Fixes stride calculation when unboxing a dpnp ndarray

numba_dpex/core/runtime/_dpexrt_python.c

@@ -731,7 +731,7 @@ static int DPEXRT_sycl_usm_ndarray_from_python(PyObject *obj,
                                                arystruct_t *arystruct)
 {
     struct PyUSMArrayObject *arrayobj = NULL;
-    int i = 0, ndim = 0, exp = 0;
+    int i = 0, j = 0, k = 0, ndim = 0, exp = 0;
     npy_intp *shape = NULL, *strides = NULL;
     npy_intp *p = NULL, nitems;
     void *data = NULL;
@@ -812,10 +812,12 @@ static int DPEXRT_sycl_usm_ndarray_from_python(PyObject *obj,
         }
     }
     else {
-        for (i = 1; i < ndim; ++i, ++p) {
-            *p = shape[i] << exp;
+        for (i = ndim * 2 - 1; i >= ndim; --i, ++p) {
+            *p = 1;
+            for (j = i, k = ndim - 1; j > ndim; --j, --k)
+                *p *= shape[k];
+            *p <<= exp;
         }
-        *p = 1;
     }
 
     return 0;
@@ -859,13 +861,21 @@ static PyObject *box_from_arystruct_parent(arystruct_t *arystruct,
     struct PyUSMArrayObject *arrayobj = NULL;
     npy_intp itemsize = 0;
 
-    DPEXRT_DEBUG(drt_debug_print("DPEXRT-DEBUG: In try_to_return_parent.\n"));
+    DPEXRT_DEBUG(
+        drt_debug_print("DPEXRT-DEBUG: In box_from_arystruct_parent.\n"));
 
-    if (!(arrayobj = PyUSMNdArray_ARRAYOBJ(arystruct->parent)))
+    if (!(arrayobj = PyUSMNdArray_ARRAYOBJ(arystruct->parent))) {
+        DPEXRT_DEBUG(
+            drt_debug_print("DPEXRT-DEBUG: Arrayobj cannot be boxed from "
+                            "parent as parent pointer is NULL.\n"));
         return NULL;
+    }
 
-    if ((void *)UsmNDArray_GetData(arrayobj) != arystruct->data)
+    if ((void *)UsmNDArray_GetData(arrayobj) != arystruct->data) {
+        DPEXRT_DEBUG(drt_debug_print("DPEXRT-DEBUG: Arrayobj cannot be boxed "
+                                     "from parent as data pointer is NULL.\n"));
         return NULL;
+    }
 
     if (UsmNDArray_GetNDim(arrayobj) != ndim)
         return NULL;
@@ -985,6 +995,10 @@ DPEXRT_sycl_usm_ndarray_to_python_acqref(arystruct_t *arystruct,
     // return back to Python memory that was allocated inside Numba and let
     // Python manage the lifetime of the memory.
     if (arystruct->meminfo) {
+        DPEXRT_DEBUG(
+            drt_debug_print("DPEXRT-DEBUG: Set the base of the boxed array "
+                            "from arystruct's meminfo pointer at %s, line %d\n",
+                            __FILE__, __LINE__));
         // wrap into MemInfoObject
         if (!(miobj = PyObject_New(MemInfoObject, &MemInfoType))) {
             PyErr_Format(PyExc_ValueError,

numba_dpex/tests/core/types/DpctlSyclQueue/test_box_unbox.py

@@ -7,7 +7,6 @@
 """
 
 import dpctl
-import pytest
 
 from numba_dpex import dpjit
 

numba_dpex/tests/core/types/DpnpNdArray/test_boxing_unboxing.py

@@ -0,0 +1,47 @@
+# SPDX-FileCopyrightText: 2020 - 2023 Intel Corporation
+#
+# SPDX-License-Identifier: Apache-2.0
+
+"""
+Tests for boxing for dpnp.ndarray
+"""
+
+import dpnp
+
+from numba_dpex import dpjit
+
+
+def test_boxing_unboxing():
+    """Tests basic boxing and unboxing of a dpnp.ndarray object.
+
+    Checks if we can pass in and return a dpctl.ndarray object to and
+    from a dpjit decorated function.
+    """
+
+    @dpjit
+    def func(a):
+        return a
+
+    a = dpnp.empty(10)
+    try:
+        b = func(a)
+    except:
+        assert False, "Failure during unbox/box of dpnp.ndarray"
+
+    assert a.shape == b.shape
+    assert a.device == b.device
+    assert a.strides == b.strides
+    assert a.dtype == b.dtype
+
+
+def test_stride_calc_at_unboxing():
+    """Tests if strides were correctly computed during unboxing."""
+
+    def _tester(a):
+        return a.strides
+
+    b = dpnp.empty((4, 16, 4))
+    strides = dpjit(_tester)(b)
+
+    # Numba computes strides as bytes
+    assert list(strides) == [512, 32, 8]

numba_dpex/tests/dpjit_tests/test_slicing.py

@@ -0,0 +1,62 @@
+# SPDX-FileCopyrightText: 2020 - 2023 Intel Corporation
+#
+# SPDX-License-Identifier: Apache-2.0
+
+"""
+Tests for boxing for dpnp.ndarray
+"""
+
+import dpnp
+import numpy
+
+from numba_dpex import dpjit
+
+
+def test_1d_slicing():
+    """Tests if dpjit properly computes strides and returns them to Python."""
+
+    def _tester(a):
+        return a[1:5]
+
+    a = dpnp.arange(10)
+    b = dpnp.asnumpy(dpjit(_tester)(a))
+
+    na = numpy.arange(10)
+    nb = _tester(na)
+
+    assert (b == nb).all()
+
+
+def test_1d_slicing2():
+    """Tests if dpjit properly computes strides and returns them to Python."""
+
+    def _tester(a):
+        b = a[1:4]
+        a[6:9] = b
+
+    a = dpnp.arange(10)
+    b = dpnp.asnumpy(dpjit(_tester)(a))
+
+    na = numpy.arange(10)
+    nb = _tester(na)
+
+    assert (b == nb).all()
+
+
+def test_multidim_slicing():
+    """Tests if dpjit properly slices strides and returns them to Python."""
+
+    def _tester(a, b):
+        b[:, :, 0] = a
+
+    a = dpnp.arange(64, dtype=numpy.int64)
+    a = a.reshape(4, 16)
+    b = dpnp.empty((4, 16, 4), dtype=numpy.int64)
+    dpjit(_tester)(a, b)
+
+    na = numpy.arange(64, dtype=numpy.int64)
+    na = na.reshape(4, 16)
+    nb = numpy.empty((4, 16, 4), dtype=numpy.int64)
+    _tester(na, nb)
+
+    assert (nb[:, :, 0] == dpnp.asnumpy(b)[:, :, 0]).all()