performance - Pros/cons to using char for small integers in C -

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Is there a disadvantage in using char for the small integer? What is the benefit other than occupancy / memory benefit?

Specifically, the processor is likely to face with integer arithmetic on a char , better than or worse (a long / < Code> short ) int ?

I know that this processor / system / compiler will be unique, but I am hoping to respond normally, or, at least, the normal case for 32-bit Windows and Solaris, I present I'm working on the system. I also agree that things like Overflow / Cover Problems have already been dealt with.

Update: In Visual Studio 6.0, exactly like stdint.h Christopher has not suggested that one with windows on stacks (VS 6.0, debug build, 32-bit) Small benchmarking gives int and long to provide similar performance, which is almost twice as fast as four . The same test on Linux is similar to int and long running with GCC, and both are faster than char, though the difference is less clear.

As a side note, I have not spent a lot of time, but (via) uint_fast8_t defines unsigned char Despite this, at least in my trials slow, thus the moral of the story, as Christopha correctly suggests: always the benchmark!

C99 Added so called 'Fastest' minimum-width integer type to solve this problem For the category that interests you, type int_fast8_t and uint_fast8_t , which can be found in stdint.h .

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Keep in mind that there may be no performance gain (the increase in memory consumption may be slow); As always, the benchmark!

Do not prematurely or fully optimize the possible flawed assumptions of the work.

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