Re: [SVE] PR86753

[Prathamesh Kulkarni <prathamesh dot kulkarni at linaro dot org>]

On Tue, 10 Sep 2019 at 19:05, Matthew Malcomson
<Matthew.Malcomson@arm.com> wrote:
>
> Resending because I forgot to avoid the disclaimer and hence my email
> didn't go to the gcc-patches list.
>
>
>
> On 09/09/19 21:55, Prathamesh Kulkarni wrote:
> > On Mon, 9 Sep 2019 at 22:06, Prathamesh Kulkarni
> > <prathamesh.kulkarni@linaro.org> wrote:
> >>
> >> On Mon, 9 Sep 2019 at 16:45, Richard Sandiford
> >> <richard.sandiford@arm.com> wrote:
> >>>
> >>>
> >>> Thanks for doing this.
> >> Thanks for the suggestions, I have updated the patch accordingly.
> >> Boostrap+test in progress on x86_64-unknown-linux-gnu and aarch64-linux-gnu.
> >> Richi, does the patch look OK to you ?
> > Hi,
> > Bootstrap+test passes for x86_64-unknown-linux-gnu and aarch64-linux-gnu.
> > On x86_64, there's a "strange" failure of c-c++-common/builtins.c, log shows:
> >
> > /home/prathamesh.kulkarni/gnu-toolchain/gcc/pr86753-v2-3/gcc/gcc/test
> > FAIL: c-c++-common/builtins.c  -Wc++-compat  (test for excess errors)
> > Excess errors:
> > /home/prathamesh.kulkarni/gnu-toolchain/gcc/pr86753-v2-3/gcc/gcc/test
> >
>
> Just FYI I have seen this error come from a restriction in DejaGNU itself.
> https://gcc.gnu.org/ml/gcc/2019-05/msg00066.html
>
> The reply to that email mentions that this restriction was removed in
> later DejaGNU versions.
> https://gcc.gnu.org/ml/gcc/2019-05/msg00070.html
>
> If you see the snippet mentioned in the first email (don't continue if
> you've already read greater than 512000 bytes of output) in your DejaGNU
> install (remote.exp file), and the error messages from the
> "-Wc++-compat" test are greater than 512000 bytes then it's likely the
> problem is because of DejaGNU rather than your code.
>
> If that is the case, then a test is to remove the `if` mentioned in the
> first email and re-trying the regression test.
>
> (i.e. replace
>
>          if { [string length $output] < 512000 } {
>          exp_continue -continue_timer
>          }
>
> with
>
>              exp_continue -continue_timer
>
> in the "local_exec" procedure from $DEJAGNU_INSTALL/remote.exp)
>
>
> > Which shouldn't really happen since the test doesn't seem relevant to patch,
> > and only passes -O2 which shouldn't enable the vectorizer ? Manually
> > testing it results in PASS with:
> > make check-gcc RUNTESTFLAGS="dg.exp=builtins.c"
> > Would it be OK to ignore the FAIL during reg-test ?
> >
>
> This also matches the symptoms of this DejaGNU restriction -- it only
> comes up when the OS read returned not all the output from the test, and
> that happens a lot more when there are many parallel tests running.
Hi Matthew,
Thanks for the clarification! I had started another bootstrap+regtest
before reading your
mail, and this time there were no FAIL's, so I assume the FAIL in
previous regtest, was due the
dejaGNU issue you mentioned.

Thanks,
Prathamesh
>
> > Thanks,
> > Prathamesh
> >>
> >> Thanks,
> >> Prathamesh
> >>>
> >>> Richard
>