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author | Rémi Verschelde <remi@verschelde.fr> | 2021-05-21 18:30:02 +0200 |
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committer | GitHub <noreply@github.com> | 2021-05-21 18:30:02 +0200 |
commit | 3ee034451a9349e7de26decc662afefd7ab8c460 (patch) | |
tree | a8bec3fbb06c2eaca05a075f5ffe2cdd2d94f04a /thirdparty/embree/common/algorithms/parallel_partition.h | |
parent | 8fa07eae145e1e37eb8708ce8c117188b58e3ecc (diff) | |
parent | 767e374dced69b45db0afb30ca2ccf0bbbeef672 (diff) |
Merge pull request #48885 from JFonS/upgrade_embree
Upgrade Embree to the latest official release (3.13.0).
Diffstat (limited to 'thirdparty/embree/common/algorithms/parallel_partition.h')
-rw-r--r-- | thirdparty/embree/common/algorithms/parallel_partition.h | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/thirdparty/embree/common/algorithms/parallel_partition.h b/thirdparty/embree/common/algorithms/parallel_partition.h new file mode 100644 index 0000000000..a1cbdc8e04 --- /dev/null +++ b/thirdparty/embree/common/algorithms/parallel_partition.h @@ -0,0 +1,283 @@ +// Copyright 2009-2021 Intel Corporation +// SPDX-License-Identifier: Apache-2.0 + +#pragma once + +#include "parallel_for.h" +#include "../math/range.h" + +namespace embree +{ + /* serial partitioning */ + template<typename T, typename V, typename IsLeft, typename Reduction_T> + __forceinline size_t serial_partitioning(T* array, + const size_t begin, + const size_t end, + V& leftReduction, + V& rightReduction, + const IsLeft& is_left, + const Reduction_T& reduction_t) + { + T* l = array + begin; + T* r = array + end - 1; + + while(1) + { + /* *l < pivot */ + while (likely(l <= r && is_left(*l) )) + { + //prefetchw(l+4); // FIXME: enable? + reduction_t(leftReduction,*l); + ++l; + } + /* *r >= pivot) */ + while (likely(l <= r && !is_left(*r))) + { + //prefetchw(r-4); FIXME: enable? + reduction_t(rightReduction,*r); + --r; + } + if (r<l) break; + + reduction_t(leftReduction ,*r); + reduction_t(rightReduction,*l); + xchg(*l,*r); + l++; r--; + } + + return l - array; + } + + template<typename T, typename V, typename Vi, typename IsLeft, typename Reduction_T, typename Reduction_V> + class __aligned(64) parallel_partition_task + { + ALIGNED_CLASS_(64); + private: + + static const size_t MAX_TASKS = 64; + + T* array; + size_t N; + const IsLeft& is_left; + const Reduction_T& reduction_t; + const Reduction_V& reduction_v; + const Vi& identity; + + size_t numTasks; + __aligned(64) size_t counter_start[MAX_TASKS+1]; + __aligned(64) size_t counter_left[MAX_TASKS+1]; + __aligned(64) range<ssize_t> leftMisplacedRanges[MAX_TASKS]; + __aligned(64) range<ssize_t> rightMisplacedRanges[MAX_TASKS]; + __aligned(64) V leftReductions[MAX_TASKS]; + __aligned(64) V rightReductions[MAX_TASKS]; + + public: + + __forceinline parallel_partition_task(T* array, + const size_t N, + const Vi& identity, + const IsLeft& is_left, + const Reduction_T& reduction_t, + const Reduction_V& reduction_v, + const size_t BLOCK_SIZE) + + : array(array), N(N), is_left(is_left), reduction_t(reduction_t), reduction_v(reduction_v), identity(identity), + numTasks(min((N+BLOCK_SIZE-1)/BLOCK_SIZE,min(TaskScheduler::threadCount(),MAX_TASKS))) {} + + __forceinline const range<ssize_t>* findStartRange(size_t& index, const range<ssize_t>* const r, const size_t numRanges) + { + size_t i = 0; + while(index >= (size_t)r[i].size()) + { + assert(i < numRanges); + index -= (size_t)r[i].size(); + i++; + } + return &r[i]; + } + + __forceinline void swapItemsInMisplacedRanges(const size_t numLeftMisplacedRanges, + const size_t numRightMisplacedRanges, + const size_t startID, + const size_t endID) + { + size_t leftLocalIndex = startID; + size_t rightLocalIndex = startID; + const range<ssize_t>* l_range = findStartRange(leftLocalIndex,leftMisplacedRanges,numLeftMisplacedRanges); + const range<ssize_t>* r_range = findStartRange(rightLocalIndex,rightMisplacedRanges,numRightMisplacedRanges); + + size_t l_left = l_range->size() - leftLocalIndex; + size_t r_left = r_range->size() - rightLocalIndex; + T *__restrict__ l = &array[l_range->begin() + leftLocalIndex]; + T *__restrict__ r = &array[r_range->begin() + rightLocalIndex]; + size_t size = endID - startID; + size_t items = min(size,min(l_left,r_left)); + + while (size) + { + if (unlikely(l_left == 0)) + { + l_range++; + l_left = l_range->size(); + l = &array[l_range->begin()]; + items = min(size,min(l_left,r_left)); + } + + if (unlikely(r_left == 0)) + { + r_range++; + r_left = r_range->size(); + r = &array[r_range->begin()]; + items = min(size,min(l_left,r_left)); + } + + size -= items; + l_left -= items; + r_left -= items; + + while(items) { + items--; + xchg(*l++,*r++); + } + } + } + + __forceinline size_t