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<base href="https://bugs.llvm.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - X86DisassemblerDecoder.cpp - readPrefixes - always true condition"
href="https://bugs.llvm.org/show_bug.cgi?id=41659">41659</a>
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<th>Summary</th>
<td>X86DisassemblerDecoder.cpp - readPrefixes - always true condition
</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>
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<th>OS</th>
<td>Windows NT
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>Backend: X86
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>llvm-dev@redking.me.uk
</td>
</tr>
<tr>
<th>CC</th>
<td>craig.topper@gmail.com, llvm-bugs@lists.llvm.org, llvm-dev@redking.me.uk, spatel+llvm@rotateright.com
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</tr>
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<th>Blocks</th>
<td>41655
</td>
</tr></table>
<p>
<div>
<pre>Reported in <a href="https://www.viva64.com/en/b/0629/">https://www.viva64.com/en/b/0629/</a>
static int readPrefixes(struct InternalInstruction* insn) {
....
uint8_t byte = 0;
uint8_t nextByte;
....
if (byte == 0xf3 && (nextByte == 0x88 || nextByte == 0x89 ||
nextByte == 0xc6 || nextByte == 0xc7)) {
insn->xAcquireRelease = true;
if (nextByte != 0x90) // PAUSE instruction support // <=
break;
}
....
}
The (nextByte != 0x90) test is always true - should we just break here or is
there a logic error?</pre>
</div>
</p>
<div id="referenced">
<hr style="border: 1px dashed #969696">
<b>Referenced Bugs:</b>
<ul>
<li>
[<a class="bz_bug_link
bz_status_NEW "
title="NEW - Finding Bugs in LLVM 8 with PVS-Studio"
href="https://bugs.llvm.org/show_bug.cgi?id=41655">Bug 41655</a>] Finding Bugs in LLVM 8 with PVS-Studio
</li>
</ul>
</div>
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