🚀 go-pugleaf

This is a question that can be directed towards any general C compiler,
but for the moment, it has to deal with SGI's C compiler:

I am working with some code, written by someone else, that contains a *lot*
of math.  In this code, the authors have statements like:

*(R+4) = *(R+3) + h24*(55*(*(RdotS+3)) - 59*(*(RdotS+2)) + 37*(*(RdotS+1)) - 9*(*(RdotS)));

I'm attempting to clean this all up so it is legible (yes, that's a cut &
paste, no indentations here :-( ), and would like to know if using the 
following format is less efficient:

   R[4] = R[3] + h24*(55*RdotS[3] - 59*RdotS[2] + 37*RdotS[1] - 9*RdotS[0]);

So, is subscripting like this less efficient?  My guess would be that a 
smart compiler would detect that these two statements are identical, and 
produce identical object code.  However, is this always true?  Say the 
above code were in a loop:

   for (j = 0; j < bignumber; j++) {
      R[j] = ...
         -or-
      *(R+j) = ...

Would a good compiler still interpret the code the same?  Specifically,
would the SGI compiler produce efficient code (with -Ox turned on)?

Thanks for any help.  If you have an answer, post or email, either
way I'm happy!  :-)

-daniel weber
dweber@ncsa.uiuc.edu