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Re: Having the -mfused-madd option honored


Hi,

Just to be sure, have you compiled the program with optimization (such as -O,
-O2, or -O3)? The GCC combiner that builds up complex insns like multiply and
add is only run when optimizing. I happen to have a PowerPC cross compiler
built from a few weeks ago, and it generates fmadd and fmadds instructions if I
use -mcpu=power5 and -mfused-madd.

Yes, I tried again with -O -O2 and -O3. None worked. I had already figured out that gcc would only trigger fmadd and fmasub as optimizations. I also removed the options that enforce the C99 compliance, since fmad and fsub break the semantics of the operations from the rounding point of view.


Thank four your help.

Regards,

Serge Torres


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