17/06/2020 12:40, Bruce Richardson: > Rather than checking the binutils version number, which can lead to > unnecessary disabling of AVX512 if fixes have been backported to distro > versions, we can instead check the output of "as" from binutils to see if > it is correct. > > These checks use the minimal assembly reproduction code posted to the > public bug tracker for gcc/binutils for those issues [1][2]. If the > binutils bug is present, the instruction parameters - specifically the > displacement parameter - will be different in the disassembled output > compared to the input. Therefore each check involves assembling a single > instruction and disassembling it again, checking that the two match.
Whaoh, that's a very specific optimization :) Which distro is affected (backported binutils fix)? > [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90028 > [2] https://sourceware.org/bugzilla/show_bug.cgi?id=23465 > > Signed-off-by: Bruce Richardson <bruce.richard...@intel.com> > --- > --- a/buildtools/meson.build > +++ b/buildtools/meson.build > -subdir('pmdinfogen') Why removing pmdinfogen? > --- a/meson.build > +++ b/meson.build > +# do configuration and get tool paths > +subdir('buildtools') > subdir('config') > > # build libs and drivers > -subdir('buildtools') > +subdir('buildtools/pmdinfogen') Is it related to binutils check? [...] > - ldver = run_command('ld', '-v').stdout().strip() > - if ldver.contains('2.30') and cc.has_argument('-mno-avx512f') > + as_ok = run_command(binutils_avx512_check) > + if as_ok.returncode() != 0 and cc.has_argument('-mno-avx512f') "as_ok" is difficult to understand. I would suggest "binutils_avx512_ok". > + message('Binutils error with AVX512 assembly, disabling AVX512 > support') It looks like something which should be part of meson itself.
