<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 - clang miscompiles with "-newgvn" at -O2 on valid code"
href="https://bugs.llvm.org/show_bug.cgi?id=39056">39056</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>clang miscompiles with "-newgvn" at -O2 on valid code
</td>
</tr>
<tr>
<th>Product</th>
<td>clang
</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>LLVM Codegen
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>helloqirun@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>clang-r329389: first working build
clang-r329395: next failing build
$ clang-trunk -v
clang version 8.0.0 (trunk 342833)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/bin
$ clang-trunk abc.c ; ./a.out
0
0
1
0
0
0
$ clang-trunk -mllvm -enable-newgvn -O2 abc.c ; ./a.out
0
0
0
0
0
0
$ cat abc.c
int printf(const char *, ...);
volatile int a, d, f;
short b;
char c[6][1];
char e;
int main() {
int g = 7;
for (; d <= 1; d++) {
b = e = g || b;
c[2][0] = e;
a;
g = 0;
}
for (; f < 6; f++)
printf("%d\n", c[f][0]);
}</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>