[Relay][Frontend][Torch] fix pytorch frontend linspace op (#16417)

fix pytorch frontend linspace op

Author: taomiao

python/tvm/relay/frontend/pytorch.py

@@ -918,7 +918,7 @@ def linspace(self, inputs, input_types):
         # Find the spacing between values as step
         if step != 1:
             step = (stop - start) / (step - 1)
-            stop = stop + step
+            stop = stop + (step / 2)
         else:
             stop = start + step
 

tests/python/frontend/pytorch/test_forward.py

@@ -3632,6 +3632,10 @@ class Linspace8(Module):
         def forward(self, *args):
             return torch.linspace(1, 2, 1, dtype=torch.int16)
 
+    class Linspace9(Module):
+        def forward(self, *args):
+            return torch.linspace(0, 8, 10)
+
     verify_model(Linspace1().float().eval())
     verify_model(Linspace2().float().eval())
     verify_model(Linspace3().float().eval())
@@ -3640,6 +3644,7 @@ def forward(self, *args):
     verify_model(Linspace6().float().eval())
     verify_model(Linspace7().float().eval())
     verify_model(Linspace8().float().eval())
+    verify_model(Linspace9().float().eval())
 
 
 @tvm.testing.uses_gpu