fix dot2bar delete.

python/paddle/autograd/primx.py

@@ -144,7 +144,9 @@ def delete(self, key_var):
 
     def delete_keyvars(self, key_vars):
         for var in key_vars:
-            del self.tab[id(var)]
+            varid = id(var)
+            if varid in self.tab:
+                del self.tab[varid]
 
     def delete_valuevars(self, value_vars):
         ids = [id(v) for v in value_vars]
@@ -408,9 +410,10 @@ def _gradients(ys, xs, ys_bar=None):
     orig2prim(block, new_vars)
 
     ad = Transform(block)
-    new_xs = new_vars[:len(xs)]
-    new_ys = new_vars[len(xs):]
-    xs_dot, ys_dot = ad.linearize(new_xs, new_ys)
+    xs = new_vars[:len(xs)]
+    ys = new_vars[len(xs):]
+
+    xs_dot, ys_dot = ad.linearize(xs, ys)
     ys_bar, xs_bar = ad.transpose(ys_dot, xs_dot, ys_bar)
     # remove xs_dot and their constructor ops
 

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

@@ -222,13 +222,12 @@ def test_gradients_set2(self):
             x = paddle.static.data('X', shape=[3, 3], dtype='float32')
             y = paddle.static.data('Y', shape=[3, 3], dtype='float32')
             # z = prog2(x, y)
-            t = paddle.multiply(x, x)
+            t = paddle.matmul(x, x)
             z = paddle.norm(t, p=2)
-            orig2prim(x.block)
-            # x_grad, y_grad = _gradients([z], [x, y])
+            x_grad, y_grad = _gradients([z], [x, y])
             # path, _, _ = topo_path([x, y], [x_grad, y_grad])
             # print(f'-------test_gradients_set2-------')
-            # print(x.block)
+            print(x.block)
 
     def test_gradients_set3(self):
         main = paddle.static.Program()