fix sort where the number of elements to be sorted is 1

Author: ndgrigorian

dpctl/tensor/libtensor/source/sorting/py_argsort_common.hpp

@@ -126,22 +126,42 @@ py_argsort(const dpctl::tensor::usm_ndarray &src,
     bool is_dst_c_contig = dst.is_c_contiguous();
 
     if (is_src_c_contig && is_dst_c_contig) {
-        static constexpr py::ssize_t zero_offset = py::ssize_t(0);
+        if (sort_nelems > 1) {
+            static constexpr py::ssize_t zero_offset = py::ssize_t(0);
 
-        auto fn = sort_contig_fns[src_typeid][dst_typeid];
+            auto fn = sort_contig_fns[src_typeid][dst_typeid];
 
-        if (fn == nullptr) {
-            throw py::value_error("Not implemented for dtypes of input arrays");
+            if (fn == nullptr) {
+                throw py::value_error(
+                    "Not implemented for dtypes of input arrays");
+            }
+
+            sycl::event comp_ev =
+                fn(exec_q, iter_nelems, sort_nelems, src.get_data(),
+                   dst.get_data(), zero_offset, zero_offset, zero_offset,
+                   zero_offset, depends);
+
+            sycl::event keep_args_alive_ev =
+                dpctl::utils::keep_args_alive(exec_q, {src, dst}, {comp_ev});
+
+            return std::make_pair(keep_args_alive_ev, comp_ev);
         }
+        else {
+            int dst_elemsize = dst.get_elemsize();
+            static constexpr int memset_val(0);
 
-        sycl::event comp_ev =
-            fn(exec_q, iter_nelems, sort_nelems, src.get_data(), dst.get_data(),
-               zero_offset, zero_offset, zero_offset, zero_offset, depends);
+            sycl::event fill_ev = exec_q.submit([&](sycl::handler &cgh) {
+                cgh.depends_on(depends);
 
-        sycl::event keep_args_alive_ev =
-            dpctl::utils::keep_args_alive(exec_q, {src, dst}, {comp_ev});
+                cgh.memset(reinterpret_cast<void *>(dst.get_data()), memset_val,
+                           iter_nelems * dst_elemsize);
+            });
 
-        return std::make_pair(keep_args_alive_ev, comp_ev);
+            sycl::event keep_args_alive_ev =
+                dpctl::utils::keep_args_alive(exec_q, {src, dst}, {fill_ev});
+
+            return std::make_pair(keep_args_alive_ev, fill_ev);
+        }
     }
 
     throw py::value_error(

dpctl/tensor/libtensor/source/sorting/py_sort_common.hpp

@@ -127,23 +127,37 @@ py_sort(const dpctl::tensor::usm_ndarray &src,
     bool is_dst_c_contig = dst.is_c_contiguous();
 
     if (is_src_c_contig && is_dst_c_contig) {
-        static constexpr py::ssize_t zero_offset = py::ssize_t(0);
+        if (sort_nelems > 1) {
+            static constexpr py::ssize_t zero_offset = py::ssize_t(0);
 
-        auto fn = sort_contig_fns[src_typeid];
+            auto fn = sort_contig_fns[src_typeid];
 
-        if (nullptr == fn) {
-            throw py::value_error(
-                "Not implemented for the dtype of input arrays");
-        }
+            if (nullptr == fn) {
+                throw py::value_error(
+                    "Not implemented for the dtype of input arrays");
+            }
+
+            sycl::event comp_ev =
+                fn(exec_q, iter_nelems, sort_nelems, src.get_data(),
+                   dst.get_data(), zero_offset, zero_offset, zero_offset,
+                   zero_offset, depends);
 
-        sycl::event comp_ev =
-            fn(exec_q, iter_nelems, sort_nelems, src.get_data(), dst.get_data(),
-               zero_offset, zero_offset, zero_offset, zero_offset, depends);
+            sycl::event keep_args_alive_ev =
+                dpctl::utils::keep_args_alive(exec_q, {src, dst}, {comp_ev});
 
-        sycl::event keep_args_alive_ev =
-            dpctl::utils::keep_args_alive(exec_q, {src, dst}, {comp_ev});
+            return std::make_pair(keep_args_alive_ev, comp_ev);
+        }
+        else {
+            int src_elemsize = src.get_elemsize();
 
-        return std::make_pair(keep_args_alive_ev, comp_ev);
+            sycl::event copy_ev =
+                exec_q.copy<char>(src.get_data(), dst.get_data(),
+                                  src_elemsize * iter_nelems, depends);
+
+            return std::make_pair(
+                dpctl::utils::keep_args_alive(exec_q, {src, dst}, {copy_ev}),
+                copy_ev);
+        }
     }
 
     throw py::value_error(

dpctl/tests/test_usm_ndarray_sorting.py

@@ -338,3 +338,43 @@ def test_sort_complex_fp_nan(dtype):
         assert np.array_equal(
             r1.view(np.int64), r2.view(np.int64)
         ), f"Failed for {i} and {j}"
+
+
+def test_radix_sort_size_1_axis():
+    get_queue_or_skip()
+
+    x1 = dpt.ones((), dtype="i1")
+    r1 = dpt.sort(x1, kind="radixsort")
+    assert r1 == x1
+
+    x2 = dpt.ones([1], dtype="i1")
+    r2 = dpt.sort(x2, kind="radixsort")
+    assert r2 == x2
+
+    x3 = dpt.reshape(dpt.arange(10, dtype="i1"), (10, 1))
+    r3 = dpt.sort(x3, kind="radixsort")
+    assert dpt.all(r3 == x3)
+
+    x4 = dpt.reshape(dpt.arange(10, dtype="i1"), (1, 10))
+    r4 = dpt.sort(x4, axis=0, kind="radixsort")
+    assert dpt.all(r4 == x4)
+
+
+def test_radix_argsort_size_1_axis():
+    get_queue_or_skip()
+
+    x1 = dpt.ones((), dtype="i1")
+    r1 = dpt.argsort(x1, kind="radixsort")
+    assert r1 == 0
+
+    x2 = dpt.ones([1], dtype="i1")
+    r2 = dpt.argsort(x2, kind="radixsort")
+    assert r2 == 0
+
+    x3 = dpt.reshape(dpt.arange(10, dtype="i1"), (10, 1))
+    r3 = dpt.argsort(x3, kind="radixsort")
+    assert dpt.all(r3 == 0)
+
+    x4 = dpt.reshape(dpt.arange(10, dtype="i1"), (1, 10))
+    r4 = dpt.argsort(x4, axis=0, kind="radixsort")
+    assert dpt.all(r4 == 0)