[Bug tree-optimization/103440] New: wrong code at -Os and above on x86_64-linux-gnu

[zhendong.su at inf dot ethz.ch]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103440

            Bug ID: 103440
           Summary: wrong code at -Os and above 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: ---

It seems to be recent and a regression from GCC 11.2.

[671] % 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 --disable-multilib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 12.0.0 20211126 (experimental) [master r12-4647-g3f861a5c8fd] (GCC) 
[672] % 
[672] % gcctk -O1 small.c; ./a.out
[673] % 
[673] % gcctk -Os small.c
[674] % timeout -s 9 10 ./a.out
Killed
[675] % 
[675] % cat small.c
int a, b, c, d, e;
int main() {
  int f = 2, g = 1, h = -3;
L1:
  c = b ^ 1;
  if (!f)
    goto L3;
  if (d)
    g = e;
  f = h;
  if (!c)
    goto L1;
L2:
  if (g)
    a = 0;
L3:
  if (d == g)
    goto L2;
  return 0;
}