agx: Fix 2D MSAA array texture register allocation

Sample index and layer index are both 16-bits, even though they are zero
extended for compiler simplicity in some cases. In particular this means that 2D
MSAA arrays consume 6 half-regs for their coordinates, not 8. This is what the
IR translation (actually agx_nir_lower_texture) produces, we just need to fix
the calculation in agx_read_registers to agree.

Fixes validation failure in tests like
dEQP-GLES31.functional.texture.multisample.samples_4.use_texture_color_2d_array

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21708>

diff --git a/src/asahi/compiler/agx_register_allocate.c b/src/asahi/compiler/agx_register_allocate.c
index dc12436..57483ba 100644 (file)
--- a/src/asahi/compiler/agx_register_allocate.c
+++ b/src/asahi/compiler/agx_register_allocate.c
@@ -119,7 +119,9 @@ agx_read_registers(agx_instr *I, unsigned s)
    case AGX_OPCODE_TEXTURE_LOAD:
    case AGX_OPCODE_TEXTURE_SAMPLE:
       if (s == 0) {
-         /* Coordinates. We internally handle sample index as 32-bit */
+         /* Coordinates. We handle layer + sample index as 32-bit even when only
+          * the lower 16-bits are present.
+          */
          switch (I->dim) {
          case AGX_DIM_1D:
             return 2 * 1;
@@ -138,7 +140,7 @@ agx_read_registers(agx_instr *I, unsigned s)
          case AGX_DIM_CUBE_ARRAY:
             return 2 * 4;
          case AGX_DIM_2D_MS_ARRAY:
-            return 2 * 4;
+            return 2 * 3;
          }
 
          unreachable("Invalid texture dimension");