[Bug target/98853] New: [11 Regression] wrong use of bfxil at -O1

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98853

            Bug ID: 98853
           Summary: [11 Regression] wrong use of bfxil at -O1
           Product: gcc
           Version: 11.0
            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: aarch64-unknown-linux-gnu

Created attachment 50068
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50068&action=edit
reduced testcase

Output:
$ aarch64-unknown-linux-gnu-gcc -O testcase.c -static
$ ./a.out 
qemu: uncaught target signal 6 (Aborted) - core dumped
Aborted

$ aarch64-unknown-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-aarch64/bin/aarch64-unknown-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r11-6925-20210127102218-g6cf43433750-checking-yes-rtl-df-extra-aarch64/bin/../libexec/gcc/aarch64-unknown-linux-gnu/11.0.0/lto-wrapper
Target: aarch64-unknown-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
--with-sysroot=/usr/aarch64-unknown-linux-gnu --build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu --target=aarch64-unknown-linux-gnu
--with-ld=/usr/bin/aarch64-unknown-linux-gnu-ld
--with-as=/usr/bin/aarch64-unknown-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r11-6925-20210127102218-g6cf43433750-checking-yes-rtl-df-extra-aarch64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 11.0.0 20210127 (experimental) (GCC)