zink: Re-emit the SpvBuiltInSampleMask access chain each load.

Otherwise, the access chain you emitted last time may not dominate the
current use.

Fixes the following validation failure in
dEQP-GLES31.functional.shaders.sample_variables.sample_mask_in.bits_unique_per_sample.multisample_texture_2:

  UNASSIGNED-CoreValidation-Shader-InconsistentSpirv(ERROR / SPEC):
  msgNum: 7060244 - Validation Error: [
  UNASSIGNED-CoreValidation-Shader-InconsistentSpirv ] Object 0: handle =
  0x55cf3cea2c60, type = VK_OBJECT_TYPE_DEVICE; | MessageID = 0x6bbb14 |
  SPIR-V module not valid: ID '67[%67]' defined in block '23[%23]' does
  not dominate its use in block '31[%31]'

Fixes: 8899f6a19857 ("zink: fix gl_SampleMaskIn spirv generation")
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20756>

diff --git a/src/gallium/drivers/zink/nir_to_spirv/nir_to_spirv.c b/src/gallium/drivers/zink/nir_to_spirv/nir_to_spirv.c
index d289a49..5a9d9af 100644 (file)
--- a/src/gallium/drivers/zink/nir_to_spirv/nir_to_spirv.c
+++ b/src/gallium/drivers/zink/nir_to_spirv/nir_to_spirv.c
@@ -2779,17 +2779,19 @@ emit_load_uint_input(struct ntv_context *ctx, nir_intrinsic_instr *intr, SpvId *
                                    SpvStorageClassInput,
                                    var_name,
                                    builtin);
-      if (builtin == SpvBuiltInSampleMask) {
-         SpvId zero = emit_uint_const(ctx, 32, 0);
-         var_type = spirv_builder_type_uint(&ctx->builder, 32);
-         SpvId pointer_type = spirv_builder_type_pointer(&ctx->builder,
-                                                         SpvStorageClassInput,
-                                                         var_type);
-         *var_id = spirv_builder_emit_access_chain(&ctx->builder, pointer_type, *var_id, &zero, 1);
-      }
    }
 
-   SpvId result = spirv_builder_emit_load(&ctx->builder, var_type, *var_id);
+   SpvId load_var = *var_id;
+   if (builtin == SpvBuiltInSampleMask) {
+      SpvId zero = emit_uint_const(ctx, 32, 0);
+      var_type = spirv_builder_type_uint(&ctx->builder, 32);
+      SpvId pointer_type = spirv_builder_type_pointer(&ctx->builder,
+                                                      SpvStorageClassInput,
+                                                      var_type);
+      load_var = spirv_builder_emit_access_chain(&ctx->builder, pointer_type, load_var, &zero, 1);
+   }
+
+   SpvId result = spirv_builder_emit_load(&ctx->builder, var_type, load_var);
    assert(1 == nir_dest_num_components(intr->dest));
    store_dest(ctx, &intr->dest, result, nir_type_uint);
 }