On Fri, Oct 16, 2015 at 02:55:54PM +0200, Bernd Schmidt wrote: > On 10/16/2015 02:53 PM, Segher Boessenkool wrote: > >For x86, STC still gives better results for optimise-for-size than > >"simple" does. So use STC at -Os as well. > > For how many targets is this true, and for the others, what is the > biggest win from "simple"?
See <http://gcc.gnu.org/ml/gcc-patches/2015-10/msg00882.html>. Of the targets I could test there, only x86 and mn10300 like STC better. My theory is that is because they have a smaller encoding for very short branches. Simple is about half a percent smaller on most targets. > If the list of targets which get patches such > as this one is too large, maybe we ought to admit defeat on the "simple" > algorithm and revert it. (Revert it for -Os, not -O1). Yes, but it's just these two. For everything else simple wins now. Segher
