47 lines
1.3 KiB
C
47 lines
1.3 KiB
C
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/*
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* Copyright 2021 Blender Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#pragma once
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CCL_NAMESPACE_BEGIN
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/* Parallel prefix sum.
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*
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* TODO: actually make this work in parallel.
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*
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* This is used for an array the size of the number of shaders in the scene
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* which is not usually huge, so might not be a significant bottleneck. */
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#include "util/util_atomic.h"
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#define GPU_PARALLEL_PREFIX_SUM_DEFAULT_BLOCK_SIZE 512
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template<uint blocksize> __device__ void gpu_parallel_prefix_sum(int *values, const int num_values)
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{
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if (!(ccl_gpu_block_idx_x == 0 && ccl_gpu_thread_idx_x == 0)) {
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return;
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}
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int offset = 0;
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for (int i = 0; i < num_values; i++) {
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const int new_offset = offset + values[i];
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values[i] = offset;
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offset = new_offset;
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}
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}
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CCL_NAMESPACE_END
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