<html>
<head>
<base href="http://llvm.org/bugs/" />
</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 --- - Clang's assembler doesn't ignore extraneous "#" characters in ARM inline assembly."
href="http://llvm.org/bugs/show_bug.cgi?id=20117">20117</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Clang's assembler doesn't ignore extraneous "#" characters in ARM inline assembly.
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>Other
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</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>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>jacob.bramley@arm.com
</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>I'm using Clang as packaged by Ubuntu: Ubuntu clang version 3.5-1ubuntu1
(trunk) (based on LLVM 3.5)
This doesn't seem to agree with the available options in the 'version' field.
----
Consider the following test function:
int test(void) {
int out;
asm(" ldr %0, =%1\n" : "=r" (out) : "i" (0x000f0002));
return out;
}
The instruction generated by the inline assembly is "ldr r0, =#983042", since
"i" constraints get a leading hash character by default. The GNU assembler
ignores this character, but Clang does not:
test.c:4:7: error: unknown token in expression
asm(" ldr %0, =%1\n" : "=r" (out) : "i" (0x000f0002));
^
<inline asm>:1:13: note: instantiated into assembly here
ldr r0, =#983042
^
1 error generated.
GCC has an (undocumented) substitution predicate which causes the hash
character to be omitted ("ldr %0, =%c1"), and Clang appears to support this,
but this still represents an incompatibility with GCC and therefore might be
considered a bug.</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>