<html>
<head>
<base href="https://bugs.freedesktop.org/" />
</head>
<body>
<p>
<div>
<b><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - [SNB]Piglit spec_arb_shading_language_packing_execution_built-in-functions_fs-packSnorm4x8 fails"
href="https://bugs.freedesktop.org/show_bug.cgi?id=81150#c3">Comment # 3</a>
on <a class="bz_bug_link
bz_status_NEW "
title="NEW --- - [SNB]Piglit spec_arb_shading_language_packing_execution_built-in-functions_fs-packSnorm4x8 fails"
href="https://bugs.freedesktop.org/show_bug.cgi?id=81150">bug 81150</a>
from <span class="vcard"><a class="email" href="mailto:neil@linux.intel.com" title="Neil Roberts <neil@linux.intel.com>"> <span class="fn">Neil Roberts</span></a>
</span></b>
<pre>Glenn Kennard on IRC pointed out that setting bit 22 like that resembles a NaN
value getting munged when loading and storing through a floating-point
register. Indeed if I write a quick test that does fld and fst with 0x7f817f81
it comes out as 0x7fc17f81. I guess this works on 64-bit because that will use
SSE which apparently doesn't try to fix up NaNs on store. It also gets fixed on
the 32-bit SandyBridge build if I use -mfpmath=sse and -msse2.</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>