[Bug tree-optimization/102736] New: wrong code at -O2 and -O3 on x86_64-linux-gnu

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102736

            Bug ID: 102736
           Summary: wrong code at -O2 and -O3 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: ---

This appears to be a recent regression.

[592] % 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 20211013 (experimental) [master r12-4363-g52055987fba] (GCC) 
[593] % 
[593] % gcctk -Os small.c; ./a.out
[594] % 
[594] % gcctk -O2 small.c
[595] % ./a.out
Aborted
[596] % 
[596] % cat small.c
int a, b = -1, c;
int d = 1;
char e(char f, int g) { return g ? f : 0; }
char h(char f) { return f < a ? f : f < a; }
unsigned char i(unsigned char f, int g) { return g ? f : f > g; }
void j() {
L:
  c = e(1, i(h(b), d));
  if (b)
    return;
  goto L;
}
int main() {
  j();
  if (c != 1)
    __builtin_abort ();
  return 0;
}