1850     IS       irows = NULL, icols = NULL;  in MatConvert_IS_XAIJ()  local
1871         PetscCall(ISInvertPermutation(rows, PETSC_DECIDE, &irows));  in MatConvert_IS_XAIJ()
1876       if (irows && matis->rmapping != matis->cmapping) {  in MatConvert_IS_XAIJ()
1892       } else if (irows) {  in MatConvert_IS_XAIJ()
1893         PetscCall(PetscObjectReference((PetscObject)irows));  in MatConvert_IS_XAIJ()
1894         icols = irows;  in MatConvert_IS_XAIJ()
1897       PetscCall(PetscObjectQuery((PetscObject)*M, "_MatIS_IS_XAIJ_irows", (PetscObject *)&irows));  in MatConvert_IS_XAIJ()
1899       if (irows) PetscCall(PetscObjectReference((PetscObject)irows));  in MatConvert_IS_XAIJ()
1902     if (!irows || !icols) {  in MatConvert_IS_XAIJ()
1904       PetscCall(ISDestroy(&irows));  in MatConvert_IS_XAIJ()
1909       PetscCall(MatCreateSubMatrix(B, irows, icols, reuse, M));  in MatConvert_IS_XAIJ()
1910       PetscCall(PetscObjectCompose((PetscObject)*M, "_MatIS_IS_XAIJ_irows", (PetscObject)irows));  in MatConvert_IS_XAIJ()
1915       PetscCall(MatCreateSubMatrix(B, irows, icols, MAT_INITIAL_MATRIX, &C));  in MatConvert_IS_XAIJ()
1920     PetscCall(ISDestroy(&irows));  in MatConvert_IS_XAIJ()