On 10/26/18 6:10 AM, Gordon Henderson via cctalk wrote: > However it was a royal PITA to code for although a 32-bit CPU, it would > read memory 64 bits at a time (actually 128 IIRC to satisfy the cache), > with half that 64-bit word being an instruction for the integer unit and > half for the floating point unit, so you effectively had to build a > floating point pipeline by hand coded instructions, so 8 (I think) > instructions to load the pipeline, then each subsequent instruction > would feed another value into the pipe, then another 8 at the end to > empty it. Great for big matrix operations, rubbish for a single add of 2 > FP numbers.
My impression of the i860 was that it might have been fun for about 2 weeks for which to code assembly, but after that, you'd really start looking hard for an HLL to do the dirty work for you. While there's a sense of accomplishment over looking at a page of painfully hand-optimized code that manages to keep everything busy with no "bubbles", you begin to wonder if there isn't a better way to spend your life. --Chuck
