<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - Add FP64 support to the i965 shader backends" href="https://bugs.freedesktop.org/show_bug.cgi?id=92760#c85">Comment # 85</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - Add FP64 support to the i965 shader backends" href="https://bugs.freedesktop.org/show_bug.cgi?id=92760">bug 92760</a> from <a class="email" href="mailto:currojerez@riseup.net" title="Francisco Jerez <currojerez@riseup.net>"> Francisco Jerez</a> <pre>(In reply to Francisco Jerez from <a href="show_bug.cgi?id=92760#c84">comment #84</a>) >[...] > >> - Class A (48/256 swizzles) can be subdivided into: > >> - Class A+ (12/256 swizzles) which can always be supported > >> natively. It applies for swizzles such that the first and third > >> components pair up correctly and the second and fourth components > >> pair up as well -- To be more precise, two swizzle components i > >> and j are said to "pair up" correctly if they are equal modulo > >> two, i.e. if they refer to the same subcomponent within the oword > >> they refer to respectively -- E.g. x pairs up with z and y pairs > >> up with w. > > > > As far as I understand, some of these don't need the vstride trick (like XYZW, > > which we can represent with a region like <2,2,1>.xyzw:df) while others do > > (like XYXY, which would need something like <0,2,1>.xyzw:df) > > > > Yeah, it depends on whether the second pair of vector components of the > instruction map to the same oword of the input (in which case you need > the trick) or a different one (in which case you don't). Er, that sentence should have read "it depends on whether the first and second pairs of vector components...", also sorry for the weird line wrapping -- Should have used the preview function before saving. ;) >[...] ></pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>