Mesa (master): intel: Only prefer separate stencil when we can do HiZ.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: 5c9a55665d78b96bfb8ce8eab43b5558dd656a6d
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=5c9a55665d78b96bfb8ce8eab43b5558dd656a6d

Author: Eric Anholt <eric at anholt.net>
Date:   Wed Nov 30 08:52:54 2011 -0800

intel: Only prefer separate stencil when we can do HiZ.

This required is_hiz_depth_format to start returning true on S8_Z24 as
well, since that's the format we have here.  The two previous callers
are only calling it on non-depthstencil formats.

This avoids us needing to have HiZ working on a new Z format
immediately upon exposing the format (particularly painful for
Z32_FLOAT_X24S8, which means all the fake packed depth/stencil paths).

Reviewed-by: Chad Versace <chad.versace at linux.intel.com>

---

 src/mesa/drivers/dri/i965/brw_vtbl.c           |   12 ++++++++++--
 src/mesa/drivers/dri/intel/intel_mipmap_tree.c |    6 ++++--
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_vtbl.c b/src/mesa/drivers/dri/i965/brw_vtbl.c
index dd2e05a..c0a0b52 100644
--- a/src/mesa/drivers/dri/i965/brw_vtbl.c
+++ b/src/mesa/drivers/dri/i965/brw_vtbl.c
@@ -214,8 +214,16 @@ static void brw_invalidate_state( struct intel_context *intel, GLuint new_state
 static bool brw_is_hiz_depth_format(struct intel_context *intel,
                                     gl_format format)
 {
-   /* In the future, this will support Z_FLOAT32. */
-   return intel->has_hiz && (format == MESA_FORMAT_X8_Z24);
+   if (!intel->has_hiz)
+      return false;
+
+   switch (format) {
+   case MESA_FORMAT_X8_Z24:
+   case MESA_FORMAT_S8_Z24:
+      return true;
+   default:
+      return false;
+   }
 }
 
 void brwInitVtbl( struct brw_context *brw )
diff --git a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
index f8ef262..3e4baa1 100644
--- a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
+++ b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
@@ -119,8 +119,10 @@ intel_miptree_create_internal(struct intel_context *intel,
    brw_miptree_layout(intel, mt);
 #endif
 
-   if (intel->has_separate_stencil &&
-       _mesa_is_depthstencil_format(_mesa_get_format_base_format(format))) {
+   if (_mesa_is_depthstencil_format(_mesa_get_format_base_format(format)) &&
+       (intel->must_use_separate_stencil ||
+	(intel->has_separate_stencil &&
+	 intel->vtbl.is_hiz_depth_format(intel, format)))) {
       mt->stencil_mt = intel_miptree_create(intel,
                                             mt->target,
                                             MESA_FORMAT_S8,