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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Decreasing for loops over shared arrays hang the GPU (GEN9)"
href="https://bugs.freedesktop.org/show_bug.cgi?id=100134">100134</a>
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<th>Summary</th>
<td>Decreasing for loops over shared arrays hang the GPU (GEN9)
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<th>Product</th>
<td>Mesa
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<th>Version</th>
<td>13.0
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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
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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/Vulkan/intel
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<th>Assignee</th>
<td>intel-3d-bugs@lists.freedesktop.org
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<th>Reporter</th>
<td>freiling@google.com
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<th>QA Contact</th>
<td>intel-3d-bugs@lists.freedesktop.org
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<th>CC</th>
<td>jason@jlekstrand.net
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<div>
<pre>Created <span class=""><a href="attachment.cgi?id=130135" name="attach_130135" title="Offending SPIR-V">attachment 130135</a> <a href="attachment.cgi?id=130135&action=edit" title="Offending SPIR-V">[details]</a></span>
Offending SPIR-V
We have a very simple glsl compute shader which hangs gen9
#version 450
#extension GL_ARB_separate_shader_objects : enable
shared int roi[8];
void main() {
for (uint i = 7; i >= 0; i--) {
roi[i] = 1;
}
}
Heres some things we know about it
-changing the loop condition to "for (uint i = 0; i < 8; i++)" fixes the
problem
-making roi a function scoped "local" variable fixes the problem
-the spir-v we get out of GLSLang looks legit afaict (attached for your
reference)
-the same spir-v works on nvidia
Let us know if you have any questions.
Forrest</pre>
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