[lvl_s4t3_entry() //  [R1]
         { info_tbls: [(c4uB,
                        label: lvl_s4t3_info
                        rep: HeapRep 1 ptrs { Thunk }
                        srt: Nothing)]
           stack_info: arg_space: 8 updfr_space: Just 8
         }
     {offset
       c4uB: // global
           if ((Sp + -32) < SpLim) (likely: False) goto c4uC; else goto c4uD;
       c4uC: // global
           R1 = R1;
           call (stg_gc_enter_1)(R1) args: 8, res: 0, upd: 8;
       c4uD: // global
           I64[Sp - 16] = stg_upd_frame_info;
           P64[Sp - 8] = R1;
           R2 = P64[R1 + 16];
           I64[Sp - 32] = stg_ap_p_info;
           P64[Sp - 24] = Main.fib3_closure+1;
           Sp = Sp - 32;
           call GHC.Num.fromInteger_info(R2) args: 40, res: 0, upd: 24;
     }
 }