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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - The cure for all kinds of weirdness caused by list defects in release builds"
href="https://bugs.freedesktop.org/show_bug.cgi?id=91320">91320</a>
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<th>Summary</th>
<td>The cure for all kinds of weirdness caused by list defects in release builds
</td>
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<th>Product</th>
<td>Mesa
</td>
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<th>Version</th>
<td>git
</td>
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<th>Hardware</th>
<td>Other
</td>
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<th>OS</th>
<td>All
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>normal
</td>
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<th>Priority</th>
<td>medium
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<th>Component</th>
<td>glsl-compiler
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<th>Assignee</th>
<td>idr@freedesktop.org
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<th>Reporter</th>
<td>tschwinger@isonews2.com
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<th>QA Contact</th>
<td>intel-3d-bugs@lists.freedesktop.org
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<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=117080" name="attach_117080" title="exec_list fix for optimizing compilers">attachment 117080</a> <a href="attachment.cgi?id=117080&action=edit" title="exec_list fix for optimizing compilers">[details]</a></span>
exec_list fix for optimizing compilers
Observed:
Segfaulting and optimization passes that fail to terminate. Problems were
observed with both GCC and Clang.
Expected:
None of it.
Analysis:
Optimizing compilers will ignore modification through the sentinel nodes cast
from the list structure.
Code like
while (! list.is_empty()) ... list.pop_head(); ...
breaks, because the compiler assumes that the list structure doesn't change.
Fix:
Good old Amiga-style lists can still work with modern, optimizing compilers as
long as they are told to check for side effects on the sentinels' respective
next / prev pointers. See contained patch - it's actually quite simple and
should leave most optimizations intact.</pre>
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