<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/137588>137588</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            【clang】The while loop is lost when in -O1 or higher Optimization level
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          hippyll123
      </td>
    </tr>
</table>

<pre>
    in llvm18，the following code will be in an infinite loop at -O0, but not at -O1 or higher Optimization level, Is this expected or bug ?  This problem can be avoided by using `-fno-finite-loops` .

In GCC, -O0 or higher Optimization level are all infinite loops.

```
#include <stdio.h>

void bar() {
    int a = 0;
    int b = 10;
    printf("a = %p\n", &a);
    while (a < b) {}
    printf("b = %p\n", &b);
}

int main() {
    bar();
    return 0;
}
```

command:

`clang++  --target=x86_64-unknown-linux-gnu 1.cpp -O0 && ./a.out`

`clang++  --target=x86_64-unknown-linux-gnu 1.cpp -O1 && ./a.out`
</pre>
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