<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#c37">Comment # 37</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:siglesias@igalia.com" title="Samuel Iglesias <siglesias@igalia.com>"> Samuel Iglesias</a> <pre>(In reply to Samuel Iglesias from <a href="show_bug.cgi?id=92760#c36">comment #36</a>) > (In reply to Samuel Iglesias from <a href="show_bug.cgi?id=92760#c35">comment #35</a>) > > I found i965 driver is currently running vec4 visitor and generator for > > geometry shaders and we have some crashed/failed tests due to its lack of > > support for doubles. After enabling scalar GS, piglit shows no regressions. > > > > I forgot to mention we are currently focusing on the scalar backend to fix > failed fp64 tests and running the tests on Broadwell (gen8) for now. > > By enabling scalar GS in Broadwell by default, we would take advantage of > our previous work to add support for doubles in the scalar backend. Thanks > to that work, scalar GS not only shows no regressions on piglit but also > passes the crashed/failed fp64's geometry shader tests we have seen with > vec4 backend. > > Then, my question is if we can enable scalar GS in Broadwell by default or > if there are reasons to keep it disabled. > > > I would like to know if there is a strong reason to disable scalar GS by > > default (perhaps I am missing something) because then we would need to add > > support for doubles in vec4. Oh, I did a wrong comparative of the piglit results: There are 11 piglit regressions when enabling scalar GS. Those regressions are unrelated to fp64 but they show why scalar GS was disabled by default in Broadwell: the instanced GS support. 7 regressions are related to a failed assert in brw_compile_gs(): assert(prog_data->invocations == 1). Removing that assert, they pass. Is instanced GS supported already in scalar backend? The other 4 regressions seem to be a different issue, but I have not analyzed it yet: shader_runner: brw_fs_nir.cpp:1813: void fs_visitor::emit_gs_input_load(const fs_reg&, const nir_src&, unsigned int, const nir_src&, unsigned int): Assertion `imm_offset == 0' failed.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>