[Bug tree-optimization/102636] New: wrong code at -O1 on x86_64-linux-gnu

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102636

            Bug ID: 102636
           Summary: wrong code at -O1 on x86_64-linux-gnu
           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: ---

[591] % 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/12.0.0/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 12.0.0 20211007 (experimental) [master r12-4219-g6496ae5c965] (GCC) 
[592] % 
[592] % gcctk -O0 small.c; ./a.out
[593] % gcctk -Os small.c; ./a.out
[594] % gcctk -O2 small.c; ./a.out
[595] % gcctk -O3 small.c; ./a.out
[596] % 
[596] % gcctk -O1 small.c; ./a.out
Aborted
[597] % 
[597] % cat small.c
unsigned a;
int main() {
  unsigned b = 1;
  for (; b < 4; b++) {
    a = (a ^ 2000000000) * -b;
    if (b > a) {
      __builtin_abort ();
    }
    a = 3000000000;
  }
  return 0;
}