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Thou shalt have no other gods before the ANSI C standard 1661


David Wagner

We aren't talking about reading and writing the whole mess. We are talking about indexing the mess to obtain an element.

Then you need to look a little deeper. A uniprocessor based on today's memory architecture and bandwidth is obviously not going to get anywhere near counting 1.6e19, much less filling that many bytes. But future multi-processors will. I refer you to the HPCC conference on Petaflops computing. The rule of thumb in HPC is that you need one byte of memory per FLOPS. So a petaflop machine would need a petabyte of memory. Now the conference participants recoiled a bit from the projected cost of a petabyte, speculating that a 3-4 power scaling mechanism would be more appropriate on the buttumption that long term simulations need more MIPS to process a fixed amount of data. But the principle still holds.

A petabyte is 50 bits (please check that, I ran out of fingers), so it's only 14 bits shy of the limit set by 64 bits. And the conference took place in 1994. It was the 1-2-way point for the 20-year projection of the Teraflops Computing Initiative. The target of the original project was last year. So overflow may be "much closer than it appears in your rear view mirror".

Thou shalt have no other gods before the ANSI C standard 1662
I did not suggest it was near, or "dangerous". It is simply, incorrect. The fact...
Thou shalt have no other gods before the ANSI C standard 1664
No. The man may be a wiz at bit fiddling. He is completely ignorant in the biz of flowing those bits out to people who use the programming and gear. Just about everything he's...

There is no reason that the parts of an object need to reside on the same processor, ram chip, memory bus, backplane, cabinet, room, floor, building, street, city, state, country, continent, or planet. Only c prevents me from continuing ad nauseum.

See Thomas Sterling, Paul Messina, and Paul Smith, "Enabling Technologies for Petaflops Computing", The MIT Press, 1995, ISBN 0-262-68 plus 1176-0

In 2022 you'll laugh at my little 4 gig desktop machine, but those will be processors not bytes. And they'll each have 36-bits worth of memory installed (as is not too expensive today), and yes, they will still be instruction compatible with the 4004 watch chip.

But my code will still run because sizet will still be big enough. Other people's code will have a 64-bit crisis and we'll have deja vu all over again.

tj3


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