<div dir="ltr"><div>Reviewed-by: Jason Ekstrand <<a href="mailto:jason@jlekstrand.net">jason@jlekstrand.net</a>> </div>Ken? </div><div class="gmail_extra"> <div class="gmail_quote">On Wed, Jan 3, 2018 at 6:55 PM, Iago Toral Quiroga <<a href="mailto:itoral@igalia.com" target="_blank">itoral@igalia.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Although on gen8+ platforms we can in theory use 3DSTATE_VF_SGVS to put these beyond the last vertex element it seems that we still need to allocate the SVGS element, otherwise we have observed cases where we end up reading garbage. Specifically, the CTS test mentioned below was flaky with a fail rate of ~1% on some gen9+ platforms caused by reading garbage for the gl_InstanceID value. The flakyness goes away as soon as we start allocating the SVGS element. v2: - Do this for gen8+, not just gen9+, and pull the boolean outside the #if block (Jason) Fixes flaky test: KHR-GL45.vertex_attrib_64bit.limits_test Bugzilla: <a href="https://bugs.freedesktop.org/show_bug.cgi?id=104335" rel="noreferrer" target="_blank">https://bugs.freedesktop.org/show_bug.cgi?id=104335</a> --- src/mesa/drivers/dri/i965/genX_state_upload.c | 17 ++--------------- 1 file changed, 2 insertions(+), 15 deletions(-) diff --git a/src/mesa/drivers/dri/i965/genX_state_upload.c b/src/mesa/drivers/dri/i965/genX_state_upload.c index 50ac5bc59f..d0a980f973 100644 --- a/src/mesa/drivers/dri/i965/genX_state_upload.c +++ b/src/mesa/drivers/dri/i965/genX_state_upload.c @@ -486,26 +486,13 @@ genX(emit_vertices)(struct brw_context *brw) } else { brw_batch_emit(brw, GENX(3DSTATE_VF_SGVS), vfs); } +#endif - /* Normally we don't need an element for the SGVS attribute because the - * 3DSTATE_VF_SGVS instruction lets you store the generated attribute in an - * element that is past the list in 3DSTATE_VERTEX_ELEMENTS. However if - * we're using draw parameters then we need an element for the those - * values. Additionally if there is an edge flag element then the SGVS - * can't be inserted past that so we need a dummy element to ensure that - * the edge flag is the last one. - */ - const bool needs_sgvs_element = (vs_prog_data->uses_basevertex || - vs_prog_data->uses_baseinstance || - ((vs_prog_data->uses_instanceid || - vs_prog_data->uses_vertexid) - && uses_edge_flag)); -#else const bool needs_sgvs_element = (vs_prog_data->uses_basevertex || vs_prog_data->uses_baseinstance || vs_prog_data->uses_instanceid || vs_prog_data->uses_vertexid); -#endif + unsigned nr_elements = brw->vb.nr_enabled + needs_sgvs_element + vs_prog_data->uses_drawid; -- 2.11.0 </blockquote></div> </div>