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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - gl_TessLevel* writes have no effect for all but the last TCS invocation"
href="https://bugs.freedesktop.org/show_bug.cgi?id=91461">91461</a>
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<th>Summary</th>
<td>gl_TessLevel* writes have no effect for all but the last TCS invocation
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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
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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>Drivers/Gallium/radeonsi
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<th>Assignee</th>
<td>dri-devel@lists.freedesktop.org
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<th>Reporter</th>
<td>daniel@constexpr.org
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<th>QA Contact</th>
<td>dri-devel@lists.freedesktop.org
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<pre>The tessellator ignores all writes to gl_TessLevelInner and gl_TessLevelOuter
by the tessellation control shader except except those done by the last TCS
invocation (gl_InvocationID == patch output vertices - 1).
This results in no primitives being generated unless all entries of
gl_TessLevelOuter are written in that invocation (the 'initial' values seem to
be 0 for gl_TessLevelOuter and 1 for gl_TessLevelInner).
Additionally, barrier() does not synchronize changes to the gl_TessLevel*
between TCS invocations.
Neither of these problems can be reproduced with user-defined 'patch out'
variables - writes by any TCS invocation are visible in the evaluation shader
and barrier() makes them visible to the other TCS invocations.
GPU: Radeon HD 7950 (TAHITI)
Mesa: 10.7.0-devel (git-9deb614)
LLVM: r243203</pre>
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