Re: [gem5-users] LLVM and GE/M5
Thank you, but as a rule all gem5 conversations should happen on the mailing list unless somebody specifically asks to be emailed directly. Korey is right that it's written gem5, not GE/M5. gem5 is currently designed to be compiled with gcc, not llvm. llvm is a perfectly fine compiler, but not what we're using with gem5 right now which is why it's not mentioned. Changing compilers would likely be a lot of work and llvm is less likely to already be installed on users machines, so we'd have to get a substantial benefit from it as far as significantly improved performance or some feature gcc doesn't provide before it would be worthwhile. Since gem5 is open source, you're welcome to make it work under llvm yourself. If you do and you can show us that it -does- give a substantial benefit (we like those), please let us know. External programs like benchmarks can be compiled with any tool you like as long as the output is in a format gem5 can understand, for instance an ELF file. Gabe On 05/19/11 00:41, Tarek Chammah wrote: Hello Gabriel Black, I noticed you answering users' questions and figure you're generally knowledgeable about GE/M5. Though I didn't get much traction on the mailing list. All of the postings on the home page mentioned using GE/M5 with GCC, as in compiling the simulator, as well as cross compiling programs for target architectures to run on the simulator. Though no mention is made of LLVM in this context. Is is not preferred to use LLVM or has it never been attempted before? If it is possible to use LLVM to cross compile programs, are there reported successful instances where this has occurred? Sincerely, Tarek Chammah ___ gem5-users mailing list gem5-users@m5sim.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
Re: [gem5-users] LLVM and GE/M5
I would say that if the changes to get gem5 to compile with LLVM are modest and reasonable we should include them even if they don't provide any additional benefit. I'd also say that compiling benchmarks with LLVM and compiling gem5 itself with LLVM are two different topics that involve very different issues (and I'd think would have very different motivations) so it'd be easier in future discussions if we focused on one or the other. Steve On Thu, May 19, 2011 at 1:36 AM, Gabe Black gbl...@eecs.umich.edu wrote: Thank you, but as a rule all gem5 conversations should happen on the mailing list unless somebody specifically asks to be emailed directly. Korey is right that it's written gem5, not GE/M5. gem5 is currently designed to be compiled with gcc, not llvm. llvm is a perfectly fine compiler, but not what we're using with gem5 right now which is why it's not mentioned. Changing compilers would likely be a lot of work and llvm is less likely to already be installed on users machines, so we'd have to get a substantial benefit from it as far as significantly improved performance or some feature gcc doesn't provide before it would be worthwhile. Since gem5 is open source, you're welcome to make it work under llvm yourself. If you do and you can show us that it -does- give a substantial benefit (we like those), please let us know. External programs like benchmarks can be compiled with any tool you like as long as the output is in a format gem5 can understand, for instance an ELF file. Gabe On 05/19/11 00:41, Tarek Chammah wrote: Hello Gabriel Black, I noticed you answering users' questions and figure you're generally knowledgeable about GE/M5. Though I didn't get much traction on the mailing list. All of the postings on the home page mentioned using GE/M5 with GCC, as in compiling the simulator, as well as cross compiling programs for target architectures to run on the simulator. Though no mention is made of LLVM in this context. Is is not preferred to use LLVM or has it never been attempted before? If it is possible to use LLVM to cross compile programs, are there reported successful instances where this has occurred? Sincerely, Tarek Chammah ___ gem5-users mailing list gem5-users@m5sim.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users ___ gem5-users mailing list gem5-users@m5sim.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
Re: [gem5-users] LLVM and GE/M5
