[llvm-bugs] [Bug 51043] New: wrong code at -O3 on x86_64-linux-gnu

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=51043

            Bug ID: 51043
           Summary: wrong code at -O3 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

[706] % clangtk -v
clang version 13.0.0 (https://github.com/llvm/llvm-project.git
4a3b0556536d5a2555f7a19f953f0eec0f79f1a9)
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
[707] % 
[707] % clangtk -O2 small.c; ./a.out
[708] % 
[708] % clangtk -O3 small.c
[709] % ./a.out
Aborted
[710] % 
[710] % cat small.c
int a = 1, b = 1;
int main() {
  short d, g, i;
  int e = 34000, h;
  d = b;
  g = 100 | b;
L1:
  i = g;
L2:
  g = ~(d / e);
  e = ~((2 / g) & d);
  h = a;
  while (!e) {
    a = b;
    e = ~(1L << i);
  }
  if (g > 0)
    goto L2;
  if (!g)
    goto L1;
  if (h < e)
    __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/20210709/f2f10682/attachment.html>