[Bug c++/104670] New: ICE when using decltype of a lambda returning a struct inside of a struct
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104670
Bug ID: 104670
Summary: ICE when using decltype of a lambda returning a struct
inside of a struct
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: krzysio.kurek at wp dot pl
Target Milestone: ---
Created attachment 52502
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52502=edit
-freport-bug output
GCC ICEs when compiling the following piece of code:
struct foo {
decltype([] { return (struct {
int fn() {}
}){}; }) bar;
};
Compiled with `-std=c++20`
Past stable releases of GCC report "confused by earlier errors, bailing out"
without crashing instead.
[Bug libstdc++/94960] New: extern template prevents inlining of standard library objects
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94960
Bug ID: 94960
Summary: extern template prevents inlining of standard library
objects
Product: gcc
Version: 9.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: krzysio.kurek at wp dot pl
Target Milestone: ---
Consider this example
void foo()
{
std::string(1, 0);
}
(https://godbolt.org/z/AlkBBJ)
This function creates a string using the `basic_string(size_t, CharT)`
constructor and then discards it. This particular constructor uses _M_construct
internally, which is declared as an out of line member function. Because of
this, and because the function isn't marked as `inline`, when the compiler
reaches the `extern template class basic_string;`, it foregoes trying to
find the definition for _M_construct, instead generating a call to it, causing
foo() to fully instantiate a string object and then delete it, since the
compiler can't find _M_construct within its own translation unit.
This problem applies to every member function of any class which has an extern
template, is defined out of line and is not marked as `inline`.
[Bug lto/88516] Internal LTO error when linking against static libSFML
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88516 krzysio.kurek at wp dot pl changed: What|Removed |Added Status|WAITING |RESOLVED Resolution|--- |INVALID --- Comment #4 from krzysio.kurek at wp dot pl --- I've been trying to put the issue in a repository however the ICE stopped occurring for me, and I don't know how to replicate it anymore. I'll reopen this issue when I have something ready.
[Bug lto/88516] Internal LTO error when linking against static libSFML
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88516 --- Comment #2 from krzysio.kurek at wp dot pl --- Created attachment 45243 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=45243=edit preprocessed file Oh I just noticed that the preprocessed file didn't get attached.
[Bug lto/88516] Internal LTO error when linking against static libSFML
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88516 --- Comment #1 from krzysio.kurek at wp dot pl --- I'm afraid this is as minimal as it gets. Should I set up a git repo with all sources needed to reproduce the error?
[Bug lto/88516] New: Internal LTO error when linking against static libSFML
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88516 Bug ID: 88516 Summary: Internal LTO error when linking against static libSFML Product: gcc Version: 8.2.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: lto Assignee: unassigned at gcc dot gnu.org Reporter: krzysio.kurek at wp dot pl CC: marxin at gcc dot gnu.org Target Milestone: --- sysinfo: gcc (SUSE Linux) 8.2.1 20181108 [gcc-8-branch revision 265914] OpenSUSE Tumbleweed 20181213 GCC configuration: ../configure --prefix=/usr --infodir=/usr/share/info --mandir=/usr/share/man --libdir=/usr/lib64 --libexecdir=/usr/lib64 --enable-languages=c,c++,objc,fortran,obj-c++,ada,go --enable-offload-targets=hsa,nvptx-none=/usr/nvptx-none, --without-cuda-driver --enable-checking=release --disable-werror --with-gxx-include-dir=/usr/include/c++/8 --enable-ssp --disable-libssp --disable-libvtv --disable-cet --disable-libcc1 --enable-plugin --with-bugurl=http://bugs.opensuse.org/ --with-pkgversion='SUSE Linux' --with-slibdir=/lib64 --with-system-zlib --enable-libstdcxx-allocator=new --disable-libstdcxx-pch --enable-version-specific-runtime-libs --with-gcc-major-version-only --enable-linker-build-id --enable-linux-futex --enable-gnu-indirect-function --program-suffix=-8 --without-system-libunwind --enable-multilib --with-arch-32=x86-64 --with-tune=generic --build=x86_64-suse-linux --host=x86_64-suse-linux exact commandline: g++ main.cpp /usr/local/lib/libsfml-graphics-s.a /usr/local/lib/libsfml-window-s.a /usr/local/lib/libsfml-system-s.a -lpthread -lrt /usr/lib64/libudev.so /usr/lib64/libOpenGL.so /usr/lib64/libX11.so /usr/lib64/libXrandr.so /usr/lib64/libfreetype.so error message: lto1: internal compiler error: in add_symbol_to_partition_1, at lto/lto-partition.c:155 Please submit a full bug report, with preprocessed source if appropriate. See <http://bugs.opensuse.org/> for instructions. lto-wrapper: fatal error: g++ returned 1 exit status compilation terminated. /usr/lib64/gcc/x86_64-suse-linux/8/../../../../x86_64-suse-linux/bin/ld: error: lto-wrapper failed collect2: error: ld returned 1 exit status Happens with a locally compiled SFML, commit b9fdaf487f878fac17c3d4c1182acd8c4182eecc, with LTO enabled and compiled to static libraries.
