+ {
+ /* Pop 2, push 1 */
+ if (vstack_pop(stack)) {
+ ret = -EINVAL;
+ goto end;
+ }
+ if (!vstack_ax(stack)) {
+ ERR("Empty stack\n");
+ ret = -EINVAL;
+ goto end;
+ }
+ switch (vstack_ax(stack)->type) {
+ case REG_S64:
+ case REG_U64:
+ case REG_DOUBLE:
+ case REG_STRING:
+ case REG_STAR_GLOB_STRING:
+ case REG_UNKNOWN:
+ break;
+ default:
+ ERR("Unexpected register type %d for operation\n",
+ (int) vstack_ax(stack)->type);
+ ret = -EINVAL;
+ goto end;
+ }
+
+ vstack_ax(stack)->type = REG_S64;
+ next_pc += sizeof(struct binary_op);
+ break;
+ }
+