On 5/22/19 8:44 AM, Vladislav Ivanishin wrote: > Christophe, Rainer, > > Rainer Orth <r...@cebitec.uni-bielefeld.de> writes: > >> Hi Christophe, >> >>> On Fri, 17 May 2019 at 10:12, Vladislav Ivanishin <v...@ispras.ru> wrote: >>>> >>> As you have probably noticed already, the new test uninit-28.c fails: >>> /gcc/testsuite/gcc.dg/uninit-28-gimple.c:9:16: warning: 'undef' may be >>> used uninitialized in this function [-Wmaybe-uninitialized] >>> FAIL: gcc.dg/uninit-28-gimple.c (test for bogus messages, line 9) >>> at least on arm & aarch64 > > Thanks for spotting. I managed to reproduce the failure on x86_64 (I > started from revision and configure options in one of H.J.'s test > results [1]) and it seems, another check-in is to blame. The stage1 > compiler is always fine w.r.t. the result on uninit-28-gimple.c. The > stage2 compiler seems to be miscompiled. > > r271460 is already bad, yes, but the problem starts earlier (better to > pick another test as an indicator, or bisect just the stage1 compiler, > compiling pseudo-stage2 with it from newer sources). > > I'm going to bisect the regression and report to the appropriate thread > unless someone beats me to it. > > [1]: https://gcc.gnu.org/ml/gcc-testresults/2019-05/msg02436.html > >> I'm seeing it on sparc-sun-solaris2.11, and there are gcc-testresults >> reports for i?86, mips64el, powerpc*, s390x, and x86_64. FWIW I'm also seeing uninit-18 failing on the ppc targets.
And I'll reiterate my concern that these are likely masking issues earlier in the optimizer pipeline. For example uninit-18 really should be fixed by threading in either DOM or VRP. Jeff
