Andrea:
On Wed, 26 May 2004, Andrea Riciputi wrote:
On 26 May 2004, at 13:17, [EMAIL PROTECTED] wrote:
1) what is the "real" meaning of the --enable-float flag?
Tells it to build a single precision (32 bit) library.
I see, but what is the reason for this choice? Is there any problem with the default double precision?
No - the package builds both single and double precision libs.
2) why the --enable-altivec options is omitted?
Because not everyone has a G4 or G5, and the thought is to have the package build exactly the same on every system (including G3s).
Uhm, but looking at fftw manual I've found:
--enable-sse, --enable-sse2, --enable-k7, --enable-altivec: Enable the compilation of SIMD code for SSE (Pentium III+), SSE2 (Pentium IV+), 3dNow! (AMD K7 and others), or AltiVec (PowerPC G4+). SSE, 3dNow!, and AltiVec only work with --enable-float (above), while SSE2 only works in double precision (the default). The resulting code will still work on earlier CPUs lacking the SIMD extensions (SIMD is automatically disabled, although the FFTW library is still larger).
So it seems that you can use --enable-altivec (with --enable-float) even with not-Altivec CPU (like G3s). Isn't it?
Yep - looks like you are right. I'll change that in the next revision.
-Jeff
-- Jeffrey S. Whitaker Phone : (303)497-6313 Meteorologist FAX : (303)497-6449 NOAA/OAR/CDC R/CDC1 Email : [EMAIL PROTECTED] 325 Broadway Web : www.cdc.noaa.gov/~jsw Boulder, CO, USA 80303-3328 Office : Skaggs Research Cntr 1D-124
-------------------------------------------------------
This SF.Net email is sponsored by: Oracle 10g
Get certified on the hottest thing ever to hit the market... Oracle 10g. Take an Oracle 10g class now, and we'll give you the exam FREE.
http://ads.osdn.com/?ad_id=3149&alloc_id=8166&op=click
_______________________________________________
Fink-users mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/fink-users
