Richard Guenther <[EMAIL PROTECTED]> wrote: >>>> I guess the issue is what does "huge" mean, it is hard to discuss based >>>> on loaded adjectives taking the place of data :-) >>> >>> Huge here means 15-20% on x86* hosts. >> >> I don't consider this huge for -O3. I think -O3 can be slower if it >> achieves better code, and -funroll-loops makes it do just that. > > First of all, this is too late for 4.1, second, we enable loop-unrolling > with FDO. And without FDO, -funroll-loops is not necessarily an > improvement.
What is FDO? My feeling is that -funroll-loops is almost always an improvement. It might be false sometimes, but this can be said of many optimization passes. -- Giovanni Bajo
