time.time() strangeness

[Nitro]

Ok, my final solution is to add the D3DCREATE_FPU_PRESERVE flag. It didn't
harm performance in a noticeable way at all. I was under the impression
SSE would be affected by this, too. Additionally I was under the
impression that float precision would suffice for time.time(). Obviously I
was blatantly wrong
Thanks to Gabriel, Ross and Roel for commenting on this and sharing their
insights!

They should really make the fpu preserve flag the default. It just causes
very sneaky bugs.

-Matthias

 

[Ross Ridge]

They should really make the fpu preserve flag the default. It just causes
very sneaky bugs.

They did in Direct3D 10, which doesn't change the flags. It's too late
to change the behaviour Direct3D 9 which was created a time where changing
FPU precision could have an effect on low end configurations.

Ross Ridge

 

[Roel Schroeven]

Nitro schreef:

Ok, my final solution is to add the D3DCREATE_FPU_PRESERVE flag. It didn't
harm performance in a noticeable way at all. I was under the impression
SSE would be affected by this, too. Additionally I was under the
impression that float precision would suffice for time.time(). Obviously I
was blatantly wrong

Float precision might even be enough but DirectX (without the flag)
switches to even lower precision than that; only 22 bits IIRC.

They should really make the fpu preserve flag the default. It just causes
very sneaky bugs.

Absolutely.


Cheers,
Roel