Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!uunet!visix!ip2020!adamksh
From: adam@visix.com
Newsgroups: comp.lang.c
Subject: Re: Should I use macros to inline code?
Message-ID: <1991Mar28.054111.1465@visix.com>
Date: 28 Mar 91 05:41:11 GMT
References: <1991Mar27.024602.21399@visix.com> <15601@smoke.brl.mil>
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Reply-To: adam@visix.com
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In article <1991Mar27.024602.21399@visix.com> I wrote:
-> Assuming that's useful, is there any use for subroutines, so that a
-> routine is only inlined once per function?
	:
	:
-> (Actually, I don't see any way to pass arguments to and return from
-> subroutines that would make them useful in C.)

In article <15601@smoke.brl.mil>, gwyn@smoke.brl.mil (Doug Gwyn) writes:
> ???

Oops!  Normally I am really quite intelligible, sorry about that.

I've been playing with the idea of a toy preprocessor to provide some
automagic premangling of my C source.  Among other things, I thought
it would be nice to automatically generate inlining macros from
existing function definitions (if inlining is useful).

Now, given inlining, I wondered, what if a two-line function gets
inlined twenty times in one function?  Wouldn't it be more efficient
to inline the actual code only once, with a label, and then expand
calls to it into goto's to the label?  Since the goto itself doesn't
push any arguments, I called this option a subroutine, out of analogy
to BASIC's GOSUB.

This gives the programmer three choices:

	inlining when time is a lot more important than memory
	subroutines when time is a little more important than memory
	functions when time is not more important than memory

But subroutines look like a lot of trouble to implement, so before I
even start thinking about it, I have to ask, is it worth it?

Adam