[Mesa-dev] [PATCH 3b/3] i965: Stop muging cube array lengths by 6

[Jason Ekstrand]

>From the Sky Lake PRM:

   "For SURFTYPE_CUBE: For Sampling Engine Surfaces and Typed Data Port
   Surfaces, the range of this field is [0,340], indicating the number of
   cube array elements (equal to the number of underlying 2D array elements
   divided by 6). For other surfaces, this field must be zero."

In other words, the depth field for cube maps is in number of cubes not
number of 2-D slices so we need to divide by 6.  ISL will do this correctly
for us assuming that we provide it with the correct array bounds which it
expects to be in 2-D slices.  It appears as if we've been doing this wrong
ever since we first added cube map arrays for Sandy Bridge and the change
to ISL made things slightly worse.  While we're at it, we now need to remoe
the shader hacks we've always done since they were only needed because we
were setting the depth field six times too large.

Signed-off-by: Jason Ekstrand <jason at jlekstrand.net>
---
 src/mesa/drivers/dri/i965/brw_fs_nir.cpp         | 21 +++++----------------
 src/mesa/drivers/dri/i965/brw_wm_surface_state.c |  4 +---
 2 files changed, 6 insertions(+), 19 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
index 6265dc6..14a8adb 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp
@@ -4457,26 +4457,15 @@ fs_visitor::nir_emit_texture(const fs_builder &bld, nir_tex_instr *instr)
    for (unsigned i = 0; i < dest_size; i++)
       nir_dest[i] = offset(dst, bld, i);
 
-   bool is_cube_array = instr->sampler_dim == GLSL_SAMPLER_DIM_CUBE &&
-                        instr->is_array;
-
    if (instr->op == nir_texop_query_levels) {
       /* # levels is in .w */
       nir_dest[0] = offset(dst, bld, 3);
-   } else if (instr->op == nir_texop_txs && dest_size >= 3 &&
-              (devinfo->gen < 7 || is_cube_array)) {
+   } else if (instr->op == nir_texop_txs &&
+              dest_size >= 3 && devinfo->gen < 7) {
+      /* Gen4-6 return 0 instead of 1 for single layer surfaces. */
       fs_reg depth = offset(dst, bld, 2);
-      fs_reg fixed_depth = vgrf(glsl_type::int_type);
-
-      if (is_cube_array) {
-         /* fixup #layers for cube map arrays */
-         bld.emit(SHADER_OPCODE_INT_QUOTIENT, fixed_depth, depth, brw_imm_d(6));
-      } else if (devinfo->gen < 7) {
-         /* Gen4-6 return 0 instead of 1 for single layer surfaces. */
-         bld.emit_minmax(fixed_depth, depth, brw_imm_d(1), BRW_CONDITIONAL_GE);
-      }
-
-      nir_dest[2] = fixed_depth;
+      nir_dest[2] = vgrf(glsl_type::int_type);
+      bld.emit_minmax(nir_dest[2], depth, brw_imm_d(1), BRW_CONDITIONAL_GE);
    }
 
    bld.LOAD_PAYLOAD(get_nir_dest(instr->dest), nir_dest, dest_size, 0);
diff --git a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
index d896789..e5a3acf 100644
--- a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
+++ b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
@@ -396,11 +396,9 @@ brw_update_texture_surface(struct gl_context *ctx,
       /* If this is a view with restricted NumLayers, then our effective depth
        * is not just the miptree depth.
        */
-      const unsigned mt_num_layers =
-         mt->logical_depth0 * (_mesa_is_cube_map_texture(mt->target) ? 6 : 1);
       const unsigned view_num_layers =
          (obj->Immutable && obj->Target != GL_TEXTURE_3D) ? obj->NumLayers :
-                                                            mt_num_layers;
+                                                            mt->logical_depth0;
 
       /* Handling GL_ALPHA as a surface format override breaks 1.30+ style
        * texturing functions that return a float, as our code generation always
-- 
2.5.0.400.gff86faf