| Date: Wed, 20 Jun 2001 12:32:22 -0500 |
| From: Vikram Adve <vadve@cs.uiuc.edu> |
| To: Chris Lattner <lattner@cs.uiuc.edu> |
| Subject: .NET vs. our VM |
| |
| One significant difference between .NET CLR and our VM is that the CLR |
| includes full information about classes and inheritance. In fact, I just |
| sat through the paper on adding templates to .NET CLR, and the speaker |
| indicated that the goal seems to be to do simple static compilation (very |
| little lowering or optimization). Also, the templates implementation in CLR |
| "relies on dynamic class loading and JIT compilation". |
| |
| This is an important difference because I think there are some significant |
| advantages to have a much lower level VM layer, and do significant static |
| analysis and optimization. |
| |
| I also talked to the lead guy for KAI's C++ compiler (Arch Robison) and he |
| said that SGI and other commercial compilers have included options to export |
| their *IR* next to the object code (i.e., .il files) and use them for |
| link-time code generation. In fact, he said that the .o file was nearly |
| empty and was entirely generated from the .il at link-time. But he agreed |
| that this limited the link-time interprocedural optimization to modules |
| compiled by the same compiler, whereas our approach allows us to link and |
| optimize modules from multiple different compilers. (Also, of course, they |
| don't do anything for runtime optimization). |
| |
| All issues to bring up in Related Work. |
| |
| --Vikram |
| |