Mesa (master): i965/blorp: Prepare blits for lossless compression

[Topi Pohjolainen]

Module: Mesa
Branch: master
Commit: 01ba26d0b0eb4c31d6c89f8f45eb551d9ba56610
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=01ba26d0b0eb4c31d6c89f8f45eb551d9ba56610

Author: Topi Pohjolainen <topi.pohjolainen at intel.com>
Date:   Mon Apr 18 08:51:10 2016 +0300

i965/blorp: Prepare blits for lossless compression

Signed-off-by: Topi Pohjolainen <topi.pohjolainen at intel.com>
Reviewed-by: Ben Widawsky <ben at bwidawsk.net>

---

 src/mesa/drivers/dri/i965/brw_blorp.c        |  2 +-
 src/mesa/drivers/dri/i965/brw_blorp_blit.cpp | 26 +++++++++++++++++++++-----
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_blorp.c b/src/mesa/drivers/dri/i965/brw_blorp.c
index 247fd75..85402aa 100644
--- a/src/mesa/drivers/dri/i965/brw_blorp.c
+++ b/src/mesa/drivers/dri/i965/brw_blorp.c
@@ -43,7 +43,7 @@ brw_blorp_surface_info_init(struct brw_context *brw,
     */
    if (mt->msaa_layout == INTEL_MSAA_LAYOUT_UMS ||
        mt->msaa_layout == INTEL_MSAA_LAYOUT_CMS) {
-      assert(layer % mt->num_samples == 0);
+      assert(mt->num_samples <= 1 || layer % mt->num_samples == 0);
    }
 
    intel_miptree_check_level_layer(mt, level, layer);
diff --git a/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp b/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
index e270540..f26701d 100644
--- a/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
+++ b/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
@@ -1824,6 +1824,14 @@ compute_msaa_layout_for_pipeline(struct brw_context *brw, unsigned num_samples,
                                  intel_msaa_layout true_layout)
 {
    if (num_samples <= 1) {
+      /* Layout is used to determine if ld2dms is needed for sampling. In
+       * single sampled case normal ld is enough avoiding also the need to
+       * fetch mcs. Therefore simply set the layout to none.
+       */
+      if (brw->gen >= 9 && true_layout == INTEL_MSAA_LAYOUT_CMS) {
+         return INTEL_MSAA_LAYOUT_NONE;
+      }
+
       /* When configuring the GPU for non-MSAA, we can still accommodate IMS
        * format buffers, by transforming coordinates appropriately.
        */
@@ -1870,12 +1878,7 @@ brw_blorp_blit_miptrees(struct brw_context *brw,
     * the destination buffer because we use the standard render path to render
     * to destination color buffers, and the standard render path is
     * fast-color-aware.
-    * Lossless compression is only introduced for gen9 onwards whereas
-    * blorp is not supported even for gen8. Therefore it should be impossible
-    * to end up here with single sampled compressed surfaces.
     */
-   assert(!intel_miptree_is_lossless_compressed(brw, src_mt));
-   assert(!intel_miptree_is_lossless_compressed(brw, dst_mt));
    intel_miptree_resolve_color(brw, src_mt, 0);
    intel_miptree_slice_resolve_depth(brw, src_mt, src_level, src_layer);
    intel_miptree_slice_resolve_depth(brw, dst_mt, dst_level, dst_layer);
@@ -2060,6 +2063,19 @@ brw_blorp_blit_miptrees(struct brw_context *brw,
    wm_prog_key.src_layout = src_mt->msaa_layout;
    wm_prog_key.dst_layout = dst_mt->msaa_layout;
 
+   /* On gen9+ compressed single sampled buffers carry the same layout type as
+    * multisampled. The difference is that they can be sampled using normal
+    * ld message and as render target behave just like non-compressed surface
+    * from compiler point of view. Therefore override the type in the program
+    * key.
+    */
+   if (brw->gen >= 9 && params.src.num_samples <= 1 &&
+       src_mt->msaa_layout == INTEL_MSAA_LAYOUT_CMS)
+      wm_prog_key.src_layout = INTEL_MSAA_LAYOUT_NONE;
+   if (brw->gen >= 9 && params.dst.num_samples <= 1 &&
+       dst_mt->msaa_layout == INTEL_MSAA_LAYOUT_CMS)
+      wm_prog_key.dst_layout = INTEL_MSAA_LAYOUT_NONE;
+
    wm_prog_key.src_tiled_w = params.src.map_stencil_as_y_tiled;
    wm_prog_key.dst_tiled_w = params.dst.map_stencil_as_y_tiled;
    /* Round floating point values to nearest integer to avoid "off by one texel"