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      <base href="https://bugs.llvm.org/">
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    <body><span class="vcard"><a class="email" href="mailto:john.brawn@arm.com" title="John Brawn <john.brawn@arm.com>"> <span class="fn">John Brawn</span></a>
</span> changed
          <a class="bz_bug_link 
          bz_status_RESOLVED  bz_closed"
   title="RESOLVED INVALID - Inconsistent behavior in FP_TO_UINT compared to gcc-4.9"
   href="https://bugs.llvm.org/show_bug.cgi?id=24805">bug 24805</a>
          <br>
             <table border="1" cellspacing="0" cellpadding="8">
          <tr>
            <th>What</th>
            <th>Removed</th>
            <th>Added</th>
          </tr>

         <tr>
           <td style="text-align:right;">Status</td>
           <td>NEW
           </td>
           <td>RESOLVED
           </td>
         </tr>

         <tr>
           <td style="text-align:right;">Resolution</td>
           <td>---
           </td>
           <td>INVALID
           </td>
         </tr>

         <tr>
           <td style="text-align:right;">CC</td>
           <td>
                
           </td>
           <td>john.brawn@arm.com
           </td>
         </tr></table>
      <p>
        <div>
            <b><a class="bz_bug_link 
          bz_status_RESOLVED  bz_closed"
   title="RESOLVED INVALID - Inconsistent behavior in FP_TO_UINT compared to gcc-4.9"
   href="https://bugs.llvm.org/show_bug.cgi?id=24805#c1">Comment # 1</a>
              on <a class="bz_bug_link 
          bz_status_RESOLVED  bz_closed"
   title="RESOLVED INVALID - Inconsistent behavior in FP_TO_UINT compared to gcc-4.9"
   href="https://bugs.llvm.org/show_bug.cgi?id=24805">bug 24805</a>
              from <span class="vcard"><a class="email" href="mailto:john.brawn@arm.com" title="John Brawn <john.brawn@arm.com>"> <span class="fn">John Brawn</span></a>
</span></b>
        <pre>Adjusting the test case slightly to expand things out:

  int main() {
    a = a * b;
    printf("%d", a);
    return 0;
  }

In 'a * b' as one operand is double the other is converted to double so the
result is a double. That then needs to be converted to unsigned char for the
assignment, which means we actually have:

  int main() {
    a = (unsigned char)((double)a * b);
    printf("%d", a);
    return 0;
  }

According to section 6.3.1.4 of C99: 'If the value of the integral part cannot
be represented by the integer type, the behavior is undefined.' so here we have
undefined behaviour as 255*18=4590 which cannot be represented in unsigned
char.</pre>
        </div>
      </p>


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