On Fri, Apr 8, 2011 at 11:20 AM, Robert Raicer <[email protected]> wrote: > What Paul points out is not done only by Java VMs. Members on this > list might remember the "z" compatible machine built by PSI (Platform > Solutions, Inc). Ron Hilton from PSI gave a presentation at SHARE in > August 2004 during which he discussed the rather clever "on the fly" > conversion of the "z" I-stream to the native Intel Itanium I-stream > which performed the emulation operations. This conversion process was > highly adaptive and the results were very impressive.
This wasn't really new or as successful as: http://en.wikipedia.org/wiki/Mac_68K_emulator (see comments about dynamic recompilation) One could argue that the Java JIT is a variant of the same id, although the "byte code" machine is the source architecture. But still, it dynamically generates machine code rather than emulation. > > I wonder whatever happened to the PSI technology after IBM purchased > the company around the July 2008 time frame? > > Bob Raicer > >> Date: Thu, 7 Apr 2011 14:17:46 -0600 >> From: Paul Gilmartin <[email protected]> >> Subject: Re: ASM vs HLL (Was: CPU: ASSM vs ENTERPRISE COBOL - SOLVED!) >> >> OTOH, I am led to believe that some Java VMs do dynamic recompilation, >> monitoring the execution profile and adjusting the sequence of instructions >> executed accordingly. This is real time information scarcely available >> to the assembler programmer. >> >> -- gil >
