<html>
<head>
<base href="https://bugs.freedesktop.org/" />
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Priority</th>
<td>medium
</td>
</tr>
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - GLSL: vectorize optimization goes wrong on dot products"
href="https://bugs.freedesktop.org/show_bug.cgi?id=75224">75224</a>
</td>
</tr>
<tr>
<th>Assignee</th>
<td>idr@freedesktop.org
</td>
</tr>
<tr>
<th>Summary</th>
<td>GLSL: vectorize optimization goes wrong on dot products
</td>
</tr>
<tr>
<th>QA Contact</th>
<td>intel-3d-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr>
<tr>
<th>OS</th>
<td>All
</td>
</tr>
<tr>
<th>Reporter</th>
<td>aras@unity3d.com
</td>
</tr>
<tr>
<th>Hardware</th>
<td>All
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Version</th>
<td>git
</td>
</tr>
<tr>
<th>Component</th>
<td>glsl-compiler
</td>
</tr>
<tr>
<th>Product</th>
<td>Mesa
</td>
</tr></table>
<p>
<div>
<pre>"Vectorize multiple scalar assignments" optimization (added in 4bd6e0d7c69 on
master) goes wrong on dot products.
For example, on a fragment shader like this:
varying vec3 inA;
varying vec2 inB;
void main()
{
vec2 v;
v.x = dot(inA.xy, inB);
v.y = dot(inA.yz, inB);
gl_FragColor = vec4(v.x, v.y, 0.0, 1.0);
}
It produces two problems:
1) tries to vectorize both dots into a v=dot(inA.xy,inB), which is different
result.
2) in the result it ends up with an expression node of vec2 type, but a
ir_binop_dot operation. asserts in ir_validate in debug build.
It feels like these kinds of "horizontal" operations (probably only dot?)
shouldn't be attempted to vectorize.</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>