From: Alexandre Oliva <oliva@gnu.org>
To: Jonathan Wakely via Gcc-patches <gcc-patches@gcc.gnu.org>
Cc: whh8b@obs.cr, Jonathan Wakely <jwakely@redhat.com>,
libstdc++@gcc.gnu.org
Subject: Re: [PATCH] libstdc++: Optimize operator+(string/char*, string/char*) equally
Date: Wed, 24 Aug 2022 19:39:02 -0300 [thread overview]
Message-ID: <orczcpxo55.fsf@lxoliva.fsfla.org> (raw)
In-Reply-To: <CACb0b4n=MOL4muPH8XojL8qs5-ue3zJFoL4izOUsy+dtLajP7g@mail.gmail.com> (Jonathan Wakely via Gcc-patches's message of "Wed, 24 Aug 2022 15:24:11 +0100")
On Aug 24, 2022, Jonathan Wakely via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> * include/bits/basic_string.h (operator+(const string&,
> const char*)):
> Remove naive implementation.
> * include/bits/basic_string.tcc (operator+(const string&,
> const char*)):
> Add single-allocation implementation.
ISTM this requires the following additional tweak:
diff --git a/libstdc++-v3/src/c++11/string-inst.cc b/libstdc++-v3/src/c++11/string-inst.cc
index bfae6d902a1dd..2ec0e9d85f947 100644
--- a/libstdc++-v3/src/c++11/string-inst.cc
+++ b/libstdc++-v3/src/c++11/string-inst.cc
@@ -58,6 +58,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template class basic_string<C>;
template S operator+(const C*, const S&);
+ template S operator+(const S&, const C*);
template S operator+(C, const S&);
template S operator+(const S&, const S&);
Without this, I'm getting undefined references to this specialization in
libstdc++.so, that I tracked down to a std::system_error ctor in
cxx11-ios_failure.o. I got this while testing another patch that might
be the reason why the template instantiation doesn't get inlined, but...
we can't depend on its being inlined, can we?
--
Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/
Free Software Activist GNU Toolchain Engineer
Disinformation flourishes because many people care deeply about injustice
but very few check the facts. Ask me about <https://stallmansupport.org>
next prev parent reply other threads:[~2022-08-24 22:39 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-22 18:15 whh8b
2022-08-22 18:15 ` whh8b
2022-08-23 16:33 ` Jonathan Wakely
2022-08-24 6:18 ` Will Hawkins
2022-08-24 9:49 ` Jonathan Wakely
2022-08-24 6:16 ` [PATCH v2] libstdc++: Optimize operator+(string/char*,string/char*) whh8b
2022-08-24 6:16 ` [PATCH] libstdc++: Optimize operator+(string/char*,string/char*) equally whh8b
2022-08-24 6:16 ` [PATCH] libstdc++: Optimize operator+(string/char*, string/char*) equally whh8b
2022-08-24 14:24 ` Jonathan Wakely
2022-08-24 22:39 ` Alexandre Oliva [this message]
2022-08-24 22:47 ` Jonathan Wakely
2022-08-24 23:02 ` Jonathan Wakely
2022-08-25 5:52 ` Will Hawkins
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