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.
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
