intel: Replace checks for hiz_mt with intel_has*hiz()

When appropriate, replace each check `hiz_mt != NULL` with either a call
to intel_miptree_slice_has_hiz() or intel_renderbuffer_has_hiz().  No
behavioral change.

This prepares for selectively enabling hiz on individual miptree slices
for Haswell.

This refactoring had several side effects.

  1. To prevent new warnings about discarding the const qualifier,
     I removed 'const' from some variable declarations in
     intel_validate_framebuffer().  The alternative was to add const
     qualifiers to multiple function signatures in the
     intel_renderbuffer_has_hiz call graph. Since the dominant convention
     in the Intel code is to not qualify function parameters as const,
     I chose to remove rather than add const qualifiers.

  2. I changed the signature of brw_emit_depth_stencil_hiz() by replacing
     `struct intel_mipmap_tree *hiz_mt` with `bool hiz`. The function used
     hiz_mt mostly as a boolean indicator of the presence of hiz, so the
     signature change is consistent with the patch's goal.

Reviewed-by: Eric Anholt <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>
Signed-off-by: Chad Versace <[email protected]>

3 files changed, 6 insertions, 11 deletions

diff --git a/src/mesa/drivers/dri/intel/intel_context.h b/src/mesa/drivers/dri/intel/intel_context.h
index 22d29be278b..c519de9adc8 100644
--- a/src/mesa/drivers/dri/intel/intel_context.h
+++ b/src/mesa/drivers/dri/intel/intel_context.h
@@ -217,8 +217,7 @@ struct intel_context
                                      uint32_t depthbuffer_format,
                                      uint32_t depth_surface_type,
                                      struct intel_mipmap_tree *stencil_mt,
-                                     struct intel_mipmap_tree *hiz_mt,
-                                     bool separate_stencil,
+                                     bool hiz, bool separate_stencil,
                                      uint32_t width, uint32_t height,
                                      uint32_t tile_x, uint32_t tile_y);
 
diff --git a/src/mesa/drivers/dri/intel/intel_fbo.c b/src/mesa/drivers/dri/intel/intel_fbo.c
index 23cd97c00b3..c79b56af098 100644
--- a/src/mesa/drivers/dri/intel/intel_fbo.c
+++ b/src/mesa/drivers/dri/intel/intel_fbo.c
@@ -715,9 +715,9 @@ static void
 intel_validate_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb)
 {
    struct intel_context *intel = intel_context(ctx);
-   const struct intel_renderbuffer *depthRb =
+   struct intel_renderbuffer *depthRb =
       intel_get_renderbuffer(fb, BUFFER_DEPTH);
-   const struct intel_renderbuffer *stencilRb =
+   struct intel_renderbuffer *stencilRb =
       intel_get_renderbuffer(fb, BUFFER_STENCIL);
    struct intel_mipmap_tree *depth_mt = NULL, *stencil_mt = NULL;
    int i;
@@ -759,7 +759,7 @@ intel_validate_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb)
 		_mesa_get_format_name(stencil_mt->format));
 	    fb->_Status = GL_FRAMEBUFFER_UNSUPPORTED_EXT;
 	 }
-	 if (intel->gen < 7 && depth_mt->hiz_mt == NULL) {
+	 if (intel->gen < 7 && !intel_renderbuffer_has_hiz(depthRb)) {
 	    /* Before Gen7, separate depth and stencil buffers can be used
 	     * only if HiZ is enabled. From the Sandybridge PRM, Volume 2,
 	     * Part 1, Bit 3DSTATE_DEPTH_BUFFER.SeparateStencilBufferEnable:
diff --git a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
index 9c0a865c3cb..df6badebace 100644
--- a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
+++ b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
@@ -1043,9 +1043,7 @@ intel_miptree_slice_set_needs_hiz_resolve(struct intel_mipmap_tree *mt,
 					  uint32_t level,
 					  uint32_t layer)
 {
-   intel_miptree_check_level_layer(mt, level, layer);
-
-   if (!mt->hiz_mt)
+   if (!intel_miptree_slice_has_hiz(mt, level, layer))
       return;
 
    intel_resolve_map_set(&mt->hiz_map,
@@ -1058,9 +1056,7 @@ intel_miptree_slice_set_needs_depth_resolve(struct intel_mipmap_tree *mt,
                                             uint32_t level,
                                             uint32_t layer)
 {
-   intel_miptree_check_level_layer(mt, level, layer);
-
-   if (!mt->hiz_mt)
+   if (!intel_miptree_slice_has_hiz(mt, level, layer))
       return;
 
    intel_resolve_map_set(&mt->hiz_map,