Re: [cfe-users] optimize template-heavy project with duplicate code removal
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? 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. 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 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 ___ cfe-users mailing list cfe-users@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-users
Re: [cfe-users] optimize template-heavy project with duplicate code removal
On Thu, Sep 24, 2015 at 3:12 PM, chen xu 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 > > > ___ cfe-users mailing list cfe-users@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-users
Re: [cfe-users] optimize template-heavy project with duplicate code removal
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? 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 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 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 ___ cfe-users mailing list cfe-users@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-users
