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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 - compile-time explosion with assumes at -O1"
href="https://bugs.llvm.org/show_bug.cgi?id=49475">49475</a>
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</tr>
<tr>
<th>Summary</th>
<td>compile-time explosion with assumes at -O1
</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>All
</td>
</tr>
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<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.
This program, small.c, makes Clang-trunk hung on with -O1 at compile time.
$cat small.c
#include <stdint.h>
int a;
void b() {
int c;
uint16_t d;
uint64_t e;
if (d = a) {
uint8_t *f;
for (;;) {
for (; *f;)
f = &d;
uint8_t g = &e;
}
}
for (;;) {
int8_t i;
int32_t j;
int64_t k;
if (a) {
int64_t *l = &e;
j = e - (*l = 0);
for (; i; i++) {
int32_t *m = &j;
k ^= a & (5 ? j || d : 0);
if (d |= (k |= e &= a) >= i - *m)
for (c = 3; c; c)
;
}
}
}
}
$clang -w -c -O1 small.c
//endless compiling
#clang -v
clang version 13.0.0 (<a href="https://github.com/llvm/llvm-project">https://github.com/llvm/llvm-project</a>
a968e7b82eac364d411c81aae58722a0b3a4b29c)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir:
/home/haoxin/haoxin-data/dut-research/compilers/llvm-project/build-20210304/bin
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Candidate multilib: .;@m64
Selected multilib: .;@m64
Thanks,
Haoxin</pre>
</div>
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