[Mono-list] Math precision.

Thomas F. Burdick tfb@OCF.Berkeley.EDU
Thu, 19 Jul 2001 11:50:10 -0700

Michael Meeks writes:
 > Hi Bob,
 > On 19 Jul 2001, Bob Smith wrote:
 > > > I've been working on the System.Math class, trying to implement
 > > > everything in C# without useing P/Invoke. I've been fairly successfull
 > > > at implementing the trig functions like sin/cos,
 > 	Your implementation, although interesting is never going to be as
 > quick as the native versions of these functions built into modern
 > processors. A 'sin' is a handful of cycles and can be interleaved with
 > other floating point ops [ ok so not via PInvoke it can't :-], it would be
 > hundreds of times more efficient to just invoke the C routine which should
 > go to the co-proc.

I'd say use PInvoke for simplicity (if it's in the libc, we may as
well use it), and leave the question of efficiency to the JIT.  If it
open-codes functions that have hardware built-ins, we'll win quite a
bit over going through PInvoke.