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<body><span class="vcard"><a class="email" href="mailto:kenneth@whitecape.org" title="Kenneth Graunke <kenneth@whitecape.org>"> <span class="fn">Kenneth Graunke</span></a>
</span> changed
<a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - fp64 division gives imprecise results"
href="https://bugs.freedesktop.org/show_bug.cgi?id=110435">bug 110435</a>
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<tr>
<th>What</th>
<th>Removed</th>
<th>Added</th>
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<td style="text-align:right;">Status</td>
<td>NEW
</td>
<td>RESOLVED
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<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 - fp64 division gives imprecise results"
href="https://bugs.freedesktop.org/show_bug.cgi?id=110435#c6">Comment # 6</a>
on <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - fp64 division gives imprecise results"
href="https://bugs.freedesktop.org/show_bug.cgi?id=110435">bug 110435</a>
from <span class="vcard"><a class="email" href="mailto:kenneth@whitecape.org" title="Kenneth Graunke <kenneth@whitecape.org>"> <span class="fn">Kenneth Graunke</span></a>
</span></b>
<pre>Thanks for the fix! Fixed by:
commit 974c4d679c23373dbed386c696e3e3bc1bfa23ae
Author: Ruslan Kabatsayev <<a href="mailto:b7.10110111@gmail.com">b7.10110111@gmail.com</a>>
Date: Sat May 11 14:04:36 2019 +0300
nir: Fix wrong sign in lower_rcp
The nested fma calls were supposed to implement
x_new = x + x * (1 - x*src),
but instead current code is equivalent to
x_new = x - x * (1 - x*src).
The result is that Newton-Raphson steps don't improve precision at all.
This patch fixes this problem.
Bugzilla: <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - fp64 division gives imprecise results"
href="show_bug.cgi?id=110435">https://bugs.freedesktop.org/show_bug.cgi?id=110435</a>
Reviewed-by: Kenneth Graunke <<a href="mailto:kenneth@whitecape.org">kenneth@whitecape.org</a>></pre>
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