[INFRA] Import NVIDIA/CCCL upstream as optimization reference library

CCCL (CUDA C++ Core Libraries) provides:
- CUB: device/block/warp-level GPU primitives (reduce, scan, sort, topk)
- Thrust: high-level parallel algorithms (transform_reduce, sort, scan)
- libcudacxx: CUDA C++ standard library (atomics, barriers, memory)
- cudax: experimental features (memory resources, allocators)
- Tuning policies: per-SM hardware-specific algorithm parameters

Competition optimization vectors mapped to CCCL:
- Output TPS (83% weight): warp_reduce, block_reduce, device_topk
- Input TPS (14% weight): device_scan, block_load, prefetch
- Cache TPS (3% weight): prefix caching strategy patterns
- Memory (0.9 util): pooled/cached/buddy allocators

Source: https://github.com/NVIDIA/cccl (shallow clone, HEAD only)
License: Apache-2.0

cccl_upstream/thrust/testing/uninitialized_fill.cu

@@ -0,0 +1,229 @@
+#include <thrust/device_malloc_allocator.h>
+#include <thrust/iterator/retag.h>
+#include <thrust/uninitialized_fill.h>
+
+#include <nv/target>
+
+#include <unittest/unittest.h>
+
+template <typename ForwardIterator, typename T>
+void uninitialized_fill(my_system& system, ForwardIterator, ForwardIterator, const T&)
+{
+  system.validate_dispatch();
+}
+
+void TestUninitializedFillDispatchExplicit()
+{
+  thrust::device_vector<int> vec(1);
+
+  my_system sys(0);
+  thrust::uninitialized_fill(sys, vec.begin(), vec.begin(), 0);
+
+  ASSERT_EQUAL(true, sys.is_valid());
+}
+DECLARE_UNITTEST(TestUninitializedFillDispatchExplicit);
+
+template <typename ForwardIterator, typename T>
+void uninitialized_fill(my_tag, ForwardIterator first, ForwardIterator, const T&)
+{
+  *first = 13;
+}
+
+void TestUninitializedFillDispatchImplicit()
+{
+  thrust::device_vector<int> vec(1);
+
+  thrust::uninitialized_fill(thrust::retag<my_tag>(vec.begin()), thrust::retag<my_tag>(vec.begin()), 0);
+
+  ASSERT_EQUAL(13, vec.front());
+}
+DECLARE_UNITTEST(TestUninitializedFillDispatchImplicit);
+
+template <typename ForwardIterator, typename Size, typename T>
+ForwardIterator uninitialized_fill_n(my_system& system, ForwardIterator first, Size, const T&)
+{
+  system.validate_dispatch();
+  return first;
+}
+
+void TestUninitializedFillNDispatchExplicit()
+{
+  thrust::device_vector<int> vec(1);
+
+  my_system sys(0);
+  thrust::uninitialized_fill_n(sys, vec.begin(), vec.size(), 0);
+
+  ASSERT_EQUAL(true, sys.is_valid());
+}
+DECLARE_UNITTEST(TestUninitializedFillNDispatchExplicit);
+
+template <typename ForwardIterator, typename Size, typename T>
+ForwardIterator uninitialized_fill_n(my_tag, ForwardIterator first, Size, const T&)
+{
+  *first = 13;
+  return first;
+}
+
+void TestUninitializedFillNDispatchImplicit()
+{
+  thrust::device_vector<int> vec(1);
+
+  my_system sys(0);
+  thrust::uninitialized_fill_n(sys, vec.begin(), vec.size(), 0);
+
+  ASSERT_EQUAL(true, sys.is_valid());
+}
+DECLARE_UNITTEST(TestUninitializedFillNDispatchImplicit);
+
+template <class Vector>
+void TestUninitializedFillPOD()
+{
+  using T = typename Vector::value_type;
+
+  Vector v{0, 1, 2, 3, 4};
+
+  T exemplar(7);
+
+  thrust::uninitialized_fill(v.begin() + 1, v.begin() + 4, exemplar);
+
+  Vector ref{0, exemplar, exemplar, exemplar, 4};
+  ASSERT_EQUAL(v, ref);
+
+  exemplar = 8;
+
+  thrust::uninitialized_fill(v.begin() + 0, v.begin() + 3, exemplar);
+
+  ref = {exemplar, exemplar, exemplar, 7, 4};
+  ASSERT_EQUAL(v, ref);
+
+  exemplar = 9;
+
+  thrust::uninitialized_fill(v.begin() + 2, v.end(), exemplar);
+
+  ref = {8, 8, exemplar, exemplar, 9};
+  ASSERT_EQUAL(v, ref);
+
+  exemplar = 1;
+
