[Mesa-dev] [PATCH] i965/skl: Use more compact hiz dimensions

[Ben Widawsky]

gen8 had some special restrictions which don't seem to carry over to gen9.
Quoting the spec for SKL:
"The Z_Height and Z_Width values must equal those present in
3DSTATE_DEPTH_BUFFER incremented by one."

This fixes nothing in piglit (and regresses nothing).

Cc: Jordan Justen <jordan.l.justen at intel.com>
Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
 src/mesa/drivers/dri/i965/intel_mipmap_tree.c | 32 ++++++++++++++-------------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
index 6aa969a..432a47c 100644
--- a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
+++ b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
@@ -1550,21 +1550,23 @@ intel_gen8_hiz_buf_create(struct brw_context *brw,
    /* Gen7 PRM Volume 2, Part 1, 11.5.3 "Hierarchical Depth Buffer" documents
     * adjustments required for Z_Height and Z_Width based on multisampling.
     */
-   switch (mt->num_samples) {
-   case 0:
-   case 1:
-      break;
-   case 2:
-   case 4:
-      z_width *= 2;
-      z_height *= 2;
-      break;
-   case 8:
-      z_width *= 4;
-      z_height *= 2;
-      break;
-   default:
-      unreachable("unsupported sample count");
+   if (brw->gen < 9) {
+      switch (mt->num_samples) {
+      case 0:
+      case 1:
+         break;
+      case 2:
+      case 4:
+         z_width *= 2;
+         z_height *= 2;
+         break;
+      case 8:
+         z_width *= 4;
+         z_height *= 2;
+         break;
+      default:
+         unreachable("unsupported sample count");
+      }
    }
 
    const unsigned vertical_align = 8; /* 'j' in the docs */
-- 
2.4.4