On Thu, Sep 24, 2015 at 4:46 PM, chen xu <chen...@outlook.com> wrote:
> That's very helpful. Thanks a lot. I will try them out. > > By the way, when linking two libraries, say, they both instantiate classes > from the same template class (e.g. defined in a 'common' component), into > an executable, will the linker remove the duplicate class instance? > The linker will remove the duplicate code, but not the duplicate debug info (unless you use -fdebug-types-section - which will actually make your object files a little bigger, but the executable will be smaller since the duplicates will be removed) > > > ------------------------------ > Date: Thu, 24 Sep 2015 15:29:09 -0700 > > Subject: Re: [cfe-users] optimize template-heavy project with duplicate > code removal > From: dblai...@gmail.com > To: chen...@outlook.com > CC: cfe-users@lists.llvm.org > > > > On Thu, Sep 24, 2015 at 3:12 PM, chen xu <chen...@outlook.com> wrote: > > Thanks, David. The build type is Debug. Today I tried removing the debug > info (-g), the size of the executable could be cut 90%, to around 100MB, > which looks not bad. Do you know whether there is a way to separate debug > info file from the executable file on Linux? > > > Yep, -gsplit-dwarf - latest versions of GDB can cope with this debug info > > You can also compress the debug info: -Wa,--compress-debug-sections > > If you want linked debug info (rather than split debug info), consider > enabling type units to deduplicate debug info in your final executable > (-fdebug-types-section). > > > Mainly our code is already there, refactoring might require big effort.. > Also, does clang support -fno-implicit-templates? if yes, maybe we could > use it to eliminate duplicate template instances to control the final size. > > > Not sure, off hand, whether Clang supports that. > > > > ------------------------------ > Date: Wed, 23 Sep 2015 16:59:04 -0700 > Subject: Re: [cfe-users] optimize template-heavy project with duplicate > code removal > From: dblai...@gmail.com > To: chen...@outlook.com > CC: cfe-users@lists.llvm.org > > > debug or non-debug build? > > & no, for a full release build, measuring the final executable size, > there's not much you can do with the compiler. > > you can try to factor common portions out of your templates (eg: remove > template parameters where possible - if, for example, a member function of > a class template doesn't need all the template parameters - pull it out > into a standalone function template that takes fewer template parameters, > and call it from the member one) > > On Wed, Sep 23, 2015 at 4:43 PM, chen xu via cfe-users < > cfe-users@lists.llvm.org> wrote: > > Hi, our project heavily uses c++ template, and the resulting executable is > almost 1.5G Bytes, which is too big to be acceptable. Adding -O2 or -Os > does not seem helping. Is there any way (like link option, etc) to reduce > the size? > > _______________________________________________ > cfe-users mailing list > cfe-users@lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-users > > > >
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