intel/fs: handle interpolation modes for at_sample and at_offset too

Fixes dEQP-VK.draw.*.linear_interpolation.*

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: mesa-stable
Reviewed-by: Ivan Briano <ivan.briano@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19647>

src/intel/compiler/brw_fs.cpp

@@ -7159,6 +7159,8 @@ brw_compute_barycentric_interp_modes(const struct intel_device_info *devinfo,
             case nir_intrinsic_load_barycentric_pixel:
             case nir_intrinsic_load_barycentric_centroid:
             case nir_intrinsic_load_barycentric_sample:
+            case nir_intrinsic_load_barycentric_at_sample:
+            case nir_intrinsic_load_barycentric_at_offset:
                break;
             default:
                continue;
@@ -7375,6 +7377,20 @@ brw_nir_populate_wm_prog_data(const nir_shader *shader,
 
    prog_data->barycentric_interp_modes =
       brw_compute_barycentric_interp_modes(devinfo, shader);
+
+   /* From the BDW PRM documentation for 3DSTATE_WM:
+    *
+    *    "MSDISPMODE_PERSAMPLE is required in order to select Perspective
+    *     Sample or Non- perspective Sample barycentric coordinates."
+    *
+    * So cleanup any potentially set sample barycentric mode when not in per
+    * sample dispatch.
+    */
+   if (prog_data->persample_dispatch == BRW_NEVER) {
+      prog_data->barycentric_interp_modes &=
+         ~BITFIELD_BIT(BRW_BARYCENTRIC_PERSPECTIVE_SAMPLE);
+   }
+
    prog_data->uses_nonperspective_interp_modes |=
       (prog_data->barycentric_interp_modes &
       BRW_BARYCENTRIC_NONPERSPECTIVE_BITS) != 0;