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Add workaround for gcc-12 and above where the prefetch call is ignored

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This commit is contained in:
Christian Mazakas
2023-05-26 08:16:02 -07:00
parent c5df4ec069
commit 2ab4225473
1 changed files with 6 additions and 1 deletions
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7
include/boost/unordered/detail/foa/core.hpp
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@ -1040,7 +1040,12 @@ void swap_if(T&,T&){}
inline void prefetch(const void* p)
{
(void) p;
#if defined(BOOST_GCC)||defined(BOOST_CLANG)
#if BOOST_WORKAROUND(BOOST_GCC, >= 120000) && defined(BOOST_UNORDERED_SSE2)
// gcc-12 and above seem to remove the `__bulitin_prefetch` call below so we
// manually insert the instruction via an asm declaration.
// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109985
asm("prefetcht0 %[ptr]"::[ptr]"m"(*(char const*)p):);
#elif defined(BOOST_GCC)||defined(BOOST_CLANG)
__builtin_prefetch((const char*)p);
#elif defined(BOOST_UNORDERED_SSE2)
_mm_prefetch((const char*)p,_MM_HINT_T0);