[Prim] Add prod backward composite rule (#51238)

* first commit

* add registry

* add unit test

* fix format

* add unit test

* fix  bug

* replace unsuqeeze to reshape

* fix

* fix unit test

* update test

* update test

* fix unit test

* fix

* fix

paddle/fluid/operators/reduce_ops/reduce_prod_op.cc

@@ -13,6 +13,9 @@
 // limitations under the License.
 
 #include "paddle/fluid/operators/reduce_ops/reduce_prod_op.h"
+#include "paddle/fluid/prim/api/composite_backward/composite_backward_api.h"
+#include "paddle/fluid/prim/utils/static/composite_grad_desc_maker.h"
+#include "paddle/fluid/prim/utils/static/desc_tensor.h"
 
 #include "paddle/fluid/framework/infershape_utils.h"
 #include "paddle/phi/core/infermeta_utils.h"
@@ -27,6 +30,42 @@ class OpBase;
 }  // namespace imperative
 }  // namespace paddle
 
+namespace paddle {
+namespace operators {
+class ReduceProdCompositeGradOpMaker : public prim::CompositeGradOpMakerBase {
+ public:
+  using prim::CompositeGradOpMakerBase::CompositeGradOpMakerBase;
+  void Apply() override {
+    // get inputs
+    paddle::Tensor x = this->GetSingleForwardInput("X");
+    paddle::Tensor out = this->GetSingleForwardOutput("Out");
+    paddle::Tensor out_grad = this->GetSingleOutputGrad("Out");
+
+    // get attr
+    std::vector<int> axis = this->Attr<std::vector<int>>("dim");
+    bool keep_dim = this->Attr<bool>("keep_dim");
+    bool reduce_all = this->Attr<bool>("reduce_all");
+
+    // get output
+    paddle::Tensor x_grad_t = this->GetSingleInputGrad("X");
+
+    // get output ptr
+    auto x_grad = this->GetOutputPtr(&x_grad_t);
+
+    // get output orginal name
+    std::string x_grad_name = this->GetOutputName(x_grad_t);
+    VLOG(6) << "Runing prod_grad composite func";
+    // call composite backward func
+    prim::prod_grad<prim::DescTensor>(
+        x, out, out_grad, axis, keep_dim, reduce_all, x_grad);
+    // recover output name
+    this->RecoverOutputName(x_grad_t, x_grad_name);
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle
+
 namespace ops = paddle::operators;
 
 class ReduceProdOpMaker : public ops::ReduceBaseOpMaker {
@@ -46,5 +85,6 @@ REGISTER_OPERATOR(
     ReduceProdOpMaker,
     paddle::framework::DefaultGradOpMaker<paddle::framework::OpDesc, true>,
     paddle::framework::DefaultGradOpMaker<paddle::imperative::OpBase, true>,
+    ops::ReduceProdCompositeGradOpMaker,
     ReduceProdInferShapeFunctor);
 REGISTER_OPERATOR(reduce_prod_grad, ops::ReduceGradOp);

paddle/fluid/prim/api/composite_backward/composite_backward_api.h

@@ -1069,6 +1069,58 @@ void gather_nd_grad(const Tensor& x,
   }
 }
 
+template <typename T>
+void prod_grad(const Tensor& x,
+               const Tensor& out,
+               const Tensor& out_grad,
+               const IntArray& axis,
+               bool keep_dim,
+               bool reduce_all,
+               Tensor* x_grad) {
+  if (x_grad) {
+    std::vector<int64_t> x_dim = phi::vectorize<int64_t>(x.dims());
+    int64_t axis_size = axis.size();
+    int64_t x_dim_size = x_dim.size();
+    reduce_all = false;
+    if (reduce_all || axis_size == 0 || axis_size == x_dim_size) {
+      reduce_all = true;
+    } else {
+      reduce_all = false;
+    }
+    auto x_grad_tmp = Tensor();
+    auto out_tmp = Tensor();
+    if (x_dim_size == 1) {
+      x_grad_tmp = out_grad.expand(IntArray(x_dim));
+      out_tmp = out.expand(IntArray(x_dim));
+    } else {
+      if (!keep_dim) {
+        auto axis_ = std::vector<int64_t>();
+        if (reduce_all) {
+          for (int64_t i = 1; i < x_dim_size; i++) {
+            axis_.push_back(i);
+          }
+        } else {
+          axis_ = axis.GetData();
+          for (int64_t i = 0; i < axis_size; i++) {
+            if (axis[i] < 0) {
+              axis_[i] = axis[i] + x_dim_size;
+            }
+          }
+        }
+        auto out_grad_ = unsqueeze<T>(out_grad, axis_);
+        x_grad_tmp = out_grad_.expand(IntArray(x_dim));
+        auto out_ = unsqueeze<T>(out, axis_);
+        out_tmp = out_.expand(IntArray(x_dim));
+      } else {
+        x_grad_tmp = out_grad.expand(IntArray(x_dim));
+        out_tmp = out.expand(IntArray(x_dim));
+      }
+    }
+    auto x_grad_res = x_grad_tmp * out_tmp * (1 / x);
+    set_output<T>(x_grad_res, x_grad);
+  }
+}
+
 template <typename T>
 void max_grad(const Tensor& x,
               const Tensor& out,

