polish the code of fusion group test=develop (#23370)

paddle/fluid/framework/ir/fusion_group/code_generator.cc

@@ -77,6 +77,7 @@ std::vector<OperationExpression> CodeGenerator::ConvertToExpressions(
       auto* op = node->Op();
       AttributeMap attr = *(op->MutableAttrMap());
 
+      // Input ids should be set in fixed order, like:
       //  - X, Y in forward operations
       //  - X, Y, Out, out@GRAD in backward operations
       std::vector<int> input_ids;

paddle/fluid/framework/ir/fusion_group/code_generator_helper.cc

@@ -20,11 +20,6 @@ limitations under the License. */
 #include "glog/logging.h"
 #include "paddle/fluid/framework/block_desc.h"
 #include "paddle/fluid/framework/ir/fusion_group/operation.h"
-#include "paddle/fluid/framework/op_call_stack.h"
-#include "paddle/fluid/framework/op_proto_maker.h"
-#include "paddle/fluid/framework/operator.h"
-#include "paddle/fluid/framework/program_desc.h"
-#include "paddle/fluid/framework/shape_inference.h"
 #include "paddle/fluid/framework/var_type_inference.h"
 
 namespace paddle {
@@ -164,8 +159,7 @@ std::string OperationExpression::GetRHS(std::unordered_set<int>* used,
                               ">. Received %d.",
                               index, op_type_, input_ids_[index]));
         // TODO(wangchaochaohu): Here fp16 convert to float to do comupte, we
-        // need
-        // to add general fp16 compute later.
+        // need to add general fp16 compute later.
         std::string var_name;
         if (rhs_type_ == "float16") {
           half2fp32_statement->append(OptimzeFP16RHS(used, index, input_ids_));

paddle/fluid/framework/ir/fusion_group/operation.cc

@@ -199,7 +199,7 @@ void OperationMap::InsertMultivariateElementwiseOperations() {
   auto insert_handler_without_input = [&](std::string op_type, std::string expr,
                                           std::vector<std::string> grad_exprs) {
     int type = 0;
-    int num_oprands = -1;
+    int num_oprands = 0;
     Insert(type, num_oprands, op_type, expr, grad_exprs, {}, {"Out"});
   };
   // fill_constant: