Assembler vs C

[gwyn at BRL-VLD.ARPA]

From:      Doug Gwyn (VLD/VMB) <gwyn at BRL-VLD.ARPA>

About the only use of assembler on our many UNIX systems is by kernel
workers or C run-time library maintainers in direct support of the
software used by everybody else.  If the UNIX System V manuals appear
to dissuade programmers from using assembler, then that is a good sign.

The ONLY times I resort to assembler rather than C are:
	--  function cannot be performed in C.  There are very few
	    cases where this is true; implementing setjmp/longjmp is
	    a good example.
	--  C implementation is a bottleneck.  One identifies such
	    cases by profiling the code, then considering whether the
	    improved speed is going to be worth the maintenance costs
	    associated with use of assembler.  Seldom is it really
	    worthwhile to use assembler, all things considered.