[Bug tree-optimization/70310] New: [6 Regression] wrong code with vector compare at -O0

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70310

            Bug ID: 70310
           Summary: [6 Regression] wrong code with vector compare at -O0
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
  Target Milestone: ---

Created attachment 38029
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38029&action=edit
reduced testcase

Output:
$ gcc -O0 testcase.c
$ ./a.out 
000000ff
Aborted

$ gcc -v            
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-234340-checking-yes-rtl-df-nobootstrap-nographite/bin/../libexec/gcc/x86_64-pc-linux-gnu/6.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-checking=yes,rtl,df --disable-bootstrap --without-cloog --without-ppl
--without-isl --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-234340-checking-yes-rtl-df-nobootstrap-nographite
Thread model: posix
gcc version 6.0.0 20160318 (experimental) (GCC)