<html>
<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 - [AMDGPU][MC][GFX9][disassembler] incorrect default value of op_sel_hi for v_mad_mix*"
href="https://bugs.llvm.org/show_bug.cgi?id=35148">35148</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[AMDGPU][MC][GFX9][disassembler] incorrect default value of op_sel_hi for v_mad_mix*
</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>Windows NT
</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>Backend: AMDGPU
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>dpreobrazhensky@luxoft.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>v_mad_mix* opcodes aren't really packed instructions.
They use op_sel and op_sel_hi in a different fashion than other VOP3P opcodes.
The most important difference from other VOP3P instructions is that the default
value of op_sel_hi bits is 0 rather than 1.
Currently disassembler does not account for this difference.
The following instruction is encoded as follows:
v_mad_mix_f32 v0, v1, v2, v3 op_sel_hi:[1,1,1]
[0x00,0x40,0xa0,0xd3,0x01,0x05,0x0e,0x1c]
However, disassembler decodes it incorrectly assuming that default value of
op_sel_hi is 0:
v_mad_mix_f32 v0, v1, v2, v3</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>