17 Oct
2003
17 Oct
'03
3:36 a.m.
On Friday 17 October 2003 01:20, Steve Harris wrote:
On Thu, Oct 16, 2003 at 08:09:13 -0300, Juan Linietsky
wrote:
There's 2 ways, if you check the benchmarks, the ones that say "float"
use a cast, and the ones that say "fistl" use that instruction (which is
faster in most cases). I think what surprised me the most about all this
is the slow performance of the G4 on floating point.. I heard several times
that they have instant float->int conversion... and this is using apple's gcc
compiler.
Juan Linietsky
My own conclusions about the subject is that the
float -> int conversion
is STILL the biggest bottleneck on most common architectures. And until
this is sorted out, fixed point is still the best solution for some
specific cases,
How are you doing the conversion, casts are horribly slow, but lrintf()
etc. are quite fast (a few cycles).