[Bug tree-optimization/115579] [15 regression] wrong code at -Os with "-fno-tree-sra" on x86_64-linux-gnu since r15-1391-g4b75ed33fa5fd6

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115579

--- Comment #3 from Zhendong Su <zhendong.su at inf dot ethz.ch> ---
Perhaps the same or a related issue.  It reproduces for -O{s,2,3}. 

Compiler Explorer: https://godbolt.org/z/x779P9b5a

[570] % 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/15.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-trunk/configure --disable-bootstrap
--enable-checking=yes --prefix=/local/suz-local/software/local/gcc-trunk
--enable-sanitizers --enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 15.0.0 20240620 (experimental) (GCC) 
[571] % 
[571] % gcctk -O2 small.c; ./a.out
[572] % 
[572] % gcctk -O2 -fno-tree-fre -fno-tree-sra -fno-tree-ch -fno-tree-dce
small.c
[573] % ./a.out
Floating point exception
[574] % 
[574] % cat small.c
int a = 1;
int main() {
  int b[1], c;
  for (c = 0; c < 2; c++) {
    int d = a, e = 1 / d;
    while (!e) {
      b[0] = 0;
      while (b[0])
        ;
      a = 0;
    }
  }
  return 0;
}