🚀 go-pugleaf

Dan T. Abell wrote:
> 
> This may sound like a dumb question, but can someone tell me how C
> compilers do pointer arithmetic?  In particular, consider an integer array
>         p[0], p[1], ... , p[n]
> whose entry p[k] we might access using *(p + k).  I imagine the typical
> compiler would multiply the size of an integer by k, add the result to p,
> and then report the integer located at that address.  Now for my question:
> Do most compilers use plain ol' multiplication or do they use bit-shift
> operators.  Also, does the answer depend on the type of the array p?
> 

It is implementation dependant, but I'd guess that most compilers use multiplication since 
it's easier to implement. Shifts would be faster, but in many cases you would have to use 
a few shifts and additions to accomplish the same task. For instance, if the size of the 
element is 80 bytes, you would have to do shifts by 10 and 8 and add the results together, 
which is harder to implement in a compiler.

Later,
 AriL
-- 
All my opinions are mine and mine alone.