[Bug lto/82229] GCC7's LTO underperforms compared to GCC6
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82229 --- Comment #28 from krzysio.kurek at wp dot pl --- I mean the relative performance is worse but still Profiled GCC6 is faster than GCC 7 or GCC 8.
[Bug lto/82229] GCC7's LTO underperforms compared to GCC6
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82229 krzysio.kurek at wp dot pl changed: What|Removed |Added Attachment #44025|0 |1 is obsolete|| --- Comment #26 from krzysio.kurek at wp dot pl --- Created attachment 44040 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44040=edit Annotates and report logs from perf I don't have an FTP, I'm just doing this stuff locally by hand.
[Bug lto/82229] GCC7's LTO underperforms compared to GCC6
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82229 krzysio.kurek at wp dot pl changed: What|Removed |Added Attachment #42199|0 |1 is obsolete|| --- Comment #24 from krzysio.kurek at wp dot pl --- Created attachment 44025 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44025=edit Performance logs from perf Alright so I've generated 4 profiles with the following flags: "pure6": -O3 -DNDEBUG -flto "profiled6": -O3 -DNDEBUG -flto + profile run "pure7": -O3 -DNDEBUG -flto "profiled7": -O3 -DNDEBUG -flto + profile run On GCC6 the profile run impacted performance of the application negatively compared to "pure6".
[Bug lto/82229] GCC7's LTO underperforms compared to GCC6
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82229 --- Comment #22 from krzysio.kurek at wp dot pl --- I'm sorry but profiling doesn't seem to be well documented, what tools should I use to generate a profiling log?
[Bug lto/82229] GCC7's LTO underperforms compared to GCC6
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82229 krzysio.kurek at wp dot pl changed: What|Removed |Added Status|RESOLVED|REOPENED Resolution|INVALID |--- --- Comment #20 from krzysio.kurek at wp dot pl --- Reopening.
[Bug lto/82229] GCC7's LTO underperforms compared to GCC6
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82229 --- Comment #19 from krzysio.kurek at wp dot pl --- I'm sorry if it's not clear, English isn't my native language. So to reiterate. The normal, unoptimized path is: World::update() simulates world which uses Random::get() to generate a random number. Random::get() calls std::uniform_int_distribution, which then calls std::mersenne_twister_engine(). And this is what GCC7 uses. Now GCC6 with LTO manages to optimize the path by: Calling Random::get() only once per frame. Omitting std::uniform_int_distribution, calling std::mersenne_twister_engine() instead every time a random number is needed.
[Bug lto/82229] GCC7's LTO underperforms compared to GCC6
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82229 --- Comment #18 from krzysio.kurek at wp dot pl --- I'm sorry if it's not clear, English isn't my native language. So to reiterate. The normal, unoptimized path is: World::update() simulates world which uses Random::get() on every person. Random::get() calls
[Bug lto/82229] GCC7's LTO underperforms compared to GCC6
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82229 krzysio.kurek at wp dot pl changed: What|Removed |Added Version|7.1.0 |7.2.0 --- Comment #17 from krzysio.kurek at wp dot pl --- I've been trying to create a minimal testcase but I've not been able to. Seemingly random actions like changing the directory from the build dir back into it prevents the bug from manifesting. Looking at results of Valgrind's tool, Callgrind, I've managed to find the hog being Random::get() calls not being optimized as aggressively on GCC7 as on GCC6. On GCC6, std::mersenne_twister_engine is being called directly from the main world simulation loop, whereas on GCC7, Random::get() is called every time calculations on random numbers are made. Random::get() in turn calls std::uniform_int_distribution which then calls the mersenne engine.
