Fix different types in rsub caused bug (#15707)

Summary:
Before this pr, rsub did not convert two elements into the same dtype, therefore "1 - x" may export to an onnx model that two elements of rsub having different dtype.
By adding this symbolic patch this bug should be fixed.
Related test cases also created.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/15707

Differential Revision: D13583042

Pulled By: zrphercule

fbshipit-source-id: 3a2de47a1a8d1ded1a0adfb911adbe6ac729cdef

diff --git a/test/onnx/expect/TestOperators.test_rsub.expect b/test/onnx/expect/TestOperators.test_rsub.expect
index dca90da..504f5d7 100644 (file)
--- a/test/onnx/expect/TestOperators.test_rsub.expect
+++ b/test/onnx/expect/TestOperators.test_rsub.expect
@@ -8,8 +8,8 @@ graph {
     attribute {
       name: "value"
       t {
-        data_type: 7
-        raw_data: "\001\000\000\000\000\000\000\000"
+        data_type: 11
+        raw_data: "\000\000\000\000\000\000\360?"
       }
       type: TENSOR
     }

diff --git a/test/onnx/test_pytorch_onnx_caffe2.py b/test/onnx/test_pytorch_onnx_caffe2.py
index cc1950e..2ea4352 100644 (file)
--- a/test/onnx/test_pytorch_onnx_caffe2.py
+++ b/test/onnx/test_pytorch_onnx_caffe2.py
@@ -1001,6 +1001,14 @@ class TestCaffe2Backend(unittest.TestCase):
         model = nn.GroupNorm(3, 6)
         self.run_model_test(model, train=True, input=c, batch_size=BATCH_SIZE)
 
+    def test_rsub(self):
+        class RsubModel(torch.nn.Module):
+            def forward(self, x):
+                return 1 - x
+
+        x = torch.randn(1, 2)
+        self.run_model_test(RsubModel(), train=False, input=(x,),
+                            batch_size=BATCH_SIZE, use_gpu=False)
 
 # a bit of metaprogramming to set up all the rnn tests
 

diff --git a/torch/onnx/symbolic.py b/torch/onnx/symbolic.py
index dca3b20..6bae829 100644 (file)
--- a/torch/onnx/symbolic.py
+++ b/torch/onnx/symbolic.py
@@ -229,6 +229,8 @@ def sub(g, self, other, alpha=None):
 
 
 def rsub(g, self, other, alpha=None):
+    other = _maybe_get_scalar(other)
+    other = _if_scalar_type_as(g, other, self)
     return sub(g, other, self, alpha=alpha)