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    <head>
      <base href="https://bugs.llvm.org/">
    </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 - KILL instruction has dangling memory operand"
   href="https://bugs.llvm.org/show_bug.cgi?id=33111">33111</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>KILL instruction has dangling memory operand
          </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>Linux
          </td>
        </tr>

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

        <tr>
          <th>Severity</th>
          <td>enhancement
          </td>
        </tr>

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

        <tr>
          <th>Component</th>
          <td>Register Allocator
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>paulsson@linux.vnet.ibm.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Created <span class=""><a href="attachment.cgi?id=18483" name="attach_18483" title="reduced testcase">attachment 18483</a> <a href="attachment.cgi?id=18483&action=edit" title="reduced testcase">[details]</a></span>
reduced testcase

bin/llc -mtriple=s390x-linux-gnu -mcpu=z13 -verify-regalloc -disable-cgp
-disable-machine-dce ./tc_miss_mayloadflag.ll

It seems that while changing opcode to KILL, there is a memory operand that
isn't removed:

144B    BB#4: derived from LLVM BB %CF369
            Predecessors according to CFG: BB#3
160B            CHIMux %vreg0, 0, %CC<imp-def>; GRX32Bit:%vreg0
176B            %vreg1<def,tied1> = LOCG %vreg1<undef,tied0>, %vreg5<undef>, 0,
14, 6, %CC<imp-use,kill>; mem:LD8[undef] GR64Bit:%vreg1 ADDR64Bit:%vreg5
192B            %vreg6<def> = LHIMux 0; GRX32Bit:%vreg6

->

# *** IR Dump After Simple Register Coalescing ***:

144B    BB#4: derived from LLVM BB %CF369
            Predecessors according to CFG: BB#3
160B            CHIMux %vreg0, 0, %CC<imp-def>; GRX32Bit:%vreg0
176B            KILL %CC<imp-use,kill>; mem:LD8[undef]
192B            %vreg6<def> = LHIMux 0; GRX32Bit:%vreg6

*** Bad machine code: Missing mayLoad flag ***
- function:    autogen_SD7792
- basic block: BB#4 CF369 (0x4f6b988) [144B;208B)
- instruction: 176B     KILL</pre>
        </div>
      </p>


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