fix multi Ops.CONTIGUOUS_BACKWARD [pr] (tinygrad#8843)

Author: geohot

test/test_multitensor.py

@@ -288,6 +288,9 @@ def test_backprop_conv(self):
       optim.step()
       out.numpy()
 
+  def test_backprop_conv_wino(self):
+    with Context(WINO=1): self.test_backprop_conv()
+
   def test_backward_sum(self):
     x = Tensor([[1.,2,3,4], [5,6,7,8]]).shard(devices_2, axis=0)
     w = Tensor([1.,2,3,4], requires_grad=True).shard(devices_2)

tinygrad/engine/multi.py

@@ -158,7 +158,8 @@ def passthrough_multi(root:UOp, multi:UOp): return UOp.multi(*[root.replace(src=
   (UPat(Ops.FLIP, src=(UPat(Ops.MULTI, name="multi"), ), name="root"), flip_multi),
   (UPat(Ops.ASSIGN, src=(UPat(Ops.MULTI, name="dest"), UPat(Ops.MULTI, name="src"))), assign_multi),
   (UPat(Ops.COPY, src=(UPat(Ops.DEVICE, name="device"), UPat(Ops.MULTI, name="multi"), )), copy_multi),
-  (UPat((Ops.CAST, Ops.BITCAST, Ops.CONTIGUOUS, Ops.DETACH), src=(UPat(Ops.MULTI, name="multi"), ), name="root"), passthrough_multi),
+  (UPat((Ops.CAST, Ops.BITCAST, Ops.CONTIGUOUS, Ops.DETACH, Ops.CONTIGUOUS_BACKWARD),
+        src=(UPat(Ops.MULTI, name="multi"), ), name="root"), passthrough_multi),
 ])
 
 @track_rewrites(named=True)