Alpha and Merced news

Compaq's 200 Digital engineers are busy working on two new Alpha designs: the 21364 (aka EV 7) and 21464. The 21364 is being designed for symmetric-multiprocessing boards holding up to 64 CPUs... and will a pretty enormous chip with 100 million transistors on-board. Speeds are expected to range from 750Mhz to 1.2Ghz. In the mean-time, more details of Merced have come to light: it will include a "prefetch to branch mechanism (I assume an explicit instruction: preload addresses x into the cache) and register windowing since the way predication and speculation use the registers may require more that the 128 of them Merced has. Furthermore, to optimize effectively, compilers' code generators will need a more global view of the code than the local view they currently are given, which will require significant rewrites of compiler back-ends.