[Simh] Hardware fidelity in the VAX family simulators

[Clem cole]

Sent from my handheld. More typos likely which is quite a thought. 

> On Jul 8, 2015, at 6:17 PM, Timothe Litt <litt at ieee.org> wrote:
> 
> Vectors?  What you add to an architecture just before you give up on it.  Rigel and the 9000 supported VAX  vectors.  Alpha had them on its roadmap for Ev8 before it died... CDC's ETA-10 implemented vectors, and died.  However, Cray and its clones had a good run.  And of course there were the bolt-on 'array processors' for various machines.

Tim

Point taken and a reasonable observation.  But to be fair most current architectures have them-they are pretty much deriger in the high end these days (along with lots of thread support). The key point is that the current compilers all generate code for them (thank you Mark, Dave, Kent, Rich et al who blazed the trail with Vax Fortran and then went on to 'reinject' that DNA into the current code base). 

Funny I listened to a google guy give a talk about LLVM today and many of the questions and concerns from our crew was how to get it to be as good as GEM or intel particular wrt vectors and the usual Fortran stuff.  Fine for C but a long way to go for HPC.  

Also I don't think the Intel*64 architecture is going to die any time soon (nor Power for that matter).   Fact is vectors are cute trick for fortran code and a good fortran implementation (particularly one that supported vectors and parallel execution) has paid many of our salaries over the years 😂

Clem