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libstdc++: Use memset to optimize std::bitset::set() [PR113807]

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As pointed out in the PR we already do this for reset().

libstdc++-v3/ChangeLog:

	PR libstdc++/113807
	* include/std/bitset (bitset::set()): Use memset instead of a
	loop over the individual words.
This commit is contained in:
Jonathan Wakely 2024-02-08 15:46:08 +00:00
parent 4d819db7f2
commit e7ae13a858
1 changed files with 9 additions and 2 deletions
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11
libstdc++-v3/include/std/bitset
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@ -177,8 +177,15 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
_GLIBCXX14_CONSTEXPR void
_M_do_set() _GLIBCXX_NOEXCEPT
{
for (size_t __i = 0; __i < _Nw; __i++)
_M_w[__i] = ~static_cast<_WordT>(0);
#if __cplusplus >= 201402L
if (__builtin_is_constant_evaluated())
{
for (_WordT& __w : _M_w)
__w = ~static_cast<_WordT>(0);;
return;
}
#endif
__builtin_memset(_M_w, 0xFF, _Nw * sizeof(_WordT));
}
_GLIBCXX14_CONSTEXPR void