RE: [Algorithms] FIST optimization

[Tony C. <to...@mi...>]

>Then I thought about the recent mails here. I then changed the way I
>initialize Direct3D, and used DDSCL_FPUPRESERVE instead of DDSCL_FPUSETUP.
>Nothing changed.
>
>...but the guilty one is D3D anyway...
>
>When I reset the FPU to the "chop" rounding mode before calling
>Renderer->Init(), it still does not work.
>
>When I reset the FPU to the "chop" rounding mode after Renderer->Init(), it
>*does* work.

Bet your Renderer->Init() function winds up loading a DLL somewhere along
the line (for example, by initialising D3D). It's the DLL load that is
probably whacking your FPU state.

You should set the FPU state to the one you want after you do your Init().
Thereafter, D3D won't mess with it if you set the FPU_PRESERVE flag.

Tony Cox - DirectX Luminary
Windows Gaming Developer Relations Group
http://msdn.microsoft.com/directx