fix grad missing due to indirect dependent free morphism

mindspore/ccsrc/optimizer/ad/dfunctor.cc

@@ -185,19 +185,32 @@ AdjointPtr DFunctor::MapMorphism(const AnfNodePtr &morph) {
   return node_adjoint;
 }
 
+bool DFunctor::IsFreeMorphism(const AnfNodePtr &node) {
+  // Do not care about non-CNode
+  if (!node->isa<CNode>()) {
+    return false;
+  }
+  // Do not care about kPrimReturn
+  if (IsPrimitiveCNode(node, prim::kPrimReturn)) {
+    return false;
+  }
+  auto &users = primal_graph_->manager()->node_users()[node];
+  // Do not care about isolated morphisms
+  if (users.empty()) {
+    return false;
+  }
+  // Not free if it's used by some node in primal_graph
+  bool nonfree = std::any_of(std::begin(users), std::end(users), [&](const auto &kv) {
+    auto &user = kv.first;
+    return user->func_graph() == primal_graph_;
+  });
+  return !nonfree;
+}
+
 void DFunctor::MapFreeMorphism() {
   // Handle cnode not attached to output, that might be refered in other functions.
   for (auto &node : primal_graph_->nodes()) {
-    auto adjoint = FindAdjoint(node);
-    if (adjoint != nullptr) {
-      continue;
-    }
-    if (!node->isa<CNode>()) {
-      MS_LOG(DEBUG) << "MapFreeMorphism noncnode not mapped after MapMorphism " << node->ToString() << " "
-                    << node->type_name() << ".";
-      continue;
-    }
-    if (IsPrimitiveCNode(node, prim::kPrimReturn)) {
+    if (!IsFreeMorphism(node)) {
       continue;
     }
     MS_LOG(DEBUG) << "MapFreeMorphism map nonoutput cnode after MapMorphism " << node->ToString() << ".";
@@ -256,9 +269,10 @@ void DFunctor::MapMorphism() {
   // Set stop_gradient before MapMorphism.
   BroadCastStopFlag();
 
+  // Handle free morphism before output, because in some case, free morphism might depend on output's fv tangent
+  MapFreeMorphism();
   // Handle morphism from output.
   (void)MapMorphism(primal_graph_->output());
-  MapFreeMorphism();
 
   // Construct K for primal_graph_
   auto output_adjoint = anfnode_to_adjoin_.find(primal_graph_->output());
@@ -298,9 +312,10 @@ FuncGraphPtr DFunctor::KUserDefined(const FuncGraphPtr &primal) {
     const size_t param_diff = 1;
     if (bprop_graph->output()->isa<CNode>() &&
         bprop_graph->output()->cast<CNodePtr>()->size() + param_diff != bprop_graph->parameters().size()) {
-      MS_LOG(EXCEPTION) << "User defined Cell bprop " << primal->ToString() << " in scope "
-                        << primal->output()->scope()->name()
-                        << " output must be a tuple and output number should be the same with inputs.";
+      // It does not matter with the final tangents, just a tip for debugging
+      MS_LOG(DEBUG) << "User defined Cell bprop " << primal->ToString() << " in scope "
+                    << primal->output()->scope()->name()
+                    << " output must be a tuple and output number should be the same with inputs.";
     }
     resources_->manager()->AddFuncGraph(bprop_graph);
 

mindspore/ccsrc/optimizer/ad/dfunctor.h

@@ -61,6 +61,7 @@ class DFunctor {
  private:
   // Map one morphism.
   AdjointPtr MapMorphism(const AnfNodePtr &morph);
+  bool IsFreeMorphism(const AnfNodePtr &node);
   // Map morphism that's not attached to output.
   void MapFreeMorphism();
   void BackPropagateFv(const AnfNodePtr &fv, const AnfNodePtr &din);

mindspore/ccsrc/pipeline/pass.cc

@@ -111,7 +111,7 @@ OptPassGroupMap GetOptPassesA(const opt::irpass::OptimizeIRPassLib& irpass) {
     irpass.replace_applicator_,
   });
   opt::OptPassConfig virtual_dataset = opt::OptPassConfig({irpass.virtual_dataset_eliminate_});
-  opt::OptPassConfig grad = opt::OptPassConfig({irpass.inline_, irpass.expand_jprim_}, true);
+  opt::OptPassConfig grad = opt::OptPassConfig({irpass.expand_jprim_}, true);
 
   OptPassGroupMap map_a({{"a_1", a_1},
                          {"a_2", a_2},

tests/ut/python/pynative_mode/test_cell_bprop.py

@@ -304,5 +304,4 @@ class MulAddWithWrongOutputNum(nn.Cell):
 
 def test_grad_mul_add_with_wrong_output_num():
     mul_add = MulAddWithWrongOutputNum()
-    with pytest.raises(RuntimeError):
-        C.grad_all(mul_add)(1, 2)
+    C.grad_all(mul_add)(1, 2)

tests/ut/python/pynative_mode/test_framstruct.py

@@ -15,6 +15,7 @@
 """ test_framstruct """
 import pytest
 import numpy as np
+import mindspore as ms
 import mindspore.nn as nn
 from mindspore import context
 from mindspore.ops import composite as C
@@ -706,3 +707,24 @@ def grad_refactor_14(a, b):
     return inner1(b) + inner2(a) + inner3(a)
 def test_grad_refactor_14():
     assert C.grad_all(grad_refactor_14)(2, 3) == (3, 9)
+
+
+class IfDeferInline(nn.Cell):
+    def __init__(self, mul_size):
+        super().__init__()
+        self.mul_weight = Tensor(np.full(mul_size, 0.6, dtype=np.float32))
+        self.mul = P.Mul()
+
+    def construct(self, inputs):
+        x = self.mul(inputs, self.mul_weight)
+        if True:
+            x = x
+        return x
+
+def test_grad_if_defer_inline():
+    """ test_grad_if_defer_inline """
+    network = IfDeferInline([128, 96])
+    network.add_flags(defer_inline=False)
+    inp = Tensor(np.ones([128, 96]).astype(np.float32))
+    grads = C.grad_all(network)(inp)
+    assert grads == (Tensor(np.full([128, 96], 0.6, dtype=np.float32)),)