+  thrust::uninitialized_fill(v.begin(), v.end(), exemplar);
+
+  ref = {exemplar, exemplar, exemplar, exemplar, exemplar};
+  ASSERT_EQUAL(v, ref);
+}
+DECLARE_VECTOR_UNITTEST(TestUninitializedFillPOD);
+
+struct CopyConstructTest
+{
+  CopyConstructTest() = default;
+
+  _CCCL_HOST_DEVICE CopyConstructTest(const CopyConstructTest&)
+  {
+    NV_IF_TARGET(NV_IS_DEVICE,
+                 (copy_constructed_on_device = true; copy_constructed_on_host = false;),
+                 (copy_constructed_on_device = false; copy_constructed_on_host = true;));
+  }
+
+  CopyConstructTest& operator=(const CopyConstructTest&) = default;
+
+  bool copy_constructed_on_host{false};
+  bool copy_constructed_on_device{false};
+};
+
+struct TestUninitializedFillNonPOD
+{
+  void operator()(const size_t)
+  {
+    using T                 = CopyConstructTest;
+    thrust::device_ptr<T> v = thrust::device_malloc<T>(5);
+
+    T exemplar;
+    ASSERT_EQUAL(false, exemplar.copy_constructed_on_device);
+    ASSERT_EQUAL(false, exemplar.copy_constructed_on_host);
+
+    T host_copy_of_exemplar(exemplar); // NOLINT(performance-unnecessary-copy-initialization)
+    ASSERT_EQUAL(false, exemplar.copy_constructed_on_device);
+    ASSERT_EQUAL(true, exemplar.copy_constructed_on_host);
+
+    // copy construct v from the exemplar
+    thrust::uninitialized_fill(v, v + 1, exemplar);
+
+    T x;
+    ASSERT_EQUAL(false, x.copy_constructed_on_device);
+    ASSERT_EQUAL(false, x.copy_constructed_on_host);
+
+    x = v[0];
+    ASSERT_EQUAL(true, x.copy_constructed_on_device);
+    ASSERT_EQUAL(false, x.copy_constructed_on_host);
+
+    thrust::device_free(v);
+  }
+};
+DECLARE_UNITTEST(TestUninitializedFillNonPOD);
+
+template <class Vector>
+void TestUninitializedFillNPOD()
+{
+  using T = typename Vector::value_type;
+
+  Vector v{0, 1, 2, 3, 4};
+
+  T exemplar(7);
+
+  typename Vector::iterator iter = thrust::uninitialized_fill_n(v.begin() + 1, 3, exemplar);
+
+  Vector ref{0, exemplar, exemplar, exemplar, 4};
+  ASSERT_EQUAL_QUIET(v.begin() + 4, iter);
+
+  exemplar = 8;
+
+  iter = thrust::uninitialized_fill_n(v.begin() + 0, 3, exemplar);
+
+  ref = {exemplar, exemplar, exemplar, 7, 4};
+  ASSERT_EQUAL_QUIET(v.begin() + 3, iter);
+
+  exemplar = 9;
+
+  iter = thrust::uninitialized_fill_n(v.begin() + 2, 3, exemplar);
+
+  ref = {8, 8, exemplar, exemplar, 9};
+  ASSERT_EQUAL_QUIET(v.end(), iter);
+
+  exemplar = 1;
+
+  iter = thrust::uninitialized_fill_n(v.begin(), v.size(), exemplar);
+
+  ref = {exemplar, exemplar, exemplar, exemplar, exemplar};
+  ASSERT_EQUAL_QUIET(v.end(), iter);
+}
+DECLARE_VECTOR_UNITTEST(TestUninitializedFillNPOD);
+
+struct TestUninitializedFillNNonPOD
+{
+  void operator()(const size_t)
+  {
+    using T                 = CopyConstructTest;
+    thrust::device_ptr<T> v = thrust::device_malloc<T>(5);
+
+    T exemplar;
+    ASSERT_EQUAL(false, exemplar.copy_constructed_on_device);
+    ASSERT_EQUAL(false, exemplar.copy_constructed_on_host);
+
+    T host_copy_of_exemplar(exemplar); // NOLINT(performance-unnecessary-copy-initialization)
+    ASSERT_EQUAL(false, exemplar.copy_constructed_on_device);
+    ASSERT_EQUAL(true, exemplar.copy_constructed_on_host);
+
+    // copy construct v from the exemplar
+    thrust::uninitialized_fill_n(v, 1, exemplar);
+
+    T x;
+    ASSERT_EQUAL(false, x.copy_constructed_on_device);
+    ASSERT_EQUAL(false, x.copy_constructed_on_host);
+
+    x = v[0];
+    ASSERT_EQUAL(true, x.copy_constructed_on_device);
+    ASSERT_EQUAL(false, x.copy_constructed_on_host);
+
+    thrust::device_free(v);
+  }
+};
+DECLARE_UNITTEST(TestUninitializedFillNNonPOD);