[Bug rtl-optimization/98793] New: [11 Regression] wrong code with --param=max-jump-thread-duplication-stmts=4

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98793

            Bug ID: 98793
           Summary: [11 Regression] wrong code with
                    --param=max-jump-thread-duplication-stmts=4
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          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

Created attachment 50033
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50033&action=edit
reduced testcase

Output:
$ x86_64-pc-linux-gnu-gcc -O2 --param=max-jump-thread-duplication-stmts=3
testcase.c -Wno-psabi && ./a.out
$ x86_64-pc-linux-gnu-gcc -O2 --param=max-jump-thread-duplication-stmts=4
testcase.c -Wno-psabi && ./a.out  
Aborted

$ 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-r11-6849-20210122123514-gee78c20e74d-checking-yes-rtl-df-extra-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/11.0.0/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
--with-cloog --with-ppl --with-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-r11-6849-20210122123514-gee78c20e74d-checking-yes-rtl-df-extra-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 11.0.0 20210122 (experimental) (GCC) 

I am unable to further reduce the testcase. I have several similar testcases,
all seem to be related to higher values of
--param=max-jump-thread-duplication-stmts=