[llvm-bugs] [Bug 50498] New: wrong code at -O1 and above on x86_64-linux-gnu

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=50498

            Bug ID: 50498
           Summary: wrong code at -O1 and above on x86_64-linux-gnu
           Product: libraries
           Version: trunk
          Hardware: PC
                OS: All
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: Scalar Optimizations
          Assignee: unassignedbugs at nondot.org
          Reporter: zhendong.su at inf.ethz.ch
                CC: llvm-bugs at lists.llvm.org

[507] % clangtk -v
clang version 13.0.0 (https://github.com/llvm/llvm-project.git
5dd86aadf0b014913bd35bb7435808eb081bc049)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /local/suz-local/opfuzz/bin
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.5.0
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Candidate multilib: x32;@mx32
Selected multilib: .;@m64
[508] % 
[508] % clangtk -O0 small.c; ./a.out
[509] % 
[509] % clangtk -O1 small.c
[510] % ./a.out
Aborted
[511] % 
[511] % cat small.c
int a;
int main() {
  int b;
 L:
  b = a;
  if (a >= 0) {
    int c;
    if ((!a) <= 0)
      goto L;
    a = -1;
  }
  if (b != 0)
    __builtin_abort ();
  return 0;
}

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20210526/da0e3e38/attachment-0001.html>