【PIR】modify backward for controlflow op (#59020)

* add refresh stopgradint

* add refresh stopgradint

* modofy

* modify backward

* modify

python/paddle/autograd/ir_backward.py

@@ -317,7 +317,12 @@ def inverse_sort_op(ops):
 
 
 def append_backward_ops(
-    block, effective_forward_ops, no_grad_set, backward_ops, state
+    fwd_block,
+    bwd_block,
+    effective_forward_ops,
+    no_grad_set,
+    backward_ops,
+    state,
 ):
     '''
     add grad_op in order of topological inverse sort
@@ -351,11 +356,12 @@ def append_backward_ops(
         value_to_valuegrad[v12] = [[v12_g]]
         value_to_valuegrad[v2] = [[v2_g]]
 
-    if op don't has grad_op, if it don't has input and it's output has more than
-    one output_grad, add sumop for grad aggregation.
+    if op don't has grad_op:
+        if it don't has input and it's output has more than
+        one output_grad, add sumop for grad aggregation.
         (eg: full op and get_parameter op etc.)
 
-    else continue to next op.
+        else continue to next op.
     '''
 
     def make_output_with_output_grad(op):
@@ -374,8 +380,8 @@ def make_output_with_output_grad(op):
                 paddle.add_n(
                     [item[0] for item in state.value_to_valuegrad[value]]
                 )
-                combineop = block.ops[len(block.ops) - 2]
-                sumop = block.ops[len(block.ops) - 1]
+                combineop = bwd_block.ops[len(bwd_block.ops) - 2]
+                sumop = bwd_block.ops[len(bwd_block.ops) - 1]
                 update_bwdop_structure(
                     backward_ops, state.op_to_opgrad[op], combineop
                 )
@@ -507,16 +513,19 @@ def update_input_grad_map(op, input_grads):
     # [op2 , builtin.split] (op2's inputs are not vectorType, one output is vectorType)
     # [builtin.combine , op3 , buitin.split] (op3's one input and one output are vectorType)
     # [op4] (op4's inputs and outputs are not vectorType)
-    # einsum has twp vectorType outputs, special pattern
 
+    inverse_effective_forward_ops = inverse_sort_op(effective_forward_ops)
     clear_effective_forward_ops = []
 
-    for op in effective_forward_ops:
+    for op in inverse_effective_forward_ops:
         if op.name() != "builtin.combine" and op.name() != "builtin.split":
             clear_effective_forward_ops.append(op)
-
+    # with bwd_block:
     for op in clear_effective_forward_ops:
         if paddle.framework.core.has_vjp(op):
+            if op.name() == "pd_op.if" or op.name() == "pd_op.while":
+                continue
+
             # prepare output_grad
             zero_flag, outputs, output_grads = make_output_with_output_grad(op)
 
@@ -532,16 +541,16 @@ def update_input_grad_map(op, input_grads):
             ) = make_input_with_input_stopgradient(op)
 
             # create grad_op
-            before_ops_num = len(block.ops)
+            before_ops_num = len(bwd_block.ops)
             input_grads = paddle.framework.core.call_vjp(
                 op, inputs, outputs, output_grads, input_grad_stopgradients
             )
-            after_ops_num = len(block.ops)
+            after_ops_num = len(bwd_block.ops)
 
             # update grad_op structure
             for i in range(before_ops_num, after_ops_num):
                 update_bwdop_structure(
-                    backward_ops, state.op_to_opgrad[op], block.ops[i]
+                    backward_ops, state.op_to_opgrad[op], bwd_block.ops[i]
                 )
 
             # update input_grad map
@@ -558,8 +567,8 @@ def update_input_grad_map(op, input_grads):
                                 for item in state.value_to_valuegrad[value]
                             ]
                         )
-                        combineop = block.ops[len(block.ops) - 2]
-                        sumop = block.ops[len(block.ops) - 1]
+                        combineop = bwd_block.ops[len(bwd_block.ops) - 2]
+                        sumop = bwd_block.ops[len(bwd_block.ops) - 1]
                         update_bwdop_structure(
                             backward_ops, state.op_to_opgrad[op], combineop
                         )
@@ -651,10 +660,8 @@ def calc_gradient_helper(outputs, inputs, grad_outputs, no_grad_set):
         block, effective_forward_ops, no_grad_set, inputs, complete_outputs
     )
 
-    inverse_effective_forward_ops = inverse_sort_op(effective_forward_ops)
-
     append_backward_ops(
-        block, inverse_effective_forward_ops, no_grad_set, backward_ops, state
+        block, block, effective_forward_ops, no_grad_set, backward_ops, state
     )
     # now value_to_valuegrad should be value <-> value (add sum op for the same values's gradvalue)
     outputs_set, inputs_set, no_gradvar_set = create_backward_prune_set(