Assembly or ....

[Henry Spencer]

In article <1031 at l.cc.purdue.edu> cik at l.cc.purdue.edu (Herman Rubin) writes:
>... What can one think of a compiler 
>designer who has relegated to a subroutine an operation whose inline code
>is shorter than the caller's code to use the subroutine? ...

If the operation is infrequently used and not efficiency-critical, then
what one can think is "this guy knows his tradeoffs".  Adding an operation
to a compiler is not free.

>... But one
>of the most amazing things that I have seen in the workings of the 
>designers is the assumption that the compiler has all the information
>necessary to produce optimized code!  There is no provision for input
>as to frequency of branches...

Not true; some C implementations will take advice from the profiler on
this.  It's practically a necessity for the VLIW folks.  (Oh, you meant
advice from the *programmer*? :-)  The guy who's wrong 3/4 of the time
about such things?  Silly idea.)  (No, I'm not kidding -- programmer
intuition is vastly inferior to measured data in such matters.  This
has been known for many years.)
-- 
SunOSish, adj:  requiring      |     Henry Spencer at U of Toronto Zoology
32-bit bug numbers.            | uunet!attcan!utzoo!henry henry at zoo.toronto.edu