Bill Gosper <billgosper@gmail.com> writes:

Tom Duff>It worked pretty well on old enough hardware, but it mostly can't Tom Duff>keep up on modern machines with built-in sqrt (last I checked, Tom Duff>which wasn't recently.)

Eh? The last hardware sqrt I recall was on the Packard Bell 250 (1963?). (Integer sqrt, with remainder.) I have been griping for years at its absence from modern order codes, since it is far simpler than divide. So they've finally come around to reviving it? --rwg

Intel has had a sqrt instruction [FSQRT] since the 8087 FPU (identical functionality has been integrated into the x86 CPU instruction set since the 486DX. 8087 was introduced in 1980, 486DX in 1989.) It's pretty much a requirement of IEEE 754, if you read between the lines. (754 has accuracy requirements that are hard to achieve by any obvious software solution, for small values of 'obvious.') -- Tom Duff. Reality does not exist but appears to exist as expressed by human beings.