On Thu, Dec 24, 2015 at 3:40 PM, Gary Funck <g...@intrepid.com> wrote: > > Currently, the default optimization level when building, > bootstrapping GCC is -O2. > > We routinely build with --with-build-config='bootstrap-debug bootstrap-O3' > because we want to verify that our UPC changes don't affect the > compiler when built with full optimizations. We also build > with --enable-checking=all. > > Since most developers probably build/test GCC with the default -O2 options, > we fairly often run into -O3 related issues when building GCC. > Enough so that we're considering just using the default -O2 settings. > > I'm wondering if there might be benefit in changing the current defaults > to use -O3 instead? Or perhaps have the configure infrastructure > determine that the build is for a development version of GCC > and set the flags and options accordingly? > > Somewhat related: has anyone recently determined whether a GCC built > with -O3 is generally faster/smaller than one built at -O2?
-O3 will just result in larger code IIRC. You get benefits from profiledboostrap, both size and performance-wise (profiledbootstrap also enables most of what -O3 enables). So no, we don't want to change the defaults. Richard. > thanks, > - Gary
