generic-library/cxx
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Taking another swing at correctly optimizing fill_n.

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@187587 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Howard Hinnant
2013-08-01 17:29:28 +00:00
parent eb34122153
commit 56dcf0b809
2 changed files with 52 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
include/algorithm
View File

@@ -1987,17 +1987,23 @@ replace_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator _
template <class _OutputIterator, class _Size, class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
_OutputIterator
__fill_n(_OutputIterator __first, _Size __n, const _Tp& __value_, false_type)
__fill_n(_OutputIterator __first, _Size __n, const _Tp& __value_)
{
for (; __n > 0; ++__first, --__n)
*__first = __value_;
return __first;
}
template <class _OutputIterator, class _Size, class _Tp>
template <class _Tp, class _Size, class _Up>
inline _LIBCPP_INLINE_VISIBILITY
_OutputIterator
__fill_n(_OutputIterator __first, _Size __n, const _Tp& __value_, true_type)
typename enable_if
<
is_integral<_Tp>::value && sizeof(_Tp) == 1 &&
!is_same<_Tp, bool>::value &&
is_integral<_Up>::value && sizeof(_Up) == 1,
_Tp*
>::type
__fill_n(_Tp* __first, _Size __n,_Up __value_)
{
if (__n > 0)
_VSTD::memset(__first, (unsigned char)__value_, (size_t)(__n));
@@ -2009,11 +2015,7 @@ inline _LIBCPP_INLINE_VISIBILITY
_OutputIterator
fill_n(_OutputIterator __first, _Size __n, const _Tp& __value_)
{
return _VSTD::__fill_n(__first, __n, __value_, integral_constant<bool,
is_pointer<_OutputIterator>::value &&
is_trivially_assignable<typename remove_pointer<_OutputIterator>::type, _Tp>::value &&
is_convertible<_Tp, unsigned char>::value &&
sizeof(typename remove_pointer<_OutputIterator>::type) == 1>());
return _VSTD::__fill_n(__first, __n, __value_);
}
// fill