chore: import upstream snapshot with attribution

2026-07-13 12:47:05 +08:00
commit 4f3b7da785
7394 changed files with 2005594 additions and 0 deletions
@@ -0,0 +1,79 @@
+/* ******************************************************************************
+ *
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ *  See the NOTICE file distributed with this work for additional
+ *  information regarding copyright ownership.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+//
+// Created by Yurii Shyrma on 12.12.2017
+//
+#include <execution/Threads.h>
+#include <ops/declarable/helpers/zeta.h>
+#if NOT_EXCLUDED(OP_zeta)
+namespace sd {
+namespace ops {
+namespace helpers {
+
+const int maxIter = 1000000;  // max number of loop iterations
+
+//////////////////////////////////////////////////////////////////////////
+// slow implementation
+template <typename T>
+static SD_INLINE T zetaScalarSlow(const T x, const T q) {
+  const T precision = (T)1e-7;  // function stops the calculation of series when next item is <= precision
+
+  // if (x <= (T)1.)
+  //     throw("zeta function: x must be > 1 !");
+
+  // if (q <= (T)0.)
+  //     throw("zeta function: q must be > 0 !");
+
+  T item;
+  T result = (T)0.;
+  for (int i = 0; i < maxIter; ++i) {
+    item = math::sd_pow((q + i), -x);
+    result += item;
+
+    if (item <= precision) break;
+  }
+
+  return result;
+}
+
+//////////////////////////////////////////////////////////////////////////
+// calculate the Hurwitz zeta function for arrays
+template <typename T>
+static void zeta_(sd::LaunchContext* context, NDArray& x, NDArray& q, NDArray& z) {
+  // auto result = NDArray(&x, false, context);
+  int xLen = x.lengthOf();
+
+  auto func = PRAGMA_THREADS_FOR {
+    for (auto i = start; i < stop; i++) z.p(i, zetaScalar<T>(x.e<T>(i), q.e<T>(i)));
+  };
+
+  samediff::Threads::parallel_for(func, 0, xLen);
+}
+
+void zeta(sd::LaunchContext* context, NDArray& x, NDArray& q, NDArray& z) {
+  BUILD_SINGLE_SELECTOR(x.dataType(), zeta_, (context, x, q, z), SD_FLOAT_TYPES);
+}
+
+BUILD_SINGLE_TEMPLATE(  void zeta_,
+                      (sd::LaunchContext * context, NDArray& x, NDArray& q, NDArray& z), SD_FLOAT_TYPES);
+
+}  // namespace helpers
+}  // namespace ops
+}  // namespace sd
+#endif