[Bug lto/82302] LTO producing bad code
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82302 --- Comment #12 from krzysio.kurek at wp dot pl --- UBSAN errors regarding integer overflow is by design, and is a part of libnoise. I can't find any documentation or help on what invalid vptr errors are though.
[Bug libstdc++/82346] [5.5 Regression] String is not detected as a part of std
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82346 --- Comment #8 from krzysio.kurek at wp dot pl --- Wouldn't this bug affect all gcc compilers? I have 5, 6 and 7 installed, and only 5 is affected.
[Bug lto/82302] LTO producing bad code
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82302 --- Comment #9 from krzysio.kurek at wp dot pl --- I think I located the issue, it works fine on my machine, but using I found an error using glslangValidator. Please try pulling and compiling again.
[Bug libstdc++/82346] [5.5 Regression] String is not detected as a part of std
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82346 --- Comment #5 from krzysio.kurek at wp dot pl --- $ g++-5 -std=c++11 main.cpp -o string -v Using built-in specs. COLLECT_GCC=g++-5 COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/5/lto-wrapper Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu 5.4.1-12ubuntu4' --with-bugurl=file:///usr/share/doc/gcc-5/README.Bugs --enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-5 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-5-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-5-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-5-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix gcc version 5.4.1 20170906 (Ubuntu 5.4.1-12ubuntu4) COLLECT_GCC_OPTIONS='-std=c++11' '-o' 'string' '-v' '-shared-libgcc' '-mtune=generic' '-march=x86-64' /usr/lib/gcc/x86_64-linux-gnu/5/cc1plus -quiet -v -imultiarch x86_64-linux-gnu -D_GNU_SOURCE main.cpp -quiet -dumpbase main.cpp -mtune=generic -march=x86-64 -auxbase main -std=c++11 -version -fstack-protector-strong -Wformat -Wformat-security -o /tmp/ccUSBFkt.s GNU C++11 (Ubuntu 5.4.1-12ubuntu4) version 5.4.1 20170906 (x86_64-linux-gnu) compiled by GNU C version 5.4.1 20170906, GMP version 6.1.2, MPFR version 3.1.6-rc1, MPC version 1.0.3 warning: MPFR header version 3.1.6-rc1 differs from library version 3.1.6. GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 ignoring duplicate directory "/usr/include/x86_64-linux-gnu/c++/5" ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu" ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/5/../../../../x86_64-linux-gnu/include" #include "..." search starts here: #include <...> search starts here: /usr/include/c++/5 /usr/include/x86_64-linux-gnu/c++/5 /usr/include/c++/5/backward /usr/lib/gcc/x86_64-linux-gnu/5/include /usr/local/include /usr/lib/gcc/x86_64-linux-gnu/5/include-fixed /usr/include/x86_64-linux-gnu /usr/include End of search list. GNU C++11 (Ubuntu 5.4.1-12ubuntu4) version 5.4.1 20170906 (x86_64-linux-gnu) compiled by GNU C version 5.4.1 20170906, GMP version 6.1.2, MPFR version 3.1.6-rc1, MPC version 1.0.3 warning: MPFR header version 3.1.6-rc1 differs from library version 3.1.6. GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 Compiler executable checksum: 4fa6e505be5bb1fff9039a541d8268ee main.cpp: In function ‘int main()’: main.cpp:6:25: error: ‘to_string’ is not a member of ‘std’ std::string perfect = std::to_string(1+2+4+7+14) + " is a perfect number"; ^
[Bug c++/82346] String is not detected as a part of std
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82346 krzysio.kurek at wp dot pl changed: What|Removed |Added Status|RESOLVED|UNCONFIRMED Resolution|INVALID |--- --- Comment #2 from krzysio.kurek at wp dot pl --- Oh yeah I could have mentioned, my bad. -std=c++11/-std=c++14 do not fix the issue. It only fails on 5.4.1, and works on 5.4.0.
[Bug c++/82346] New: String is not detected as a part of std
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82346
Bug ID: 82346
Summary: String is not detected as a part of std
Product: gcc
Version: 5.4.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: krzysio.kurek at wp dot pl
Target Milestone: ---
Most basic code fails to compile.
