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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - compile-time explosion at -O3"
href="https://bugs.llvm.org/show_bug.cgi?id=51841">51841</a>
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<tr>
<th>Summary</th>
<td>compile-time explosion at -O3
</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>
<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>Scalar Optimizations
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>haoxintu@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>Hi all.
It's quite weird that this simple valid code makes clang-10 to clang-trunk
versions hang at -O3. This issue only happens when "-g -O3" is enabled.
$cat small.c
#include <stdint.h>
int a, b, c, d;
e() {
if (a)
;
else {
uint32_t *f = &d;
for (*f = 4; *f <= 33; *f += 1)
for (b = -27; b <= 48; b++) {
int16_t g;
int32_t *i = e;
(c -= 10) % (g = c ^= i != 0);
a &= b;
}
}
}
$clang -w -g -O3 small.c
//endless compiling
$clang -v
clang version 14.0.0 (<a href="https://github.com/llvm/llvm-project">https://github.com/llvm/llvm-project</a>
203cd01b54ddd720be17b8e19207ff5af4a22d4c)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /home/haoxin/haoxin-data/compilers/llvm-project/build/bin
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/9
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/9
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Candidate multilib: x32;@mx32
Selected multilib: .;@m64
Reproduced in Godbolt: <a href="https://godbolt.org/z/YacWx1fnE">https://godbolt.org/z/YacWx1fnE</a>
Thanks,
Haoxin</pre>
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