<html>
    <head>
      <base href="https://llvm.org/bugs/" />
    </head>
    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW --- - licm miscompile with noalias and call which exits program"
   href="https://llvm.org/bugs/show_bug.cgi?id=27857">27857</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>licm miscompile with noalias and call which exits program
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>libraries
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>trunk
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>PC
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Windows NT
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>Loop Optimizer
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>unassignedbugs@nondot.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>eli.friedman@gmail.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Testcase:

#include <stdlib.h>
void f() { exit(0); }
void (*ff)() = f;
void g(int* restrict a) {
    for (int i = 0; i < 1000; ++i) {
        ff();
        *a += 1;
    }
}
void (*gg)(int* restrict) = g;
int main() {
    gg(0);
}

Works with gcc and clang -O0; crashes with clang -O2.

I think LICM is relying too much on "MayThrow" to conclude that function calls
will return normally.

Testcase is artificial.</pre>
        </div>
      </p>
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