<html>
<head>
<base href="https://bugs.freedesktop.org/" />
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - dEQP-GLES3: tanh produces incorrect results for some limit cases"
href="https://bugs.freedesktop.org/show_bug.cgi?id=89640">89640</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>dEQP-GLES3: tanh produces incorrect results for some limit cases
</td>
</tr>
<tr>
<th>Product</th>
<td>Mesa
</td>
</tr>
<tr>
<th>Version</th>
<td>git
</td>
</tr>
<tr>
<th>Hardware</th>
<td>Other
</td>
</tr>
<tr>
<th>OS</th>
<td>All
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>medium
</td>
</tr>
<tr>
<th>Component</th>
<td>Drivers/DRI/i965
</td>
</tr>
<tr>
<th>Assignee</th>
<td>idr@freedesktop.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>itoral@igalia.com
</td>
</tr>
<tr>
<th>QA Contact</th>
<td>intel-3d-bugs@lists.freedesktop.org
</td>
</tr></table>
<p>
<div>
<pre>List of affected tests:
dEQP-GLES3.functional.shaders.builtin_functions.precision.tanh.highp_vertex.scalar
dEQP-GLES3.functional.shaders.builtin_functions.precision.tanh.highp_vertex.vec2
dEQP-GLES3.functional.shaders.builtin_functions.precision.tanh.highp_vertex.vec3
dEQP-GLES3.functional.shaders.builtin_functions.precision.tanh.highp_vertex.vec4
dEQP-GLES3.functional.shaders.builtin_functions.precision.tanh.highp_fragment.scalar
dEQP-GLES3.functional.shaders.builtin_functions.precision.tanh.highp_fragment.vec2
dEQP-GLES3.functional.shaders.builtin_functions.precision.tanh.highp_fragment.vec3
dEQP-GLES3.functional.shaders.builtin_functions.precision.tanh.highp_fragment.vec4
tanh is implemented as:
body.emit(ret(div(sub(exp(x), exp(neg(x))),
add(exp(x), exp(neg(x))))));
For some values of x this leads to a infinity values in the denominator and
numerator. The division of such values leads to a NaN instead of 1.0 (the
result expected by dEQP and the result of tanh from libc too).
I suppose we can add as-hoc code to handle these cases and produce a result of
1.0 directly in software when we detect them, but I wonder if it is worth the
cost.</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are the QA Contact for the bug.</li>
</ul>
</body>
</html>