[Bug tree-optimization/126415] New: Wrong code at -O2/3/s on x86_64-pc-linux-gnu

[xintong.zhou1 at uwaterloo dot ca via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126415

            Bug ID: 126415
           Summary: Wrong code at -O2/3/s on x86_64-pc-linux-gnu
           Product: gcc
           Version: 17.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: xintong.zhou1 at uwaterloo dot ca
  Target Milestone: ---

Compiler Explorer: https://godbolt.org/z/6G68E88hE

$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=/data/x27zhou/compiler-nightly/install/gcc/bin/gcc
COLLECT_LTO_WRAPPER=/data/x27zhou/compiler-nightly/install/gcc/libexec/gcc/x86_64-pc-linux-gnu/17.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /data/x27zhou/compiler-nightly/src/gcc/configure
--enable-checking=yes --disable-bootstrap --disable-multilib
--enable-languages=c,c++--prefix=/data/x27zhou/compiler-nightly/install/gcc
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 17.0.0 20260724 (experimental) (GCC) 
$
$ gcc-trunk -O0 small.c && ./a.out                                              
0
$ gcc-trunk -O2 small.c && ./a.out                                              
75
$ gcc-trunk -O3 small.c && ./a.out                                              
75
$ gcc-trunk -Os small.c && ./a.out                                              
75
$
$ cat small.c
int printf(const char *, ...);
long d(short p1, unsigned e, char f) {
  if (246 >= 149u - f)
    return 0;
  return f;
}
int g(char p1) { return d(0, 0, p1); }
int fn3(char p1) {
  long i = g(p1 + 159);
  return i;
}
int main() {
  int j = fn3(-84);
  printf("%d\n", j);
}