radeonsi/gfx9: update & clean up a DPBB heuristic

Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>

diff --git a/src/gallium/drivers/radeonsi/si_state_binning.c b/src/gallium/drivers/radeonsi/si_state_binning.c
index 6877cc0a62dc66fe9e4222a0f87e70a7fab56a77..19b403f9bd8e70b913cad14c351974ec6b92b00d 100644 (file)
--- a/src/gallium/drivers/radeonsi/si_state_binning.c
+++ b/src/gallium/drivers/radeonsi/si_state_binning.c
@@ -339,18 +339,14 @@ void si_emit_dpbb_state(struct si_context *sctx)
                           G_02880C_COVERAGE_TO_MASK_ENABLE(db_shader_control) ||
                           blend->alpha_to_coverage;
 
-       /* This is ported from Vulkan, but it doesn't make much sense to me.
-        * Maybe it's for RE-Z? But Vulkan doesn't use RE-Z. TODO: Clarify this.
-        */
-       bool ps_can_reject_z_trivially =
+       bool db_can_reject_z_trivially =
                !G_02880C_Z_EXPORT_ENABLE(db_shader_control) ||
-               G_02880C_CONSERVATIVE_Z_EXPORT(db_shader_control);
+               G_02880C_CONSERVATIVE_Z_EXPORT(db_shader_control) ||
+               G_02880C_DEPTH_BEFORE_SHADER(db_shader_control);
 
-       /* Disable binning if PS can kill trivially with DB writes.
-        * Ported from Vulkan. (heuristic?)
-        */
+       /* Disable DPBB when it's believed to be inefficient. */
        if (ps_can_kill &&
-           ps_can_reject_z_trivially &&
+           db_can_reject_z_trivially &&
            sctx->framebuffer.state.zsbuf &&
            dsa->db_can_write) {
                si_emit_dpbb_disable(sctx);