[Bug target/69307] New: [6 Regression] wrong code with -O2 -fselective-scheduling @ armv7a

["zsojka at seznam dot cz" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69307

            Bug ID: 69307
           Summary: [6 Regression] wrong code with -O2
                    -fselective-scheduling @ armv7a
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: armv7a-*-linux-gnueabi-gcc

Output (qemu userspace emulation):
$ armv7a-softfp-linux-gnueabi-gcc -v                                   
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-armv7a-softfp/bin/armv7a-softfp-linux-gnueabi-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-232232-checking-yes-rtl-df-nographite-armv7a-softfp/bin/../libexec/gcc/armv7a-softfp-linux-gnueabi/6.0.0/lto-wrapper
Target: armv7a-softfp-linux-gnueabi
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-checking=yes,rtl,df --without-cloog --without-ppl --without-isl
--with-float=softfp --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu
--target=armv7a-softfp-linux-gnueabi
--with-ld=/usr/bin/armv7a-softfp-linux-gnueabi-ld
--with-as=/usr/bin/armv7a-softfp-linux-gnueabi-as
--with-sysroot=/usr/armv7a-softfp-linux-gnueabi --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-232232-checking-yes-rtl-df-nographite-armv7a-softfp
Thread model: posix
gcc version 6.0.0 20160111 (experimental) (GCC) 

$ armv7a-softfp-linux-gnueabi-gcc -O2 testcase.c -fselective-scheduling
$ ./a.out 
1d01000000000000
qemu: uncaught target signal 6 (Aborted) - core dumped
Aborted

Tested revisions:
trunk r232232 - FAIL
5-branch r231950 - OK
4_9-branch r231949 - OK
4_8-branch r224828 - OK
4.9.3 - FAIL