Loop performance

[GJ]

Hi,

I am just querious regarding the performance of the different loops
(do-while, for, while) in "C". Is ther any difference between them
performance wise ...

Regards,
GJ

 

[Flash Gordon]

I am just querious regarding the performance of the different loops
(do-while, for, while) in "C". Is ther any difference between them
performance wise ...

This has been asked many times, and it depends entirely on you compiler.
However, since most compilers are quite good at optimising it is almost
always better to write the code so that it expresses your intent clearly
to your readers (including yourself) since then the code is more likely
to actually *be* correct.

Alternatively, I'm sure I can speed up the ATM you use a great deal.
Admittedly it won't give you the money after deducting it from your
account, but that's not a problem is it, as long as it is fast?

 

[pete]

The loops aren't the same.

for loops and while loops respond
differently to the continue keyword.

for loops and while loops are more interchangable
with each other than they are with do loops.

Sometimes I see code,
where the for loop or while loop control expression,
is preloaded so that the loop will execute at least once.
That's usually a good time to use a do loop.

 

[SM Ryan]

# Hi,
#
# I am just querious regarding the performance of the different loops
# (do-while, for, while) in "C". Is ther any difference between them
# performance wise ...

The primary performance determinant is how often you execute the
innermost loop or function body. That decides the O(fN) efficiency
of the program. Anything is just a linear multiple of that, and
compiled control structures are a very small multiple.

 

[g.kanaka.raju]

Hi,

I am just querious regarding the performance of the different loops
(do-while, for, while) in "C". Is ther any difference between them
performance wise ...

Regards,
GJ

Every thing depends on what code COMPILER generates! Smart compilers
will generate almost similar code for different loops. In assembly, a
loop is nothing but keeping count in a register, decrementing it's
value after each iteration and jumping back.

Regards,
Raju

 

[Mabden]

Hi,

I am just querious regarding the performance of the different loops
(do-while, for, while) in "C". Is ther any difference between them
performance wise ...

Use a profiler, to show exactly how much time you are wasting.

Use a spell-checker, to show exactly how bad your spelling is.

Use a looping construct that exactly matches the problem, to show you
can program.