[DoubleGrad PR #3] Supported higher-order GradNode generation (#41051)

* [Refactor] refactored eager_gen.py PR #2

* [DoubleGrad PR #1] Decoupled code generation logics for Dygraph ForwardFunctions and GradNodes

* Fixed minor issue

* Adjusted logics of GenerateNodeCreationCodes and GenerateForwardDefinition

* Fixed issues

* Supported higher-order grad node generation

* [DoubleGrad PR #4] Supported higher-order GradNode generation

* Fixed yaml typo

paddle/fluid/eager/auto_code_generator/final_state_generator/codegen_utils.py

@@ -89,6 +89,10 @@ def FindForwardName(string):
     return string[:-5]
 
 
+def IsGradName(string):
+    return string.endswith("_grad")
+
+
 def IsPlainTensorType(string):
     plain_tensor_types = ['Tensor&', 'Tensor', 'const Tensor&', 'const Tensor']
     if string in plain_tensor_types:
@@ -166,6 +170,12 @@ def GetForwardFunctionName(string):
     return f"{string}_final_state_dygraph_function"
 
 
+def TransformGradVarNameForDoubleGradGeneration(string):
+    if IsGradName(string):
+        string = "grad_" + string[:-5]
+    return string
+
+
 ######################
 ###  Yaml Parsers  ###
 ######################

python/paddle/utils/code_gen/backward.yaml

@@ -649,6 +649,16 @@
   kernel :
     func : put_along_axis_grad
 
+- backward_api : relu_double_grad
+  forward : relu_grad (Tensor out, Tensor grad_out) -> Tensor(grad_x)
+  args : (Tensor out, Tensor grad_x_grad)
+  output : Tensor(out_grad), Tensor(grad_out_grad)
+  infer_meta :
+    func : GeneralBinaryGradInferMeta
+    param : [out, out]
+  kernel :
+    func : relu_double_grad
+
 - backward_api : relu_grad
   forward : relu (Tensor x) -> Tensor(out)
   args : (Tensor out, Tensor out_grad)
@@ -658,6 +668,7 @@
     param : [out]
   kernel :
     func : relu_grad
+  backward: relu_double_grad
 
 - backward_api : reshape_grad
   forward : reshape_with_xshape (Tensor x, ScalarArray shape) -> Tensor(out), Tensor(xshape)