<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [llvmpipe] piglit linestipple regression" href="https://bugs.freedesktop.org/show_bug.cgi?id=96518#c1">Comment # 1</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [llvmpipe] piglit linestipple regression" href="https://bugs.freedesktop.org/show_bug.cgi?id=96518">bug 96518</a> from <a class="email" href="mailto:sroland@vmware.com" title="Roland Scheidegger <sroland@vmware.com>"> Roland Scheidegger</a> <pre>I suppose I missed that when I did a piglit run... This is fairly interesting, it seems to be due to inaccurate float math. The stipple code gets for position x0,x1 10.5, 34.5 leading to a length 24. However, with the MADs used for vertex transform replaced by fmas, I get position 10.500002, 34.500000 instead. Hence length 23.999998. And subsequently patterns getting different (I think it makes no difference on the first segment, but the second due to the stipple->counter += length line). Not sure though why the results would be seemingly less accurate with fma. (And not sure there shouldn't be some different behavior wrt rounding in the line stipple code?)</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>