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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 - [inline asm] invalid asm is sometimes reported via fatal error mechanism"
href="https://bugs.llvm.org/show_bug.cgi?id=37896">37896</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[inline asm] invalid asm is sometimes reported via fatal error mechanism
</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>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>new bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>greg.bedwell@sony.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr>
<tr>
<th>Blocks</th>
<td>18113, 31171
</td>
</tr></table>
<p>
<div>
<pre>Clang correctly spots that the following inline asm is invalid. Unfortunately
it reports this via a fatal error which makes it appear as a compiler crash
rather than a user error.
$ clang.exe --version
clang version 7.0.0 (trunk 335220) (llvm/trunk 335219)
Target: x86_64-pc-windows-msvc
Thread model: posix
InstalledDir: e:\work\upstream-llvm\build-vs2015-native-ninja\bin
$ cat 1.c
void f() { asm("subb %dh, %r9b"); }
$ gcc -c 1.c
1.c: Assembler messages:
1.c:1: Error: can't encode register '%dh' in an instruction requiring REX
prefix.
$ clang.exe -c 1.c
fatal error: error in backend: Cannot encode high byte register in REX-prefixed
instruction
clang.exe: error: clang frontend command failed with exit code 70 (use -v to
see invocation)
clang version 7.0.0 (trunk 335220) (llvm/trunk 335219)
Target: x86_64-pc-windows-msvc
Thread model: posix
InstalledDir: e:\work\upstream-llvm\build-vs2015-native-ninja\bin
clang.exe: note: diagnostic msg: PLEASE submit a bug report to
<a href="https://bugs.llvm.org/">https://bugs.llvm.org/</a> and include the crash backtrace, preprocessed source,
and associated run script.
clang.exe: note: diagnostic msg:
********************
PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang.exe: note: diagnostic msg: C:\Users\GREG\AppData\Local\Temp\1-c31ac3.c
clang.exe: note: diagnostic msg: C:\Users\GREG\AppData\Local\Temp\1-c31ac3.sh
clang.exe: note: diagnostic msg:
********************</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 - asm declaration makes the backend crash"
href="https://bugs.llvm.org/show_bug.cgi?id=18113">Bug 18113</a>] asm declaration makes the backend crash
</li>
<li>
[<a class="bz_bug_link
bz_status_NEW "
title="NEW - [inline asm] clang ungracefull exit, asm regex"
href="https://bugs.llvm.org/show_bug.cgi?id=31171">Bug 31171</a>] [inline asm] clang ungracefull exit, asm regex
</li>
</ul>
</div>
<br>
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