On Thu, Apr 5, 2012 at 1:59 PM, William J. Schmidt <wschm...@linux.vnet.ibm.com> wrote: > On Thu, 2012-04-05 at 11:30 +0200, Richard Guenther wrote: >> On Thu, Apr 5, 2012 at 6:22 AM, Mike Stump <mikest...@comcast.net> wrote: >> > On Apr 4, 2012, at 7:56 PM, William J. Schmidt wrote: >> >> There seems to be tacit agreement that the vector tests should use >> >> -fno-common on all targets to avoid the recent spate of failures (see >> >> discussion in 52571 and 52603). >> > >> >> OK for trunk? >> > >> > Ok. Any other solution I think will be real work and we shouldn't loose >> > the testing between now and then by not having the test cases working. >> >> Ian, you are the "source" of all of these problems. While I did not notice >> any degradations in SPEC (on x86) with handling commons "correctly" >> now, the fact >> that our testsuite needs -fno-common to make things vectorizable shows >> that users might be impacted negatively by this, which is only a real problem >> in corner cases. Why can the link editor not promote the definitions >> alignment >> when merging with a common with bigger alignment? >> >> Richard. >> > > Follow-up question: Should -ftree-vectorize imply -fno-common in the > short term?
That's probably more a C language question - you would get valid C rejected with -fno-common. But maybe -ftree-vectorize should suggest -fno-common when it encounters a case it would like to promote alignment for. Not sure if for example Fortran would ever work with -fno-common though. Richard. > Thanks, > Bill >