Having the -mfused-madd option honored

Serge Torres <Serge.Torres@xxxxxxxxxxx> · Wed, 07 Nov 2007 15:05:17 +0100

Hi,

I'm using gcc 4.1.2 on an openPower 720 (Power5 processors) box running 
Linux OpenSUSE 10.2.

I would like to compile a C program with the fused multiply-add and 
multiply-sub instructions enabled. I can't figure out the right set of 
options.

I've been trying many combinations of -mcpu=power5, -mhard-float, 
-mfused-madd, -m64 but none has worked yet.

An idea any one?  Or even better: a personnal successful experience.

Cheers,

Serge Torres

PS : IBM XL V 9 works (as matter of fact, with no particular option)