<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 --- - Intel parser doesn't recognize cmp${cc}ss"
   href="https://llvm.org/bugs/show_bug.cgi?id=23455">23455</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Intel parser doesn't recognize cmp${cc}ss
          </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>ahmed.bougacha@gmail.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>Consider:

 $ echo 'cmpnless xmm0, xmm1' | ./bin/llvm-mc -x86-asm-syntax=intel
    .section    __TEXT,__text,regular,pure_instructions
<stdin>:1:1: error: invalid operand for instruction
cmpnless xmm0, xmm1

 $ echo 'cmpnless %xmm1, %xmm0' | ./bin/llvm-mc
    .section    __TEXT,__text,regular,pure_instructions
    cmpnless    %xmm1, %xmm0


This is an old problem, that is now triggered because we started actually
parsing the cmpCCss forms, rather than just string-replacing the CC to an
immediate (as of r229266).

Here's the relevant part of the matchers:

  { 1170 /* cmp */, X86::CMPSSrr, Convert__Reg1_2__Tie0__Reg1_3__Imm1_0, 0, {
MCK_Imm, MCK_SS, MCK_FR32, MCK_FR32 }, },

And here's the same matcher for AT&T syntax:

  { 1170 /* cmp */, X86::CMPSSrr, Convert__Reg1_3__Tie0__Reg1_2__Imm1_0, 0, {
MCK_Imm, MCK_ss, MCK_FR32, MCK_FR32 }, },


Notice _ss vs _SS: with Intel syntax, when TableGen generates the matcher from
the AsmString, it splits "cmp${cc}ss" into tokens, and the "ss" suffix is
recognized as a register ...the SS segment register.

It should probably know that when the token ("ss") doesn't follow a space, it's
not a register (I can't think of a case where that would make sense).</pre>
        </div>
      </p>
      <hr>
      <span>You are receiving this mail because:</span>
      
      <ul>
          <li>You are on the CC list for the bug.</li>
      </ul>
    </body>
</html>