Re: [Flightgear-devel] Compiler Warnings

[ThorstenB <br...@gm...>]

On 2010-09-27, at 17:25, James Turner wrote:
>>> The SSE math flags are a no-brainer where supported - the
>>> -march-native and -sse flags are all Apple defaults in Xcode.
>> BTW, as far as I remember the -sse and -sse2 are on by default for GCC
>> on AMD64 (alias x86_64).
> It would be good if someone who found -O3 -march=native -sse -sse3
> made a difference, ciuld verify this, i.e try without the explicit SSE flags,
> and see if the performance is the same. march=native might be they key
> thing here, if the default arch is i386 or i686, and hence prohibiting SSE
> from being considered.

I just did a similar comparison this weekend ("-march=native" vs "...
-sse -sse3" vs ".... -mfpmath=sse" on AMD64). But I tricked myself by
forgetting to disable "real weather fetch" (stupid!). So I mainly
compared the effect of this weekends' changing weather (cloud)
scenarios... :-(
Better do not repeat my mistake... :-)

cheers,
Thorsten