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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 --- - arm926ej-s: Assertion `ARM::GPRRegClass.contains(DestReg, SrcReg) && "Thumb1 can only copy GPR registers"'"
   href="http://llvm.org/bugs/show_bug.cgi?id=19935">19935</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>arm926ej-s: Assertion `ARM::GPRRegClass.contains(DestReg, SrcReg) && "Thumb1 can only copy GPR registers"'
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>new-bugs
          </td>
        </tr>

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

        <tr>
          <th>Hardware</th>
          <td>Other
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>other
          </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>new bugs
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>sgundapa@codeaurora.org
          </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>Created <span class=""><a href="attachment.cgi?id=12599" name="attach_12599" title="A bugpoint reduced test case">attachment 12599</a> <a href="attachment.cgi?id=12599&action=edit" title="A bugpoint reduced test case">[details]</a></span>
A bugpoint reduced test case

Hi,
   I have been seeing an assertion up until very recently on my arm926 target.
I have attached a bug point reduced test case for your reference.
You can see the assertion with the below command
$ llc bugpoint-reduced-simplified.ll -mcpu=arm926ej-s -mattr=+vfp2

I run my benchmarks usually with 
clang  -mfloat-abi=softfp -mfpu=vfp -mcpu=arm926ej-s -O2 -mthumb -c /tmp/test.c

The assertion is observed on thumb mode only. The arm mode seem fine.

I used git bisect to triage the issue and figured out the following commit is
the cause.

commit e2948385b92b5aec6ac5187ca4fee367db2f0dd1
Author: Oliver Stannard <<a href="mailto:oliver.stannard@arm.com">oliver.stannard@arm.com</a>>
Date:   Fri May 9 14:01:47 2014 +0000

    ARM: HFAs must be passed in consecutive registers</pre>
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