From 63dcc3316a37a134b69299af030a248b58d2bd21 Mon Sep 17 00:00:00 2001
From: Alexander Kalistratov <alexander.kalistratov@intel.com>
Date: Thu, 20 Jul 2023 00:54:54 +0200
Subject: [PATCH 1/2] Use specilized kernel for f-arrays and sum by axis=1. Add
 keepdims support

---
 dpnp/dpnp_iface_mathematical.py | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/dpnp/dpnp_iface_mathematical.py b/dpnp/dpnp_iface_mathematical.py
index 2c45f05e2b9a..a7e6800c6e22 100644
--- a/dpnp/dpnp_iface_mathematical.py
+++ b/dpnp/dpnp_iface_mathematical.py
@@ -1828,12 +1828,18 @@ def sum(
     elif where is not True:
         pass
     else:
-        if axis == (0,) and len(x.shape) == 2 and not keepdims:
+        if len(x.shape) == 2 and (
+            (axis == (0,) and x.flags.c_contiguous)
+            or (axis == (1,) and x.flags.f_contiguous)
+        ):
             from dpctl.tensor._reduction import _default_reduction_dtype
 
             from dpnp.backend.extensions.sycl_ext import _sycl_ext_impl
 
-            input = dpnp.get_usm_ndarray(x)
+            input = x
+            if axis == (1,):
+                input = input.T
+            input = dpnp.get_usm_ndarray(input)
 
             queue = input.sycl_queue
             out_dtype = (
@@ -1850,7 +1856,14 @@ def sum(
 
             if sum:
                 sum(input, output, []).wait()
-                return dpnp_array._create_from_usm_ndarray(output)
+                result = dpnp_array._create_from_usm_ndarray(output)
+
+                if keepdims:
+                    result = result.reshape((1,) + output.shape)
+                    if axis == (1,):
+                        result = result.T
+
+                return result
 
         y = dpt.sum(
             dpnp.get_usm_ndarray(x), axis=axis, dtype=dtype, keepdims=keepdims

From 48348c95c1114d2988932cbc8054e437588644c0 Mon Sep 17 00:00:00 2001
From: Alexander Kalistratov <alexander.kalistratov@intel.com>
Date: Thu, 20 Jul 2023 19:28:47 +0200
Subject: [PATCH 2/2] Review remarks

---
 dpnp/dpnp_iface_mathematical.py | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/dpnp/dpnp_iface_mathematical.py b/dpnp/dpnp_iface_mathematical.py
index a7e6800c6e22..36e9804618f8 100644
--- a/dpnp/dpnp_iface_mathematical.py
+++ b/dpnp/dpnp_iface_mathematical.py
@@ -1859,9 +1859,11 @@ def sum(
                 result = dpnp_array._create_from_usm_ndarray(output)
 
                 if keepdims:
-                    result = result.reshape((1,) + output.shape)
-                    if axis == (1,):
-                        result = result.T
+                    if axis == (0,):
+                        res_sh = (1,) + output.shape
+                    else:
+                        res_sh = output.shape + (1,)
+                    result = result.reshape(res_sh)
 
                 return result