On 27/02/2019 10:56, Jakub Jelinek wrote: > On Mon, Feb 25, 2019 at 10:23:52AM +0000, Kyrill Tkachov wrote: >>> The only bootstraps I'm doing are distro builds with >>> --with-tune=generic-armv7-a --with-arch=armv7-a \ >>> --with-float=hard --with-fpu=vfpv3-d16 --with-abi=aapcs-linux >>> I don't have setup nor experience with configuring anything else, don't >>> really know what is and what isn't ABI compatible etc. >>> Isn't --with-mode=arm the default with the above set of options? Can >>> --with-mode=thumb be used ABI compatibly with that, or is that incompatible? >> >> >> They are ABI-compatible. Running the testsuite with -mthumb in RUNTESTFLAGS >> would also be enough in this case if you don't have the cycles for a >> bootstrap. > > Ok, so tried to do two distro builds with the above plus --with-mode=thumb, > one without the casesi patch, the other one with that. > Both bootstrapped successfully, but dunno why the regtests were too slow to > fit under our hard 2 days timeout limit. When I grabbed the build logs, the > only difference in the grep ^FAIL | sort -u lines was one fewer go failure > with the patch (but that is most likely a random failure rather than the > patch actually changing anything). Is -mthumb generally slower than ARM > mode? > > Anyway, I'm afraid this is as far as I can go in my testing. > > Jakub >
Thumb performance on v7-a should be nearly identical to Arm performance (sometimes a bit faster, sometimes a bit slower, depending on the precise code generated). So if you're timing out, something else is probably going wrong. R.
