On Jun 30,  4:09pm, Shawn T. Rutledge wrote:

> > What is the Linux equivalent of assembly ?
> 
> You can do assembly in Linux, the assembler is as86.  There is also
> nasm I believe.  

Don't forget gas.  (The GNU ASsembler used by gcc.)

> But I haven't done it.  I suspect you could still
> make function calls to libc functions for doing output, etc.  I
> don't think it gets much use outside the kernel itself.

I think you're talking about inline assembler.  It comes in handy from
time to time for directly accessing the CPU's registers and for
executing instructions (e.g, cache flushing / synchronization
instructions) which the compiler will never emit.  Of course, it's
best avoided if possible since it is extremely non-portable.

But when you really need it, inline assembler is invaluable because
the only other choice is to write the whole function in assembler. 
For a good example of a wise use of inline assembler, take a look at
the dmalloc package.  (At http://dmalloc.com/ ...  dmalloc is a malloc
debugging library.) dmalloc uses inline assembler for getting at the
return address in the various replacement functions (malloc, free,
realloc, etc).