#include
#include
int main ()
{
std::string perfect = std::to_string(1+2+4+7+14) + " is a perfect number";
std::cout << perfect << '\n';
return 0;
}
[Bug lto/82302] LTO producing bad code
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82302 --- Comment #8 from krzysio.kurek at wp dot pl --- In a sense that there is no error, the program goes into infinite loop.
[Bug lto/82302] LTO producing bad code
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82302 --- Comment #7 from krzysio.kurek at wp dot pl --- No, the error you're having is completely different from what I originally reported.
[Bug lto/82302] LTO producing bad code
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82302 --- Comment #5 from krzysio.kurek at wp dot pl --- I can't reproduce your error.
[Bug lto/82302] LTO producing bad code
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82302 --- Comment #3 from krzysio.kurek at wp dot pl --- This happens only on GCC7 with -flto activated. clang-6, GCC6 and GCC5 with either flag enabled or disabled compile code that runs fine. I don't know why this error is occurring for you Martin.
[Bug lto/82302] New: LTO producing bad code
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82302 Bug ID: 82302 Summary: LTO producing bad code Product: gcc Version: 7.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: lto Assignee: unassigned at gcc dot gnu.org Reporter: krzysio.kurek at wp dot pl CC: marxin at gcc dot gnu.org Target Milestone: --- I've found a repository with code which upon compilation with -flto under GCC7 creates a softlock. Works fine on GCC6. Here's a fork of the repo: https://github.com/kiroma/MineCraft-One-Week-Challenge It's made so that cmake defaults to a build configuration with -flto enabled. On GCC6 the program will output to the console: Attempting to load chunk Finished loading chunk, all clear! Spawn found! Attempts: x Time Taken: y seconds On GCC7 it will print: Attempting to load chunk but will not proceed.
[Bug lto/82229] GCC7's LTO underperforms compared to GCC6
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82229 --- Comment #11 from krzysio.kurek at wp dot pl --- Done, cmake will now default to Release config with altered compiler flags that include -flto.
[Bug lto/82229] GCC7's LTO underperforms compared to GCC6
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82229 --- Comment #8 from krzysio.kurek at wp dot pl --- Okay, I'm terribly sorry for the amount of messages but I'm failing over and over again trying to grasp the issue. The seed is only static for the first request, but changes later on becoming random once more. After making few (what seemed at the time) minor cosmetic changes GCC6 had optimized out at least one additional function completely.
[Bug lto/82229] GCC7's LTO underperforms compared to GCC6
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82229 --- Comment #7 from krzysio.kurek at wp dot pl --- I've created a fork with "devel" branch here: https://github.com/kiroma/Empire/tree/devel I've tweaked some things, so now random seed is set, the simulation will exit after 250 iterations and after exiting it will output to console average fps for the whole run.
[Bug lto/82229] GCC7's LTO underperforms compared to GCC6
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82229 --- Comment #6 from krzysio.kurek at wp dot pl --- Oh, two comments about the callgrind output. Random::get() is being called 14 times less often on GCC6 There is a function created from template in GCC7 that is completely absent on GCC6.
[Bug lto/82229] GCC7's LTO underperforms compared to GCC6
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82229 --- Comment #5 from krzysio.kurek at wp dot pl --- Created attachment 42199 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=42199=edit callgrind output I can make the program output to console average fps after 20 iterations with 10 warmup cycles. The program will still run with GUI, but will output just FPS to the console and exit. Will this be sufficient? I'm a complete newbie to the whole language, but I got some profiling done. I'm attaching callgrind output files, they're named after which compiler was used.
[Bug c++/82229] GCC7's LTO underperforms compared to GCC6
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82229 --- Comment #2 from krzysio.kurek at wp dot pl --- I'm using CMake to generate a Makefile. The Release build adds -O3 and -DNDEBUG by default to compile options. I modify the config so that it also adds -flto. Should I attach make verbose output?
[Bug c++/82229] New: GCC7's LTO underperforms compared to GCC6
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82229 Bug ID: 82229 Summary: GCC7's LTO underperforms compared to GCC6 Product: gcc Version: 7.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: krzysio.kurek at wp dot pl Target Milestone: --- A small SFML project on github: https://github.com/Hopson97/Empire Takes huge advantage of -flto flag on GCC6, but after upgrading to GCC7, the difference is negligible. Here are some of my test results: gcc6.3 no flto: 24-25 fps gcc7.2 no flto: 24 fps gcc6.3 with flto: 40-42fps gcc7.2 with flto: 26-27fps
