Relaxed tolerance for cumultivae_logsumexp closed form test

Made failure more informative

Author: oleksandr-pavlyk

dpctl/tests/test_tensor_accumulation.py

@@ -408,5 +408,12 @@ def test_cumulative_logsumexp_closed_form(fpdt):
     r = dpt.cumulative_logsumexp(dpt.arange(-n, 0, dtype=fpdt, device=q))
     expected = geometric_series_closed_form(n, dtype=fpdt, device=q)
 
-    tol = 4 * dpt.finfo(fpdt).eps
-    assert dpt.allclose(r, expected, atol=tol, rtol=tol)
+    tol = 32 * dpt.finfo(fpdt).eps
+    if not dpt.allclose(r, expected, atol=tol, rtol=tol):
+        ad = dpt.abs(r - expected)
+        max = dpt.max(ad)
+        viols = ad > tol + tol * dpt.maximum(dpt.abs(r), dpt.abs(expected))
+        viols_count = dpt.sum(viols)
+        assert (
+            False
+        ), f"allclose failed, absdiff = {max}, violations = {viols_count}"