128 bit floating point arithmetic

[Eljay Love-Jensen]

Hi Jirka,

A quick Google search indicates that the Pentium 4 does not natively support 128-bit floating point arithmetic.  It does support 64-bit precision mantissa, which would (I presume) be utilized in full via long double (80-bit on Intel architecture, 96-bit on Motorolla 680x0 architecture).

Unless I'm mistaken, to use 128-bit floating point, you'll need to write your own "software FPU" or download a floating point bignum to suite your needs.

Chongo's calc software can do that at even higher precision, and more <http://freshmeat.net/projects/calc/>... mind the licensing restrictions.

Performance will be far less than that of the Pentium 4's FPU, however.

HTH,
--Eljay