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From: "qiu.chaofan at outlook dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/100912] powerpc64le: ieee128 long double incorrectly printed when using shared libstdc++
Date: Mon, 11 Oct 2021 10:08:24 +0000 [thread overview]
Message-ID: <bug-100912-4-yMh0lrtbAm@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-100912-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100912
Qiu Chaofan <qiu.chaofan at outlook dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |qiu.chaofan at outlook dot com
--- Comment #5 from Qiu Chaofan <qiu.chaofan at outlook dot com> ---
Hi, I encountered the same problem when dynamically linking against libstdcxx,
while static linking works fine. The HEAD of git history is 8f323c712 (early
Sep.) so it shouldn't be old.
The configure option is: --enable-languages=c,c++ --disable-nls
--disable-bootstrap --with-long-double-format=ieee --disable-libgomp
--enable-multilib --with-cpu=power9 --with-advance-toolchain=at15.0
(Disabling multilib still has this issue)
By digging into make log, I found something interesting (some omitted):
libtool: link: /build/./gcc/xgcc -shared-libgcc ... -fPIC -DPIC
-D_GLIBCXX_SHARED -shared -nostdlib /opt/at15.0/lib/../lib64/crti.o
/build/./gcc/crtbeginS.o .libs/compatibility.o
.libs/compatibility-debug_list.o .libs/compatibility-debug_list-2.o
.libs/compatibility-ldbl.o .libs/compatibility-c++0x.o
.libs/compatibility-atomic-c++0x.o .libs/compatibility-thread-c++0x.o
.libs/compatibility-chrono.o .libs/compatibility-condvar.o
.libs/compatibility-ldbl-alt128.o .libs/compatibility-ldbl-alt128-cxx11.o
-Wl,--whole-archive ../libsupc++/.libs/libsupc++convenience.a
../src/c++98/.libs/libc++98convenience.a
../src/c++11/.libs/libc++11convenience.a
../src/c++17/.libs/libc++17convenience.a
../src/c++20/.libs/libc++20convenience.a ... -Wl,-soname -Wl,libstdc++.so.6 -o
.libs/libstdc++.so.6.0.29
Only the 'compatibility' objects joined the link, and they're built using
`-mabi=ibmlongdouble`, not IEEE. Manually adding `c++11/wlocale-inst.o`
produces error complaining about multiple definition.
While libstdc++.a contains all of these definitions, actually seven
(compatibility-ldbl.o compatibility-ldbl-alt128.o
compatibility-ldbl-alt128-cxx11.o cxx11-locale-inst.o cxx11-wlocale-inst.o
locale-inst.o wlocale-inst.o
), so ld can find the correct one properly. (although I'm still not clear how
ld does it)
If I understood correctly, the reason why result is incorrect is that the
`libstdc++.so` only contains symbols built for compatibility. Maybe something
went wrong in the build scripts?
next prev parent reply other threads:[~2021-10-11 10:08 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-04 18:51 [Bug libstdc++/100912] New: " msc at linux dot ibm.com
2021-06-04 22:27 ` [Bug target/100912] " pinskia at gcc dot gnu.org
2021-06-05 10:51 ` redi at gcc dot gnu.org
2021-06-07 13:27 ` msc at linux dot ibm.com
2021-06-07 13:50 ` msc at linux dot ibm.com
2021-10-11 10:08 ` qiu.chaofan at outlook dot com [this message]
2021-10-13 8:56 ` [Bug libstdc++/100912] " qiu.chaofan at outlook dot com
2021-10-13 9:16 ` redi at gcc dot gnu.org
2021-10-21 3:47 ` qiu.chaofan at outlook dot com
2021-12-06 6:26 ` qiu.chaofan at outlook dot com
2022-01-10 9:57 ` qiu.chaofan at outlook dot com
2022-01-10 10:01 ` redi at gcc dot gnu.org
2022-02-14 17:27 ` cvs-commit at gcc dot gnu.org
2022-02-14 17:29 ` redi at gcc dot gnu.org
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