CACM article on Stretch & ACS

Mark Smotherman & Dag Spicer's article on the Stretch & ACS in the latest CACM is worth a read. I've been handed down some of this history as part of my work at IBM but it's great to see it made more public. This was truly the Golden age of computer architecture at IBM and in the industry at large and it is still amazing to see what was accomplished so many years ago and, perhaps shamefully, how little we've progressed beyond these innovations even today.

There are a couple of interesting points I would have made that Smotherman & Spicer missed. First, the work by Cocke & Allen (and many others) on the 801 led fairly directly to the IBM RT and then the IBM RS/6000 - now known as IBM Power systems. As the co-development of architecture and compiler were so fundamental to this RISC design, the conjoined compiler effort went on and evolved as well into what is now known as the XL compiler suite. The other point that I think I would have made is to challenge computer architects today to think as boldly as these pioneers did 40 years ago. If they could imagine superscalar and out-of-order execution, what could we be imagining and prototyping today?