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
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+/* ******************************************************************************
+ *
+ *
+ * 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
+ ******************************************************************************/
+
+//
+// @author raver119@gmail.com, created on 6/30/2018
+// @author Yurii Shyrma (iuriish@yahoo.com)
+//
+#include <helpers/OmpLaunchHelper.h>
+#include <math/templatemath.h>
+#include <system/Environment.h>
+
+namespace sd {
+
+////////////////////////////////////////////////////////////////////////////////
+OmpLaunchHelper::OmpLaunchHelper(const LongType N, float desiredNumThreads) {
+  auto maxItersPerThread = Environment::getInstance().elementwiseThreshold();
+
+  if (N < maxItersPerThread)
+    _numThreads = 1;
+  else {
+#ifdef _OPENMP
+    if (desiredNumThreads == -1)
+      desiredNumThreads = omp_get_max_threads();
+    else if (desiredNumThreads < 1)
+      desiredNumThreads = 1;
+    else
+      desiredNumThreads = sd::math::sd_min<int>(omp_get_max_threads(), desiredNumThreads);
+#else
+    desiredNumThreads = Environment::getInstance().maxThreads();
+#endif
+    _numThreads = sd::math::sd_min<int>(N / maxItersPerThread, desiredNumThreads);
+  }
+
+  _itersPerThread = N / _numThreads;
+  _remainder = N % _numThreads;  // last thread may contain bigger number of iterations
+}
+
+LongType OmpLaunchHelper::betterSpan(LongType N) { return betterSpan(N, betterThreads(N)); }
+
+LongType OmpLaunchHelper::betterSpan(LongType N, LongType numThreads) {
+  auto r = N % numThreads;
+  auto t = N / numThreads;
+
+  if (r == 0)
+    return t;
+  else {
+    // breaks alignment
+    return t + 1;
+  }
+}
+
+int OmpLaunchHelper::betterThreads(LongType N) {
+#ifdef _OPENMP
+  return betterThreads(N, omp_get_max_threads());
+#else
+  return betterThreads(N, Environment::getInstance().maxThreads());
+  ;
+#endif
+}
+
+int OmpLaunchHelper::betterThreads(LongType N, int maxThreads) {
+  auto t = Environment::getInstance().elementwiseThreshold();
+  if (N < t)
+    return 1;
+  else {
+    return static_cast<int>(sd::math::sd_min<LongType>(N / t, maxThreads));
+  }
+}
+
+int OmpLaunchHelper::tadThreads(LongType tadLength, LongType numTads) {
+#ifdef _OPENMP
+  auto maxThreads = omp_get_max_threads();
+#else
+  auto maxThreads = Environment::getInstance().maxThreads();
+#endif
+
+  // if there's only 1 thread allowed - nothing to do here
+  if (maxThreads <= 1) return 1;
+
+  auto totalLength = tadLength * numTads;
+
+  // if array is tiny - no need to spawn any threeds
+  if (totalLength < Environment::getInstance().elementwiseThreshold()) return 1;
+
+  // by default we're spawning as many threads we can, but not more than number of TADs
+  return sd::math::sd_min<int>(numTads, maxThreads);
+}
+}  // namespace sd