[ODE] I´m totally unhappy with ODE ... Please Help me

Jon Watte (ODE) hplus-ode at mindcontrol.org
Mon Dec 18 11:12:52 MST 2006

Don't assume that function calls can be replaced using CSE. Only if you 
enable intrinsics will that be possible, because the compiler can't 
assume that you won't link with some library where sin() and cos() use 
static data, and return different results for different calls.


             / h+

Andreas Fredriksson wrote:
> On 12/18/06, Pavel Antokolsky aka Zigmar <zigmar at gmail.com> wrote:
>> Considering the following code that calls 29 times (!) to
>> trigonometric functions to construct one single matrix, I'm  surprised
>> it moves at all. You really should re-consider your implementation if
>> you want to make your game run at reasonable speed.
> A decent optimizer should replace these variations with a few
> calculations through common subexpression elimination. That said, I
> would use the more optimizer-friendly floating point versions of the
> cos and sin functions (sinf and cosf) and move the calculations
> outside to get a speedup in debug builds as well.
> // Andreas
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