<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 - x86 assembler immediates should be limited to 32 bit"
href="https://bugs.llvm.org/show_bug.cgi?id=33654">33654</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>x86 assembler immediates should be limited to 32 bit
</td>
</tr>
<tr>
<th>Product</th>
<td>new-bugs
</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>enhancement
</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>dimitry@andric.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>In <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED INVALID - LLVM ERROR: Error parsing inline asm"
href="show_bug.cgi?id=33386">bug 33386</a>, Jonas Vekeman encountered a situation where OpenSSL's inline
assembly in combination with function inlining could sometimes lead to errors
from the inline asm parser, e.g.:
<inline asm>:1:12: error: invalid operand for instruction
divq $-8446744073709551616
^~~~~~~~~~~~~~~~~~~~~
LLVM ERROR: Error parsing inline asm
For this particular case, I created a test.s file with just:
divq 0x7fffffff
divq 0x80000000
divq 0xffffffff
divq 0x100000000
divq 0xffffffffffffffff
For this assembly, GNU as rightfully complains about lines 2 through 4:
divtest.s: Assembler messages:
divtest.s:2: Error: operand type mismatch for `div'
divtest.s:3: Error: operand type mismatch for `div'
divtest.s:4: Error: operand type mismatch for `div'
However, clang 5.0.0 doesn't complain at all, and produces an object file.
Disassembling it shows that clang has silently wrapped the too-large values:
0: 48 f7 34 25 ff ff ff 7f divq 2147483647
8: 48 f7 34 25 00 00 00 80 divq -2147483648
10: 48 f7 34 25 ff ff ff ff divq -1
18: 48 f7 34 25 00 00 00 00 divq 0
20: 48 f7 34 25 ff ff ff ff divq -1
At the very least, it should complain here like GNU as does, IMHO.</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>