[ODE] Some SSE in Quick step

[tbp]

GARY VANSICKLE wrote:
> AFAIK, nobody's actually ever verified that D3DX's mathematical
> manipulations are slower than ODE's built-in.  Which is part of why a
> referred to this as a "non-argument".
Convenient.

>>Then there's no need to do some jumptable chachacha à la DirectX when
>>you're dynamically linking Ode: link against the proper dll (ie
>>ode-sse2.dll) at run time.
> 
> 
> As a wise man once sang, "We'd all love to see the plan" ;-).  I'm guessing
> D3DX does at least as well as that.
Guessing is the key word. Sing with me.

>  It's certainly not doing anything like:
> 
> If(SSE2)
> {
> 	SSE2MatrixMultiply();
> }
> Else if(SSE)
> {
> 	SSEMatrixMultiply();
> }
> Else if...
> 
> if that's what you're getting at.
No. Read what i've said again. "jumptable chachacha" has nothing to do 
with the code you've posted.

Picking the proper dll at runtime may be equivalent (more or less) to 
some jumptable adjustment (ie on windows), but it puts some of the 
burden on the toolchain as it relies on compiler/linker mechanisms.

and
>>That just require some rather thin per platform gluing.

> And a huge number of DLL's/.so's, 
You can't have the cake and eat it.

> which will need to keep growing on an
> almost monthly basis as new processors come out with new features.
Yeah sure.

> I say let Bill do it; he already is anyway.
Again those 2 solutions (linking against different ode libs vs D3D) 
aren't equivalent.
In the former every paths are optmized for one combo (cpu/features).

And you're still conveniently forgetting that Bill only cares about a 
subset of Ode supported platforms (i know i know, it's one of your 
famous non-argument).