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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 - Compilation does not end when -O3 or more is set."
href="https://bugs.llvm.org/show_bug.cgi?id=40757">40757</a>
</td>
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<th>Summary</th>
<td>Compilation does not end when -O3 or more is set.
</td>
</tr>
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<th>Product</th>
<td>new-bugs
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>Linux
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>new bugs
</td>
</tr>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>ueno.masakazu@jp.fujitsu.com
</td>
</tr>
<tr>
<th>CC</th>
<td>htmldeveloper@gmail.com, llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>When compiling the following program(<a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [llvm-gcc] [meta] Make llvm-gcc4 completely replace llvm-gcc3"
href="show_bug.cgi?id=498">bug498</a>.c) with -O3 or more, compilation
does not end.
I think there is something wrong with Loop Strength Reduction Pass.
This problem can be avoided by the -mllvm -disable-lsr option.
* source program(<a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [llvm-gcc] [meta] Make llvm-gcc4 completely replace llvm-gcc3"
href="show_bug.cgi?id=498">bug498</a>.c)
#include <stdio.h>
int main () {
int i,j,l=0,m=3,n=40;
unsigned long v1=1,v2=2,v3=3;
int a[50][50],b[50][50];
for (i=0; i<50; i++) {
for (j=0; j<50; j++) {
a[i][j]=0;
b[i][j]=1;
}
}
for(i=0;i<10;i++) {
for (l=0; l<4; l++) {
for(m=0; m<30; m++) {
for(j=0;j<2;j++) {
v3=v2 * v2;
}
v1=v3 - v1;
v2=v1 - i;
b[i][j]=a[i][j]+b[i][j];
}
}
}
printf("%lu %lu %lu %d\n",v1,v2,v3, b[0][0]);
return 0;
}
* compile/exec log using -mllvm -disable-lsr option
$ clang -O3 <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [llvm-gcc] [meta] Make llvm-gcc4 completely replace llvm-gcc3"
href="show_bug.cgi?id=498">bug498</a>.c -mllvm -disable-lsr
$ ./a.out
12145924650467887591 12145924650467887582 3040934746218291456 1</pre>
</div>
</p>
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