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    <head>
      <base href="https://llvm.org/bugs/" />
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW " title="NEW --- - -Wfloat-equal issued too much" href="https://urldefense.proofpoint.com/v2/url?u=https-3A__llvm.org_bugs_show-5Fbug.cgi-3Fid-3D23717&d=AwMBaQ&c=8hUWFZcy2Z-Za5rBPlktOQ&r=pF93YEPyB-J_PERP4DUZOJDzFVX5ZQ57vQk33wu0vio&m=07316fmOfenPLY8AZDF4PfE9sL9rhxRyJbjWXlRUhPU&s=i1xTeRoTaoqfDdgErFzWRQacC7GFrdwCOtrmdRt2rlY&e=">23717</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>-Wfloat-equal issued too much
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>clang
          </td>
        </tr>

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

        <tr>
          <th>Hardware</th>
          <td>All
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>All
          </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>Frontend
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>javier_3@runbox.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvmbugs@cs.uiuc.edu
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr></table>
      <p>
        <div>
        <pre>The code at SemaChecking.cpp, function Sema::CheckFloatComparison, issues the
warning warn_floatingpoint_eq (-Wfloat-equal) in case of using == or != with
floating point operands, but prevents the issuing of the warning in some
special cases, among which:

  // Special case: check for comparisons against literals that can be exactly
  //  represented by APFloat.

So if the code reads if(x==0.0F) no warning is issued, but if the user simply
writes if(x==0) the warning is issued.

Given that both pieces of code get translated to exactly the same and the user
obviously knows what he is doing when writing if(x==0), my point is that in the
second case the warning should not be issued too.

I get dozens of annoying warning because of comparisons against zero, but I
don't want to turn off that warning because I think it's really meaningful in
the other cases, e.g. if(x==y).</pre>
        </div>
      </p>
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