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Re: [RFC] Enabling loop unrolls at -O3?


Steven Bosscher wrote:

You must not have been paying attention to one of the most frequent
complaints about gcc, which is that it is dog slow already ;-)

Sure, but to me -O2 says you don't care much about compilation time. As I say for complete large applications, I am not sure -O2 gains that much over -O2 in performance so you are asking to squeeze out a small amount of performance at the expense of compile time. It seems wrong in such a case to shy away from an optimization on the grounds that it improves performance but increases compile time.

I am not clear what the philosophy of the difference between -O2
and -O3 is supposed to be ...


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