[Mingw-users] Odd problem with optimisations...

[Peter R. <p.r...@sh...>]

As an obvious follow-up, I have repeated my previously posted tests on 
Linux (gcc 4.5.2). I get:

Code version with double argument:

1) No optimisation = 0.27665

2) -O1 = 0.132152

3) -O2 = 0.270331

4) -O1 & -O2 = 0.132152


Code version with 1D vector argument (but semantically identical):

1) No optimisation = 0.27665

2) -O1 = 0.132152

3) -O2 = 3.16427

4) -O1 & -O2 = 0.132152


So the same inconsistencies appear with Linux although the exact numbers 
are different. So this suggests an up-stream issue/feature?

As an aside, I am curious why two Intel boxes give different results 
depending on the OS. In what way are the different OSs using nominally 
the same hardware to produce different results?

P.