From 86becfd2de3feed66d41350c828391524a7b4052 Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Sat, 11 Nov 2017 15:44:23 -0800 Subject: [PATCH] intel/blorp: Add fast-clear to the special case in MSAA resolves This doesn't go all the way of avoiding the txf_ms if it's fast-cleared, however it does at least make us only do it once. This should improve performance of MSAA resolves in the presence of lots of clear color. Without the patch, enabling fast-clears in the multisampling Sascha demo drops the framerate by about 10%. With this patch, enabling fast-clears increases the demo's framerate by 25%. Reviewed-by: Lionel Landwerlin Reviewed-by: Nanley Chery --- src/intel/blorp/blorp_blit.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/src/intel/blorp/blorp_blit.c b/src/intel/blorp/blorp_blit.c index 19f6c363f1e..d119a99b31f 100644 --- a/src/intel/blorp/blorp_blit.c +++ b/src/intel/blorp/blorp_blit.c @@ -21,7 +21,7 @@ * IN THE SOFTWARE. */ -#include "compiler/nir/nir_builder.h" +#include "blorp_nir_builder.h" #include "blorp_priv.h" @@ -680,6 +680,11 @@ blorp_nir_manual_blend_average(nir_builder *b, struct brw_blorp_blit_vars *v, * ld2dms are equivalent (since all samples are on sample slice 0). * Since we have already sampled from sample 0, all we need to do is * skip the remaining fetches and averaging if MCS is zero. + * + * It's also trivial to detect when the MCS has the magic clear color + * value. In this case, the txf we did on sample 0 will return the + * clear color and we can skip the remaining fetches just like we do + * when MCS == 0. */ nir_ssa_def *mcs_zero = nir_ieq(b, nir_channel(b, mcs, 0), nir_imm_int(b, 0)); @@ -687,9 +692,11 @@ blorp_nir_manual_blend_average(nir_builder *b, struct brw_blorp_blit_vars *v, mcs_zero = nir_iand(b, mcs_zero, nir_ieq(b, nir_channel(b, mcs, 1), nir_imm_int(b, 0))); } + nir_ssa_def *mcs_clear = + blorp_nir_mcs_is_clear_color(b, mcs, tex_samples); nir_if *if_stmt = nir_if_create(b->shader); - if_stmt->condition = nir_src_for_ssa(mcs_zero); + if_stmt->condition = nir_src_for_ssa(nir_ior(b, mcs_zero, mcs_clear)); nir_cf_node_insert(b->cursor, &if_stmt->cf_node); b->cursor = nir_after_cf_list(&if_stmt->then_list);