<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/63727>63727</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Wrong code at -O3 on x86_64-linux_gnu (a recent regression)
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          shao-hua-li
      </td>
    </tr>
</table>

<pre>
    This looks like a recent regression. Clang trunk at -O3 emits wrong code. `opt-bisect-limit` suggests that the issue might be in `GVNPass`.

Compiler explorer: https://godbolt.org/z/b6Mdvq453

```console
% cat a.c
int printf(const char *, ...);
int a, b, c, d;
long e;
int f(int g) {
  if (g < 68)
    return 0;
  return g < 768 ? 5 & 1 << (g - 68) : 1 << (g - 2);
}
int main() {
  for (; d < 2; d++)
    c = 1;
 a = 1;
  for (; a <= 9; a++)
    ;
  for (;;) {
    for (; f(a) + b - 30 + e; ++e)
      ;
    if (c)
      break;
  }
 printf("%d\n", (int)e);
}
%
% clang-tk -O0 a.c && ./a.out
30
% clang-tk -O3 a.c && ./a.out
0
%
% clang-tk -v
clang version 17.0.0 (https://github.com/llvm/llvm-project.git 99074aafc31593c9935da483edab1333d6ce5a5b)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /zdata/shaoli/compilers/ccbuilder-compilers
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/10
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/11
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/9
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/11
Candidate multilib: .;@m64
Selected multilib: .;@m64
%
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJy0Vd-P4yYQ_mvIy8gWhvjXgx92E_nUh_Yq9dQ-njBMbBoCKeC9bf_6CjubZKPVSZWuioXJMHzz-WOGESHo0SJ2pHwm5X4j5jg534VJuGyaRWb0ZnDq7-7LpAMY544BjD4iCPAo0UbwOHoMQTubw84IO0L0sz2CiJB95oAnHQN8886OIJ3CHEhF3Tlmgw4oY2b0SUdSUQjzOGKIAeIkIsQJQYcwI5z0OEUYELRNWz_9_suvIgRS0ZzQPaFP67hzp7M26AFfz8Z59IQ_wRTjORD-RFhPWD86NTgTc-dHwvp_COuH6mf18te25PdIpKLrI50NzuDFykqQIoLI5WrQNsLZaxsPhDXJNYKchAfCngjbQZ7nhLWEP9-8RbIPaZBpUNdFk7TBd74JNL1Hwlog9WUFQB-AsGYEwndQNSnCZQHAY5y9BXrFuZpW97pqgPAeSiCsgiLZknmBy1YwSKI9rrD77yD1_kbyJLQlrHmgeHBJhIbwZ1BLYLZMCXtenjvGEgjfQ3EjLB4N92Bi5bWHdvn3Ad6H-9LznuA71CS0WBzYMwyQAafLNB0HrDHwXZB3Yd4ORD64DB7F8c7vKtstZQhjhJWKlDu7TBe9tY2Etfih4oSVd6mYCi2LR8g-05ST6UzTseaE9SJ3c1xdOf1wC__OFvrdaC-rcTHAC_pU9lDUOc2TbM1Dwek4zUMu3Ymw3piXt1d29u5PlDEfdYS2pfVWiIPkRdly2ba8VGLbcFRiKDjnqpJYinK4KvxF-BFjytTXpvpabbPZHq37ZjOj7fyajXa--E0ehYKTU2iS99kF_bou_WRDFMag2uvlnkjXgRJRENane89ownp5uVBCmsth1kahz27WBah3s1UghVVaiYjwabcDvYKLqJ29gM_Bp0_XQxJFSsL6C_UbZdYX9H_ALH485uUYfkODMqL6Ifx2V2an2USddvEnyFMRbOmp2j6E_J7TLXHf7vGN6rhqeSs22BVV09RFxTndTJ1UrNkWLUXe8Ar5tmgZxQPyth4aybHe6I5RxmmdfiUraC63ohwKKmrF24IfBNlSPAlt8pTWqbFslp7VVbxm9caIAU14a6y-W3J_mMdAttToEMNtW9TRYPfHtUu-dU9n4V62r6OdU5190HwJazezN91_K0HC-oVxyvKF9L8BAAD__zJ4SIk">