libcxx: update to LLVM 17

release/17.x branch, commit 8f4dd44097c9ae25dd203d5ac87f3b48f854bba8

This adds the flag `-D_LIBCPP_PSTL_CPU_BACKEND_SERIAL`. A future
enhancement could possibly pass something different if there is a
compelling parallel implementation. That libdispatch one might be worth
looking into.

1 files changed, 16 insertions, 21 deletions

diff --git a/lib/libcxx/src/algorithm.cpp b/lib/libcxx/src/algorithm.cpp
index bd47e08b38..af9d60a8e2 100644
--- a/lib/libcxx/src/algorithm.cpp
+++ b/lib/libcxx/src/algorithm.cpp
@@ -7,11 +7,25 @@
 //===----------------------------------------------------------------------===//
 
 #include <algorithm>
+#include <bit>
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-// TODO(varconst): this currently doesn't benefit `ranges::sort` because it uses `ranges::less` instead of `__less`.
+template <class Comp, class RandomAccessIterator>
+void __sort(RandomAccessIterator first, RandomAccessIterator last, Comp comp) {
+  auto depth_limit = 2 * std::__bit_log2(static_cast<size_t>(last - first));
 
+  // Only use bitset partitioning for arithmetic types.  We should also check
+  // that the default comparator is in use so that we are sure that there are no
+  // branches in the comparator.
+  std::__introsort<_ClassicAlgPolicy,
+                   ranges::less,
+                   RandomAccessIterator,
+                   __use_branchless_sort<ranges::less, RandomAccessIterator>::value>(
+      first, last, ranges::less{}, depth_limit);
+}
+
+// clang-format off
 template void __sort<__less<char>&, char*>(char*, char*, __less<char>&);
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 template void __sort<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&);
@@ -29,25 +43,6 @@ template void __sort<__less<unsigned long long>&, unsigned long long*>(unsigned
 template void __sort<__less<float>&, float*>(float*, float*, __less<float>&);
 template void __sort<__less<double>&, double*>(double*, double*, __less<double>&);
 template void __sort<__less<long double>&, long double*>(long double*, long double*, __less<long double>&);
-
-template bool __insertion_sort_incomplete<__less<char>&, char*>(char*, char*, __less<char>&);
-#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
-template bool __insertion_sort_incomplete<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&);
-#endif
-template bool __insertion_sort_incomplete<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&);
-template bool __insertion_sort_incomplete<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&);
-template bool __insertion_sort_incomplete<__less<short>&, short*>(short*, short*, __less<short>&);
-template bool __insertion_sort_incomplete<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&);
-template bool __insertion_sort_incomplete<__less<int>&, int*>(int*, int*, __less<int>&);
-template bool __insertion_sort_incomplete<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&);
-template bool __insertion_sort_incomplete<__less<long>&, long*>(long*, long*, __less<long>&);
-template bool __insertion_sort_incomplete<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&);
-template bool __insertion_sort_incomplete<__less<long long>&, long long*>(long long*, long long*, __less<long long>&);
-template bool __insertion_sort_incomplete<__less<unsigned long long>&, unsigned long long*>(unsigned long long*, unsigned long long*, __less<unsigned long long>&);
-template bool __insertion_sort_incomplete<__less<float>&, float*>(float*, float*, __less<float>&);
-template bool __insertion_sort_incomplete<__less<double>&, double*>(double*, double*, __less<double>&);
-template bool __insertion_sort_incomplete<__less<long double>&, long double*>(long double*, long double*, __less<long double>&);
-
-template unsigned __sort5<__less<long double>&, long double*>(long double*, long double*, long double*, long double*, long double*, __less<long double>&);
+// clang-format on
 
 _LIBCPP_END_NAMESPACE_STD