SQL> with
  2    t(n) as (select level from dual connect by level<=5e3)
  3   ,s0(x) as (select t1.n*1e6 + t2.n as x from t t1,t t2) -- 5e3^2 - 38.7sec - 757085000
  4  select
  5     sum(to_number(replace(substr(dump(cast(x as binary_double),16), 17,3),','),'XX')+1) sum_msb
  6  from s0
  7  /

   SUM_MSB
----------
 757085000

Elapsed: 00:01:23.79
SQL>
SQL> with
  2    t(n) as (select level from dual connect by level<=5e3)
  3   ,s0(x) as (select t1.n*1e6 + t2.n as x from t t1,t t2) -- 5e3^2 - 38.7sec - 757085000 --94c
  4  select sum ( length(s)*4
  5             - case
  6                 when substr(s,1,1) >= '8' then 1
  7                 when substr(s,1,1) >= '4' then 2
  8                 when substr(s,1,1) >= '2' then 3
  9                 when substr(s,1,1) >= '1' then 4
 10               end
 11              ) msb_sum
 12  from(
 13  select to_char(x,'fmxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx') s
 14  from s0 )
 15  /

   MSB_SUM
----------
 757085000

Elapsed: 00:00:16.95
SQL>

SQL> with
  2    t(n) as (select level from dual connect by level<=5e3)
  3   ,s0 (x) as (select t1.n*1e6 + t2.n as x from t t1,t t2) -- 5e3^2 - 38.7 - 757085000
  4   , powers as  (select /*+ materialize*/ power(2,level-1) msb, level-1 msb_pos from dual connect by level < 129 order by power(2,level-1) desc)
  5  select sum(Msb_pos)
  6  from s0
  7     , lateral(select * from (
  8              select msb_pos from dropme_powers where msb<=x order by msb desc
  9              ) where rownum =1
 10              )
 11  ;

SUM(MSB_POS)
------------
   757085000

Elapsed: 00:01:11.96
SQL>

create table dropme_powers(msb primary key, msb_pos) organization index
as 
select power(2,level-1) msb, level-1 msb_pos from dual connect by level < 129 order by power(2,level-1) desc
;