<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 --- - [x86, SSE] recognize that pcmp produces bitmask results"
   href="https://llvm.org/bugs/show_bug.cgi?id=28484">28484</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>[x86, SSE] recognize that pcmp produces bitmask results
          </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>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>Backend: X86
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>spatel+llvm@rotateright.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>define <4 x i32> @foo(<4 x i32> %a, <4 x i32> %b) {
  %cmp = icmp eq <4 x i32> %a, %b
  %zext = zext <4 x i1> %cmp to <4 x i32>  ; "wrong" extend for SSE
  ret <4 x i32> %zext
}

$ ./llc -o - boolvec2.ll
LCPI2_0:
    .long    1                       ## 0x1
    .long    1                       ## 0x1
    .long    1                       ## 0x1
    .long    1                       ## 0x1
...
    pcmpeqd    %xmm1, %xmm0
    pand    LCPI2_0(%rip), %xmm0   <--- load + logic
    retq

----------------------------------------------------------------------------

Instead of and'ing, we could shift right logical (psrld 31, %xmm0) and not need
to load the constant.</pre>
        </div>
      </p>
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