[Bug tree-optimization/104280] New: wrong code at -O1 and above

[zhendong.su at inf dot ethz.ch via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104280

            Bug ID: 104280
           Summary: wrong code at -O1 and above
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zhendong.su at inf dot ethz.ch
  Target Milestone: ---

It is a recent regression. 

[548] % gcctk -v
Using built-in specs.
COLLECT_GCC=gcctk
COLLECT_LTO_WRAPPER=/local/suz-local/software/local/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/12.0.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-trunk/configure --disable-bootstrap
--prefix=/local/suz-local/software/local/gcc-trunk --enable-languages=c,c++
--disable-werror --enable-multilib --with-system-zlib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 12.0.1 20220129 (experimental) [master r12-6930-gf6f2d6cfec1] (GCC) 
[549] % 
[549] % gcctk -O0 small.c; ./a.out
[550] % 
[550] % gcctk -O1 small.c
[551] % ./a.out
Aborted
[552] % 
[552] % cat small.c
int a(unsigned b, int c) { return b / c; }
int main() {
  if (a(1, 2) != 0)
    __builtin_abort();
  return 0;
}