43 lines
1.0 KiB
C
43 lines
1.0 KiB
C
/* SPDX-FileCopyrightText: 2021-2022 Blender Foundation
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*
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* SPDX-License-Identifier: Apache-2.0 */
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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/atomic.h"
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#ifdef __HIP__
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# define GPU_PARALLEL_PREFIX_SUM_DEFAULT_BLOCK_SIZE 1024
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#else
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# define GPU_PARALLEL_PREFIX_SUM_DEFAULT_BLOCK_SIZE 512
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#endif
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__device__ void gpu_parallel_prefix_sum(const int global_id,
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ccl_global int *counter,
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ccl_global int *prefix_sum,
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const int num_values)
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{
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if (global_id != 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 + counter[i];
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prefix_sum[i] = offset;
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counter[i] = 0;
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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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