printf or sprintf and puts

[pfournier]

Does anyone know right off the bat, which would consume the least amount of code space, a printf or a sprintf followed by a puts?
-Pete
_________________
-Pete

[PCM programmer]

Compile some test files and look at the ROM usage that's given at the top
of the .LST file. You'll see something like this:

[pfournier]

I'll let you know what I find
_________________
-Pete

[pfournier]

Here is what I ran.
Here are the code sizes.
With the simple printf it was 98, sprintf was 180
With the printf with a variable it was 344, sprintf was 426
I guess printf wins.
-Pete


void main()
{
char buffer[20];
char count=1;

//printf("test\n\r");
//sprintf(buffer, "test\n\r");
//puts(buffer);

//printf("Count %04d\n", Count);
sprintf(buffer, "Count %04d\n", Count);
puts(buffer);

}
_________________
-Pete

[Ttelmah]

It is what I'd 'expect, since with the sprintf, you are adding two sets of character array accesses, but it is nice to have it confirmed.

Best Wishes

[pfournier]

This was interesting because I am told that with the Dynamic C compiler on the Rabbit processor the reverse is true. I gotta try that out when I get time.
_________________
-Pete

[Ttelmah]

That might make sense, if the compiler uses a form of buffered I/O, and 'knows' to do a single memory copy from the string to the buffer. Or if the individual 'putc' commands used inside the printf, are 'inline', and appear in a lot of places. With a normal I/O structure it does not make sense.

Best Wishes

[DragonPIC]

Does the CCS compiler optimize when printf is used more often in the same program? Is there anything else that could cause printf to compile differently? You might have to do another test to confirm total use.
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-Matt