------- Comment #90 from lucier at math dot purdue dot edu 2009-02-13 17:37 ------- Subject: Re: [4.3/4.4 Regression] Inordinate compile times on large routines
On Fri, 2009-02-13 at 16:54 +0000, bonzini at gnu dot org wrote: > > > ------- Comment #87 from bonzini at gnu dot org 2009-02-13 16:54 ------- > The problem is that -O1 was never meant to give "very fast" code. I'm not looking for "very fast" code, I'm looking for code that doesn't get > 30% slower from one SVN revision number to the next. > You > are using it only because our throttling of expensive passes is > insufficient. I am using -O1 because code of this type compiled with -O2 runs significantly more slowly than code of this type compiled with -O1. I have never used -O2 on this type of code. > Fixing that has two sides, as done in PR39157's > discussion: 1) disabling more passes at -O1, 2) establishing some > parameters to throttle down passes at -O2. I don't see that (1) and (2) form the main strategy to fix "that", it seems that understanding the existing optimizations that are being disabled in preference for new ones is a good start. And generally ensuring that -O1 code doesn't get significantly slower while compile times get significantly higher. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26854
