[Mesa-dev] [RFC v2 14/15] i965: refactor miptree alignment calculation code

Nanley Chery nanleychery at gmail.com
Mon Jun 1 10:13:52 PDT 2015


From: Nanley Chery <nanley.g.chery at intel.com>

- Remove redundant checks and comments by grouping our calculations for
  align_w and align_h wherever possible.
- Don't pass more parameters than necessary.
- Minor code simplifications.

Signed-off-by: Nanley Chery <nanley.g.chery at intel.com>
---
 src/mesa/drivers/dri/i965/brw_tex_layout.c | 181 +++++++++++++----------------
 1 file changed, 83 insertions(+), 98 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_tex_layout.c b/src/mesa/drivers/dri/i965/brw_tex_layout.c
index 5aadd00..a54b77d 100644
--- a/src/mesa/drivers/dri/i965/brw_tex_layout.c
+++ b/src/mesa/drivers/dri/i965/brw_tex_layout.c
@@ -40,16 +40,9 @@
 #define FILE_DEBUG_FLAG DEBUG_MIPTREE
 
 static unsigned int
-intel_horizontal_texture_alignment_unit(struct brw_context *brw,
-                                        struct intel_mipmap_tree *mt)
+intel_horizontal_texture_alignment_unit(int gen, const struct intel_mipmap_tree *mt)
 {
    /**
-    * From the "Alignment Unit Size" section of various specs, namely:
-    * - Gen3 Spec: "Memory Data Formats" Volume,         Section 1.20.1.4
-    * - i965 and G45 PRMs:             Volume 1,         Section 6.17.3.4.
-    * - Ironlake and Sandybridge PRMs: Volume 1, Part 1, Section 7.18.3.4
-    * - BSpec (for Ivybridge and slight variations in separate stencil)
-    *
     * +----------------------------------------------------------------------+
     * |                                        | alignment unit width  ("i") |
     * | Surface Property                       |-----------------------------|
@@ -67,47 +60,19 @@ intel_horizontal_texture_alignment_unit(struct brw_context *brw,
     * On IVB+, non-special cases can be overridden by setting the SURFACE_STATE
     * "Surface Horizontal Alignment" field to HALIGN_4 or HALIGN_8.
     */
-    if (_mesa_is_format_compressed(mt->format)) {
-       /* The hardware alignment requirements for compressed textures
-        * happen to match the block boundaries.
-        */
-      unsigned int i, j;
-      _mesa_get_format_block_size(mt->format, &i, &j);
-
-      /* On Gen9+ we can pick our own alignment for compressed textures but it
-       * has to be a multiple of the block size. The minimum alignment we can
-       * pick is 4 so we effectively have to align to 4 times the block
-       * size
-       */
-      if (brw->gen >= 9)
-         return i * 4;
-      else
-         return i;
-    }
-
-   if (mt->format == MESA_FORMAT_S_UINT8)
-      return 8;
-
-   if (brw->gen >= 7 && mt->format == MESA_FORMAT_Z_UNORM16)
+   if (gen >= 7 && mt->format == MESA_FORMAT_Z_UNORM16)
       return 8;
 
-   if (brw->gen == 8 && mt->mcs_mt && mt->num_samples <= 1)
+   if (gen == 8 && mt->mcs_mt && mt->num_samples <= 1)
       return 16;
 
    return 4;
 }
 
 static unsigned int
-intel_vertical_texture_alignment_unit(struct brw_context *brw,
-                                      mesa_format format, bool multisampled)
+intel_vertical_texture_alignment_unit(int gen, const struct intel_mipmap_tree *mt)
 {
    /**
-    * From the "Alignment Unit Size" section of various specs, namely:
-    * - Gen3 Spec: "Memory Data Formats" Volume,         Section 1.20.1.4
-    * - i965 and G45 PRMs:             Volume 1,         Section 6.17.3.4.
-    * - Ironlake and Sandybridge PRMs: Volume 1, Part 1, Section 7.18.3.4
-    * - BSpec (for Ivybridge and slight variations in separate stencil)
-    *
     * +----------------------------------------------------------------------+
     * |                                        | alignment unit height ("j") |
     * | Surface Property                       |-----------------------------|
@@ -124,34 +89,25 @@ intel_vertical_texture_alignment_unit(struct brw_context *brw,
     * Where "*" means either VALIGN_2 or VALIGN_4 depending on the setting of
     * the SURFACE_STATE "Surface Vertical Alignment" field.
     */
-   if (_mesa_is_format_compressed(format)) {
-      unsigned int i, j;
-      _mesa_get_format_block_size(format, &i, &j);
-      /* See comment above for the horizontal alignment */
-      return brw->gen >= 9 ? j * 4 : 4;
-   }
-
-   if (format == MESA_FORMAT_S_UINT8)
-      return brw->gen >= 7 ? 8 : 4;
 