Some versions of llvm use a gcc front end, so it that should just work. I don't know how compatible Clang is, but I think the stdc++ library is going to provide any uglyiness there. Ali On Thu, 19 May 2011 07:21:31 -0700, Steve Reinhardt wrote: I would say that if the changes to get gem5 to compile with LLVM are modest and reasonable we should include them even if they don't provide any additional benefit. I'd also say that compiling benchmarks with LLVM and compiling gem5 itself with LLVM are two different topics that involve very different issues (and I'd think would have very different motivations) so it'd be easier in future discussions if we focused on one or the other. Steve On Thu, May 19, 2011 at 1:36 AM, Gabe Black wrote: Thank you, but as a rule all gem5 conversations should happen on the mailing list unless somebody specifically asks to be emailed directly. Korey is right that it's written gem5, not GE/M5. gem5 is currently designed to be compiled with gcc, not llvm. llvm is a perfectly fine compiler, but not what we're using with gem5 right now which is why it's not mentioned. Changing compilers would likely be a lot of work and llvm is less likely to already be installed on users machines, so we'd have to get a substantial benefit from it as far as significantly improved performance or some feature gcc doesn't provide before it would be worthwhile. Since gem5 is open source, you're welcome to make it work under llvm yourself. If you do and you can show us that it -does- give a substantial benefit (we like those), please let us know. External programs like benchmarks can be compiled with any tool you like as long as the output is in a format gem5 can understand, for instance an ELF file. Gabe On 05/19/11 00:41, Tarek Chammah wrote: Hello Gabriel Black, I noticed you answering users' questions and figure you're generally knowledgeable about GE/M5. Though I didn't get much traction on the mailing list. All of the postings on the home page mentioned using GE/M5 with GCC, as in compiling the simulator, as well as cross compiling programs for target architectures to run on the simulator. Though no mention is made of LLVM in this context. Is is not preferred to use LLVM or has it never been attempted before? If it is possible to use LLVM to cross compile programs, are there reported successful instances where this has occurred? Sincerely, Tarek Chammah ___ gem5-users mailing list gem5-users@m5sim.org [2] http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users [3] Links: -- [1] mailto:gbl...@eecs.umich.edu [2] mailto:gem5-users@m5sim.org [3] http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users ___ gem5-users mailing list gem5-users@m5sim.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
Re: [gem5-users] LLVM and GE/M5
I cross compile for ARM using LLVM. I actually have better success with LLVM than with CodeSourcery's gcc cross compiler. I've also used LLVM to compile for X86 and Sparc, run on M5, and it worked fine. LLVM is just a compiler. There's no reason it shouldn't work just as well as any other compiler, even with M5 now being gem5. On Tue, May 17, 2011 at 11:37 PM, Korey Sewell ksew...@umich.edu wrote: I believe people have use llvm and arm and it has worked. But it doesnt hurt to try it out right? Makes sure you compile your binary statically and give it a go. If it doesnt work, I'm sure that others would want llvm support in gem5 so you can post your problem to the mailing list and see what the community says. Also, gem5 is what I believe is the appropriate term (rather than ge/m5). On Wed, May 18, 2011 at 12:27 AM, Tarek Chammah tcham...@uwaterloo.cawrote: Hello, All of the postings on the home page mentioned using GE/M5 with GCC, as in compiling the simulator, as well as cross compiling programs for target architectures to run on the simulator. Though no mention is made of LLVM in this context. Is is not preferred to use LLVM or has it never been attempted before? If it is possible to use LLVM to cross compile programs, are there reported successful instances where this has occurred? Sincerely, Tarek Chammah ___ gem5-users mailing list gem5-users@m5sim.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users -- - Korey ___ gem5-users mailing list gem5-users@m5sim.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users ___ gem5-users mailing list gem5-users@m5sim.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
Re: [gem5-users] LLVM and GE/M5
I believe people have use llvm and arm and it has worked. But it doesnt hurt to try it out right? Makes sure you compile your binary statically and give it a go. If it doesnt work, I'm sure that others would want llvm support in gem5 so you can post your problem to the mailing list and see what the community says. Also, gem5 is what I believe is the appropriate term (rather than ge/m5). On Wed, May 18, 2011 at 12:27 AM, Tarek Chammah tcham...@uwaterloo.cawrote: Hello, All of the postings on the home page mentioned using GE/M5 with GCC, as in compiling the simulator, as well as cross compiling programs for target architectures to run on the simulator. Though no mention is made of LLVM in this context. Is is not preferred to use LLVM or has it never been attempted before? If it is possible to use LLVM to cross compile programs, are there reported successful instances where this has occurred? Sincerely, Tarek Chammah ___ gem5-users mailing list gem5-users@m5sim.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users -- - Korey ___ gem5-users mailing list gem5-users@m5sim.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