paddle/phi/api/yaml/legacy_backward.yaml

@@ -875,6 +875,7 @@
     param : [x]
   kernel :
     func : prod_grad
+  composite: prod_grad(x, out, out_grad, dims, keep_dim, reduce_all, x_grad)
 
 - backward_op : psroi_pool_grad
   forward : psroi_pool (Tensor x, Tensor boxes, Tensor boxes_num, int pooled_height, int pooled_width, int output_channels, float spatial_scale) -> Tensor(out)

python/paddle/fluid/tests/unittests/test_reduce_op.py

@@ -407,6 +407,9 @@ class TestProdOp(OpTest):
     def setUp(self):
         self.op_type = "reduce_prod"
         self.python_api = raw_reduce_prod
+        self.public_python_api = raw_reduce_prod
+        self.prim_op_type = "prim"
+
         self.init_data_type()
         self.inputs = {'X': np.random.random((5, 6, 10)).astype(self.data_type)}
         self.outputs = {'Out': self.inputs['X'].prod(axis=0)}
@@ -420,17 +423,27 @@ class TestProdOp(OpTest):
         self.check_output()
 
     def test_check_grad(self):
-        self.check_grad(['X'], 'Out')
+        self.check_grad(['X'], 'Out', check_prim=True)
+
+
+class TestProdOpFp64(TestProdOp):
+    def init_data_type(self):
+        self.data_type = "float64"
 
 
 class TestProdOp_ZeroDim(OpTest):
     def setUp(self):
-        self.python_api = paddle.prod
+        self.python_api = raw_reduce_prod
+        self.public_python_api = raw_reduce_prod
         self.op_type = "reduce_prod"
+        self.prim_op_type = "prim"
         self.inputs = {'X': np.random.random([]).astype("float64")}
         self.outputs = {'Out': self.inputs['X'].prod()}
         self.attrs = {'dim': [], 'reduce_all': True}
 
+        # 0-D tensor doesn't support in cinn
+        self.enable_cinn = False
+
     def test_check_output(self):
         self.check_output()
 
@@ -442,6 +455,8 @@ class TestProd6DOp(OpTest):
     def setUp(self):
         self.op_type = "reduce_prod"
         self.python_api = raw_reduce_prod
+        self.public_python_api = raw_reduce_prod
+        self.prim_op_type = "prim"
         self.init_data_type()
         self.inputs = {
             'X': np.random.random((5, 6, 2, 3, 4, 2)).astype(self.data_type)
@@ -460,13 +475,14 @@ class TestProd6DOp(OpTest):
         self.check_output()
 
     def test_check_grad(self):
-        self.check_grad(['X'], 'Out')
+        self.check_grad(['X'], 'Out', check_prim=True)
 
 
 class TestProd8DOp(OpTest):
     def setUp(self):
         self.op_type = "reduce_prod"
         self.python_api = raw_reduce_prod
+        self.public_python_api = raw_reduce_prod
         self.init_data_type()
         self.inputs = {
             'X': np.random.random((2, 5, 3, 2, 2, 3, 4, 2)).astype(
@@ -1178,6 +1194,7 @@ class TestReduceWithDtype2(TestReduceWithDtype):
 
 class TestReduceSumOpError(unittest.TestCase):
     def test_errors(self):
+        with paddle.fluid.framework._static_guard():
             with program_guard(Program(), Program()):
                 # The input type of reduce_sum_op must be Variable.
                 x1 = fluid.create_lod_tensor(