From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1888) id 292653858CDA; Tue, 4 Oct 2022 14:54:44 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 292653858CDA DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1664895284; bh=KRDtTk+e+PWybnip7QHJ/X0a73wIVnO2+8LJAtdWqQs=; h=From:To:Subject:Date:From; b=ZoECG96oCBg9nlq9N0iKhNlhNCnt8EjgG/2ZkAXdM8eOvbTy74ihwHYGDdOsDNyoZ EBWVTz3M7UNadYP4Sm0lk6mi7zL9OkRgrBVtNVq05PjVI6jd4iHiguzq3wsWZvxds6 9ivq/OFztZdggjsAH04cVGZZ/fvGMPo+f/f9LRFg= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Patrick Palka To: gcc-cvs@gcc.gnu.org, libstdc++-cvs@gcc.gnu.org Subject: [gcc r13-3062] libstdc++: Avoid heavyweight std::visit in ranges::join_with_view X-Act-Checkin: gcc X-Git-Author: Patrick Palka X-Git-Refname: refs/heads/master X-Git-Oldrev: beeb6898fe8ad44731bc58cad7220511b8225797 X-Git-Newrev: 3b8bcc3f8b821e7359f8504334488ff2b1fc8f30 Message-Id: <20221004145444.292653858CDA@sourceware.org> Date: Tue, 4 Oct 2022 14:54:44 +0000 (GMT) List-Id: https://gcc.gnu.org/g:3b8bcc3f8b821e7359f8504334488ff2b1fc8f30 commit r13-3062-g3b8bcc3f8b821e7359f8504334488ff2b1fc8f30 Author: Patrick Palka Date: Tue Oct 4 10:54:36 2022 -0400 libstdc++: Avoid heavyweight std::visit in ranges::join_with_view libstdc++-v3/ChangeLog: * include/std/ranges (join_with_view::_Iterator::operator*): Replace use of std::visit with manual visitation. (join_with_view::_Iterator::operator++): Likewise. (join_with_view::_Iterator::operator--): Likewise. (join_with_view::_Iterator::iter_move): Likewise. (join_with_view::_Iterator::iter_swap): Likewise. Diff: --- libstdc++-v3/include/std/ranges | 47 +++++++++++++++++++++++++++++++---------- 1 file changed, 36 insertions(+), 11 deletions(-) diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges index d0d6ce61a87..1f821128d2d 100644 --- a/libstdc++-v3/include/std/ranges +++ b/libstdc++-v3/include/std/ranges @@ -7165,18 +7165,23 @@ namespace views::__adaptor _M_inner_it.template emplace<1>(std::get<1>(std::move(__i._M_inner_it))); } - constexpr decltype(auto) + constexpr common_reference_t, + iter_reference_t<_PatternIter>> operator*() const { - using reference = common_reference_t, - iter_reference_t<_PatternIter>>; - return std::visit([](auto& __it) -> reference { return *__it; }, _M_inner_it); + if (_M_inner_it.index() == 0) + return *std::get<0>(_M_inner_it); + else + return *std::get<1>(_M_inner_it); } constexpr _Iterator& operator++() { - std::visit([](auto& __it){ ++__it; }, _M_inner_it); + if (_M_inner_it.index() == 0) + ++std::get<0>(_M_inner_it); + else + ++std::get<1>(_M_inner_it); _M_satisfy(); return *this; } @@ -7232,7 +7237,10 @@ namespace views::__adaptor } } - std::visit([](auto& __it){ --__it; }, _M_inner_it); + if (_M_inner_it.index() == 0) + --std::get<0>(_M_inner_it); + else + --std::get<1>(_M_inner_it); return *this; } @@ -7253,18 +7261,35 @@ namespace views::__adaptor && equality_comparable<_OuterIter> && equality_comparable<_InnerIter> { return __x._M_outer_it == __y._M_outer_it && __x._M_inner_it ==__y._M_inner_it; } - friend constexpr decltype(auto) + friend constexpr common_reference_t, + iter_rvalue_reference_t<_PatternIter>> iter_move(const _Iterator& __x) { - using __rval_ref = common_reference_t, - iter_rvalue_reference_t<_PatternIter>>; - return std::visit<__rval_ref>(ranges::iter_move, __x._M_inner_it); + if (__x._M_inner_it.index() == 0) + return ranges::iter_move(std::get<0>(__x._M_inner_it)); + else + return ranges::iter_move(std::get<1>(__x._M_inner_it)); } friend constexpr void iter_swap(const _Iterator& __x, const _Iterator& __y) requires indirectly_swappable<_InnerIter, _PatternIter> - { std::visit(ranges::iter_swap, __x._M_inner_it, __y._M_inner_it); } + { + if (__x._M_inner_it.index() == 0) + { + if (__y._M_inner_it.index() == 0) + ranges::iter_swap(std::get<0>(__x._M_inner_it), std::get<0>(__y._M_inner_it)); + else + ranges::iter_swap(std::get<0>(__x._M_inner_it), std::get<1>(__y._M_inner_it)); + } + else + { + if (__y._M_inner_it.index() == 0) + ranges::iter_swap(std::get<1>(__x._M_inner_it), std::get<0>(__y._M_inner_it)); + else + ranges::iter_swap(std::get<1>(__x._M_inner_it), std::get<1>(__y._M_inner_it)); + } + } }; template