xref: /freebsd-src/contrib/llvm-project/libcxx/src/pstl/libdispatch.cpp (revision 5f757f3ff9144b609b3c433dfd370cc6bdc191ad)
106c3fb27SDimitry Andric //===----------------------------------------------------------------------===//
206c3fb27SDimitry Andric //
306c3fb27SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
406c3fb27SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
506c3fb27SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
606c3fb27SDimitry Andric //
706c3fb27SDimitry Andric //===----------------------------------------------------------------------===//
806c3fb27SDimitry Andric 
906c3fb27SDimitry Andric #include <__algorithm/min.h>
1006c3fb27SDimitry Andric #include <__algorithm/pstl_backends/cpu_backends/libdispatch.h>
1106c3fb27SDimitry Andric #include <__config>
1206c3fb27SDimitry Andric #include <dispatch/dispatch.h>
1306c3fb27SDimitry Andric 
1406c3fb27SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
1506c3fb27SDimitry Andric 
1606c3fb27SDimitry Andric namespace __par_backend::inline __libdispatch {
1706c3fb27SDimitry Andric 
1806c3fb27SDimitry Andric void __dispatch_apply(size_t chunk_count, void* context, void (*func)(void* context, size_t chunk)) noexcept {
1906c3fb27SDimitry Andric   ::dispatch_apply_f(chunk_count, DISPATCH_APPLY_AUTO, context, func);
2006c3fb27SDimitry Andric }
2106c3fb27SDimitry Andric 
22*5f757f3fSDimitry Andric __chunk_partitions __partition_chunks(ptrdiff_t element_count) noexcept {
2306c3fb27SDimitry Andric   __chunk_partitions partitions;
24*5f757f3fSDimitry Andric   partitions.__chunk_count_      = std::max<ptrdiff_t>(1, element_count / 256);
2506c3fb27SDimitry Andric   partitions.__chunk_size_       = element_count / partitions.__chunk_count_;
26*5f757f3fSDimitry Andric   partitions.__first_chunk_size_ = element_count - (partitions.__chunk_count_ - 1) * partitions.__chunk_size_;
27*5f757f3fSDimitry Andric   if (partitions.__chunk_count_ == 0 && element_count > 0)
28*5f757f3fSDimitry Andric     partitions.__chunk_count_ = 1;
2906c3fb27SDimitry Andric   return partitions;
3006c3fb27SDimitry Andric }
3106c3fb27SDimitry Andric 
3206c3fb27SDimitry Andric // NOLINTNEXTLINE(llvm-namespace-comment) // This is https://llvm.org/PR56804
3306c3fb27SDimitry Andric } // namespace __par_backend::inline __libdispatch
3406c3fb27SDimitry Andric 
3506c3fb27SDimitry Andric _LIBCPP_END_NAMESPACE_STD
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