtime "
-        "shape, but skip infershape in runtime. Note that it is a temporal "
-        "attribute, please do DOT set it in python layer.")
+    AddAttr<bool>(framework::kAllKernelsMustComputeRuntimeShape, "")
         .SetDefault(true);
   }
 };

paddle/fluid/operators/sequence_ops/sequence_enumerate_op.cc

@@ -59,13 +59,7 @@ class SequenceEnumerateOpMaker : public framework::OpProtoAndCheckerMaker {
         });
     AddAttr<int>("pad_value", "(int) The enumerate sequence padding value.")
         .SetDefault(0);
-    AddAttr<bool>(
-        "all_kernels_must_compute_runtime_shape",
-        "(boolean, default true) "
-        "An attribute to speed up OperatorWithKernel::RunImpl."
-        "If true, all the kernels of this Op would compute runtime "
-        "shape, but skip infershape in runtime. Note that it is a temporal "
-        "attribute, please do DOT set it in python layer.")
+    AddAttr<bool>(framework::kAllKernelsMustComputeRuntimeShape, "")
         .SetDefault(true);
     AddComment(R"DOC(
 Sequence Enumerate Operator.