On Mon, 2016-01-11 at 14:58 -0800, Khem Raj wrote: > > On Jan 7, 2016, at 3:40 PM, Phil Blundell <p...@pbcl.net> wrote: > > > > On Thu, 2016-01-07 at 14:29 -0800, Andre McCurdy wrote: > > > FULL_OPTIMIZATION_armv7a = "-fexpensive-optimizations -fomit > > > -frame-pointer -O4 -ffast-math" > > > +FULL_OPTIMIZATION_armv7ve = "-fexpensive-optimizations -fomit > > > -frame-pointer -O4 -ffast-math" > > > > O4 ? may be just replace this whole thing with -Ofast now a days > -fexpensive-optimizations is enabled at -O2,-O3 anyway same for fomit > -frame-pointer and -Ofast turns on > feast-match on top of -O3 > > > I wonder if this would be better as just FULL_OPTIMIZATION_arm. > > That > > said, the OPTIMIZATION variables are primarily distro knobs and > > it's not > > entirely clear that individual packages ought to be overriding them > > at > > all. > > > > Does anybody know whether there is any actual science behind the > > use of > > those flags on armv7a specifically? > > it came into ffmpeg circa 2008 and proliferated into related > components primarily to support vectorization and neon > which was quite nascent for ARM architecture in those days in gcc. > Today if you were to configure libav with default options > then it uses mainly -fomit-frame-pointer-O3 -fno-math-errno -fno > -signed-zeros -fno-tree-vectorize > > which is primarily -Ofast -fno-tree-vectorize
I have to admit that my personal instinct on these is simply to remove them. I doubt they're buying much now and if people really want to tune specific recipes by hand they still can do so from their local/distro config. Cheers, Richard -- _______________________________________________ Openembedded-core mailing list Openembedded-core@lists.openembedded.org http://lists.openembedded.org/mailman/listinfo/openembedded-core
