GCC 4.5 Optimization Problem

[Tim Prince]

On 5/5/2011 2:16 PM, Quant wrote:
>
> I have recently upgrade my Ubuntu from 10.10 to 11.04. GCC version is also
> upgraded from 4.4 to 4.5 automatically. However, some of my heavy math. C
> codes run slower when compiled with GCC 4.5.
> I have tried various optimization flags including "-fexcess-precision=fast".
> But nothing changes, it runs slower comparing to the executable compiled
> with GCC 4.4.
>
> By the way, I complied them with GCC 4.4 with "-03 -ffast-math". My machine
> is IMAC I7. Ubuntu is 64bit.
>
> Any idea?
Surely, no idea why you are using 32-bit gcc with 387 code (must be so, 
if you have excess-precision) if you are on 64-bit OS.
With no idea of what you mean by "heavy math," (an example would go a 
long way), no relevant ideas are likely to appear.

-- 
Tim Prince