Optimising C snippet

suin's Avatar, Join Date: Mar 2010
Newbie Member
Dear Friends!
Can Anybody help me to optimise the following c code size.
I have list of macro definition which i have to pass as argument to a function

example:

#define ABC_1 123
#define ABC_2 124
#define ABC_3 125
#define ABC_4 126
#define ABC_5 127


int main(void)
{
Function(ABC_1);
Function(ABC_2);
Function(ABC_3);
Function(ABC_4);
Function(ABC_5);
}


i tried token cancatenation but it doesn't help me while using loop.


Thanks in advance
0
techgeek.in's Avatar, Join Date: Dec 2009
Skilled contributor
The above code cannot be optimized becoz the # define is taken care by preprocessor.. Preprocessor knows nothing other that replacing the variable with the actual value before the compiler take the responsibility of compiling the code...nd since the logic of concatenation is never clear until and unless the code comes under the compiler, the preprocessor fails to replace the manipulated part with the actual value...
suin like this
0
xpi0t0s's Avatar, Join Date: Aug 2004
Mentor
ABC_1~5 are consecutive so you could use a for loop:
Code:
for (int i=ABC_1; i<=ABC_5; i++)
  Function(i);
Not sure it would be much smaller though, and it would definitely be slightly slower. Why do you think you need to "optimise" five function calls for size? There is NO WAY profiling will have shown this to be a bottleneck.
0
techgeek.in's Avatar, Join Date: Dec 2009
Skilled contributor
Quote:
Originally Posted by xpi0t0s View Post
ABC_1~5 are consecutive so you could use a for loop:
Code:
for (int i=ABC_1; i<=ABC_5; i++)
  Function(i);
Not sure it would be much smaller though, and it would definitely be slightly slower. Why do you think you need to "optimise" five function calls for size? There is NO WAY profiling will have shown this to be a bottleneck.
what type of programming is this??
0
suin's Avatar, Join Date: Mar 2010
Newbie Member
Quote:
Originally Posted by xpi0t0s View Post
ABC_1~5 are consecutive so you could use a for loop:
Code:
for (int i=ABC_1; i<=ABC_5; i++)
  Function(i);
Not sure it would be much smaller though, and it would definitely be slightly slower. Why do you think you need to "optimise" five function calls for size? There is NO WAY profiling will have shown this to be a bottleneck.
thanks for your reply. it is not a consecutive number.
0
Abinila's Avatar, Join Date: Feb 2010
Light Poster
Hi suin, You mentioned that "it doesn't help me while using loop".Can you give me what you tried.If the numbers are not consecutive looping is very difficult in your case. So tell me what you have tried.
0
xpi0t0s's Avatar, Join Date: Aug 2004
Mentor
You'll need to state the goal of the optimisation. The code as you've given it is pretty efficient. But the implication is that it doesn't do something you want it to. What is that?