[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: glibc very old

On 2012-07-23 14:49:35 +0900, Miles Bader wrote:
> Based on a glance at the source, it seems like the math libraries were
> changed in lots of little ways between 2.13 and 2.16 [and it looks
> like the FPU-twiddling that made expf slow in 2.13 has been _added_ to
> the generic version of the "exp" (double-precision) function, meaning
> it might actually be (much) _slower_ in 2.16 on ports without
> optimized implementations... :( ]

However (if this is the change I'm thinking of) this makes math functions
"correct" in directed rounding modes and potentially more secure.

By "correct", I mean that the result is somewhat acceptable (not that
the result is correctly rounded and the rounding direction is honored),
instead of getting completely wrong values or even a crash.

Vincent Lefèvre <vincent@vinc17.net> - Web: <http://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <http://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)

Reply to: