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partition.h (__parallel_partition): Correctly initialize chunk size.

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2009-11-19  Johannes Singler  <singler@kit.edu>

        * include/parallel/partition.h (__parallel_partition): Correctly
        initialize chunk size.
        (__parallel_nth_element): Respect nth_element_minimal_n.  Use
        sequential nth_element as base case, instead of sequential sort.

From-SVN: r154333
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Johannes Singler 2009-11-19 16:43:20 +00:00 committed by Johannes Singler
parent b66a1bac46
commit d95ba652ab
2 changed files with 13 additions and 5 deletions
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7
libstdc++-v3/ChangeLog
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@ -1,3 +1,10 @@
2009-11-19 Johannes Singler <singler@kit.edu>
* include/parallel/partition.h (__parallel_partition): Correctly
initialize chunk size.
(__parallel_nth_element): Respect nth_element_minimal_n. Use
sequential nth_element as base case, instead of sequential sort.
2009-11-17 Benjamin Kosnik <bkoz@redhat.com>
* include/profile/impl/profiler.h: Remove namespace markup.

11
libstdc++-v3/include/parallel/partition.h
View File

@ -73,7 +73,7 @@ namespace __gnu_parallel
bool* __reserved_left = NULL, * __reserved_right = NULL;
_DifferenceType __chunk_size;
_DifferenceType __chunk_size = __s.partition_chunk_size;
omp_lock_t __result_lock;
omp_init_lock(&__result_lock);
@ -345,15 +345,16 @@ namespace __gnu_parallel
_RAIter __split;
_RandomNumber __rng;
_DifferenceType __minimum_length =
std::max<_DifferenceType>(2, _Settings::get().partition_minimal_n);
const _Settings& __s = _Settings::get();
_DifferenceType __minimum_length = std::max<_DifferenceType>(2,
std::max(__s.nth_element_minimal_n, __s.partition_minimal_n));
// Break if input range to small.
while (static_cast<_SequenceIndex>(__end - __begin) >= __minimum_length)
{
_DifferenceType __n = __end - __begin;
_RAIter __pivot_pos = __begin + __rng(__n);
_RAIter __pivot_pos = __begin + __rng(__n);
// Swap __pivot_pos value to end.
if (__pivot_pos != (__end - 1))
@ -412,7 +413,7 @@ namespace __gnu_parallel
}
// Only at most _Settings::partition_minimal_n __elements __left.
__gnu_sequential::sort(__begin, __end, __comp);
__gnu_sequential::nth_element(__begin, __nth, __end, __comp);
}
/** @brief Parallel implementation of std::partial_sort().