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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 - clang miscompiles with polly and newgvn at -O2 on valid code"
href="https://bugs.llvm.org/show_bug.cgi?id=38358">38358</a>
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<th>Summary</th>
<td>clang miscompiles with polly and newgvn at -O2 on valid code
</td>
</tr>
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<th>Product</th>
<td>Polly
</td>
</tr>
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<th>Version</th>
<td>unspecified
</td>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>All
</td>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
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<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>Optimizer
</td>
</tr>
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<th>Assignee</th>
<td>polly-dev@googlegroups.com
</td>
</tr>
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<th>Reporter</th>
<td>helloqirun@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
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<p>
<div>
<pre>Affected Polly version (hash tag) is: cdc7133937ea02211ebfeddab9be3ae7ff27229d
It miscompiles with both polly and newgvn enabled.
$ clang-trunk -v
clang version 7.0.0 (trunk 338211)
$ clang-trunk -mllvm -polly -mllvm -enable-newgvn -O2 abc.c ; ./a.out
1
$ clang-trunk -mllvm -polly -O2 abc.c ; ./a.out
0
$ clang-trunk -mllvm -enable-newgvn -O2 abc.c ; ./a.out
0
$ clang-trunk abc.c ; ./a.out
0
$ cat abc.c
void printf();
int a[56];
int b = 1, e = 3;
static int *c = &b;
char d;
short f;
int main() {
int g = 0;
for (; g < 56; g++)
a[g] = g;
int h = e;
e = 2;
for (; e > -19; e--) {
f = 1 & h;
if (f)
for (; d != 8; --d)
*c = 0;
}
printf("%X\n", b);
}</pre>
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