[Bug target/77761] New: [7 Regression] wrong code with -fschedule-insns -mavx512f --param=max-pending-list-length=512

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77761

            Bug ID: 77761
           Summary: [7 Regression] wrong code with -fschedule-insns
                    -mavx512f --param=max-pending-list-length=512
           Product: gcc
           Version: 7.0
            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: x86_64-pc-linux-gnu
             Build: x86_64-pc-linux-gnu

Created attachment 39702
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=39702&action=edit
reduced testcase

Compiler output:
$ x86_64-pc-linux-gnu-gcc -O2 -fno-guess-branch-probability -fschedule-insns
-fno-tree-ter -mavx512f --param=max-pending-list-length=512 testcase.c
$ sde64 -- ./a.out 
Aborted

Correct value of x[0] is 0x0000000000ff00ff0000000000fd0002, wrong value is
0x0000000000ff00000000000100fd0001

$ x86_64-pc-linux-gnu-gcc -v 
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-240535-checking-yes-rtl-df-extra-nobootstrap-nographite-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/7.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--disable-bootstrap --without-cloog --without-ppl --without-isl
--build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu
--target=x86_64-pc-linux-gnu --with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-240535-checking-yes-rtl-df-extra-nobootstrap-nographite-amd64
Thread model: posix
gcc version 7.0.0 20160927 (experimental) (GCC)