dpa3 fix

Author: xiaoguoguo626807

paddle/fluid/framework/new_executor/instruction/control_flow/yield_instruction.cc

@@ -38,7 +38,7 @@ YieldInstruction::YieldInstruction(size_t id,
       continue;
     }
     auto in = op->operand_source(i);
-    if (in && in.type()) {
+    if (in) {
       inputs.emplace(in, GetValueIds(in, *value_exe_info));
       input_vars_.push_back(value_exe_info->GetVarByValue(in));
     }

python/paddle/autograd/ir_backward.py

@@ -433,6 +433,7 @@ def make_output_with_output_grad(op):
             if (
                 value not in state.value_to_valuegrad
                 or state.value_to_valuegrad[value] == []
+                or state.value_to_valuegrad[value][0][0] is None
             ):
                 if not value.use_empty() and get_split_op(value) is not None:
                     # pattern case: