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The article mentions that alpha was weak on bit-twiddling, which is something that almost certainly got fixed by introduction of BWX instructions on 21164.
by dfox 10y ago
The article mentions that alpha was weak on bit-twiddling, which is something that almost certainly got fixed by introduction of BWX instructions on 21164.
- dchest 10y agoInterestingly, LZ4 works mostly on nibble and byte level without much bit-twiddling.
- honkhonkpants 10y agoWas axp even the weakest of the four windows architectures for this task? PPC and MIPS can leave the bit twiddler scratching their heads, too.
- dfox 10y agoProblem with original Alpha is that accessing memory as anything other than aligned 32b or 64b words (yes, including bytes) counts as bit-twiddling because only load/store instructions that it has operate on these two word sizes. I can't remember any other non-niche architecture with 8*2^n word size that shares this (mis-)feature. (I suspect that Cray 1 and it's derivates also share this, but that probably counts as niche architecture)
- EvanAnderson 10y agoThanks for mentioning that. You sent me down a brief rabbit-hole of nostalgia looking for the EV4/EV5 differences. If anybody else wants to go down that rabbit-hole here's where I ended-up: http://alasir.com/articles/alpha_history/alpha_21164_21164pc.html http://alasir.com/articles/alpha_history/alpha_21164_21164pc...
- krylon 10y agoAlso, when was the last Alpha built? About ten years ago? It's fine for OpenBSD or NetBSD to support it, but Microsoft has not supported it in a long time.