chore: import upstream snapshot with attribution

plugin/common/nmsHelper.cpp

@@ -0,0 +1,66 @@
+/*
+ * SPDX-FileCopyrightText: Copyright (c) 1993-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.
+ */
+
+#include "common/plugin.h"
+#include <algorithm>
+#include <cuda_fp16.h>
+
+namespace nvinfer1::plugin
+{
+
+size_t detectionForwardBBoxDataSize(int32_t N, int32_t C1, DataType DT_BBOX)
+{
+    if (DT_BBOX == DataType::kFLOAT)
+    {
+        return N * C1 * sizeof(float);
+    }
+    if (DT_BBOX == DataType::kHALF)
+    {
+        return N * C1 * sizeof(__half);
+    }
+
+    printf("Only FP32/FP16 type bounding boxes are supported.\n");
+    return (size_t) -1;
+}
+
+size_t detectionForwardBBoxPermuteSize(bool shareLocation, int32_t N, int32_t C1, DataType DT_BBOX)
+{
+    if (DT_BBOX == DataType::kFLOAT)
+    {
+        return shareLocation ? 0 : N * C1 * sizeof(float);
+    }
+    if (DT_BBOX == DataType::kHALF)
+    {
+        return shareLocation ? 0 : N * C1 * sizeof(__half);
+    }
+
+    printf("Only FP32/FP16 type bounding boxes are supported.\n");
+    return (size_t) -1;
+}
+
+size_t detectionForwardPreNMSSize(int32_t N, int32_t C2)
+{
+    PLUGIN_ASSERT(sizeof(float) == sizeof(int32_t));
+    return N * C2 * sizeof(float);
+}
+
+size_t detectionForwardPostNMSSize(int32_t N, int32_t numClasses, int32_t topK)
+{
+    PLUGIN_ASSERT(sizeof(float) == sizeof(int32_t));
+    return N * numClasses * topK * sizeof(float);
+}
+} // namespace nvinfer1::plugin