xref: /freebsd/contrib/llvm-project/libcxx/src/pstl/libdispatch.cpp (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
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 <__config>
11*0fca6ea1SDimitry Andric #include <__pstl/backends/libdispatch.h>
1206c3fb27SDimitry Andric #include <dispatch/dispatch.h>
1306c3fb27SDimitry Andric 
1406c3fb27SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
15*0fca6ea1SDimitry Andric namespace __pstl::__libdispatch {
1606c3fb27SDimitry Andric 
__dispatch_apply(size_t chunk_count,void * context,void (* func)(void * context,size_t chunk))1706c3fb27SDimitry Andric void __dispatch_apply(size_t chunk_count, void* context, void (*func)(void* context, size_t chunk)) noexcept {
1806c3fb27SDimitry Andric   ::dispatch_apply_f(chunk_count, DISPATCH_APPLY_AUTO, context, func);
1906c3fb27SDimitry Andric }
2006c3fb27SDimitry Andric 
__partition_chunks(ptrdiff_t element_count)215f757f3fSDimitry Andric __chunk_partitions __partition_chunks(ptrdiff_t element_count) noexcept {
2206c3fb27SDimitry Andric   __chunk_partitions partitions;
235f757f3fSDimitry Andric   partitions.__chunk_count_      = std::max<ptrdiff_t>(1, element_count / 256);
2406c3fb27SDimitry Andric   partitions.__chunk_size_       = element_count / partitions.__chunk_count_;
255f757f3fSDimitry Andric   partitions.__first_chunk_size_ = element_count - (partitions.__chunk_count_ - 1) * partitions.__chunk_size_;
265f757f3fSDimitry Andric   if (partitions.__chunk_count_ == 0 && element_count > 0)
275f757f3fSDimitry Andric     partitions.__chunk_count_ = 1;
2806c3fb27SDimitry Andric   return partitions;
2906c3fb27SDimitry Andric }
3006c3fb27SDimitry Andric 
31*0fca6ea1SDimitry Andric } // namespace __pstl::__libdispatch
3206c3fb27SDimitry Andric _LIBCPP_END_NAMESPACE_STD
33