On 17 April 2013 14:19, John McKown <[email protected]> wrote:
> We've had discussions recently on making code CPU efficient, or space > efficient, or "programmer efficient". This is a new one on me. Making it > "energy efficient". Wish somebody would port LLVM to z/OS. LLVM is low > level virtual machine. It is a pseudo assembler code which is compiled into > machine code. The curious part is that the same "assembler" code can > compile into machine code for different ISAs, but produce the same results. > That's what makes it a "virtual machine". More like a virtual ISA. > > http://www.phoronix.com/scan.php?page=news_item&px=MTM1MzE > > The approach that gcc takes is pretty similar with a generic machine model in the middle. When frowning upon some generated s390 code, people in Boeblingen explained that the gcc tool chain did not have a notion of block concurrency and thuse produced a CS for a volatile full word, where I would think a MVC of an aligned field would do the trick. But I noticed one of the s390 gcc folks at IBM at least interested in the LLVM effort, so I expect some involvement from IBM as well. In my opinion there much more to be gained on a higher level in the middleware. It's sad to see DB2 and WAS for example use polling for communication between processes, just because some potential target platform (or the developers) may not understand more advanced form of communication. Rob
