+ if (outinfo->writes_viewport_index == true) {
+ if (ctx->options->chip_class >= GFX9) {
+ /* GFX9 has the layer in out.z[10:0] and the viewport
+ * index in out.z[19:16].
+ */
+ LLVMValueRef v = viewport_index_value;
+ v = to_integer(&ctx->ac, v);
+ v = LLVMBuildShl(ctx->builder, v,
+ LLVMConstInt(ctx->i32, 16, false),
+ "");
+ v = LLVMBuildOr(ctx->builder, v,
+ to_integer(&ctx->ac, pos_args[1].out[2]), "");
+
+ pos_args[1].out[2] = to_float(&ctx->ac, v);
+ pos_args[1].enabled_channels |= 1 << 2;
+ } else {
+ pos_args[1].out[3] = viewport_index_value;
+ pos_args[1].enabled_channels |= 1 << 3;
+ }
+ }