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<body><span class="vcard"><a class="email" href="mailto:mattst88@gmail.com" title="Matt Turner <mattst88@gmail.com>"> <span class="fn">Matt Turner</span></a>
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<a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - [i965] Alien: Isolation fails with GL_ARB_compute_shader enabled"
href="https://bugs.freedesktop.org/show_bug.cgi?id=93840">bug 93840</a>
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<td>mattst88@gmail.com
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<b><a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - [i965] Alien: Isolation fails with GL_ARB_compute_shader enabled"
href="https://bugs.freedesktop.org/show_bug.cgi?id=93840#c14">Comment # 14</a>
on <a class="bz_bug_link
bz_status_NEEDINFO "
title="NEEDINFO - [i965] Alien: Isolation fails with GL_ARB_compute_shader enabled"
href="https://bugs.freedesktop.org/show_bug.cgi?id=93840">bug 93840</a>
from <span class="vcard"><a class="email" href="mailto:mattst88@gmail.com" title="Matt Turner <mattst88@gmail.com>"> <span class="fn">Matt Turner</span></a>
</span></b>
<pre>Created <span class=""><a href="attachment.cgi?id=126122" name="attach_126122" title="patch">attachment 126122</a> <a href="attachment.cgi?id=126122&action=edit" title="patch">[details]</a></span> <a href='page.cgi?id=splinter.html&bug=93840&attachment=126122'>[review]</a>
patch
(In reply to Darius Spitznagel from <a href="show_bug.cgi?id=93840#c1">comment #1</a>)
<span class="quote">> Created <span class=""><a href="attachment.cgi?id=121746" name="attach_121746" title="Alien: Isolation GDB log">attachment 121746</a> <a href="attachment.cgi?id=121746&action=edit" title="Alien: Isolation GDB log">[details]</a></span>
> Alien: Isolation GDB log</span >
The memset() at line 935 of
a4cff18:src/mesa/drivers/dri/i965/brw_schedule_instructions.cpp is
<span class="quote">> memset(last_grf_write, 0, sizeof(last_grf_write));</span >
The backtrace shows
#1 0x00007fffe79015fe in memset (__len=482688, __ch=0, __dest=0x7fffa216e550)
at /usr/include/x86_64-linux-gnu/bits/string3.h:84
__len=482688?!
last_grf_write is sized as
<span class="quote">> schedule_node *last_grf_write[grf_count * 16];</span >
and 482688 / 16 is 30168. So we have 30168 virtual registers?!
I would very much like to see this shader... could you try to capture it with
MESA_SHADER_CAPTURE_PATH=/tmp/alienisolation [...] (after making that
directory)? It will write shaders to the directory, and I would expect the last
one it writes to be the one causing the trouble. :)
I expect the attached patch will fix it, though I'm not sure it's exactly what
we want to do. (Of course capture the shaders without this patch)</pre>
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