copy data to allow in-place edits

econtal · econtal · commit 8d2d4fa2c95e · 2019-09-20T15:04:57.000-07:00
diff --git a/cupy/cusparse.py b/cupy/cusparse.py
@@ -564,6 +564,12 @@ def cscsort(x):
 
 
 def coosort(x):
+    """Sorts indices of COO-matrix in place
+
+    Args:
+        x (cupyx.scipy.sparse.coo_matrix): A sparse matrix to sort.
+
+    """
     nnz = x.nnz
     if nnz == 0:
         return
@@ -574,16 +580,16 @@ def coosort(x):
         handle, m, n, nnz, x.row.data.ptr, x.col.data.ptr)
     buf = cupy.empty(buffer_size, 'b')
     P = cupy.empty(nnz, 'i')
-    data_sorted = cupy.empty_like(x.data)
+    # copy data to do safe in-place edits by gthr
+    data_orig = x.data.copy()
     cusparse.createIdentityPermutation(handle, nnz, P.data.ptr)
     cusparse.xcoosortByRow(
         handle, m, n, nnz, x.row.data.ptr, x.col.data.ptr,
         P.data.ptr, buf.data.ptr)
     _call_cusparse(
         'gthr', x.dtype,
-        handle, nnz, x.data.data.ptr, data_sorted.data.ptr,
+        handle, nnz, data_orig.data.ptr, x.data.data.ptr,
         P.data.ptr, cusparse.CUSPARSE_INDEX_BASE_ZERO)
-    x.data = data_sorted
 
 
 def coo2csr(x):
