1Date: Wed, 20 Jun 2001 12:32:22 -0500 2From: Vikram Adve <vadve@cs.uiuc.edu> 3To: Chris Lattner <lattner@cs.uiuc.edu> 4Subject: .NET vs. our VM 5 6One significant difference between .NET CLR and our VM is that the CLR 7includes full information about classes and inheritance. In fact, I just 8sat through the paper on adding templates to .NET CLR, and the speaker 9indicated that the goal seems to be to do simple static compilation (very 10little lowering or optimization). Also, the templates implementation in CLR 11"relies on dynamic class loading and JIT compilation". 12 13This is an important difference because I think there are some significant 14advantages to have a much lower level VM layer, and do significant static 15analysis and optimization. 16 17I also talked to the lead guy for KAI's C++ compiler (Arch Robison) and he 18said that SGI and other commercial compilers have included options to export 19their *IR* next to the object code (i.e., .il files) and use them for 20link-time code generation. In fact, he said that the .o file was nearly 21empty and was entirely generated from the .il at link-time. But he agreed 22that this limited the link-time interprocedural optimization to modules 23compiled by the same compiler, whereas our approach allows us to link and 24optimize modules from multiple different compilers. (Also, of course, they 25don't do anything for runtime optimization). 26 27All issues to bring up in Related Work. 28 29--Vikram 30 31