partition(V& leftReduction, V& rightReduction) + { + /* partition the individual ranges for each task */ + parallel_for(numTasks,[&] (const size_t taskID) { + const size_t startID = (taskID+0)*N/numTasks; + const size_t endID = (taskID+1)*N/numTasks; + V local_left(identity); + V local_right(identity); + const size_t mid = serial_partitioning(array,startID,endID,local_left,local_right,is_left,reduction_t); + counter_start[taskID] = startID; + counter_left [taskID] = mid-startID; + leftReductions[taskID] = local_left; + rightReductions[taskID] = local_right; + }); + counter_start[numTasks] = N; + counter_left[numTasks] = 0; + + /* finalize the reductions */ + for (size_t i=0; i<numTasks; i++) { + reduction_v(leftReduction,leftReductions[i]); + reduction_v(rightReduction,rightReductions[i]); + } + + /* calculate mid point for partitioning */ + size_t mid = counter_left[0]; + for (size_t i=1; i<numTasks; i++) + mid += counter_left[i]; + const range<ssize_t> globalLeft (0,mid); + const range<ssize_t> globalRight(mid,N); + + /* calculate all left and right ranges that are on the wrong global side */ + size_t numMisplacedRangesLeft = 0; + size_t numMisplacedRangesRight = 0; + size_t numMisplacedItemsLeft = 0; + size_t numMisplacedItemsRight = 0; + + for (size_t i=0; i<numTasks; i++) + { + const range<ssize_t> left_range (counter_start[i], counter_start[i] + counter_left[i]); + const range<ssize_t> right_range(counter_start[i] + counter_left[i], counter_start[i+1]); + const range<ssize_t> left_misplaced = globalLeft. intersect(right_range); + const range<ssize_t> right_misplaced = globalRight.intersect(left_range); + + if (!left_misplaced.empty()) + { + numMisplacedItemsLeft += left_misplaced.size(); + leftMisplacedRanges[numMisplacedRangesLeft++] = left_misplaced; + } + + if (!right_misplaced.empty()) + { + numMisplacedItemsRight += right_misplaced.size(); + rightMisplacedRanges[numMisplacedRangesRight++] = right_misplaced; + } + } + assert( numMisplacedItemsLeft == numMisplacedItemsRight ); + + /* if no items are misplaced we are done */ + if (numMisplacedItemsLeft == 0) + return mid; + + /* otherwise we copy the items to the right place in parallel */ + parallel_for(numTasks,[&] (const size_t taskID) { + const size_t startID = (taskID+0)*numMisplacedItemsLeft/numTasks; + const size_t endID = (taskID+1)*numMisplacedItemsLeft/numTasks; + swapItemsInMisplacedRanges(numMisplacedRangesLeft,numMisplacedRangesRight,startID,endID); + }); + + return mid; + } + }; + + template<typename T, typename V, typename Vi, typename IsLeft, typename Reduction_T, typename Reduction_V> + __noinline size_t parallel_partitioning(T* array, + const size_t begin, + const size_t end, + const Vi &identity, + V &leftReduction, + V &rightReduction, + const IsLeft& is_left, + const Reduction_T& reduction_t, + const Reduction_V& reduction_v, + size_t BLOCK_SIZE = 128) + { + /* fall back to single threaded partitioning for small N */ + if (unlikely(end-begin < BLOCK_SIZE)) + return serial_partitioning(array,begin,end,leftReduction,rightReduction,is_left,reduction_t); + + /* otherwise use parallel code */ + else { + typedef parallel_partition_task<T,V,Vi,IsLeft,Reduction_T,Reduction_V> partition_task; + std::unique_ptr<partition_task> p(new partition_task(&array[begin],end-begin,identity,is_left,reduction_t,reduction_v,BLOCK_SIZE)); + return begin+p->partition(leftReduction,rightReduction); + } + } + + template<typename T, typename V, typename Vi, typename IsLeft, typename Reduction_T, typename Reduction_V> + __noinline size_t parallel_partitioning(T* array, + const size_t begin, + const size_t end, + const Vi &identity, + V &leftReduction, + V &rightReduction, + const IsLeft& is_left, + const Reduction_T& reduction_t, + const Reduction_V& reduction_v, + size_t BLOCK_SIZE, + size_t PARALLEL_THRESHOLD) + { + /* fall back to single threaded partitioning for small N */ + if (unlikely(end-begin < PARALLEL_THRESHOLD)) + return serial_partitioning(array,begin,end,leftReduction,rightReduction,is_left,reduction_t); + + /* otherwise use parallel code */ + else { + typedef parallel_partition_task<T,V,Vi,IsLeft,Reduction_T,Reduction_V> partition_task; + std::unique_ptr<partition_task> p(new partition_task(&array[begin],end-begin,identity,is_left,reduction_t,reduction_v,BLOCK_SIZE)); + return begin+p->partition(leftReduction,rightReduction); + } + } + + + template<typename T, typename IsLeft> + inline size_t parallel_partitioning(T* array, + const size_t begin, + const size_t end, + const IsLeft& is_left, + size_t BLOCK_SIZE = 128) + { + size_t leftReduction = 0; + size_t rightReduction = 0; + return parallel_partitioning( + array,begin,end,0,leftReduction,rightReduction,is_left, + [] (size_t& t,const T& ref) { }, + [] (size_t& t0,size_t& t1) { }, + BLOCK_SIZE); + } + +} |