Fixes to tape gradient for providing outputs and having multiple targets.

PiperOrigin-RevId: 194796304

1 files changed, 20 insertions, 0 deletions

diff --git a/tensorflow/python/eager/backprop_test.py b/tensorflow/python/eager/backprop_test.py
index 991b4dbe7a..8d9959fe20 100644
--- a/tensorflow/python/eager/backprop_test.py
+++ b/tensorflow/python/eager/backprop_test.py
@@ -96,6 +96,26 @@ class BackpropTest(test.TestCase):
     self.assertAllEqual(grads_and_vars[0][0], 1.0)
     self.assertAllEqual(id(grads_and_vars[0][1]), id(x))
 
+  def testTwoTargets(self):
+    with backprop.GradientTape() as t:
+      x = constant_op.constant(3.0)
+      y = constant_op.constant(2.0)
+      t.watch([x, y])
+      xx = 2 * x
+      yy = 3 * y
+    dx, dy = t.gradient([xx, yy], [x, y])
+    self.assertAllEqual(dx, 2.0)
+    self.assertAllEqual(dy, 3.0)
+
+  def testOutputGradUsedInComputation(self):
+    with backprop.GradientTape() as t:
+      x = constant_op.constant(3.0)
+      y = constant_op.constant(2.0)
+      t.watch([x, y])
+      loss = x * y
+    dx, = t.gradient([loss, x], [x], output_gradients=[1.0, 2.0])
+    self.assertAllEqual(dx, 4.0)
+
   def testDy(self):
 
     def f(x):