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| author | Jonathan Wakely <jwakely@redhat.com> | 2024-07-05 18:58:00 +0100 |
|---|---|---|
| committer | Jonathan Wakely <redi@gcc.gnu.org> | 2024-07-07 12:26:08 +0100 |
| commit | 762ee55d369a3257997092ef7853cf9dd4d5cc4f (patch) | |
| tree | ce2b5014ad91c7aa3b4834a9ff7d9a8a9a54cc17 | |
| parent | e78c5d0ae48b7bf539d94b77382ecc1aac260f0c (diff) | |
| download | gcc-762ee55d369a3257997092ef7853cf9dd4d5cc4f.zip gcc-762ee55d369a3257997092ef7853cf9dd4d5cc4f.tar.gz gcc-762ee55d369a3257997092ef7853cf9dd4d5cc4f.tar.bz2 | |
libstdc++: Fix memchr path in std::ranges::find for non-common range [PR115799]
The memchr optimization introduced in r15-1857 needs to advance the
start iterator instead of returning the sentinel.
libstdc++-v3/ChangeLog:
PR libstdc++/115799
* include/bits/ranges_util.h (__find_fn): Return iterator
instead of sentinel.
* testsuite/25_algorithms/find/constrained.cc: Check non-common
contiguous sized range of char.
| -rw-r--r-- | libstdc++-v3/include/bits/ranges_util.h | 19 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/25_algorithms/find/constrained.cc | 10 |
2 files changed, 19 insertions, 10 deletions
diff --git a/libstdc++-v3/include/bits/ranges_util.h b/libstdc++-v3/include/bits/ranges_util.h index 186acae..a1f4287 100644 --- a/libstdc++-v3/include/bits/ranges_util.h +++ b/libstdc++-v3/include/bits/ranges_util.h @@ -501,17 +501,16 @@ namespace ranges if constexpr (contiguous_iterator<_Iter>) if (!is_constant_evaluated()) { - if (static_cast<iter_value_t<_Iter>>(__value) != __value) - return __last; - + using _Vt = iter_value_t<_Iter>; auto __n = __last - __first; - if (__n > 0) - { - const int __ival = static_cast<int>(__value); - const void* __p0 = std::to_address(__first); - if (auto __p1 = __builtin_memchr(__p0, __ival, __n)) - __n = (const char*)__p1 - (const char*)__p0; - } + if (static_cast<_Vt>(__value) == __value) [[likely]] + if (__n > 0) + { + const int __ival = static_cast<int>(__value); + const void* __p0 = std::to_address(__first); + if (auto __p1 = __builtin_memchr(__p0, __ival, __n)) + __n = (const char*)__p1 - (const char*)__p0; + } return __first + __n; } diff --git a/libstdc++-v3/testsuite/25_algorithms/find/constrained.cc b/libstdc++-v3/testsuite/25_algorithms/find/constrained.cc index e94751f..7357a40 100644 --- a/libstdc++-v3/testsuite/25_algorithms/find/constrained.cc +++ b/libstdc++-v3/testsuite/25_algorithms/find/constrained.cc @@ -66,9 +66,19 @@ test02() static_assert(ranges::find(y, 5, &Y::j) == y+3); } +void +test_pr115799() +{ + const char str[3] = { 'a', 'b', 'c' }; + __gnu_test::test_contiguous_sized_range<const char> r(str); + VERIFY(std::ranges::find(r, 'a') == std::ranges::begin(r)); + VERIFY(std::ranges::find(r, 'a'+255) == std::ranges::end(r)); +} + int main() { test01(); test02(); + test_pr115799(); } |