hello everyone, I'm wondering whether llvm can work together with simplescalar. Would anyone please give me some clarification? Thanks a lot!
On Jun 15, 2008, at 7:08 PM, ×óçù wrote:> hello everyone, > I'm wondering whether llvm can work together with simplescalar. > Would anyone > please give me some clarification? Thanks a lot!In what way do you want them to work together? -Chris
It use to. alphasim (the validated alpha model based on simplescalar) is better though. Also, since no one has needed to run simplescalar experiments, the alpha backend has bitrotted some. The last version that I know worked with most of spec was llvm 1.8 or so. You need to get or write an elf64 loader and fix a couple instruction implementations in simplescalar to get it to run linux binaries (I have both somewhere). Andrew On Sun, Jun 15, 2008 at 9:08 PM, ×óçù <zqll27 at bit.edu.cn> wrote:> hello everyone, > I'm wondering whether llvm can work together with simplescalar. Would anyone > please give me some clarification? Thanks a lot! > > > _______________________________________________ > llvm-announce mailing list > llvm-announce at cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvm-announce >
On Sunday 15 June 2008 22:30, Andrew Lenharth wrote:> It use to. alphasim (the validated alpha model based on simplescalar) > is better though. Also, since no one has needed to run simplescalar > experiments, the alpha backend has bitrotted some. The last version > that I know worked with most of spec was llvm 1.8 or so. You need to > get or write an elf64 loader and fix a couple instruction > implementations in simplescalar to get it to run linux binaries (I > have both somewhere).IMNSHO, don't use SimpleScalar. It's simulation model is WAY ourt of date. Use M5 instead: http://m5.eecs.umich.edu/wiki/index.php/Main_Page -Dave
Thank you for your answers and suggestions! Well, I want to do some experiments about the compiler optimization in llvm under SPM and I need performance evaluation. As I know, alpha is a general-purpose CPU, so I consider that arm may be an alternative. Simplesim-arm is able to do performance simulation while m5-arm is still under development. Then, what should I do? Do the experiment under m5-alpha or use simplesim-arm? And if I choose to use m5-alpha, can I use llvm as the compiler for this simulator? 2008-06-17 左琦 发件人： David Greene 发送时间： 2008-06-17 00:36:59 收件人： llvmdev at cs.uiuc.edu 抄送： 左琦 主题： Re: [LLVMdev] [llvm-announce] llvm and simplescalar On Sunday 15 June 2008 22:30, Andrew Lenharth wrote:> It use to. alphasim (the validated alpha model based on simplescalar) > is better though. Also, since no one has needed to run simplescalar > experiments, the alpha backend has bitrotted some. The last version > that I know worked with most of spec was llvm 1.8 or so. You need to > get or write an elf64 loader and fix a couple instruction > implementations in simplescalar to get it to run linux binaries (I > have both somewhere).IMNSHO, don't use SimpleScalar. It's simulation model is WAY ourt of date. Use M5 instead: http://m5.eecs.umich.edu/wiki/index.php/Main_Page -Dave -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20080617/b05685bc/attachment.html>
2008/6/16 左琦 <zqll27 at bit.edu.cn>:> Thank you for your answers and suggestions! > Well, I want to do some experiments about the compiler optimization in llvm > under SPM and I need performance evaluation. As I know, alpha is a > general-purpose CPU, so I consider that arm may be an > alternative. Simplesim-arm is able to do performance simulation while m5-arm > is still under development. Then, what should I do? Do the experiment under > m5-alpha or use simplesim-arm? And if I choose to use m5-alpha, can I use > llvm as the compiler for this simulator?I would use something like simics if you can. If you use an alpha simulator you will either need to do some work on the backend or use an older version of llvm. If you can do your work with a different cpu, then a simulator for x86, powerpc, or arm would probably be your best bet for good performance (and most mature backends) from llvm. Andrew
On Monday 16 June 2008 20:19, 左琦 wrote:> Thank you for your answers and suggestions! > Well, I want to do some experiments about the compiler optimization in llvm > under SPM and I need performance evaluation. As I know, alpha is a > general-purpose CPU, so I consider that arm may be an alternative. > Simplesim-arm is able to do performance simulation while m5-arm is still > under development. Then, what should I do? Do the experiment under m5-alpha > or use simplesim-arm? And if I choose to use m5-alpha, can I use llvm as > the compiler for this simulator?LLVM has an Alpha target but I don't know how well it's maintained. SimpleScalar is simply not a good performance simulator. It does not model the complex interactions that happen in today's processors. It's memory model is particularly bad. I'm not familiar with SimpleScalar's ARM model. As that's a relatively simple CPU, it may be adequate depending on what you want to do. But I do not trust any studies, papers, etc. that are published with SimpleScalar results and I take studies published using ANY simulator with a very large grain of salt. -Dave