fix matmul jit bug

torch_sparse/matmul.py

@@ -92,11 +92,11 @@ def spspmm_sum(src: SparseTensor, other: SparseTensor) -> SparseTensor:
     assert src.sparse_size(1) == other.sparse_size(0)
     rowptrA, colA, valueA = src.csr()
     rowptrB, colB, valueB = other.csr()
-    value = valueA
+    value = valueA if valueA is not None else valueB
     if valueA is not None and valueA.dtype == torch.half:
         valueA = valueA.to(torch.float)
-    if valueB is not None:
-        valueB = valueB.to(valueA.dtype)
+    if valueB is not None and valueB.dtype == torch.half:
+        valueB = valueB.to(torch.float)
     M, K = src.sparse_size(0), other.sparse_size(1)
     rowptrC, colC, valueC = torch.ops.torch_sparse.spspmm_sum(
         rowptrA, colA, valueA, rowptrB, colB, valueB, K)