agx: Handle linear 2D array textureSize()

We handle linear 2D arrays internally for blit shaders, so we need textureSize
to work for these. That requires some special casing, because there's a line
stride where the layer count would otherwise be. But it's not too bad.

Fixes
dEQP-GLES3.functional.shaders.texture_functions.texturesize.sampler2darray_*
when forcing linear textures.

Since we clamp array access to the maximum layer, we need textureSize() to work
for even the most basic array texturing. So this should fix blits from linear 2D
arrays as well, which finally unlocks support for compressed arrays/cubes/3D
textures.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22891>

1 files changed, 25 insertions, 0 deletions

diff --git a/src/asahi/compiler/agx_nir_lower_texture.c b/src/asahi/compiler/agx_nir_lower_texture.c
index fbd1dfb437b..48c994a981e 100644
--- a/src/asahi/compiler/agx_nir_lower_texture.c
+++ b/src/asahi/compiler/agx_nir_lower_texture.c
@@ -13,6 +13,7 @@
 
 #define AGX_TEXTURE_DESC_STRIDE   24
 #define AGX_FORMAT_RGB32_EMULATED 0x36
+#define AGX_LAYOUT_LINEAR         0x0
 
 static nir_ssa_def *
 texture_descriptor_ptr(nir_builder *b, nir_tex_instr *tex)
@@ -100,6 +101,30 @@ agx_txs(nir_builder *b, nir_tex_instr *tex)
          b, lod, nir_u2u32(b, nir_ssa_for_src(b, tex->src[lod_idx].src, 1)));
    }
 
+   if (tex->sampler_dim == GLSL_SAMPLER_DIM_2D && tex->is_array) {
+      /* Linear 2D arrays are special and have their depth in the next word,
+       * since the depth read above is actually the stride for linear. We handle
+       * this case specially.
+       *
+       * TODO: Optimize this, since linear 2D arrays aren't needed for APIs and
+       * this just gets used internally for blits.
+       */
+      nir_ssa_def *layout =
+         nir_iand_imm(b, nir_ushr_imm(b, w0, 4), BITFIELD_MASK(2));
+
+      /* Get the 2 bytes after the first 128-bit descriptor */
+      nir_ssa_def *extension =
+         nir_load_global_constant(b, nir_iadd_imm(b, ptr, 16), 8, 1, 16);
+
+      nir_ssa_def *depth_linear_m1 =
+         nir_iand_imm(b, extension, BITFIELD_MASK(11));
+
+      depth_linear_m1 = nir_u2uN(b, depth_linear_m1, depth_m1->bit_size);
+
+      depth_m1 = nir_bcsel(b, nir_ieq_imm(b, layout, AGX_LAYOUT_LINEAR),
+                           depth_linear_m1, depth_m1);
+   }
+
    /* Add 1 to width-1, height-1 to get base dimensions */
    nir_ssa_def *width = nir_iadd_imm(b, width_m1, 1);
    nir_ssa_def *height = nir_iadd_imm(b, height_m1, 1);