On Mon, Apr 25, 2011 at 22:08, Roy Stogner <firstname.lastname@example.org>
I don't know where 34 came from.
128-bit float == 113 bit precision ~= 34 digit precision, no?
This is 16-byte. It's quad, not quad-double.
Of course, somehow I misread as "34 bytes" which seemed a strange number.
It's silly but the justification is supposed to be that it's hardware
The trouble is that "long double" is usually just 80 bits stored in
12 or 16 bytes, and arithmetic is with the x87 unit. That's pretty
silly, __float128 works the way you want it to.
accelerated. Any idea how much slower you get going 64->80->128 bit
on modern CPUs? It's been years since I've used long double for
anything other than regression testing.
I'm not sure, but __float128 uses the SSE unit which has not been ignored for more than a decade.