Meta's GenerateMipmap implementation binds the same image for both sampling and rendering - but it samples from one miplevel while rendering the next. This is a false self-dependency, and there's no need to disable auxiliary buffers in this case. In fact, we really want to leave it enabled so the new miplevels gain color compression.
Thankfully, the texture object's _MaxLevel is always one shy of the miplevel being rendered. So we can simply check if irb->mt_level is overlaps with the texture's defined levels. If not, there's no self- dependency and we can leave the auxiliary buffers enabled. Fixes a performance regression in GFXBench4 Car Chase, which apparently calls glGenerateMipmap() on every frame. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103247 --- src/mesa/drivers/dri/i965/brw_draw.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_draw.c b/src/mesa/drivers/dri/i965/brw_draw.c index 51e2a26ca2f..a4c042f3f4f 100644 --- a/src/mesa/drivers/dri/i965/brw_draw.c +++ b/src/mesa/drivers/dri/i965/brw_draw.c @@ -344,6 +344,7 @@ brw_merge_inputs(struct brw_context *brw, static bool intel_disable_rb_aux_buffer(struct brw_context *brw, struct intel_mipmap_tree *tex_mt, + unsigned min_level, unsigned num_levels, const char *usage) { const struct gl_framebuffer *fb = brw->ctx.DrawBuffer; @@ -358,7 +359,9 @@ intel_disable_rb_aux_buffer(struct brw_context *brw, const struct intel_renderbuffer *irb = intel_renderbuffer(fb->_ColorDrawBuffers[i]); - if (irb && irb->mt->bo == tex_mt->bo) { + if (irb && irb->mt->bo == tex_mt->bo && + irb->mt_level >= min_level && + irb->mt_level < min_level + num_levels) { found = brw->draw_aux_buffer_disabled[i] = true; } } @@ -414,7 +417,8 @@ brw_predraw_resolve_inputs(struct brw_context *brw) } const bool disable_aux = - intel_disable_rb_aux_buffer(brw, tex_obj->mt, "for sampling"); + intel_disable_rb_aux_buffer(brw, tex_obj->mt, min_level, num_levels, + "for sampling"); intel_miptree_prepare_texture(brw, tex_obj->mt, view_format, min_level, num_levels, @@ -440,7 +444,7 @@ brw_predraw_resolve_inputs(struct brw_context *brw) tex_obj = intel_texture_object(u->TexObj); if (tex_obj && tex_obj->mt) { - intel_disable_rb_aux_buffer(brw, tex_obj->mt, + intel_disable_rb_aux_buffer(brw, tex_obj->mt, 0, ~0, "as a shader image"); intel_miptree_prepare_image(brw, tex_obj->mt); -- 2.14.2 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
