Fastest way decimal to segment in chars

Decimal can be representented as:
number=106;
sprintf(str,"%u",number);
str + 0=1;
str + 1=0;
str + 2=6;

any method faster than sprintf?

Assembly.

Or maybe if you rolled your own function.

BTW, if by
str + 0=1;
you really meant
str[0]='1';
, then you left out the most important part, the null-terminator:
str[3]='\0';

How did you determine that sprintf() is the cause of your performance problems?

The answer to that question is "Yes." However, as salem suggested, the real question that needs to be answered is "Is it worth it to invest in optimizing this portion of my program?"

Read through this thread, there are quite a few good ideas there.

itoa()

I feel like I've seen some interesting assembler algorithms for converting base 256 to base 10 (ones that aren't just divide with remainder repeatedly); but I don't think any of them used any "special" instructions like ror or anything, so you should be able to write C code that compiles to the exact same thing. Can't remember though.



That's probably the best bet since any function you rolled yourself would most likely use the same algorithm. But itoa() is deprecated in POSIX (for security reasons; same reason that gets() is unsafe), and so it's not really portable. MS compilers support it (with the underscore, _itoa), but it's not in the version of glibc I have on this machine, at least.