    /* Broadwell only supports VALIGN of 4, 8, and 16.  The BSpec says 4
     * should always be used, except for stencil buffers, which should be 8.
     */
-   if (brw->gen >= 8)
+   if (gen >= 8)
       return 4;
 
-   if (multisampled)
+   if (mt->num_samples > 1)
       return 4;
 
-   GLenum base_format = _mesa_get_format_base_format(format);
+   const GLenum base_format = _mesa_get_format_base_format(mt->format);
 
-   if (brw->gen >= 6 &&
+   if (gen >= 6 &&
        (base_format == GL_DEPTH_COMPONENT ||
 	base_format == GL_DEPTH_STENCIL)) {
       return 4;
    }
 
-   if (brw->gen == 7) {
+   if (gen == 7) {
       /* On Gen7, we prefer a vertical alignment of 4 when possible, because
        * that allows Y tiled render targets.
        *
@@ -164,7 +120,7 @@ intel_vertical_texture_alignment_unit(struct brw_context *brw,
        *
        *     VALIGN_4 is not supported for surface format R32G32B32_FLOAT.
        */
-      if (base_format == GL_YCBCR_MESA || format == MESA_FORMAT_RGB_FLOAT32)
+      if (base_format == GL_YCBCR_MESA || mt->format == MESA_FORMAT_RGB_FLOAT32)
          return 2;
 
       return 4;
@@ -174,6 +130,73 @@ intel_vertical_texture_alignment_unit(struct brw_context *brw,
 }
 
