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<body><span class="vcard"><a class="email" href="mailto:idr@freedesktop.org" title="Ian Romanick <idr@freedesktop.org>"> <span class="fn">Ian Romanick</span></a>
</span> changed
<a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - GLSL IR copy propagates loads of SSBOs"
href="https://bugs.freedesktop.org/show_bug.cgi?id=106774">bug 106774</a>
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<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>What</th>
<th>Removed</th>
<th>Added</th>
</tr>
<tr>
<td style="text-align:right;">CC</td>
<td>
</td>
<td>idr@freedesktop.org, michel@daenzer.net
</td>
</tr>
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<td style="text-align:right;">Status</td>
<td>NEW
</td>
<td>RESOLVED
</td>
</tr>
<tr>
<td style="text-align:right;">Resolution</td>
<td>---
</td>
<td>FIXED
</td>
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<b><a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - GLSL IR copy propagates loads of SSBOs"
href="https://bugs.freedesktop.org/show_bug.cgi?id=106774#c18">Comment # 18</a>
on <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - GLSL IR copy propagates loads of SSBOs"
href="https://bugs.freedesktop.org/show_bug.cgi?id=106774">bug 106774</a>
from <span class="vcard"><a class="email" href="mailto:idr@freedesktop.org" title="Ian Romanick <idr@freedesktop.org>"> <span class="fn">Ian Romanick</span></a>
</span></b>
<pre>This bug should be fixed by the commits listed below.
(In reply to Michel Dänzer from <a href="show_bug.cgi?id=106774#c10">comment #10</a>)
<span class="quote">> Please don't add piglit tests which are expected to hang the GPU, or at
> least don't set them up to be run by default. Not all drivers can reliably
> recover from GPU hangs.</span >
The updated test does not cause GPU hangs with these patches applied. Are you
ok with the test landing in piglit master?
commit 37bd9ccd21b860d2b5ffea7e1f472ec83b68b43b (HEAD -> bug-106774,
origin/master, origin/HEAD)
Author: Ian Romanick <<a href="mailto:ian.d.romanick@intel.com">ian.d.romanick@intel.com</a>>
Date: Tue Jun 5 16:02:25 2018 -0700
glsl: Don't copy propagate elements from SSBO or shared variables either
Since SSBOs can be written by a different GPU thread, copy propagating a
read can cause the value to magically change. SSBO reads are also very
expensive, so doing it twice will be slower.
The same shader was helped by this patch and the previous.
Haswell, Broadwell, and Skylake had similar results. (Skylake shown)
total instructions in shared programs: 14399119 -> 14399113 (<.01%)
instructions in affected programs: 683 -> 677 (-0.88%)
helped: 1
HURT: 0
total cycles in shared programs: 532973113 -> 532971865 (<.01%)
cycles in affected programs: 524666 -> 523418 (-0.24%)
helped: 1
HURT: 0
Signed-off-by: Ian Romanick <<a href="mailto:ian.d.romanick@intel.com">ian.d.romanick@intel.com</a>>
Reviewed-by: Caio Marcelo de Oliveira Filho <<a href="mailto:caio.oliveira@intel.com">caio.oliveira@intel.com</a>>
Cc: <a href="mailto:mesa-stable@lists.freedesktop.org">mesa-stable@lists.freedesktop.org</a>
Bugzilla: <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - GLSL IR copy propagates loads of SSBOs"
href="show_bug.cgi?id=106774">https://bugs.freedesktop.org/show_bug.cgi?id=106774</a>
commit 461a5c899c08064467abb635536381a5a5659280
Author: Ian Romanick <<a href="mailto:ian.d.romanick@intel.com">ian.d.romanick@intel.com</a>>
Date: Tue Jun 5 15:04:24 2018 -0700
glsl: Don't copy propagate from SSBO or shared variables either
Since SSBOs can be written by other GPU threads, copy propagating a read
can cause the value to magically change. SSBO reads are also very
expensive, so doing it twice will be slower.
Haswell, Broadwell, and Skylake had similar results. (Skylake shown)
total instructions in shared programs: 14399120 -> 14399119 (<.01%)
instructions in affected programs: 684 -> 683 (-0.15%)
helped: 1
HURT: 0
total cycles in shared programs: 532978931 -> 532973113 (<.01%)
cycles in affected programs: 530484 -> 524666 (-1.10%)
helped: 1
HURT: 0
Signed-off-by: Ian Romanick <<a href="mailto:ian.d.romanick@intel.com">ian.d.romanick@intel.com</a>>
Reviewed-by: Caio Marcelo de Oliveira Filho <<a href="mailto:caio.oliveira@intel.com">caio.oliveira@intel.com</a>>
Cc: <a href="mailto:mesa-stable@lists.freedesktop.org">mesa-stable@lists.freedesktop.org</a>
Bugzilla: <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - GLSL IR copy propagates loads of SSBOs"
href="show_bug.cgi?id=106774">https://bugs.freedesktop.org/show_bug.cgi?id=106774</a></pre>
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