> I've written hello.c and it's about 84 bytes of C and 8.3k as an executable. Would hand-coded assembler be that large?
The answer is generally no. A lot of that overhead is due to the C std library. If memory serves from a blog post I read long ago, with very very aggressive tuning, you can get a hello world binary down under 50 bytes (which is smaller than the ELF header). A “normal” ASM coded “hello world” binary could easily be in the range of a few hundred bytes without anything special.
You can use the `-S` switch with gcc to produce the intermediate assembler representation of your C program instead of binary output. From there you can see for yourself what optimisation has been performed and what hand optimisations are possible.
I just compiled my own 'hello.c' on Linux, with the optimisation flag set for 'code size', and the binary weighed in around 8.3k. I then removed the `printf` call and the inclusion of `stdio.h`. The resulting binary was 8.1k. This is exactly as expected. Why would the inclusion of a call to a dynamic library bloat the final binary size?
The answer is generally no. A lot of that overhead is due to the C std library. If memory serves from a blog post I read long ago, with very very aggressive tuning, you can get a hello world binary down under 50 bytes (which is smaller than the ELF header). A “normal” ASM coded “hello world” binary could easily be in the range of a few hundred bytes without anything special.