 static void
+intel_get_texture_alignment_unit(int gen, struct intel_mipmap_tree *mt)
+{
+   /**
+    * From the "Alignment Unit Size" section of various specs, namely:
+    * - Gen3 Spec: "Memory Data Formats" Volume,         Section 1.20.1.4
+    * - i965 and G45 PRMs:             Volume 1,         Section 6.17.3.4.
+    * - Ironlake and Sandybridge PRMs: Volume 1, Part 1, Section 7.18.3.4
+    * - BSpec (for Ivybridge and slight variations in separate stencil)
+    */
+   bool gen6_hiz_or_stencil = false;
+   if (gen == 6 && mt->array_layout == ALL_SLICES_AT_EACH_LOD) {
+      const GLenum base_format = _mesa_get_format_base_format(mt->format);
+      gen6_hiz_or_stencil = _mesa_is_depth_or_stencil_format(base_format);
+   }
+
+   if (gen6_hiz_or_stencil) {
+      /* On gen6, we use ALL_SLICES_AT_EACH_LOD for stencil/hiz because the
+       * hardware doesn't support multiple mip levels on stencil/hiz.
+       *
+       * PRM Vol 2, Part 1, 7.5.3 Hierarchical Depth Buffer:
+       * "The hierarchical depth buffer does not support the LOD field"
+       *
+       * PRM Vol 2, Part 1, 7.5.4.1 Separate Stencil Buffer:
+       * "The stencil depth buffer does not support the LOD field"
+       */
+      if (mt->format == MESA_FORMAT_S_UINT8) {
+         /* Stencil uses W tiling, so we force W tiling alignment for the
+          * ALL_SLICES_AT_EACH_LOD miptree layout.
+          */
+         mt->align_w = 64;
+         mt->align_h = 64;
+      } else {
+         /* Depth uses Y tiling, so we force need Y tiling alignment for the
+          * ALL_SLICES_AT_EACH_LOD miptree layout.
+          */
+         mt->align_w = 128 / mt->cpp;
+         mt->align_h = 32;
+      }
+   } else if (mt->compressed) {
+       /* The hardware alignment requirements for compressed textures
+        * happen to match the block boundaries.
+        */
+      unsigned int i, j;
+      _mesa_get_format_block_size(mt->format, &i, &j);
+      /* On Gen9+ we can pick our own alignment for compressed textures but it
+       * has to be a multiple of the block size. The minimum alignment we can
+       * pick is 4 so we effectively have to align to 4 times the block
+       * size
+       */
+      if (gen >= 9) {
+         mt->align_w = i * 4;
+         mt->align_h = j * 4;
+      } else {
+         mt->align_w = i;
+         mt->align_h = 4;
+      }
+   } else if (mt->format == MESA_FORMAT_S_UINT8) {
+      mt->align_w = 8;
+      mt->align_h = gen >= 7 ? 8 : 4;
+   } else {
+      /* align_w and align_h must be determined independently. */
+      mt->align_w = intel_horizontal_texture_alignment_unit(gen, mt);
+      mt->align_h = intel_vertical_texture_alignment_unit(gen, mt);
+   }
+}
+
+static void
 gen9_miptree_layout_1d(struct intel_mipmap_tree *mt)
 {
    unsigned x = 0;
@@ -465,43 +488,7 @@ brw_miptree_layout_texture_3d(struct brw_context *brw,
 void
 brw_miptree_layout(struct brw_context *brw, struct intel_mipmap_tree *mt)
 {
-   bool multisampled = mt->num_samples > 1;
-   bool gen6_hiz_or_stencil = false;
-
-   if (brw->gen == 6 && mt->array_layout == ALL_SLICES_AT_EACH_LOD) {
-      const GLenum base_format = _mesa_get_format_base_format(mt->format);
-      gen6_hiz_or_stencil = _mesa_is_depth_or_stencil_format(base_format);
-   }
-
-   if (gen6_hiz_or_stencil) {
-      /* On gen6, we use ALL_SLICES_AT_EACH_LOD for stencil/hiz because the
-       * hardware doesn't support multiple mip levels on stencil/hiz.
-       *
-       * PRM Vol 2, Part 1, 7.5.3 Hierarchical Depth Buffer:
-       * "The hierarchical depth buffer does not support the LOD field"
-       *
-       * PRM Vol 2, Part 1, 7.5.4.1 Separate Stencil Buffer:
-       * "The stencil depth buffer does not support the LOD field"
-       */
-      if (mt->format == MESA_FORMAT_S_UINT8) {
-         /* Stencil uses W tiling, so we force W tiling alignment for the
-          * ALL_SLICES_AT_EACH_LOD miptree layout.
-          */
-         mt->align_w = 64;
-         mt->align_h = 64;
-      } else {
-         /* Depth uses Y tiling, so we force need Y tiling alignment for the
-          * ALL_SLICES_AT_EACH_LOD miptree layout.
-          */
-         mt->align_w = 128 / mt->cpp;
-         mt->align_h = 32;
-      }
-   } else {
-      mt->align_w = intel_horizontal_texture_alignment_unit(brw, mt);
-      mt->align_h =
-         intel_vertical_texture_alignment_unit(brw, mt->format, multisampled);
-   }
-
+   intel_get_texture_alignment_unit(brw->gen, mt);
    switch (mt->target) {
    case GL_TEXTURE_CUBE_MAP:
       if (brw->gen == 4) {
@@ -547,14 +534,12 @@ brw_miptree_layout(struct brw_context *brw, struct intel_mipmap_tree *mt)
    DBG("%s: %dx%dx%d\n", __func__,
        mt->total_width, mt->total_height, mt->cpp);
 
-   /* On Gen9+ the alignment values are expressed in multiples of the block
-    * size
+   /* On Gen9+ the alignment values of compressed textures are expressed in
+    * multiples of 4. See: intel_get_texture_alignment_unit()
     */
-   if (brw->gen >= 9) {
-      unsigned int i, j;
-      _mesa_get_format_block_size(mt->format, &i, &j);
-      mt->align_w /= i;
-      mt->align_h /= j;
+   if (brw->gen >= 9 && mt->compressed) {
+      mt->align_w = 4;
+      mt->align_h = 4;
    }
 }
 
-- 
2.4.1



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